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![Xiao Guangrong](/assets/img/avatar_default.png)
This patch fix: - calculate zapped page number properly in mmu_zap_unsync_children() - calculate freeed page number properly kvm_mmu_change_mmu_pages() - if zapped children page it shoud restart hlist walking KVM-Stable-Tag. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
3432 lines
81 KiB
C
3432 lines
81 KiB
C
/*
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* Kernel-based Virtual Machine driver for Linux
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*
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* This module enables machines with Intel VT-x extensions to run virtual
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* machines without emulation or binary translation.
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*
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* MMU support
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*
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* Copyright (C) 2006 Qumranet, Inc.
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*
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* Authors:
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* Yaniv Kamay <yaniv@qumranet.com>
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* Avi Kivity <avi@qumranet.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#include "mmu.h"
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#include "x86.h"
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#include "kvm_cache_regs.h"
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#include <linux/kvm_host.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/highmem.h>
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#include <linux/module.h>
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#include <linux/swap.h>
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#include <linux/hugetlb.h>
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#include <linux/compiler.h>
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#include <linux/srcu.h>
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#include <linux/slab.h>
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#include <asm/page.h>
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#include <asm/cmpxchg.h>
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#include <asm/io.h>
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#include <asm/vmx.h>
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/*
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* When setting this variable to true it enables Two-Dimensional-Paging
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* where the hardware walks 2 page tables:
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* 1. the guest-virtual to guest-physical
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* 2. while doing 1. it walks guest-physical to host-physical
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* If the hardware supports that we don't need to do shadow paging.
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*/
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bool tdp_enabled = false;
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#undef MMU_DEBUG
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#undef AUDIT
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#ifdef AUDIT
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static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
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#else
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static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
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#endif
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#ifdef MMU_DEBUG
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#define pgprintk(x...) do { if (dbg) printk(x); } while (0)
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#define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
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#else
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#define pgprintk(x...) do { } while (0)
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#define rmap_printk(x...) do { } while (0)
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#endif
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#if defined(MMU_DEBUG) || defined(AUDIT)
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static int dbg = 0;
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module_param(dbg, bool, 0644);
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#endif
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static int oos_shadow = 1;
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module_param(oos_shadow, bool, 0644);
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#ifndef MMU_DEBUG
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#define ASSERT(x) do { } while (0)
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#else
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#define ASSERT(x) \
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if (!(x)) { \
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printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
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__FILE__, __LINE__, #x); \
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}
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#endif
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#define PT_FIRST_AVAIL_BITS_SHIFT 9
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#define PT64_SECOND_AVAIL_BITS_SHIFT 52
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#define VALID_PAGE(x) ((x) != INVALID_PAGE)
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#define PT64_LEVEL_BITS 9
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#define PT64_LEVEL_SHIFT(level) \
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(PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
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#define PT64_LEVEL_MASK(level) \
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(((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
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#define PT64_INDEX(address, level)\
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(((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
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#define PT32_LEVEL_BITS 10
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#define PT32_LEVEL_SHIFT(level) \
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(PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
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#define PT32_LEVEL_MASK(level) \
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(((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
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#define PT32_LVL_OFFSET_MASK(level) \
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(PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
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* PT32_LEVEL_BITS))) - 1))
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#define PT32_INDEX(address, level)\
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(((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
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#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
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#define PT64_DIR_BASE_ADDR_MASK \
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(PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
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#define PT64_LVL_ADDR_MASK(level) \
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(PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
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* PT64_LEVEL_BITS))) - 1))
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#define PT64_LVL_OFFSET_MASK(level) \
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(PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
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* PT64_LEVEL_BITS))) - 1))
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#define PT32_BASE_ADDR_MASK PAGE_MASK
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#define PT32_DIR_BASE_ADDR_MASK \
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(PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
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#define PT32_LVL_ADDR_MASK(level) \
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(PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
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* PT32_LEVEL_BITS))) - 1))
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#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
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| PT64_NX_MASK)
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#define RMAP_EXT 4
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#define ACC_EXEC_MASK 1
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#define ACC_WRITE_MASK PT_WRITABLE_MASK
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#define ACC_USER_MASK PT_USER_MASK
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#define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
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#include <trace/events/kvm.h>
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#undef TRACE_INCLUDE_FILE
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#define CREATE_TRACE_POINTS
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#include "mmutrace.h"
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#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
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#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
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struct kvm_rmap_desc {
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u64 *sptes[RMAP_EXT];
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struct kvm_rmap_desc *more;
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};
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struct kvm_shadow_walk_iterator {
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u64 addr;
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hpa_t shadow_addr;
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int level;
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u64 *sptep;
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unsigned index;
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};
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#define for_each_shadow_entry(_vcpu, _addr, _walker) \
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for (shadow_walk_init(&(_walker), _vcpu, _addr); \
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shadow_walk_okay(&(_walker)); \
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shadow_walk_next(&(_walker)))
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struct kvm_unsync_walk {
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int (*entry) (struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk);
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};
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typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp);
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static struct kmem_cache *pte_chain_cache;
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static struct kmem_cache *rmap_desc_cache;
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static struct kmem_cache *mmu_page_header_cache;
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static u64 __read_mostly shadow_trap_nonpresent_pte;
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static u64 __read_mostly shadow_notrap_nonpresent_pte;
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static u64 __read_mostly shadow_base_present_pte;
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static u64 __read_mostly shadow_nx_mask;
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static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
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static u64 __read_mostly shadow_user_mask;
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static u64 __read_mostly shadow_accessed_mask;
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static u64 __read_mostly shadow_dirty_mask;
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static inline u64 rsvd_bits(int s, int e)
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{
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return ((1ULL << (e - s + 1)) - 1) << s;
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}
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void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
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{
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shadow_trap_nonpresent_pte = trap_pte;
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shadow_notrap_nonpresent_pte = notrap_pte;
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}
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EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
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void kvm_mmu_set_base_ptes(u64 base_pte)
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{
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shadow_base_present_pte = base_pte;
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}
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EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
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void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
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u64 dirty_mask, u64 nx_mask, u64 x_mask)
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{
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shadow_user_mask = user_mask;
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shadow_accessed_mask = accessed_mask;
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shadow_dirty_mask = dirty_mask;
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shadow_nx_mask = nx_mask;
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shadow_x_mask = x_mask;
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}
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EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
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static int is_write_protection(struct kvm_vcpu *vcpu)
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{
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return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
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}
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static int is_cpuid_PSE36(void)
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{
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return 1;
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}
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static int is_nx(struct kvm_vcpu *vcpu)
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{
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return vcpu->arch.efer & EFER_NX;
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}
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static int is_shadow_present_pte(u64 pte)
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{
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return pte != shadow_trap_nonpresent_pte
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&& pte != shadow_notrap_nonpresent_pte;
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}
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static int is_large_pte(u64 pte)
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{
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return pte & PT_PAGE_SIZE_MASK;
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}
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static int is_writable_pte(unsigned long pte)
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{
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return pte & PT_WRITABLE_MASK;
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}
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static int is_dirty_gpte(unsigned long pte)
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{
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return pte & PT_DIRTY_MASK;
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}
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static int is_rmap_spte(u64 pte)
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{
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return is_shadow_present_pte(pte);
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}
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static int is_last_spte(u64 pte, int level)
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{
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if (level == PT_PAGE_TABLE_LEVEL)
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return 1;
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if (is_large_pte(pte))
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return 1;
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return 0;
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}
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static pfn_t spte_to_pfn(u64 pte)
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{
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return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
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}
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static gfn_t pse36_gfn_delta(u32 gpte)
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{
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int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
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return (gpte & PT32_DIR_PSE36_MASK) << shift;
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}
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static void __set_spte(u64 *sptep, u64 spte)
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{
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#ifdef CONFIG_X86_64
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set_64bit((unsigned long *)sptep, spte);
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#else
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set_64bit((unsigned long long *)sptep, spte);
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#endif
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}
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static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
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struct kmem_cache *base_cache, int min)
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{
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void *obj;
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if (cache->nobjs >= min)
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return 0;
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while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
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obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
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if (!obj)
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return -ENOMEM;
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cache->objects[cache->nobjs++] = obj;
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}
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return 0;
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}
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static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
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{
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while (mc->nobjs)
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kfree(mc->objects[--mc->nobjs]);
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}
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static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
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int min)
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{
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struct page *page;
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if (cache->nobjs >= min)
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return 0;
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while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
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page = alloc_page(GFP_KERNEL);
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if (!page)
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return -ENOMEM;
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set_page_private(page, 0);
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cache->objects[cache->nobjs++] = page_address(page);
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}
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return 0;
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}
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static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
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{
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while (mc->nobjs)
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free_page((unsigned long)mc->objects[--mc->nobjs]);
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}
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static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
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{
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int r;
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r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
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pte_chain_cache, 4);
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if (r)
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goto out;
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r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
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rmap_desc_cache, 4);
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if (r)
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goto out;
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r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
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if (r)
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goto out;
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r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
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mmu_page_header_cache, 4);
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out:
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return r;
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}
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static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
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{
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mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
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mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
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mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
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mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
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}
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static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
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size_t size)
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{
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void *p;
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BUG_ON(!mc->nobjs);
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p = mc->objects[--mc->nobjs];
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return p;
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}
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static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
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{
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return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
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sizeof(struct kvm_pte_chain));
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}
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static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
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{
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kfree(pc);
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}
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static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
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{
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return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
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sizeof(struct kvm_rmap_desc));
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}
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static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
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{
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kfree(rd);
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}
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/*
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* Return the pointer to the largepage write count for a given
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* gfn, handling slots that are not large page aligned.
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*/
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static int *slot_largepage_idx(gfn_t gfn,
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struct kvm_memory_slot *slot,
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int level)
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{
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unsigned long idx;
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idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
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(slot->base_gfn / KVM_PAGES_PER_HPAGE(level));
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return &slot->lpage_info[level - 2][idx].write_count;
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}
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static void account_shadowed(struct kvm *kvm, gfn_t gfn)
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{
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struct kvm_memory_slot *slot;
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int *write_count;
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int i;
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gfn = unalias_gfn(kvm, gfn);
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slot = gfn_to_memslot_unaliased(kvm, gfn);
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for (i = PT_DIRECTORY_LEVEL;
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i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
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write_count = slot_largepage_idx(gfn, slot, i);
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*write_count += 1;
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}
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}
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|
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static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
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{
|
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struct kvm_memory_slot *slot;
|
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int *write_count;
|
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int i;
|
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|
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gfn = unalias_gfn(kvm, gfn);
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for (i = PT_DIRECTORY_LEVEL;
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i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
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slot = gfn_to_memslot_unaliased(kvm, gfn);
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write_count = slot_largepage_idx(gfn, slot, i);
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*write_count -= 1;
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WARN_ON(*write_count < 0);
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}
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}
|
|
|
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static int has_wrprotected_page(struct kvm *kvm,
|
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gfn_t gfn,
|
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int level)
|
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{
|
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struct kvm_memory_slot *slot;
|
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int *largepage_idx;
|
|
|
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gfn = unalias_gfn(kvm, gfn);
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slot = gfn_to_memslot_unaliased(kvm, gfn);
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if (slot) {
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largepage_idx = slot_largepage_idx(gfn, slot, level);
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return *largepage_idx;
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}
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|
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return 1;
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}
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|
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static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
|
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{
|
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unsigned long page_size;
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int i, ret = 0;
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page_size = kvm_host_page_size(kvm, gfn);
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|
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for (i = PT_PAGE_TABLE_LEVEL;
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i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
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if (page_size >= KVM_HPAGE_SIZE(i))
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ret = i;
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else
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break;
|
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}
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|
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return ret;
|
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}
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|
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static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
|
|
{
|
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struct kvm_memory_slot *slot;
|
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int host_level, level, max_level;
|
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|
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slot = gfn_to_memslot(vcpu->kvm, large_gfn);
|
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if (slot && slot->dirty_bitmap)
|
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return PT_PAGE_TABLE_LEVEL;
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|
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host_level = host_mapping_level(vcpu->kvm, large_gfn);
|
|
|
|
if (host_level == PT_PAGE_TABLE_LEVEL)
|
|
return host_level;
|
|
|
|
max_level = kvm_x86_ops->get_lpage_level() < host_level ?
|
|
kvm_x86_ops->get_lpage_level() : host_level;
|
|
|
|
for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
|
|
if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
|
|
break;
|
|
|
|
return level - 1;
|
|
}
|
|
|
|
/*
|
|
* Take gfn and return the reverse mapping to it.
|
|
* Note: gfn must be unaliased before this function get called
|
|
*/
|
|
|
|
static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level)
|
|
{
|
|
struct kvm_memory_slot *slot;
|
|
unsigned long idx;
|
|
|
|
slot = gfn_to_memslot(kvm, gfn);
|
|
if (likely(level == PT_PAGE_TABLE_LEVEL))
|
|
return &slot->rmap[gfn - slot->base_gfn];
|
|
|
|
idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
|
|
(slot->base_gfn / KVM_PAGES_PER_HPAGE(level));
|
|
|
|
return &slot->lpage_info[level - 2][idx].rmap_pde;
|
|
}
|
|
|
|
/*
|
|
* Reverse mapping data structures:
|
|
*
|
|
* If rmapp bit zero is zero, then rmapp point to the shadw page table entry
|
|
* that points to page_address(page).
|
|
*
|
|
* If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
|
|
* containing more mappings.
|
|
*
|
|
* Returns the number of rmap entries before the spte was added or zero if
|
|
* the spte was not added.
|
|
*
|
|
*/
|
|
static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
struct kvm_rmap_desc *desc;
|
|
unsigned long *rmapp;
|
|
int i, count = 0;
|
|
|
|
if (!is_rmap_spte(*spte))
|
|
return count;
|
|
gfn = unalias_gfn(vcpu->kvm, gfn);
|
|
sp = page_header(__pa(spte));
|
|
sp->gfns[spte - sp->spt] = gfn;
|
|
rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
|
|
if (!*rmapp) {
|
|
rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
|
|
*rmapp = (unsigned long)spte;
|
|
} else if (!(*rmapp & 1)) {
|
|
rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
|
|
desc = mmu_alloc_rmap_desc(vcpu);
|
|
desc->sptes[0] = (u64 *)*rmapp;
|
|
desc->sptes[1] = spte;
|
|
*rmapp = (unsigned long)desc | 1;
|
|
} else {
|
|
rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
|
|
desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
|
|
while (desc->sptes[RMAP_EXT-1] && desc->more) {
|
|
desc = desc->more;
|
|
count += RMAP_EXT;
|
|
}
|
|
if (desc->sptes[RMAP_EXT-1]) {
|
|
desc->more = mmu_alloc_rmap_desc(vcpu);
|
|
desc = desc->more;
|
|
}
|
|
for (i = 0; desc->sptes[i]; ++i)
|
|
;
|
|
desc->sptes[i] = spte;
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static void rmap_desc_remove_entry(unsigned long *rmapp,
|
|
struct kvm_rmap_desc *desc,
|
|
int i,
|
|
struct kvm_rmap_desc *prev_desc)
|
|
{
|
|
int j;
|
|
|
|
for (j = RMAP_EXT - 1; !desc->sptes[j] && j > i; --j)
|
|
;
|
|
desc->sptes[i] = desc->sptes[j];
|
|
desc->sptes[j] = NULL;
|
|
if (j != 0)
|
|
return;
|
|
if (!prev_desc && !desc->more)
|
|
*rmapp = (unsigned long)desc->sptes[0];
|
|
else
|
|
if (prev_desc)
|
|
prev_desc->more = desc->more;
|
|
else
|
|
*rmapp = (unsigned long)desc->more | 1;
|
|
mmu_free_rmap_desc(desc);
|
|
}
|
|
|
|
static void rmap_remove(struct kvm *kvm, u64 *spte)
|
|
{
|
|
struct kvm_rmap_desc *desc;
|
|
struct kvm_rmap_desc *prev_desc;
|
|
struct kvm_mmu_page *sp;
|
|
pfn_t pfn;
|
|
unsigned long *rmapp;
|
|
int i;
|
|
|
|
if (!is_rmap_spte(*spte))
|
|
return;
|
|
sp = page_header(__pa(spte));
|
|
pfn = spte_to_pfn(*spte);
|
|
if (*spte & shadow_accessed_mask)
|
|
kvm_set_pfn_accessed(pfn);
|
|
if (is_writable_pte(*spte))
|
|
kvm_set_pfn_dirty(pfn);
|
|
rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], sp->role.level);
|
|
if (!*rmapp) {
|
|
printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
|
|
BUG();
|
|
} else if (!(*rmapp & 1)) {
|
|
rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
|
|
if ((u64 *)*rmapp != spte) {
|
|
printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
|
|
spte, *spte);
|
|
BUG();
|
|
}
|
|
*rmapp = 0;
|
|
} else {
|
|
rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
|
|
desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
|
|
prev_desc = NULL;
|
|
while (desc) {
|
|
for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i)
|
|
if (desc->sptes[i] == spte) {
|
|
rmap_desc_remove_entry(rmapp,
|
|
desc, i,
|
|
prev_desc);
|
|
return;
|
|
}
|
|
prev_desc = desc;
|
|
desc = desc->more;
|
|
}
|
|
pr_err("rmap_remove: %p %llx many->many\n", spte, *spte);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
|
|
{
|
|
struct kvm_rmap_desc *desc;
|
|
struct kvm_rmap_desc *prev_desc;
|
|
u64 *prev_spte;
|
|
int i;
|
|
|
|
if (!*rmapp)
|
|
return NULL;
|
|
else if (!(*rmapp & 1)) {
|
|
if (!spte)
|
|
return (u64 *)*rmapp;
|
|
return NULL;
|
|
}
|
|
desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
|
|
prev_desc = NULL;
|
|
prev_spte = NULL;
|
|
while (desc) {
|
|
for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i) {
|
|
if (prev_spte == spte)
|
|
return desc->sptes[i];
|
|
prev_spte = desc->sptes[i];
|
|
}
|
|
desc = desc->more;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int rmap_write_protect(struct kvm *kvm, u64 gfn)
|
|
{
|
|
unsigned long *rmapp;
|
|
u64 *spte;
|
|
int i, write_protected = 0;
|
|
|
|
gfn = unalias_gfn(kvm, gfn);
|
|
rmapp = gfn_to_rmap(kvm, gfn, PT_PAGE_TABLE_LEVEL);
|
|
|
|
spte = rmap_next(kvm, rmapp, NULL);
|
|
while (spte) {
|
|
BUG_ON(!spte);
|
|
BUG_ON(!(*spte & PT_PRESENT_MASK));
|
|
rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
|
|
if (is_writable_pte(*spte)) {
|
|
__set_spte(spte, *spte & ~PT_WRITABLE_MASK);
|
|
write_protected = 1;
|
|
}
|
|
spte = rmap_next(kvm, rmapp, spte);
|
|
}
|
|
if (write_protected) {
|
|
pfn_t pfn;
|
|
|
|
spte = rmap_next(kvm, rmapp, NULL);
|
|
pfn = spte_to_pfn(*spte);
|
|
kvm_set_pfn_dirty(pfn);
|
|
}
|
|
|
|
/* check for huge page mappings */
|
|
for (i = PT_DIRECTORY_LEVEL;
|
|
i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
|
|
rmapp = gfn_to_rmap(kvm, gfn, i);
|
|
spte = rmap_next(kvm, rmapp, NULL);
|
|
while (spte) {
|
|
BUG_ON(!spte);
|
|
BUG_ON(!(*spte & PT_PRESENT_MASK));
|
|
BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
|
|
pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
|
|
if (is_writable_pte(*spte)) {
|
|
rmap_remove(kvm, spte);
|
|
--kvm->stat.lpages;
|
|
__set_spte(spte, shadow_trap_nonpresent_pte);
|
|
spte = NULL;
|
|
write_protected = 1;
|
|
}
|
|
spte = rmap_next(kvm, rmapp, spte);
|
|
}
|
|
}
|
|
|
|
return write_protected;
|
|
}
|
|
|
|
static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
|
|
unsigned long data)
|
|
{
|
|
u64 *spte;
|
|
int need_tlb_flush = 0;
|
|
|
|
while ((spte = rmap_next(kvm, rmapp, NULL))) {
|
|
BUG_ON(!(*spte & PT_PRESENT_MASK));
|
|
rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
|
|
rmap_remove(kvm, spte);
|
|
__set_spte(spte, shadow_trap_nonpresent_pte);
|
|
need_tlb_flush = 1;
|
|
}
|
|
return need_tlb_flush;
|
|
}
|
|
|
|
static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
|
|
unsigned long data)
|
|
{
|
|
int need_flush = 0;
|
|
u64 *spte, new_spte;
|
|
pte_t *ptep = (pte_t *)data;
|
|
pfn_t new_pfn;
|
|
|
|
WARN_ON(pte_huge(*ptep));
|
|
new_pfn = pte_pfn(*ptep);
|
|
spte = rmap_next(kvm, rmapp, NULL);
|
|
while (spte) {
|
|
BUG_ON(!is_shadow_present_pte(*spte));
|
|
rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte);
|
|
need_flush = 1;
|
|
if (pte_write(*ptep)) {
|
|
rmap_remove(kvm, spte);
|
|
__set_spte(spte, shadow_trap_nonpresent_pte);
|
|
spte = rmap_next(kvm, rmapp, NULL);
|
|
} else {
|
|
new_spte = *spte &~ (PT64_BASE_ADDR_MASK);
|
|
new_spte |= (u64)new_pfn << PAGE_SHIFT;
|
|
|
|
new_spte &= ~PT_WRITABLE_MASK;
|
|
new_spte &= ~SPTE_HOST_WRITEABLE;
|
|
if (is_writable_pte(*spte))
|
|
kvm_set_pfn_dirty(spte_to_pfn(*spte));
|
|
__set_spte(spte, new_spte);
|
|
spte = rmap_next(kvm, rmapp, spte);
|
|
}
|
|
}
|
|
if (need_flush)
|
|
kvm_flush_remote_tlbs(kvm);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
|
|
unsigned long data,
|
|
int (*handler)(struct kvm *kvm, unsigned long *rmapp,
|
|
unsigned long data))
|
|
{
|
|
int i, j;
|
|
int ret;
|
|
int retval = 0;
|
|
struct kvm_memslots *slots;
|
|
|
|
slots = rcu_dereference(kvm->memslots);
|
|
|
|
for (i = 0; i < slots->nmemslots; i++) {
|
|
struct kvm_memory_slot *memslot = &slots->memslots[i];
|
|
unsigned long start = memslot->userspace_addr;
|
|
unsigned long end;
|
|
|
|
end = start + (memslot->npages << PAGE_SHIFT);
|
|
if (hva >= start && hva < end) {
|
|
gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
|
|
|
|
ret = handler(kvm, &memslot->rmap[gfn_offset], data);
|
|
|
|
for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
|
|
int idx = gfn_offset;
|
|
idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j);
|
|
ret |= handler(kvm,
|
|
&memslot->lpage_info[j][idx].rmap_pde,
|
|
data);
|
|
}
|
|
trace_kvm_age_page(hva, memslot, ret);
|
|
retval |= ret;
|
|
}
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
|
|
{
|
|
return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
|
|
}
|
|
|
|
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
|
|
{
|
|
kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
|
|
}
|
|
|
|
static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
|
|
unsigned long data)
|
|
{
|
|
u64 *spte;
|
|
int young = 0;
|
|
|
|
/*
|
|
* Emulate the accessed bit for EPT, by checking if this page has
|
|
* an EPT mapping, and clearing it if it does. On the next access,
|
|
* a new EPT mapping will be established.
|
|
* This has some overhead, but not as much as the cost of swapping
|
|
* out actively used pages or breaking up actively used hugepages.
|
|
*/
|
|
if (!shadow_accessed_mask)
|
|
return kvm_unmap_rmapp(kvm, rmapp, data);
|
|
|
|
spte = rmap_next(kvm, rmapp, NULL);
|
|
while (spte) {
|
|
int _young;
|
|
u64 _spte = *spte;
|
|
BUG_ON(!(_spte & PT_PRESENT_MASK));
|
|
_young = _spte & PT_ACCESSED_MASK;
|
|
if (_young) {
|
|
young = 1;
|
|
clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
|
|
}
|
|
spte = rmap_next(kvm, rmapp, spte);
|
|
}
|
|
return young;
|
|
}
|
|
|
|
#define RMAP_RECYCLE_THRESHOLD 1000
|
|
|
|
static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
|
|
{
|
|
unsigned long *rmapp;
|
|
struct kvm_mmu_page *sp;
|
|
|
|
sp = page_header(__pa(spte));
|
|
|
|
gfn = unalias_gfn(vcpu->kvm, gfn);
|
|
rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
|
|
|
|
kvm_unmap_rmapp(vcpu->kvm, rmapp, 0);
|
|
kvm_flush_remote_tlbs(vcpu->kvm);
|
|
}
|
|
|
|
int kvm_age_hva(struct kvm *kvm, unsigned long hva)
|
|
{
|
|
return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp);
|
|
}
|
|
|
|
#ifdef MMU_DEBUG
|
|
static int is_empty_shadow_page(u64 *spt)
|
|
{
|
|
u64 *pos;
|
|
u64 *end;
|
|
|
|
for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
|
|
if (is_shadow_present_pte(*pos)) {
|
|
printk(KERN_ERR "%s: %p %llx\n", __func__,
|
|
pos, *pos);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
|
|
{
|
|
ASSERT(is_empty_shadow_page(sp->spt));
|
|
list_del(&sp->link);
|
|
__free_page(virt_to_page(sp->spt));
|
|
__free_page(virt_to_page(sp->gfns));
|
|
kfree(sp);
|
|
++kvm->arch.n_free_mmu_pages;
|
|
}
|
|
|
|
static unsigned kvm_page_table_hashfn(gfn_t gfn)
|
|
{
|
|
return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
|
|
}
|
|
|
|
static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
|
|
u64 *parent_pte)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
|
|
sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
|
|
sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
|
|
sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
|
|
set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
|
|
list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
|
|
INIT_LIST_HEAD(&sp->oos_link);
|
|
bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
|
|
sp->multimapped = 0;
|
|
sp->parent_pte = parent_pte;
|
|
--vcpu->kvm->arch.n_free_mmu_pages;
|
|
return sp;
|
|
}
|
|
|
|
static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *sp, u64 *parent_pte)
|
|
{
|
|
struct kvm_pte_chain *pte_chain;
|
|
struct hlist_node *node;
|
|
int i;
|
|
|
|
if (!parent_pte)
|
|
return;
|
|
if (!sp->multimapped) {
|
|
u64 *old = sp->parent_pte;
|
|
|
|
if (!old) {
|
|
sp->parent_pte = parent_pte;
|
|
return;
|
|
}
|
|
sp->multimapped = 1;
|
|
pte_chain = mmu_alloc_pte_chain(vcpu);
|
|
INIT_HLIST_HEAD(&sp->parent_ptes);
|
|
hlist_add_head(&pte_chain->link, &sp->parent_ptes);
|
|
pte_chain->parent_ptes[0] = old;
|
|
}
|
|
hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
|
|
if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
|
|
continue;
|
|
for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
|
|
if (!pte_chain->parent_ptes[i]) {
|
|
pte_chain->parent_ptes[i] = parent_pte;
|
|
return;
|
|
}
|
|
}
|
|
pte_chain = mmu_alloc_pte_chain(vcpu);
|
|
BUG_ON(!pte_chain);
|
|
hlist_add_head(&pte_chain->link, &sp->parent_ptes);
|
|
pte_chain->parent_ptes[0] = parent_pte;
|
|
}
|
|
|
|
static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
|
|
u64 *parent_pte)
|
|
{
|
|
struct kvm_pte_chain *pte_chain;
|
|
struct hlist_node *node;
|
|
int i;
|
|
|
|
if (!sp->multimapped) {
|
|
BUG_ON(sp->parent_pte != parent_pte);
|
|
sp->parent_pte = NULL;
|
|
return;
|
|
}
|
|
hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
|
|
for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
|
|
if (!pte_chain->parent_ptes[i])
|
|
break;
|
|
if (pte_chain->parent_ptes[i] != parent_pte)
|
|
continue;
|
|
while (i + 1 < NR_PTE_CHAIN_ENTRIES
|
|
&& pte_chain->parent_ptes[i + 1]) {
|
|
pte_chain->parent_ptes[i]
|
|
= pte_chain->parent_ptes[i + 1];
|
|
++i;
|
|
}
|
|
pte_chain->parent_ptes[i] = NULL;
|
|
if (i == 0) {
|
|
hlist_del(&pte_chain->link);
|
|
mmu_free_pte_chain(pte_chain);
|
|
if (hlist_empty(&sp->parent_ptes)) {
|
|
sp->multimapped = 0;
|
|
sp->parent_pte = NULL;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
BUG();
|
|
}
|
|
|
|
|
|
static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
|
|
mmu_parent_walk_fn fn)
|
|
{
|
|
struct kvm_pte_chain *pte_chain;
|
|
struct hlist_node *node;
|
|
struct kvm_mmu_page *parent_sp;
|
|
int i;
|
|
|
|
if (!sp->multimapped && sp->parent_pte) {
|
|
parent_sp = page_header(__pa(sp->parent_pte));
|
|
fn(vcpu, parent_sp);
|
|
mmu_parent_walk(vcpu, parent_sp, fn);
|
|
return;
|
|
}
|
|
hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
|
|
for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
|
|
if (!pte_chain->parent_ptes[i])
|
|
break;
|
|
parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
|
|
fn(vcpu, parent_sp);
|
|
mmu_parent_walk(vcpu, parent_sp, fn);
|
|
}
|
|
}
|
|
|
|
static void kvm_mmu_update_unsync_bitmap(u64 *spte)
|
|
{
|
|
unsigned int index;
|
|
struct kvm_mmu_page *sp = page_header(__pa(spte));
|
|
|
|
index = spte - sp->spt;
|
|
if (!__test_and_set_bit(index, sp->unsync_child_bitmap))
|
|
sp->unsync_children++;
|
|
WARN_ON(!sp->unsync_children);
|
|
}
|
|
|
|
static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
|
|
{
|
|
struct kvm_pte_chain *pte_chain;
|
|
struct hlist_node *node;
|
|
int i;
|
|
|
|
if (!sp->parent_pte)
|
|
return;
|
|
|
|
if (!sp->multimapped) {
|
|
kvm_mmu_update_unsync_bitmap(sp->parent_pte);
|
|
return;
|
|
}
|
|
|
|
hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
|
|
for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
|
|
if (!pte_chain->parent_ptes[i])
|
|
break;
|
|
kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]);
|
|
}
|
|
}
|
|
|
|
static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
|
|
{
|
|
kvm_mmu_update_parents_unsync(sp);
|
|
return 1;
|
|
}
|
|
|
|
static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *sp)
|
|
{
|
|
mmu_parent_walk(vcpu, sp, unsync_walk_fn);
|
|
kvm_mmu_update_parents_unsync(sp);
|
|
}
|
|
|
|
static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *sp)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
|
|
sp->spt[i] = shadow_trap_nonpresent_pte;
|
|
}
|
|
|
|
static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *sp)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
|
|
{
|
|
}
|
|
|
|
#define KVM_PAGE_ARRAY_NR 16
|
|
|
|
struct kvm_mmu_pages {
|
|
struct mmu_page_and_offset {
|
|
struct kvm_mmu_page *sp;
|
|
unsigned int idx;
|
|
} page[KVM_PAGE_ARRAY_NR];
|
|
unsigned int nr;
|
|
};
|
|
|
|
#define for_each_unsync_children(bitmap, idx) \
|
|
for (idx = find_first_bit(bitmap, 512); \
|
|
idx < 512; \
|
|
idx = find_next_bit(bitmap, 512, idx+1))
|
|
|
|
static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
|
|
int idx)
|
|
{
|
|
int i;
|
|
|
|
if (sp->unsync)
|
|
for (i=0; i < pvec->nr; i++)
|
|
if (pvec->page[i].sp == sp)
|
|
return 0;
|
|
|
|
pvec->page[pvec->nr].sp = sp;
|
|
pvec->page[pvec->nr].idx = idx;
|
|
pvec->nr++;
|
|
return (pvec->nr == KVM_PAGE_ARRAY_NR);
|
|
}
|
|
|
|
static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
|
|
struct kvm_mmu_pages *pvec)
|
|
{
|
|
int i, ret, nr_unsync_leaf = 0;
|
|
|
|
for_each_unsync_children(sp->unsync_child_bitmap, i) {
|
|
u64 ent = sp->spt[i];
|
|
|
|
if (is_shadow_present_pte(ent) && !is_large_pte(ent)) {
|
|
struct kvm_mmu_page *child;
|
|
child = page_header(ent & PT64_BASE_ADDR_MASK);
|
|
|
|
if (child->unsync_children) {
|
|
if (mmu_pages_add(pvec, child, i))
|
|
return -ENOSPC;
|
|
|
|
ret = __mmu_unsync_walk(child, pvec);
|
|
if (!ret)
|
|
__clear_bit(i, sp->unsync_child_bitmap);
|
|
else if (ret > 0)
|
|
nr_unsync_leaf += ret;
|
|
else
|
|
return ret;
|
|
}
|
|
|
|
if (child->unsync) {
|
|
nr_unsync_leaf++;
|
|
if (mmu_pages_add(pvec, child, i))
|
|
return -ENOSPC;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
|
|
sp->unsync_children = 0;
|
|
|
|
return nr_unsync_leaf;
|
|
}
|
|
|
|
static int mmu_unsync_walk(struct kvm_mmu_page *sp,
|
|
struct kvm_mmu_pages *pvec)
|
|
{
|
|
if (!sp->unsync_children)
|
|
return 0;
|
|
|
|
mmu_pages_add(pvec, sp, 0);
|
|
return __mmu_unsync_walk(sp, pvec);
|
|
}
|
|
|
|
static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
|
|
{
|
|
unsigned index;
|
|
struct hlist_head *bucket;
|
|
struct kvm_mmu_page *sp;
|
|
struct hlist_node *node;
|
|
|
|
pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
|
|
index = kvm_page_table_hashfn(gfn);
|
|
bucket = &kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry(sp, node, bucket, hash_link)
|
|
if (sp->gfn == gfn && !sp->role.direct
|
|
&& !sp->role.invalid) {
|
|
pgprintk("%s: found role %x\n",
|
|
__func__, sp->role.word);
|
|
return sp;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
|
|
{
|
|
WARN_ON(!sp->unsync);
|
|
sp->unsync = 0;
|
|
--kvm->stat.mmu_unsync;
|
|
}
|
|
|
|
static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
|
|
|
|
static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
|
|
{
|
|
if (sp->role.glevels != vcpu->arch.mmu.root_level) {
|
|
kvm_mmu_zap_page(vcpu->kvm, sp);
|
|
return 1;
|
|
}
|
|
|
|
trace_kvm_mmu_sync_page(sp);
|
|
if (rmap_write_protect(vcpu->kvm, sp->gfn))
|
|
kvm_flush_remote_tlbs(vcpu->kvm);
|
|
kvm_unlink_unsync_page(vcpu->kvm, sp);
|
|
if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
|
|
kvm_mmu_zap_page(vcpu->kvm, sp);
|
|
return 1;
|
|
}
|
|
|
|
kvm_mmu_flush_tlb(vcpu);
|
|
return 0;
|
|
}
|
|
|
|
struct mmu_page_path {
|
|
struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
|
|
unsigned int idx[PT64_ROOT_LEVEL-1];
|
|
};
|
|
|
|
#define for_each_sp(pvec, sp, parents, i) \
|
|
for (i = mmu_pages_next(&pvec, &parents, -1), \
|
|
sp = pvec.page[i].sp; \
|
|
i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
|
|
i = mmu_pages_next(&pvec, &parents, i))
|
|
|
|
static int mmu_pages_next(struct kvm_mmu_pages *pvec,
|
|
struct mmu_page_path *parents,
|
|
int i)
|
|
{
|
|
int n;
|
|
|
|
for (n = i+1; n < pvec->nr; n++) {
|
|
struct kvm_mmu_page *sp = pvec->page[n].sp;
|
|
|
|
if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
|
|
parents->idx[0] = pvec->page[n].idx;
|
|
return n;
|
|
}
|
|
|
|
parents->parent[sp->role.level-2] = sp;
|
|
parents->idx[sp->role.level-1] = pvec->page[n].idx;
|
|
}
|
|
|
|
return n;
|
|
}
|
|
|
|
static void mmu_pages_clear_parents(struct mmu_page_path *parents)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
unsigned int level = 0;
|
|
|
|
do {
|
|
unsigned int idx = parents->idx[level];
|
|
|
|
sp = parents->parent[level];
|
|
if (!sp)
|
|
return;
|
|
|
|
--sp->unsync_children;
|
|
WARN_ON((int)sp->unsync_children < 0);
|
|
__clear_bit(idx, sp->unsync_child_bitmap);
|
|
level++;
|
|
} while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
|
|
}
|
|
|
|
static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
|
|
struct mmu_page_path *parents,
|
|
struct kvm_mmu_pages *pvec)
|
|
{
|
|
parents->parent[parent->role.level-1] = NULL;
|
|
pvec->nr = 0;
|
|
}
|
|
|
|
static void mmu_sync_children(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *parent)
|
|
{
|
|
int i;
|
|
struct kvm_mmu_page *sp;
|
|
struct mmu_page_path parents;
|
|
struct kvm_mmu_pages pages;
|
|
|
|
kvm_mmu_pages_init(parent, &parents, &pages);
|
|
while (mmu_unsync_walk(parent, &pages)) {
|
|
int protected = 0;
|
|
|
|
for_each_sp(pages, sp, parents, i)
|
|
protected |= rmap_write_protect(vcpu->kvm, sp->gfn);
|
|
|
|
if (protected)
|
|
kvm_flush_remote_tlbs(vcpu->kvm);
|
|
|
|
for_each_sp(pages, sp, parents, i) {
|
|
kvm_sync_page(vcpu, sp);
|
|
mmu_pages_clear_parents(&parents);
|
|
}
|
|
cond_resched_lock(&vcpu->kvm->mmu_lock);
|
|
kvm_mmu_pages_init(parent, &parents, &pages);
|
|
}
|
|
}
|
|
|
|
static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
|
|
gfn_t gfn,
|
|
gva_t gaddr,
|
|
unsigned level,
|
|
int direct,
|
|
unsigned access,
|
|
u64 *parent_pte)
|
|
{
|
|
union kvm_mmu_page_role role;
|
|
unsigned index;
|
|
unsigned quadrant;
|
|
struct hlist_head *bucket;
|
|
struct kvm_mmu_page *sp;
|
|
struct hlist_node *node, *tmp;
|
|
|
|
role = vcpu->arch.mmu.base_role;
|
|
role.level = level;
|
|
role.direct = direct;
|
|
role.access = access;
|
|
if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
|
|
quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
|
|
quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
|
|
role.quadrant = quadrant;
|
|
}
|
|
index = kvm_page_table_hashfn(gfn);
|
|
bucket = &vcpu->kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
|
|
if (sp->gfn == gfn) {
|
|
if (sp->unsync)
|
|
if (kvm_sync_page(vcpu, sp))
|
|
continue;
|
|
|
|
if (sp->role.word != role.word)
|
|
continue;
|
|
|
|
mmu_page_add_parent_pte(vcpu, sp, parent_pte);
|
|
if (sp->unsync_children) {
|
|
set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
|
|
kvm_mmu_mark_parents_unsync(vcpu, sp);
|
|
}
|
|
trace_kvm_mmu_get_page(sp, false);
|
|
return sp;
|
|
}
|
|
++vcpu->kvm->stat.mmu_cache_miss;
|
|
sp = kvm_mmu_alloc_page(vcpu, parent_pte);
|
|
if (!sp)
|
|
return sp;
|
|
sp->gfn = gfn;
|
|
sp->role = role;
|
|
hlist_add_head(&sp->hash_link, bucket);
|
|
if (!direct) {
|
|
if (rmap_write_protect(vcpu->kvm, gfn))
|
|
kvm_flush_remote_tlbs(vcpu->kvm);
|
|
account_shadowed(vcpu->kvm, gfn);
|
|
}
|
|
if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
|
|
vcpu->arch.mmu.prefetch_page(vcpu, sp);
|
|
else
|
|
nonpaging_prefetch_page(vcpu, sp);
|
|
trace_kvm_mmu_get_page(sp, true);
|
|
return sp;
|
|
}
|
|
|
|
static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
|
|
struct kvm_vcpu *vcpu, u64 addr)
|
|
{
|
|
iterator->addr = addr;
|
|
iterator->shadow_addr = vcpu->arch.mmu.root_hpa;
|
|
iterator->level = vcpu->arch.mmu.shadow_root_level;
|
|
if (iterator->level == PT32E_ROOT_LEVEL) {
|
|
iterator->shadow_addr
|
|
= vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
|
|
iterator->shadow_addr &= PT64_BASE_ADDR_MASK;
|
|
--iterator->level;
|
|
if (!iterator->shadow_addr)
|
|
iterator->level = 0;
|
|
}
|
|
}
|
|
|
|
static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
|
|
{
|
|
if (iterator->level < PT_PAGE_TABLE_LEVEL)
|
|
return false;
|
|
|
|
if (iterator->level == PT_PAGE_TABLE_LEVEL)
|
|
if (is_large_pte(*iterator->sptep))
|
|
return false;
|
|
|
|
iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);
|
|
iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index;
|
|
return true;
|
|
}
|
|
|
|
static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
|
|
{
|
|
iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;
|
|
--iterator->level;
|
|
}
|
|
|
|
static void kvm_mmu_page_unlink_children(struct kvm *kvm,
|
|
struct kvm_mmu_page *sp)
|
|
{
|
|
unsigned i;
|
|
u64 *pt;
|
|
u64 ent;
|
|
|
|
pt = sp->spt;
|
|
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
|
|
ent = pt[i];
|
|
|
|
if (is_shadow_present_pte(ent)) {
|
|
if (!is_last_spte(ent, sp->role.level)) {
|
|
ent &= PT64_BASE_ADDR_MASK;
|
|
mmu_page_remove_parent_pte(page_header(ent),
|
|
&pt[i]);
|
|
} else {
|
|
if (is_large_pte(ent))
|
|
--kvm->stat.lpages;
|
|
rmap_remove(kvm, &pt[i]);
|
|
}
|
|
}
|
|
pt[i] = shadow_trap_nonpresent_pte;
|
|
}
|
|
}
|
|
|
|
static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
|
|
{
|
|
mmu_page_remove_parent_pte(sp, parent_pte);
|
|
}
|
|
|
|
static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
|
|
{
|
|
int i;
|
|
struct kvm_vcpu *vcpu;
|
|
|
|
kvm_for_each_vcpu(i, vcpu, kvm)
|
|
vcpu->arch.last_pte_updated = NULL;
|
|
}
|
|
|
|
static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
|
|
{
|
|
u64 *parent_pte;
|
|
|
|
while (sp->multimapped || sp->parent_pte) {
|
|
if (!sp->multimapped)
|
|
parent_pte = sp->parent_pte;
|
|
else {
|
|
struct kvm_pte_chain *chain;
|
|
|
|
chain = container_of(sp->parent_ptes.first,
|
|
struct kvm_pte_chain, link);
|
|
parent_pte = chain->parent_ptes[0];
|
|
}
|
|
BUG_ON(!parent_pte);
|
|
kvm_mmu_put_page(sp, parent_pte);
|
|
__set_spte(parent_pte, shadow_trap_nonpresent_pte);
|
|
}
|
|
}
|
|
|
|
static int mmu_zap_unsync_children(struct kvm *kvm,
|
|
struct kvm_mmu_page *parent)
|
|
{
|
|
int i, zapped = 0;
|
|
struct mmu_page_path parents;
|
|
struct kvm_mmu_pages pages;
|
|
|
|
if (parent->role.level == PT_PAGE_TABLE_LEVEL)
|
|
return 0;
|
|
|
|
kvm_mmu_pages_init(parent, &parents, &pages);
|
|
while (mmu_unsync_walk(parent, &pages)) {
|
|
struct kvm_mmu_page *sp;
|
|
|
|
for_each_sp(pages, sp, parents, i) {
|
|
kvm_mmu_zap_page(kvm, sp);
|
|
mmu_pages_clear_parents(&parents);
|
|
zapped++;
|
|
}
|
|
kvm_mmu_pages_init(parent, &parents, &pages);
|
|
}
|
|
|
|
return zapped;
|
|
}
|
|
|
|
static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
|
|
{
|
|
int ret;
|
|
|
|
trace_kvm_mmu_zap_page(sp);
|
|
++kvm->stat.mmu_shadow_zapped;
|
|
ret = mmu_zap_unsync_children(kvm, sp);
|
|
kvm_mmu_page_unlink_children(kvm, sp);
|
|
kvm_mmu_unlink_parents(kvm, sp);
|
|
kvm_flush_remote_tlbs(kvm);
|
|
if (!sp->role.invalid && !sp->role.direct)
|
|
unaccount_shadowed(kvm, sp->gfn);
|
|
if (sp->unsync)
|
|
kvm_unlink_unsync_page(kvm, sp);
|
|
if (!sp->root_count) {
|
|
hlist_del(&sp->hash_link);
|
|
kvm_mmu_free_page(kvm, sp);
|
|
} else {
|
|
sp->role.invalid = 1;
|
|
list_move(&sp->link, &kvm->arch.active_mmu_pages);
|
|
kvm_reload_remote_mmus(kvm);
|
|
}
|
|
kvm_mmu_reset_last_pte_updated(kvm);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Changing the number of mmu pages allocated to the vm
|
|
* Note: if kvm_nr_mmu_pages is too small, you will get dead lock
|
|
*/
|
|
void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
|
|
{
|
|
int used_pages;
|
|
|
|
used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages;
|
|
used_pages = max(0, used_pages);
|
|
|
|
/*
|
|
* If we set the number of mmu pages to be smaller be than the
|
|
* number of actived pages , we must to free some mmu pages before we
|
|
* change the value
|
|
*/
|
|
|
|
if (used_pages > kvm_nr_mmu_pages) {
|
|
while (used_pages > kvm_nr_mmu_pages &&
|
|
!list_empty(&kvm->arch.active_mmu_pages)) {
|
|
struct kvm_mmu_page *page;
|
|
|
|
page = container_of(kvm->arch.active_mmu_pages.prev,
|
|
struct kvm_mmu_page, link);
|
|
used_pages -= kvm_mmu_zap_page(kvm, page);
|
|
used_pages--;
|
|
}
|
|
kvm_nr_mmu_pages = used_pages;
|
|
kvm->arch.n_free_mmu_pages = 0;
|
|
}
|
|
else
|
|
kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
|
|
- kvm->arch.n_alloc_mmu_pages;
|
|
|
|
kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
|
|
}
|
|
|
|
static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
|
|
{
|
|
unsigned index;
|
|
struct hlist_head *bucket;
|
|
struct kvm_mmu_page *sp;
|
|
struct hlist_node *node, *n;
|
|
int r;
|
|
|
|
pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
|
|
r = 0;
|
|
index = kvm_page_table_hashfn(gfn);
|
|
bucket = &kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
|
|
if (sp->gfn == gfn && !sp->role.direct) {
|
|
pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
|
|
sp->role.word);
|
|
r = 1;
|
|
if (kvm_mmu_zap_page(kvm, sp))
|
|
n = bucket->first;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
|
|
{
|
|
unsigned index;
|
|
struct hlist_head *bucket;
|
|
struct kvm_mmu_page *sp;
|
|
struct hlist_node *node, *nn;
|
|
|
|
index = kvm_page_table_hashfn(gfn);
|
|
bucket = &kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry_safe(sp, node, nn, bucket, hash_link) {
|
|
if (sp->gfn == gfn && !sp->role.direct
|
|
&& !sp->role.invalid) {
|
|
pgprintk("%s: zap %lx %x\n",
|
|
__func__, gfn, sp->role.word);
|
|
if (kvm_mmu_zap_page(kvm, sp))
|
|
nn = bucket->first;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
|
|
{
|
|
int slot = memslot_id(kvm, gfn);
|
|
struct kvm_mmu_page *sp = page_header(__pa(pte));
|
|
|
|
__set_bit(slot, sp->slot_bitmap);
|
|
}
|
|
|
|
static void mmu_convert_notrap(struct kvm_mmu_page *sp)
|
|
{
|
|
int i;
|
|
u64 *pt = sp->spt;
|
|
|
|
if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte)
|
|
return;
|
|
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
|
|
if (pt[i] == shadow_notrap_nonpresent_pte)
|
|
__set_spte(&pt[i], shadow_trap_nonpresent_pte);
|
|
}
|
|
}
|
|
|
|
struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
|
|
{
|
|
struct page *page;
|
|
|
|
gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
|
|
|
|
if (gpa == UNMAPPED_GVA)
|
|
return NULL;
|
|
|
|
page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* The function is based on mtrr_type_lookup() in
|
|
* arch/x86/kernel/cpu/mtrr/generic.c
|
|
*/
|
|
static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
|
|
u64 start, u64 end)
|
|
{
|
|
int i;
|
|
u64 base, mask;
|
|
u8 prev_match, curr_match;
|
|
int num_var_ranges = KVM_NR_VAR_MTRR;
|
|
|
|
if (!mtrr_state->enabled)
|
|
return 0xFF;
|
|
|
|
/* Make end inclusive end, instead of exclusive */
|
|
end--;
|
|
|
|
/* Look in fixed ranges. Just return the type as per start */
|
|
if (mtrr_state->have_fixed && (start < 0x100000)) {
|
|
int idx;
|
|
|
|
if (start < 0x80000) {
|
|
idx = 0;
|
|
idx += (start >> 16);
|
|
return mtrr_state->fixed_ranges[idx];
|
|
} else if (start < 0xC0000) {
|
|
idx = 1 * 8;
|
|
idx += ((start - 0x80000) >> 14);
|
|
return mtrr_state->fixed_ranges[idx];
|
|
} else if (start < 0x1000000) {
|
|
idx = 3 * 8;
|
|
idx += ((start - 0xC0000) >> 12);
|
|
return mtrr_state->fixed_ranges[idx];
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Look in variable ranges
|
|
* Look of multiple ranges matching this address and pick type
|
|
* as per MTRR precedence
|
|
*/
|
|
if (!(mtrr_state->enabled & 2))
|
|
return mtrr_state->def_type;
|
|
|
|
prev_match = 0xFF;
|
|
for (i = 0; i < num_var_ranges; ++i) {
|
|
unsigned short start_state, end_state;
|
|
|
|
if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11)))
|
|
continue;
|
|
|
|
base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) +
|
|
(mtrr_state->var_ranges[i].base_lo & PAGE_MASK);
|
|
mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) +
|
|
(mtrr_state->var_ranges[i].mask_lo & PAGE_MASK);
|
|
|
|
start_state = ((start & mask) == (base & mask));
|
|
end_state = ((end & mask) == (base & mask));
|
|
if (start_state != end_state)
|
|
return 0xFE;
|
|
|
|
if ((start & mask) != (base & mask))
|
|
continue;
|
|
|
|
curr_match = mtrr_state->var_ranges[i].base_lo & 0xff;
|
|
if (prev_match == 0xFF) {
|
|
prev_match = curr_match;
|
|
continue;
|
|
}
|
|
|
|
if (prev_match == MTRR_TYPE_UNCACHABLE ||
|
|
curr_match == MTRR_TYPE_UNCACHABLE)
|
|
return MTRR_TYPE_UNCACHABLE;
|
|
|
|
if ((prev_match == MTRR_TYPE_WRBACK &&
|
|
curr_match == MTRR_TYPE_WRTHROUGH) ||
|
|
(prev_match == MTRR_TYPE_WRTHROUGH &&
|
|
curr_match == MTRR_TYPE_WRBACK)) {
|
|
prev_match = MTRR_TYPE_WRTHROUGH;
|
|
curr_match = MTRR_TYPE_WRTHROUGH;
|
|
}
|
|
|
|
if (prev_match != curr_match)
|
|
return MTRR_TYPE_UNCACHABLE;
|
|
}
|
|
|
|
if (prev_match != 0xFF)
|
|
return prev_match;
|
|
|
|
return mtrr_state->def_type;
|
|
}
|
|
|
|
u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
|
|
{
|
|
u8 mtrr;
|
|
|
|
mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT,
|
|
(gfn << PAGE_SHIFT) + PAGE_SIZE);
|
|
if (mtrr == 0xfe || mtrr == 0xff)
|
|
mtrr = MTRR_TYPE_WRBACK;
|
|
return mtrr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type);
|
|
|
|
static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
|
|
{
|
|
unsigned index;
|
|
struct hlist_head *bucket;
|
|
struct kvm_mmu_page *s;
|
|
struct hlist_node *node, *n;
|
|
|
|
trace_kvm_mmu_unsync_page(sp);
|
|
index = kvm_page_table_hashfn(sp->gfn);
|
|
bucket = &vcpu->kvm->arch.mmu_page_hash[index];
|
|
/* don't unsync if pagetable is shadowed with multiple roles */
|
|
hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
|
|
if (s->gfn != sp->gfn || s->role.direct)
|
|
continue;
|
|
if (s->role.word != sp->role.word)
|
|
return 1;
|
|
}
|
|
++vcpu->kvm->stat.mmu_unsync;
|
|
sp->unsync = 1;
|
|
|
|
kvm_mmu_mark_parents_unsync(vcpu, sp);
|
|
|
|
mmu_convert_notrap(sp);
|
|
return 0;
|
|
}
|
|
|
|
static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
|
|
bool can_unsync)
|
|
{
|
|
struct kvm_mmu_page *shadow;
|
|
|
|
shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
|
|
if (shadow) {
|
|
if (shadow->role.level != PT_PAGE_TABLE_LEVEL)
|
|
return 1;
|
|
if (shadow->unsync)
|
|
return 0;
|
|
if (can_unsync && oos_shadow)
|
|
return kvm_unsync_page(vcpu, shadow);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
|
|
unsigned pte_access, int user_fault,
|
|
int write_fault, int dirty, int level,
|
|
gfn_t gfn, pfn_t pfn, bool speculative,
|
|
bool can_unsync, bool reset_host_protection)
|
|
{
|
|
u64 spte;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* We don't set the accessed bit, since we sometimes want to see
|
|
* whether the guest actually used the pte (in order to detect
|
|
* demand paging).
|
|
*/
|
|
spte = shadow_base_present_pte | shadow_dirty_mask;
|
|
if (!speculative)
|
|
spte |= shadow_accessed_mask;
|
|
if (!dirty)
|
|
pte_access &= ~ACC_WRITE_MASK;
|
|
if (pte_access & ACC_EXEC_MASK)
|
|
spte |= shadow_x_mask;
|
|
else
|
|
spte |= shadow_nx_mask;
|
|
if (pte_access & ACC_USER_MASK)
|
|
spte |= shadow_user_mask;
|
|
if (level > PT_PAGE_TABLE_LEVEL)
|
|
spte |= PT_PAGE_SIZE_MASK;
|
|
if (tdp_enabled)
|
|
spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn,
|
|
kvm_is_mmio_pfn(pfn));
|
|
|
|
if (reset_host_protection)
|
|
spte |= SPTE_HOST_WRITEABLE;
|
|
|
|
spte |= (u64)pfn << PAGE_SHIFT;
|
|
|
|
if ((pte_access & ACC_WRITE_MASK)
|
|
|| (write_fault && !is_write_protection(vcpu) && !user_fault)) {
|
|
|
|
if (level > PT_PAGE_TABLE_LEVEL &&
|
|
has_wrprotected_page(vcpu->kvm, gfn, level)) {
|
|
ret = 1;
|
|
spte = shadow_trap_nonpresent_pte;
|
|
goto set_pte;
|
|
}
|
|
|
|
spte |= PT_WRITABLE_MASK;
|
|
|
|
/*
|
|
* Optimization: for pte sync, if spte was writable the hash
|
|
* lookup is unnecessary (and expensive). Write protection
|
|
* is responsibility of mmu_get_page / kvm_sync_page.
|
|
* Same reasoning can be applied to dirty page accounting.
|
|
*/
|
|
if (!can_unsync && is_writable_pte(*sptep))
|
|
goto set_pte;
|
|
|
|
if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
|
|
pgprintk("%s: found shadow page for %lx, marking ro\n",
|
|
__func__, gfn);
|
|
ret = 1;
|
|
pte_access &= ~ACC_WRITE_MASK;
|
|
if (is_writable_pte(spte))
|
|
spte &= ~PT_WRITABLE_MASK;
|
|
}
|
|
}
|
|
|
|
if (pte_access & ACC_WRITE_MASK)
|
|
mark_page_dirty(vcpu->kvm, gfn);
|
|
|
|
set_pte:
|
|
__set_spte(sptep, spte);
|
|
return ret;
|
|
}
|
|
|
|
static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
|
|
unsigned pt_access, unsigned pte_access,
|
|
int user_fault, int write_fault, int dirty,
|
|
int *ptwrite, int level, gfn_t gfn,
|
|
pfn_t pfn, bool speculative,
|
|
bool reset_host_protection)
|
|
{
|
|
int was_rmapped = 0;
|
|
int was_writable = is_writable_pte(*sptep);
|
|
int rmap_count;
|
|
|
|
pgprintk("%s: spte %llx access %x write_fault %d"
|
|
" user_fault %d gfn %lx\n",
|
|
__func__, *sptep, pt_access,
|
|
write_fault, user_fault, gfn);
|
|
|
|
if (is_rmap_spte(*sptep)) {
|
|
/*
|
|
* If we overwrite a PTE page pointer with a 2MB PMD, unlink
|
|
* the parent of the now unreachable PTE.
|
|
*/
|
|
if (level > PT_PAGE_TABLE_LEVEL &&
|
|
!is_large_pte(*sptep)) {
|
|
struct kvm_mmu_page *child;
|
|
u64 pte = *sptep;
|
|
|
|
child = page_header(pte & PT64_BASE_ADDR_MASK);
|
|
mmu_page_remove_parent_pte(child, sptep);
|
|
} else if (pfn != spte_to_pfn(*sptep)) {
|
|
pgprintk("hfn old %lx new %lx\n",
|
|
spte_to_pfn(*sptep), pfn);
|
|
rmap_remove(vcpu->kvm, sptep);
|
|
} else
|
|
was_rmapped = 1;
|
|
}
|
|
|
|
if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
|
|
dirty, level, gfn, pfn, speculative, true,
|
|
reset_host_protection)) {
|
|
if (write_fault)
|
|
*ptwrite = 1;
|
|
kvm_x86_ops->tlb_flush(vcpu);
|
|
}
|
|
|
|
pgprintk("%s: setting spte %llx\n", __func__, *sptep);
|
|
pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
|
|
is_large_pte(*sptep)? "2MB" : "4kB",
|
|
*sptep & PT_PRESENT_MASK ?"RW":"R", gfn,
|
|
*sptep, sptep);
|
|
if (!was_rmapped && is_large_pte(*sptep))
|
|
++vcpu->kvm->stat.lpages;
|
|
|
|
page_header_update_slot(vcpu->kvm, sptep, gfn);
|
|
if (!was_rmapped) {
|
|
rmap_count = rmap_add(vcpu, sptep, gfn);
|
|
kvm_release_pfn_clean(pfn);
|
|
if (rmap_count > RMAP_RECYCLE_THRESHOLD)
|
|
rmap_recycle(vcpu, sptep, gfn);
|
|
} else {
|
|
if (was_writable)
|
|
kvm_release_pfn_dirty(pfn);
|
|
else
|
|
kvm_release_pfn_clean(pfn);
|
|
}
|
|
if (speculative) {
|
|
vcpu->arch.last_pte_updated = sptep;
|
|
vcpu->arch.last_pte_gfn = gfn;
|
|
}
|
|
}
|
|
|
|
static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
|
|
{
|
|
}
|
|
|
|
static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
|
|
int level, gfn_t gfn, pfn_t pfn)
|
|
{
|
|
struct kvm_shadow_walk_iterator iterator;
|
|
struct kvm_mmu_page *sp;
|
|
int pt_write = 0;
|
|
gfn_t pseudo_gfn;
|
|
|
|
for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
|
|
if (iterator.level == level) {
|
|
mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
|
|
0, write, 1, &pt_write,
|
|
level, gfn, pfn, false, true);
|
|
++vcpu->stat.pf_fixed;
|
|
break;
|
|
}
|
|
|
|
if (*iterator.sptep == shadow_trap_nonpresent_pte) {
|
|
pseudo_gfn = (iterator.addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
|
|
sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
|
|
iterator.level - 1,
|
|
1, ACC_ALL, iterator.sptep);
|
|
if (!sp) {
|
|
pgprintk("nonpaging_map: ENOMEM\n");
|
|
kvm_release_pfn_clean(pfn);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
__set_spte(iterator.sptep,
|
|
__pa(sp->spt)
|
|
| PT_PRESENT_MASK | PT_WRITABLE_MASK
|
|
| shadow_user_mask | shadow_x_mask);
|
|
}
|
|
}
|
|
return pt_write;
|
|
}
|
|
|
|
static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
|
|
{
|
|
int r;
|
|
int level;
|
|
pfn_t pfn;
|
|
unsigned long mmu_seq;
|
|
|
|
level = mapping_level(vcpu, gfn);
|
|
|
|
/*
|
|
* This path builds a PAE pagetable - so we can map 2mb pages at
|
|
* maximum. Therefore check if the level is larger than that.
|
|
*/
|
|
if (level > PT_DIRECTORY_LEVEL)
|
|
level = PT_DIRECTORY_LEVEL;
|
|
|
|
gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
|
|
|
|
mmu_seq = vcpu->kvm->mmu_notifier_seq;
|
|
smp_rmb();
|
|
pfn = gfn_to_pfn(vcpu->kvm, gfn);
|
|
|
|
/* mmio */
|
|
if (is_error_pfn(pfn)) {
|
|
kvm_release_pfn_clean(pfn);
|
|
return 1;
|
|
}
|
|
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
if (mmu_notifier_retry(vcpu, mmu_seq))
|
|
goto out_unlock;
|
|
kvm_mmu_free_some_pages(vcpu);
|
|
r = __direct_map(vcpu, v, write, level, gfn, pfn);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
|
|
|
|
return r;
|
|
|
|
out_unlock:
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
kvm_release_pfn_clean(pfn);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void mmu_free_roots(struct kvm_vcpu *vcpu)
|
|
{
|
|
int i;
|
|
struct kvm_mmu_page *sp;
|
|
|
|
if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
|
|
return;
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
|
|
hpa_t root = vcpu->arch.mmu.root_hpa;
|
|
|
|
sp = page_header(root);
|
|
--sp->root_count;
|
|
if (!sp->root_count && sp->role.invalid)
|
|
kvm_mmu_zap_page(vcpu->kvm, sp);
|
|
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
return;
|
|
}
|
|
for (i = 0; i < 4; ++i) {
|
|
hpa_t root = vcpu->arch.mmu.pae_root[i];
|
|
|
|
if (root) {
|
|
root &= PT64_BASE_ADDR_MASK;
|
|
sp = page_header(root);
|
|
--sp->root_count;
|
|
if (!sp->root_count && sp->role.invalid)
|
|
kvm_mmu_zap_page(vcpu->kvm, sp);
|
|
}
|
|
vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
|
|
}
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
|
|
}
|
|
|
|
static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) {
|
|
set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
|
|
ret = 1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
|
|
{
|
|
int i;
|
|
gfn_t root_gfn;
|
|
struct kvm_mmu_page *sp;
|
|
int direct = 0;
|
|
u64 pdptr;
|
|
|
|
root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
|
|
|
|
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
|
|
hpa_t root = vcpu->arch.mmu.root_hpa;
|
|
|
|
ASSERT(!VALID_PAGE(root));
|
|
if (tdp_enabled)
|
|
direct = 1;
|
|
if (mmu_check_root(vcpu, root_gfn))
|
|
return 1;
|
|
sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
|
|
PT64_ROOT_LEVEL, direct,
|
|
ACC_ALL, NULL);
|
|
root = __pa(sp->spt);
|
|
++sp->root_count;
|
|
vcpu->arch.mmu.root_hpa = root;
|
|
return 0;
|
|
}
|
|
direct = !is_paging(vcpu);
|
|
if (tdp_enabled)
|
|
direct = 1;
|
|
for (i = 0; i < 4; ++i) {
|
|
hpa_t root = vcpu->arch.mmu.pae_root[i];
|
|
|
|
ASSERT(!VALID_PAGE(root));
|
|
if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
|
|
pdptr = kvm_pdptr_read(vcpu, i);
|
|
if (!is_present_gpte(pdptr)) {
|
|
vcpu->arch.mmu.pae_root[i] = 0;
|
|
continue;
|
|
}
|
|
root_gfn = pdptr >> PAGE_SHIFT;
|
|
} else if (vcpu->arch.mmu.root_level == 0)
|
|
root_gfn = 0;
|
|
if (mmu_check_root(vcpu, root_gfn))
|
|
return 1;
|
|
sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
|
|
PT32_ROOT_LEVEL, direct,
|
|
ACC_ALL, NULL);
|
|
root = __pa(sp->spt);
|
|
++sp->root_count;
|
|
vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
|
|
}
|
|
vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
|
|
return 0;
|
|
}
|
|
|
|
static void mmu_sync_roots(struct kvm_vcpu *vcpu)
|
|
{
|
|
int i;
|
|
struct kvm_mmu_page *sp;
|
|
|
|
if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
|
|
return;
|
|
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
|
|
hpa_t root = vcpu->arch.mmu.root_hpa;
|
|
sp = page_header(root);
|
|
mmu_sync_children(vcpu, sp);
|
|
return;
|
|
}
|
|
for (i = 0; i < 4; ++i) {
|
|
hpa_t root = vcpu->arch.mmu.pae_root[i];
|
|
|
|
if (root && VALID_PAGE(root)) {
|
|
root &= PT64_BASE_ADDR_MASK;
|
|
sp = page_header(root);
|
|
mmu_sync_children(vcpu, sp);
|
|
}
|
|
}
|
|
}
|
|
|
|
void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
|
|
{
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
mmu_sync_roots(vcpu);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
}
|
|
|
|
static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr,
|
|
u32 access, u32 *error)
|
|
{
|
|
if (error)
|
|
*error = 0;
|
|
return vaddr;
|
|
}
|
|
|
|
static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
|
|
u32 error_code)
|
|
{
|
|
gfn_t gfn;
|
|
int r;
|
|
|
|
pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
|
|
r = mmu_topup_memory_caches(vcpu);
|
|
if (r)
|
|
return r;
|
|
|
|
ASSERT(vcpu);
|
|
ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
|
|
|
|
gfn = gva >> PAGE_SHIFT;
|
|
|
|
return nonpaging_map(vcpu, gva & PAGE_MASK,
|
|
error_code & PFERR_WRITE_MASK, gfn);
|
|
}
|
|
|
|
static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
|
|
u32 error_code)
|
|
{
|
|
pfn_t pfn;
|
|
int r;
|
|
int level;
|
|
gfn_t gfn = gpa >> PAGE_SHIFT;
|
|
unsigned long mmu_seq;
|
|
|
|
ASSERT(vcpu);
|
|
ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
|
|
|
|
r = mmu_topup_memory_caches(vcpu);
|
|
if (r)
|
|
return r;
|
|
|
|
level = mapping_level(vcpu, gfn);
|
|
|
|
gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
|
|
|
|
mmu_seq = vcpu->kvm->mmu_notifier_seq;
|
|
smp_rmb();
|
|
pfn = gfn_to_pfn(vcpu->kvm, gfn);
|
|
if (is_error_pfn(pfn)) {
|
|
kvm_release_pfn_clean(pfn);
|
|
return 1;
|
|
}
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
if (mmu_notifier_retry(vcpu, mmu_seq))
|
|
goto out_unlock;
|
|
kvm_mmu_free_some_pages(vcpu);
|
|
r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
|
|
level, gfn, pfn);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
|
|
return r;
|
|
|
|
out_unlock:
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
kvm_release_pfn_clean(pfn);
|
|
return 0;
|
|
}
|
|
|
|
static void nonpaging_free(struct kvm_vcpu *vcpu)
|
|
{
|
|
mmu_free_roots(vcpu);
|
|
}
|
|
|
|
static int nonpaging_init_context(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct kvm_mmu *context = &vcpu->arch.mmu;
|
|
|
|
context->new_cr3 = nonpaging_new_cr3;
|
|
context->page_fault = nonpaging_page_fault;
|
|
context->gva_to_gpa = nonpaging_gva_to_gpa;
|
|
context->free = nonpaging_free;
|
|
context->prefetch_page = nonpaging_prefetch_page;
|
|
context->sync_page = nonpaging_sync_page;
|
|
context->invlpg = nonpaging_invlpg;
|
|
context->root_level = 0;
|
|
context->shadow_root_level = PT32E_ROOT_LEVEL;
|
|
context->root_hpa = INVALID_PAGE;
|
|
return 0;
|
|
}
|
|
|
|
void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
|
|
{
|
|
++vcpu->stat.tlb_flush;
|
|
kvm_x86_ops->tlb_flush(vcpu);
|
|
}
|
|
|
|
static void paging_new_cr3(struct kvm_vcpu *vcpu)
|
|
{
|
|
pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
|
|
mmu_free_roots(vcpu);
|
|
}
|
|
|
|
static void inject_page_fault(struct kvm_vcpu *vcpu,
|
|
u64 addr,
|
|
u32 err_code)
|
|
{
|
|
kvm_inject_page_fault(vcpu, addr, err_code);
|
|
}
|
|
|
|
static void paging_free(struct kvm_vcpu *vcpu)
|
|
{
|
|
nonpaging_free(vcpu);
|
|
}
|
|
|
|
static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level)
|
|
{
|
|
int bit7;
|
|
|
|
bit7 = (gpte >> 7) & 1;
|
|
return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0;
|
|
}
|
|
|
|
#define PTTYPE 64
|
|
#include "paging_tmpl.h"
|
|
#undef PTTYPE
|
|
|
|
#define PTTYPE 32
|
|
#include "paging_tmpl.h"
|
|
#undef PTTYPE
|
|
|
|
static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level)
|
|
{
|
|
struct kvm_mmu *context = &vcpu->arch.mmu;
|
|
int maxphyaddr = cpuid_maxphyaddr(vcpu);
|
|
u64 exb_bit_rsvd = 0;
|
|
|
|
if (!is_nx(vcpu))
|
|
exb_bit_rsvd = rsvd_bits(63, 63);
|
|
switch (level) {
|
|
case PT32_ROOT_LEVEL:
|
|
/* no rsvd bits for 2 level 4K page table entries */
|
|
context->rsvd_bits_mask[0][1] = 0;
|
|
context->rsvd_bits_mask[0][0] = 0;
|
|
if (is_cpuid_PSE36())
|
|
/* 36bits PSE 4MB page */
|
|
context->rsvd_bits_mask[1][1] = rsvd_bits(17, 21);
|
|
else
|
|
/* 32 bits PSE 4MB page */
|
|
context->rsvd_bits_mask[1][1] = rsvd_bits(13, 21);
|
|
context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
|
|
break;
|
|
case PT32E_ROOT_LEVEL:
|
|
context->rsvd_bits_mask[0][2] =
|
|
rsvd_bits(maxphyaddr, 63) |
|
|
rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
|
|
context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 62); /* PDE */
|
|
context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 62); /* PTE */
|
|
context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 62) |
|
|
rsvd_bits(13, 20); /* large page */
|
|
context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
|
|
break;
|
|
case PT64_ROOT_LEVEL:
|
|
context->rsvd_bits_mask[0][3] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
|
|
context->rsvd_bits_mask[0][2] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
|
|
context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 51);
|
|
context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 51);
|
|
context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3];
|
|
context->rsvd_bits_mask[1][2] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 51) |
|
|
rsvd_bits(13, 29);
|
|
context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
|
|
rsvd_bits(maxphyaddr, 51) |
|
|
rsvd_bits(13, 20); /* large page */
|
|
context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
|
|
{
|
|
struct kvm_mmu *context = &vcpu->arch.mmu;
|
|
|
|
ASSERT(is_pae(vcpu));
|
|
context->new_cr3 = paging_new_cr3;
|
|
context->page_fault = paging64_page_fault;
|
|
context->gva_to_gpa = paging64_gva_to_gpa;
|
|
context->prefetch_page = paging64_prefetch_page;
|
|
context->sync_page = paging64_sync_page;
|
|
context->invlpg = paging64_invlpg;
|
|
context->free = paging_free;
|
|
context->root_level = level;
|
|
context->shadow_root_level = level;
|
|
context->root_hpa = INVALID_PAGE;
|
|
return 0;
|
|
}
|
|
|
|
static int paging64_init_context(struct kvm_vcpu *vcpu)
|
|
{
|
|
reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
|
|
return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
|
|
}
|
|
|
|
static int paging32_init_context(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct kvm_mmu *context = &vcpu->arch.mmu;
|
|
|
|
reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
|
|
context->new_cr3 = paging_new_cr3;
|
|
context->page_fault = paging32_page_fault;
|
|
context->gva_to_gpa = paging32_gva_to_gpa;
|
|
context->free = paging_free;
|
|
context->prefetch_page = paging32_prefetch_page;
|
|
context->sync_page = paging32_sync_page;
|
|
context->invlpg = paging32_invlpg;
|
|
context->root_level = PT32_ROOT_LEVEL;
|
|
context->shadow_root_level = PT32E_ROOT_LEVEL;
|
|
context->root_hpa = INVALID_PAGE;
|
|
return 0;
|
|
}
|
|
|
|
static int paging32E_init_context(struct kvm_vcpu *vcpu)
|
|
{
|
|
reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
|
|
return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
|
|
}
|
|
|
|
static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct kvm_mmu *context = &vcpu->arch.mmu;
|
|
|
|
context->new_cr3 = nonpaging_new_cr3;
|
|
context->page_fault = tdp_page_fault;
|
|
context->free = nonpaging_free;
|
|
context->prefetch_page = nonpaging_prefetch_page;
|
|
context->sync_page = nonpaging_sync_page;
|
|
context->invlpg = nonpaging_invlpg;
|
|
context->shadow_root_level = kvm_x86_ops->get_tdp_level();
|
|
context->root_hpa = INVALID_PAGE;
|
|
|
|
if (!is_paging(vcpu)) {
|
|
context->gva_to_gpa = nonpaging_gva_to_gpa;
|
|
context->root_level = 0;
|
|
} else if (is_long_mode(vcpu)) {
|
|
reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
|
|
context->gva_to_gpa = paging64_gva_to_gpa;
|
|
context->root_level = PT64_ROOT_LEVEL;
|
|
} else if (is_pae(vcpu)) {
|
|
reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
|
|
context->gva_to_gpa = paging64_gva_to_gpa;
|
|
context->root_level = PT32E_ROOT_LEVEL;
|
|
} else {
|
|
reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
|
|
context->gva_to_gpa = paging32_gva_to_gpa;
|
|
context->root_level = PT32_ROOT_LEVEL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
|
|
{
|
|
int r;
|
|
|
|
ASSERT(vcpu);
|
|
ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
|
|
|
|
if (!is_paging(vcpu))
|
|
r = nonpaging_init_context(vcpu);
|
|
else if (is_long_mode(vcpu))
|
|
r = paging64_init_context(vcpu);
|
|
else if (is_pae(vcpu))
|
|
r = paging32E_init_context(vcpu);
|
|
else
|
|
r = paging32_init_context(vcpu);
|
|
|
|
vcpu->arch.mmu.base_role.glevels = vcpu->arch.mmu.root_level;
|
|
|
|
return r;
|
|
}
|
|
|
|
static int init_kvm_mmu(struct kvm_vcpu *vcpu)
|
|
{
|
|
vcpu->arch.update_pte.pfn = bad_pfn;
|
|
|
|
if (tdp_enabled)
|
|
return init_kvm_tdp_mmu(vcpu);
|
|
else
|
|
return init_kvm_softmmu(vcpu);
|
|
}
|
|
|
|
static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
|
|
{
|
|
ASSERT(vcpu);
|
|
if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
|
|
vcpu->arch.mmu.free(vcpu);
|
|
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
|
|
}
|
|
}
|
|
|
|
int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
|
|
{
|
|
destroy_kvm_mmu(vcpu);
|
|
return init_kvm_mmu(vcpu);
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
|
|
|
|
int kvm_mmu_load(struct kvm_vcpu *vcpu)
|
|
{
|
|
int r;
|
|
|
|
r = mmu_topup_memory_caches(vcpu);
|
|
if (r)
|
|
goto out;
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
kvm_mmu_free_some_pages(vcpu);
|
|
r = mmu_alloc_roots(vcpu);
|
|
mmu_sync_roots(vcpu);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
if (r)
|
|
goto out;
|
|
/* set_cr3() should ensure TLB has been flushed */
|
|
kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
|
|
out:
|
|
return r;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_mmu_load);
|
|
|
|
void kvm_mmu_unload(struct kvm_vcpu *vcpu)
|
|
{
|
|
mmu_free_roots(vcpu);
|
|
}
|
|
|
|
static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *sp,
|
|
u64 *spte)
|
|
{
|
|
u64 pte;
|
|
struct kvm_mmu_page *child;
|
|
|
|
pte = *spte;
|
|
if (is_shadow_present_pte(pte)) {
|
|
if (is_last_spte(pte, sp->role.level))
|
|
rmap_remove(vcpu->kvm, spte);
|
|
else {
|
|
child = page_header(pte & PT64_BASE_ADDR_MASK);
|
|
mmu_page_remove_parent_pte(child, spte);
|
|
}
|
|
}
|
|
__set_spte(spte, shadow_trap_nonpresent_pte);
|
|
if (is_large_pte(pte))
|
|
--vcpu->kvm->stat.lpages;
|
|
}
|
|
|
|
static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *sp,
|
|
u64 *spte,
|
|
const void *new)
|
|
{
|
|
if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
|
|
++vcpu->kvm->stat.mmu_pde_zapped;
|
|
return;
|
|
}
|
|
|
|
++vcpu->kvm->stat.mmu_pte_updated;
|
|
if (sp->role.glevels == PT32_ROOT_LEVEL)
|
|
paging32_update_pte(vcpu, sp, spte, new);
|
|
else
|
|
paging64_update_pte(vcpu, sp, spte, new);
|
|
}
|
|
|
|
static bool need_remote_flush(u64 old, u64 new)
|
|
{
|
|
if (!is_shadow_present_pte(old))
|
|
return false;
|
|
if (!is_shadow_present_pte(new))
|
|
return true;
|
|
if ((old ^ new) & PT64_BASE_ADDR_MASK)
|
|
return true;
|
|
old ^= PT64_NX_MASK;
|
|
new ^= PT64_NX_MASK;
|
|
return (old & ~new & PT64_PERM_MASK) != 0;
|
|
}
|
|
|
|
static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
|
|
{
|
|
if (need_remote_flush(old, new))
|
|
kvm_flush_remote_tlbs(vcpu->kvm);
|
|
else
|
|
kvm_mmu_flush_tlb(vcpu);
|
|
}
|
|
|
|
static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
|
|
{
|
|
u64 *spte = vcpu->arch.last_pte_updated;
|
|
|
|
return !!(spte && (*spte & shadow_accessed_mask));
|
|
}
|
|
|
|
static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
|
|
const u8 *new, int bytes)
|
|
{
|
|
gfn_t gfn;
|
|
int r;
|
|
u64 gpte = 0;
|
|
pfn_t pfn;
|
|
|
|
if (bytes != 4 && bytes != 8)
|
|
return;
|
|
|
|
/*
|
|
* Assume that the pte write on a page table of the same type
|
|
* as the current vcpu paging mode. This is nearly always true
|
|
* (might be false while changing modes). Note it is verified later
|
|
* by update_pte().
|
|
*/
|
|
if (is_pae(vcpu)) {
|
|
/* Handle a 32-bit guest writing two halves of a 64-bit gpte */
|
|
if ((bytes == 4) && (gpa % 4 == 0)) {
|
|
r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
|
|
if (r)
|
|
return;
|
|
memcpy((void *)&gpte + (gpa % 8), new, 4);
|
|
} else if ((bytes == 8) && (gpa % 8 == 0)) {
|
|
memcpy((void *)&gpte, new, 8);
|
|
}
|
|
} else {
|
|
if ((bytes == 4) && (gpa % 4 == 0))
|
|
memcpy((void *)&gpte, new, 4);
|
|
}
|
|
if (!is_present_gpte(gpte))
|
|
return;
|
|
gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
|
|
|
|
vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
|
|
smp_rmb();
|
|
pfn = gfn_to_pfn(vcpu->kvm, gfn);
|
|
|
|
if (is_error_pfn(pfn)) {
|
|
kvm_release_pfn_clean(pfn);
|
|
return;
|
|
}
|
|
vcpu->arch.update_pte.gfn = gfn;
|
|
vcpu->arch.update_pte.pfn = pfn;
|
|
}
|
|
|
|
static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
|
|
{
|
|
u64 *spte = vcpu->arch.last_pte_updated;
|
|
|
|
if (spte
|
|
&& vcpu->arch.last_pte_gfn == gfn
|
|
&& shadow_accessed_mask
|
|
&& !(*spte & shadow_accessed_mask)
|
|
&& is_shadow_present_pte(*spte))
|
|
set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
|
|
}
|
|
|
|
void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
|
|
const u8 *new, int bytes,
|
|
bool guest_initiated)
|
|
{
|
|
gfn_t gfn = gpa >> PAGE_SHIFT;
|
|
struct kvm_mmu_page *sp;
|
|
struct hlist_node *node, *n;
|
|
struct hlist_head *bucket;
|
|
unsigned index;
|
|
u64 entry, gentry;
|
|
u64 *spte;
|
|
unsigned offset = offset_in_page(gpa);
|
|
unsigned pte_size;
|
|
unsigned page_offset;
|
|
unsigned misaligned;
|
|
unsigned quadrant;
|
|
int level;
|
|
int flooded = 0;
|
|
int npte;
|
|
int r;
|
|
|
|
pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
|
|
mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
kvm_mmu_access_page(vcpu, gfn);
|
|
kvm_mmu_free_some_pages(vcpu);
|
|
++vcpu->kvm->stat.mmu_pte_write;
|
|
kvm_mmu_audit(vcpu, "pre pte write");
|
|
if (guest_initiated) {
|
|
if (gfn == vcpu->arch.last_pt_write_gfn
|
|
&& !last_updated_pte_accessed(vcpu)) {
|
|
++vcpu->arch.last_pt_write_count;
|
|
if (vcpu->arch.last_pt_write_count >= 3)
|
|
flooded = 1;
|
|
} else {
|
|
vcpu->arch.last_pt_write_gfn = gfn;
|
|
vcpu->arch.last_pt_write_count = 1;
|
|
vcpu->arch.last_pte_updated = NULL;
|
|
}
|
|
}
|
|
index = kvm_page_table_hashfn(gfn);
|
|
bucket = &vcpu->kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
|
|
if (sp->gfn != gfn || sp->role.direct || sp->role.invalid)
|
|
continue;
|
|
pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
|
|
misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
|
|
misaligned |= bytes < 4;
|
|
if (misaligned || flooded) {
|
|
/*
|
|
* Misaligned accesses are too much trouble to fix
|
|
* up; also, they usually indicate a page is not used
|
|
* as a page table.
|
|
*
|
|
* If we're seeing too many writes to a page,
|
|
* it may no longer be a page table, or we may be
|
|
* forking, in which case it is better to unmap the
|
|
* page.
|
|
*/
|
|
pgprintk("misaligned: gpa %llx bytes %d role %x\n",
|
|
gpa, bytes, sp->role.word);
|
|
if (kvm_mmu_zap_page(vcpu->kvm, sp))
|
|
n = bucket->first;
|
|
++vcpu->kvm->stat.mmu_flooded;
|
|
continue;
|
|
}
|
|
page_offset = offset;
|
|
level = sp->role.level;
|
|
npte = 1;
|
|
if (sp->role.glevels == PT32_ROOT_LEVEL) {
|
|
page_offset <<= 1; /* 32->64 */
|
|
/*
|
|
* A 32-bit pde maps 4MB while the shadow pdes map
|
|
* only 2MB. So we need to double the offset again
|
|
* and zap two pdes instead of one.
|
|
*/
|
|
if (level == PT32_ROOT_LEVEL) {
|
|
page_offset &= ~7; /* kill rounding error */
|
|
page_offset <<= 1;
|
|
npte = 2;
|
|
}
|
|
quadrant = page_offset >> PAGE_SHIFT;
|
|
page_offset &= ~PAGE_MASK;
|
|
if (quadrant != sp->role.quadrant)
|
|
continue;
|
|
}
|
|
spte = &sp->spt[page_offset / sizeof(*spte)];
|
|
if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
|
|
gentry = 0;
|
|
r = kvm_read_guest_atomic(vcpu->kvm,
|
|
gpa & ~(u64)(pte_size - 1),
|
|
&gentry, pte_size);
|
|
new = (const void *)&gentry;
|
|
if (r < 0)
|
|
new = NULL;
|
|
}
|
|
while (npte--) {
|
|
entry = *spte;
|
|
mmu_pte_write_zap_pte(vcpu, sp, spte);
|
|
if (new)
|
|
mmu_pte_write_new_pte(vcpu, sp, spte, new);
|
|
mmu_pte_write_flush_tlb(vcpu, entry, *spte);
|
|
++spte;
|
|
}
|
|
}
|
|
kvm_mmu_audit(vcpu, "post pte write");
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
|
|
kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
|
|
vcpu->arch.update_pte.pfn = bad_pfn;
|
|
}
|
|
}
|
|
|
|
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
|
|
{
|
|
gpa_t gpa;
|
|
int r;
|
|
|
|
if (tdp_enabled)
|
|
return 0;
|
|
|
|
gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
|
|
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
return r;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
|
|
|
|
void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
|
|
{
|
|
while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES &&
|
|
!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
|
|
struct kvm_mmu_page *sp;
|
|
|
|
sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
|
|
struct kvm_mmu_page, link);
|
|
kvm_mmu_zap_page(vcpu->kvm, sp);
|
|
++vcpu->kvm->stat.mmu_recycled;
|
|
}
|
|
}
|
|
|
|
int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
|
|
{
|
|
int r;
|
|
enum emulation_result er;
|
|
|
|
r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
|
|
if (r < 0)
|
|
goto out;
|
|
|
|
if (!r) {
|
|
r = 1;
|
|
goto out;
|
|
}
|
|
|
|
r = mmu_topup_memory_caches(vcpu);
|
|
if (r)
|
|
goto out;
|
|
|
|
er = emulate_instruction(vcpu, cr2, error_code, 0);
|
|
|
|
switch (er) {
|
|
case EMULATE_DONE:
|
|
return 1;
|
|
case EMULATE_DO_MMIO:
|
|
++vcpu->stat.mmio_exits;
|
|
return 0;
|
|
case EMULATE_FAIL:
|
|
vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
|
|
vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
|
|
vcpu->run->internal.ndata = 0;
|
|
return 0;
|
|
default:
|
|
BUG();
|
|
}
|
|
out:
|
|
return r;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
|
|
|
|
void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
|
|
{
|
|
vcpu->arch.mmu.invlpg(vcpu, gva);
|
|
kvm_mmu_flush_tlb(vcpu);
|
|
++vcpu->stat.invlpg;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
|
|
|
|
void kvm_enable_tdp(void)
|
|
{
|
|
tdp_enabled = true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_enable_tdp);
|
|
|
|
void kvm_disable_tdp(void)
|
|
{
|
|
tdp_enabled = false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_disable_tdp);
|
|
|
|
static void free_mmu_pages(struct kvm_vcpu *vcpu)
|
|
{
|
|
free_page((unsigned long)vcpu->arch.mmu.pae_root);
|
|
}
|
|
|
|
static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct page *page;
|
|
int i;
|
|
|
|
ASSERT(vcpu);
|
|
|
|
/*
|
|
* When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
|
|
* Therefore we need to allocate shadow page tables in the first
|
|
* 4GB of memory, which happens to fit the DMA32 zone.
|
|
*/
|
|
page = alloc_page(GFP_KERNEL | __GFP_DMA32);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
vcpu->arch.mmu.pae_root = page_address(page);
|
|
for (i = 0; i < 4; ++i)
|
|
vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int kvm_mmu_create(struct kvm_vcpu *vcpu)
|
|
{
|
|
ASSERT(vcpu);
|
|
ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
|
|
|
|
return alloc_mmu_pages(vcpu);
|
|
}
|
|
|
|
int kvm_mmu_setup(struct kvm_vcpu *vcpu)
|
|
{
|
|
ASSERT(vcpu);
|
|
ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
|
|
|
|
return init_kvm_mmu(vcpu);
|
|
}
|
|
|
|
void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
|
|
{
|
|
ASSERT(vcpu);
|
|
|
|
destroy_kvm_mmu(vcpu);
|
|
free_mmu_pages(vcpu);
|
|
mmu_free_memory_caches(vcpu);
|
|
}
|
|
|
|
void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
|
|
list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
|
|
int i;
|
|
u64 *pt;
|
|
|
|
if (!test_bit(slot, sp->slot_bitmap))
|
|
continue;
|
|
|
|
pt = sp->spt;
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
|
|
/* avoid RMW */
|
|
if (pt[i] & PT_WRITABLE_MASK)
|
|
pt[i] &= ~PT_WRITABLE_MASK;
|
|
}
|
|
kvm_flush_remote_tlbs(kvm);
|
|
}
|
|
|
|
void kvm_mmu_zap_all(struct kvm *kvm)
|
|
{
|
|
struct kvm_mmu_page *sp, *node;
|
|
|
|
spin_lock(&kvm->mmu_lock);
|
|
list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
|
|
if (kvm_mmu_zap_page(kvm, sp))
|
|
node = container_of(kvm->arch.active_mmu_pages.next,
|
|
struct kvm_mmu_page, link);
|
|
spin_unlock(&kvm->mmu_lock);
|
|
|
|
kvm_flush_remote_tlbs(kvm);
|
|
}
|
|
|
|
static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
|
|
{
|
|
struct kvm_mmu_page *page;
|
|
|
|
page = container_of(kvm->arch.active_mmu_pages.prev,
|
|
struct kvm_mmu_page, link);
|
|
kvm_mmu_zap_page(kvm, page);
|
|
}
|
|
|
|
static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
|
|
{
|
|
struct kvm *kvm;
|
|
struct kvm *kvm_freed = NULL;
|
|
int cache_count = 0;
|
|
|
|
spin_lock(&kvm_lock);
|
|
|
|
list_for_each_entry(kvm, &vm_list, vm_list) {
|
|
int npages, idx;
|
|
|
|
idx = srcu_read_lock(&kvm->srcu);
|
|
spin_lock(&kvm->mmu_lock);
|
|
npages = kvm->arch.n_alloc_mmu_pages -
|
|
kvm->arch.n_free_mmu_pages;
|
|
cache_count += npages;
|
|
if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
|
|
kvm_mmu_remove_one_alloc_mmu_page(kvm);
|
|
cache_count--;
|
|
kvm_freed = kvm;
|
|
}
|
|
nr_to_scan--;
|
|
|
|
spin_unlock(&kvm->mmu_lock);
|
|
srcu_read_unlock(&kvm->srcu, idx);
|
|
}
|
|
if (kvm_freed)
|
|
list_move_tail(&kvm_freed->vm_list, &vm_list);
|
|
|
|
spin_unlock(&kvm_lock);
|
|
|
|
return cache_count;
|
|
}
|
|
|
|
static struct shrinker mmu_shrinker = {
|
|
.shrink = mmu_shrink,
|
|
.seeks = DEFAULT_SEEKS * 10,
|
|
};
|
|
|
|
static void mmu_destroy_caches(void)
|
|
{
|
|
if (pte_chain_cache)
|
|
kmem_cache_destroy(pte_chain_cache);
|
|
if (rmap_desc_cache)
|
|
kmem_cache_destroy(rmap_desc_cache);
|
|
if (mmu_page_header_cache)
|
|
kmem_cache_destroy(mmu_page_header_cache);
|
|
}
|
|
|
|
void kvm_mmu_module_exit(void)
|
|
{
|
|
mmu_destroy_caches();
|
|
unregister_shrinker(&mmu_shrinker);
|
|
}
|
|
|
|
int kvm_mmu_module_init(void)
|
|
{
|
|
pte_chain_cache = kmem_cache_create("kvm_pte_chain",
|
|
sizeof(struct kvm_pte_chain),
|
|
0, 0, NULL);
|
|
if (!pte_chain_cache)
|
|
goto nomem;
|
|
rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
|
|
sizeof(struct kvm_rmap_desc),
|
|
0, 0, NULL);
|
|
if (!rmap_desc_cache)
|
|
goto nomem;
|
|
|
|
mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
|
|
sizeof(struct kvm_mmu_page),
|
|
0, 0, NULL);
|
|
if (!mmu_page_header_cache)
|
|
goto nomem;
|
|
|
|
register_shrinker(&mmu_shrinker);
|
|
|
|
return 0;
|
|
|
|
nomem:
|
|
mmu_destroy_caches();
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* Caculate mmu pages needed for kvm.
|
|
*/
|
|
unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
|
|
{
|
|
int i;
|
|
unsigned int nr_mmu_pages;
|
|
unsigned int nr_pages = 0;
|
|
struct kvm_memslots *slots;
|
|
|
|
slots = rcu_dereference(kvm->memslots);
|
|
for (i = 0; i < slots->nmemslots; i++)
|
|
nr_pages += slots->memslots[i].npages;
|
|
|
|
nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
|
|
nr_mmu_pages = max(nr_mmu_pages,
|
|
(unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
|
|
|
|
return nr_mmu_pages;
|
|
}
|
|
|
|
static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
|
|
unsigned len)
|
|
{
|
|
if (len > buffer->len)
|
|
return NULL;
|
|
return buffer->ptr;
|
|
}
|
|
|
|
static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
|
|
unsigned len)
|
|
{
|
|
void *ret;
|
|
|
|
ret = pv_mmu_peek_buffer(buffer, len);
|
|
if (!ret)
|
|
return ret;
|
|
buffer->ptr += len;
|
|
buffer->len -= len;
|
|
buffer->processed += len;
|
|
return ret;
|
|
}
|
|
|
|
static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
|
|
gpa_t addr, gpa_t value)
|
|
{
|
|
int bytes = 8;
|
|
int r;
|
|
|
|
if (!is_long_mode(vcpu) && !is_pae(vcpu))
|
|
bytes = 4;
|
|
|
|
r = mmu_topup_memory_caches(vcpu);
|
|
if (r)
|
|
return r;
|
|
|
|
if (!emulator_write_phys(vcpu, addr, &value, bytes))
|
|
return -EFAULT;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
|
|
{
|
|
kvm_set_cr3(vcpu, vcpu->arch.cr3);
|
|
return 1;
|
|
}
|
|
|
|
static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
|
|
{
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
return 1;
|
|
}
|
|
|
|
static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
|
|
struct kvm_pv_mmu_op_buffer *buffer)
|
|
{
|
|
struct kvm_mmu_op_header *header;
|
|
|
|
header = pv_mmu_peek_buffer(buffer, sizeof *header);
|
|
if (!header)
|
|
return 0;
|
|
switch (header->op) {
|
|
case KVM_MMU_OP_WRITE_PTE: {
|
|
struct kvm_mmu_op_write_pte *wpte;
|
|
|
|
wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
|
|
if (!wpte)
|
|
return 0;
|
|
return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
|
|
wpte->pte_val);
|
|
}
|
|
case KVM_MMU_OP_FLUSH_TLB: {
|
|
struct kvm_mmu_op_flush_tlb *ftlb;
|
|
|
|
ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
|
|
if (!ftlb)
|
|
return 0;
|
|
return kvm_pv_mmu_flush_tlb(vcpu);
|
|
}
|
|
case KVM_MMU_OP_RELEASE_PT: {
|
|
struct kvm_mmu_op_release_pt *rpt;
|
|
|
|
rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
|
|
if (!rpt)
|
|
return 0;
|
|
return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
|
|
}
|
|
default: return 0;
|
|
}
|
|
}
|
|
|
|
int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
|
|
gpa_t addr, unsigned long *ret)
|
|
{
|
|
int r;
|
|
struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
|
|
|
|
buffer->ptr = buffer->buf;
|
|
buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
|
|
buffer->processed = 0;
|
|
|
|
r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
|
|
if (r)
|
|
goto out;
|
|
|
|
while (buffer->len) {
|
|
r = kvm_pv_mmu_op_one(vcpu, buffer);
|
|
if (r < 0)
|
|
goto out;
|
|
if (r == 0)
|
|
break;
|
|
}
|
|
|
|
r = 1;
|
|
out:
|
|
*ret = buffer->processed;
|
|
return r;
|
|
}
|
|
|
|
int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4])
|
|
{
|
|
struct kvm_shadow_walk_iterator iterator;
|
|
int nr_sptes = 0;
|
|
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
for_each_shadow_entry(vcpu, addr, iterator) {
|
|
sptes[iterator.level-1] = *iterator.sptep;
|
|
nr_sptes++;
|
|
if (!is_shadow_present_pte(*iterator.sptep))
|
|
break;
|
|
}
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
|
|
return nr_sptes;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy);
|
|
|
|
#ifdef AUDIT
|
|
|
|
static const char *audit_msg;
|
|
|
|
static gva_t canonicalize(gva_t gva)
|
|
{
|
|
#ifdef CONFIG_X86_64
|
|
gva = (long long)(gva << 16) >> 16;
|
|
#endif
|
|
return gva;
|
|
}
|
|
|
|
|
|
typedef void (*inspect_spte_fn) (struct kvm *kvm, struct kvm_mmu_page *sp,
|
|
u64 *sptep);
|
|
|
|
static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp,
|
|
inspect_spte_fn fn)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
|
|
u64 ent = sp->spt[i];
|
|
|
|
if (is_shadow_present_pte(ent)) {
|
|
if (!is_last_spte(ent, sp->role.level)) {
|
|
struct kvm_mmu_page *child;
|
|
child = page_header(ent & PT64_BASE_ADDR_MASK);
|
|
__mmu_spte_walk(kvm, child, fn);
|
|
} else
|
|
fn(kvm, sp, &sp->spt[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
|
|
{
|
|
int i;
|
|
struct kvm_mmu_page *sp;
|
|
|
|
if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
|
|
return;
|
|
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
|
|
hpa_t root = vcpu->arch.mmu.root_hpa;
|
|
sp = page_header(root);
|
|
__mmu_spte_walk(vcpu->kvm, sp, fn);
|
|
return;
|
|
}
|
|
for (i = 0; i < 4; ++i) {
|
|
hpa_t root = vcpu->arch.mmu.pae_root[i];
|
|
|
|
if (root && VALID_PAGE(root)) {
|
|
root &= PT64_BASE_ADDR_MASK;
|
|
sp = page_header(root);
|
|
__mmu_spte_walk(vcpu->kvm, sp, fn);
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
|
|
gva_t va, int level)
|
|
{
|
|
u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
|
|
int i;
|
|
gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
|
|
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
|
|
u64 ent = pt[i];
|
|
|
|
if (ent == shadow_trap_nonpresent_pte)
|
|
continue;
|
|
|
|
va = canonicalize(va);
|
|
if (is_shadow_present_pte(ent) && !is_last_spte(ent, level))
|
|
audit_mappings_page(vcpu, ent, va, level - 1);
|
|
else {
|
|
gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, va, NULL);
|
|
gfn_t gfn = gpa >> PAGE_SHIFT;
|
|
pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
|
|
hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
|
|
|
|
if (is_error_pfn(pfn)) {
|
|
kvm_release_pfn_clean(pfn);
|
|
continue;
|
|
}
|
|
|
|
if (is_shadow_present_pte(ent)
|
|
&& (ent & PT64_BASE_ADDR_MASK) != hpa)
|
|
printk(KERN_ERR "xx audit error: (%s) levels %d"
|
|
" gva %lx gpa %llx hpa %llx ent %llx %d\n",
|
|
audit_msg, vcpu->arch.mmu.root_level,
|
|
va, gpa, hpa, ent,
|
|
is_shadow_present_pte(ent));
|
|
else if (ent == shadow_notrap_nonpresent_pte
|
|
&& !is_error_hpa(hpa))
|
|
printk(KERN_ERR "audit: (%s) notrap shadow,"
|
|
" valid guest gva %lx\n", audit_msg, va);
|
|
kvm_release_pfn_clean(pfn);
|
|
|
|
}
|
|
}
|
|
}
|
|
|
|
static void audit_mappings(struct kvm_vcpu *vcpu)
|
|
{
|
|
unsigned i;
|
|
|
|
if (vcpu->arch.mmu.root_level == 4)
|
|
audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
|
|
else
|
|
for (i = 0; i < 4; ++i)
|
|
if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
|
|
audit_mappings_page(vcpu,
|
|
vcpu->arch.mmu.pae_root[i],
|
|
i << 30,
|
|
2);
|
|
}
|
|
|
|
static int count_rmaps(struct kvm_vcpu *vcpu)
|
|
{
|
|
int nmaps = 0;
|
|
int i, j, k, idx;
|
|
|
|
idx = srcu_read_lock(&kvm->srcu);
|
|
slots = rcu_dereference(kvm->memslots);
|
|
for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
|
|
struct kvm_memory_slot *m = &slots->memslots[i];
|
|
struct kvm_rmap_desc *d;
|
|
|
|
for (j = 0; j < m->npages; ++j) {
|
|
unsigned long *rmapp = &m->rmap[j];
|
|
|
|
if (!*rmapp)
|
|
continue;
|
|
if (!(*rmapp & 1)) {
|
|
++nmaps;
|
|
continue;
|
|
}
|
|
d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
|
|
while (d) {
|
|
for (k = 0; k < RMAP_EXT; ++k)
|
|
if (d->sptes[k])
|
|
++nmaps;
|
|
else
|
|
break;
|
|
d = d->more;
|
|
}
|
|
}
|
|
}
|
|
srcu_read_unlock(&kvm->srcu, idx);
|
|
return nmaps;
|
|
}
|
|
|
|
void inspect_spte_has_rmap(struct kvm *kvm, struct kvm_mmu_page *sp, u64 *sptep)
|
|
{
|
|
unsigned long *rmapp;
|
|
struct kvm_mmu_page *rev_sp;
|
|
gfn_t gfn;
|
|
|
|
if (*sptep & PT_WRITABLE_MASK) {
|
|
rev_sp = page_header(__pa(sptep));
|
|
gfn = rev_sp->gfns[sptep - rev_sp->spt];
|
|
|
|
if (!gfn_to_memslot(kvm, gfn)) {
|
|
if (!printk_ratelimit())
|
|
return;
|
|
printk(KERN_ERR "%s: no memslot for gfn %ld\n",
|
|
audit_msg, gfn);
|
|
printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\n",
|
|
audit_msg, sptep - rev_sp->spt,
|
|
rev_sp->gfn);
|
|
dump_stack();
|
|
return;
|
|
}
|
|
|
|
rmapp = gfn_to_rmap(kvm, rev_sp->gfns[sptep - rev_sp->spt],
|
|
is_large_pte(*sptep));
|
|
if (!*rmapp) {
|
|
if (!printk_ratelimit())
|
|
return;
|
|
printk(KERN_ERR "%s: no rmap for writable spte %llx\n",
|
|
audit_msg, *sptep);
|
|
dump_stack();
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
void audit_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu)
|
|
{
|
|
mmu_spte_walk(vcpu, inspect_spte_has_rmap);
|
|
}
|
|
|
|
static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
int i;
|
|
|
|
list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
|
|
u64 *pt = sp->spt;
|
|
|
|
if (sp->role.level != PT_PAGE_TABLE_LEVEL)
|
|
continue;
|
|
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
|
|
u64 ent = pt[i];
|
|
|
|
if (!(ent & PT_PRESENT_MASK))
|
|
continue;
|
|
if (!(ent & PT_WRITABLE_MASK))
|
|
continue;
|
|
inspect_spte_has_rmap(vcpu->kvm, sp, &pt[i]);
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
static void audit_rmap(struct kvm_vcpu *vcpu)
|
|
{
|
|
check_writable_mappings_rmap(vcpu);
|
|
count_rmaps(vcpu);
|
|
}
|
|
|
|
static void audit_write_protection(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
struct kvm_memory_slot *slot;
|
|
unsigned long *rmapp;
|
|
u64 *spte;
|
|
gfn_t gfn;
|
|
|
|
list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
|
|
if (sp->role.direct)
|
|
continue;
|
|
if (sp->unsync)
|
|
continue;
|
|
|
|
gfn = unalias_gfn(vcpu->kvm, sp->gfn);
|
|
slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
|
|
rmapp = &slot->rmap[gfn - slot->base_gfn];
|
|
|
|
spte = rmap_next(vcpu->kvm, rmapp, NULL);
|
|
while (spte) {
|
|
if (*spte & PT_WRITABLE_MASK)
|
|
printk(KERN_ERR "%s: (%s) shadow page has "
|
|
"writable mappings: gfn %lx role %x\n",
|
|
__func__, audit_msg, sp->gfn,
|
|
sp->role.word);
|
|
spte = rmap_next(vcpu->kvm, rmapp, spte);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
|
|
{
|
|
int olddbg = dbg;
|
|
|
|
dbg = 0;
|
|
audit_msg = msg;
|
|
audit_rmap(vcpu);
|
|
audit_write_protection(vcpu);
|
|
if (strcmp("pre pte write", audit_msg) != 0)
|
|
audit_mappings(vcpu);
|
|
audit_writable_sptes_have_rmaps(vcpu);
|
|
dbg = olddbg;
|
|
}
|
|
|
|
#endif
|