linux-stable/arch/powerpc/kvm/book3s_64_mmu_radix.c
Sean Christopherson b1c5356e87 KVM: PPC: Convert to the gfn-based MMU notifier callbacks
Move PPC to the gfn-base MMU notifier APIs, and update all 15 bajillion
PPC-internal hooks to work with gfns instead of hvas.

No meaningful functional change intended, though the exact order of
operations is slightly different since the memslot lookups occur before
calling into arch code.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210402005658.3024832-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-17 08:31:07 -04:00

1462 lines
36 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <linux/debugfs.h>
#include <linux/pgtable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/pgalloc.h>
#include <asm/pte-walk.h>
#include <asm/ultravisor.h>
#include <asm/kvm_book3s_uvmem.h>
/*
* Supported radix tree geometry.
* Like p9, we support either 5 or 9 bits at the first (lowest) level,
* for a page size of 64k or 4k.
*/
static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
gva_t eaddr, void *to, void *from,
unsigned long n)
{
int old_pid, old_lpid;
unsigned long quadrant, ret = n;
bool is_load = !!to;
/* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
if (kvmhv_on_pseries())
return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
(to != NULL) ? __pa(to): 0,
(from != NULL) ? __pa(from): 0, n);
quadrant = 1;
if (!pid)
quadrant = 2;
if (is_load)
from = (void *) (eaddr | (quadrant << 62));
else
to = (void *) (eaddr | (quadrant << 62));
preempt_disable();
/* switch the lpid first to avoid running host with unallocated pid */
old_lpid = mfspr(SPRN_LPID);
if (old_lpid != lpid)
mtspr(SPRN_LPID, lpid);
if (quadrant == 1) {
old_pid = mfspr(SPRN_PID);
if (old_pid != pid)
mtspr(SPRN_PID, pid);
}
isync();
if (is_load)
ret = copy_from_user_nofault(to, (const void __user *)from, n);
else
ret = copy_to_user_nofault((void __user *)to, from, n);
/* switch the pid first to avoid running host with unallocated pid */
if (quadrant == 1 && pid != old_pid)
mtspr(SPRN_PID, old_pid);
if (lpid != old_lpid)
mtspr(SPRN_LPID, old_lpid);
isync();
preempt_enable();
return ret;
}
EXPORT_SYMBOL_GPL(__kvmhv_copy_tofrom_guest_radix);
static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
void *to, void *from, unsigned long n)
{
int lpid = vcpu->kvm->arch.lpid;
int pid = vcpu->arch.pid;
/* This would cause a data segment intr so don't allow the access */
if (eaddr & (0x3FFUL << 52))
return -EINVAL;
/* Should we be using the nested lpid */
if (vcpu->arch.nested)
lpid = vcpu->arch.nested->shadow_lpid;
/* If accessing quadrant 3 then pid is expected to be 0 */
if (((eaddr >> 62) & 0x3) == 0x3)
pid = 0;
eaddr &= ~(0xFFFUL << 52);
return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n);
}
long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to,
unsigned long n)
{
long ret;
ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n);
if (ret > 0)
memset(to + (n - ret), 0, ret);
return ret;
}
EXPORT_SYMBOL_GPL(kvmhv_copy_from_guest_radix);
long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from,
unsigned long n)
{
return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n);
}
EXPORT_SYMBOL_GPL(kvmhv_copy_to_guest_radix);
int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, u64 root,
u64 *pte_ret_p)
{
struct kvm *kvm = vcpu->kvm;
int ret, level, ps;
unsigned long rts, bits, offset, index;
u64 pte, base, gpa;
__be64 rpte;
rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
((root & RTS2_MASK) >> RTS2_SHIFT);
bits = root & RPDS_MASK;
base = root & RPDB_MASK;
offset = rts + 31;
/* Current implementations only support 52-bit space */
if (offset != 52)
return -EINVAL;
/* Walk each level of the radix tree */
for (level = 3; level >= 0; --level) {
u64 addr;
/* Check a valid size */
if (level && bits != p9_supported_radix_bits[level])
return -EINVAL;
if (level == 0 && !(bits == 5 || bits == 9))
return -EINVAL;
offset -= bits;
index = (eaddr >> offset) & ((1UL << bits) - 1);
/* Check that low bits of page table base are zero */
if (base & ((1UL << (bits + 3)) - 1))
return -EINVAL;
/* Read the entry from guest memory */
addr = base + (index * sizeof(rpte));
vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
if (ret) {
if (pte_ret_p)
*pte_ret_p = addr;
return ret;
}
pte = __be64_to_cpu(rpte);
if (!(pte & _PAGE_PRESENT))
return -ENOENT;
/* Check if a leaf entry */
if (pte & _PAGE_PTE)
break;
/* Get ready to walk the next level */
base = pte & RPDB_MASK;
bits = pte & RPDS_MASK;
}
/* Need a leaf at lowest level; 512GB pages not supported */
if (level < 0 || level == 3)
return -EINVAL;
/* We found a valid leaf PTE */
/* Offset is now log base 2 of the page size */
gpa = pte & 0x01fffffffffff000ul;
if (gpa & ((1ul << offset) - 1))
return -EINVAL;
gpa |= eaddr & ((1ul << offset) - 1);
for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
if (offset == mmu_psize_defs[ps].shift)
break;
gpte->page_size = ps;
gpte->page_shift = offset;
gpte->eaddr = eaddr;
gpte->raddr = gpa;
/* Work out permissions */
gpte->may_read = !!(pte & _PAGE_READ);
gpte->may_write = !!(pte & _PAGE_WRITE);
gpte->may_execute = !!(pte & _PAGE_EXEC);
gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
if (pte_ret_p)
*pte_ret_p = pte;
return 0;
}
/*
* Used to walk a partition or process table radix tree in guest memory
* Note: We exploit the fact that a partition table and a process
* table have the same layout, a partition-scoped page table and a
* process-scoped page table have the same layout, and the 2nd
* doubleword of a partition table entry has the same layout as
* the PTCR register.
*/
int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, u64 table,
int table_index, u64 *pte_ret_p)
{
struct kvm *kvm = vcpu->kvm;
int ret;
unsigned long size, ptbl, root;
struct prtb_entry entry;
if ((table & PRTS_MASK) > 24)
return -EINVAL;
size = 1ul << ((table & PRTS_MASK) + 12);
/* Is the table big enough to contain this entry? */
if ((table_index * sizeof(entry)) >= size)
return -EINVAL;
/* Read the table to find the root of the radix tree */
ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
if (ret)
return ret;
/* Root is stored in the first double word */
root = be64_to_cpu(entry.prtb0);
return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
}
int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, bool data, bool iswrite)
{
u32 pid;
u64 pte;
int ret;
/* Work out effective PID */
switch (eaddr >> 62) {
case 0:
pid = vcpu->arch.pid;
break;
case 3:
pid = 0;
break;
default:
return -EINVAL;
}
ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte,
vcpu->kvm->arch.process_table, pid, &pte);
if (ret)
return ret;
/* Check privilege (applies only to process scoped translations) */
if (kvmppc_get_msr(vcpu) & MSR_PR) {
if (pte & _PAGE_PRIVILEGED) {
gpte->may_read = 0;
gpte->may_write = 0;
gpte->may_execute = 0;
}
} else {
if (!(pte & _PAGE_PRIVILEGED)) {
/* Check AMR/IAMR to see if strict mode is in force */
if (vcpu->arch.amr & (1ul << 62))
gpte->may_read = 0;
if (vcpu->arch.amr & (1ul << 63))
gpte->may_write = 0;
if (vcpu->arch.iamr & (1ul << 62))
gpte->may_execute = 0;
}
}
return 0;
}
void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
unsigned int pshift, unsigned int lpid)
{
unsigned long psize = PAGE_SIZE;
int psi;
long rc;
unsigned long rb;
if (pshift)
psize = 1UL << pshift;
else
pshift = PAGE_SHIFT;
addr &= ~(psize - 1);
if (!kvmhv_on_pseries()) {
radix__flush_tlb_lpid_page(lpid, addr, psize);
return;
}
psi = shift_to_mmu_psize(pshift);
rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58));
rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1),
lpid, rb);
if (rc)
pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc);
}
static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid)
{
long rc;
if (!kvmhv_on_pseries()) {
radix__flush_pwc_lpid(lpid);
return;
}
rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1),
lpid, TLBIEL_INVAL_SET_LPID);
if (rc)
pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc);
}
static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
unsigned long clr, unsigned long set,
unsigned long addr, unsigned int shift)
{
return __radix_pte_update(ptep, clr, set);
}
static void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
}
static struct kmem_cache *kvm_pte_cache;
static struct kmem_cache *kvm_pmd_cache;
static pte_t *kvmppc_pte_alloc(void)
{
pte_t *pte;
pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
/* pmd_populate() will only reference _pa(pte). */
kmemleak_ignore(pte);
return pte;
}
static void kvmppc_pte_free(pte_t *ptep)
{
kmem_cache_free(kvm_pte_cache, ptep);
}
static pmd_t *kvmppc_pmd_alloc(void)
{
pmd_t *pmd;
pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
/* pud_populate() will only reference _pa(pmd). */
kmemleak_ignore(pmd);
return pmd;
}
static void kvmppc_pmd_free(pmd_t *pmdp)
{
kmem_cache_free(kvm_pmd_cache, pmdp);
}
/* Called with kvm->mmu_lock held */
void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
unsigned int shift,
const struct kvm_memory_slot *memslot,
unsigned int lpid)
{
unsigned long old;
unsigned long gfn = gpa >> PAGE_SHIFT;
unsigned long page_size = PAGE_SIZE;
unsigned long hpa;
old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
/* The following only applies to L1 entries */
if (lpid != kvm->arch.lpid)
return;
if (!memslot) {
memslot = gfn_to_memslot(kvm, gfn);
if (!memslot)
return;
}
if (shift) { /* 1GB or 2MB page */
page_size = 1ul << shift;
if (shift == PMD_SHIFT)
kvm->stat.num_2M_pages--;
else if (shift == PUD_SHIFT)
kvm->stat.num_1G_pages--;
}
gpa &= ~(page_size - 1);
hpa = old & PTE_RPN_MASK;
kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size);
if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap)
kvmppc_update_dirty_map(memslot, gfn, page_size);
}
/*
* kvmppc_free_p?d are used to free existing page tables, and recursively
* descend and clear and free children.
* Callers are responsible for flushing the PWC.
*
* When page tables are being unmapped/freed as part of page fault path
* (full == false), valid ptes are generally not expected; however, there
* is one situation where they arise, which is when dirty page logging is
* turned off for a memslot while the VM is running. The new memslot
* becomes visible to page faults before the memslot commit function
* gets to flush the memslot, which can lead to a 2MB page mapping being
* installed for a guest physical address where there are already 64kB
* (or 4kB) mappings (of sub-pages of the same 2MB page).
*/
static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
unsigned int lpid)
{
if (full) {
memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
} else {
pte_t *p = pte;
unsigned long it;
for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
if (pte_val(*p) == 0)
continue;
kvmppc_unmap_pte(kvm, p,
pte_pfn(*p) << PAGE_SHIFT,
PAGE_SHIFT, NULL, lpid);
}
}
kvmppc_pte_free(pte);
}
static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
unsigned int lpid)
{
unsigned long im;
pmd_t *p = pmd;
for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
if (!pmd_present(*p))
continue;
if (pmd_is_leaf(*p)) {
if (full) {
pmd_clear(p);
} else {
WARN_ON_ONCE(1);
kvmppc_unmap_pte(kvm, (pte_t *)p,
pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
PMD_SHIFT, NULL, lpid);
}
} else {
pte_t *pte;
pte = pte_offset_map(p, 0);
kvmppc_unmap_free_pte(kvm, pte, full, lpid);
pmd_clear(p);
}
}
kvmppc_pmd_free(pmd);
}
static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
unsigned int lpid)
{
unsigned long iu;
pud_t *p = pud;
for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
if (!pud_present(*p))
continue;
if (pud_is_leaf(*p)) {
pud_clear(p);
} else {
pmd_t *pmd;
pmd = pmd_offset(p, 0);
kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
pud_clear(p);
}
}
pud_free(kvm->mm, pud);
}
void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
{
unsigned long ig;
for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
p4d_t *p4d = p4d_offset(pgd, 0);
pud_t *pud;
if (!p4d_present(*p4d))
continue;
pud = pud_offset(p4d, 0);
kvmppc_unmap_free_pud(kvm, pud, lpid);
p4d_clear(p4d);
}
}
void kvmppc_free_radix(struct kvm *kvm)
{
if (kvm->arch.pgtable) {
kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
kvm->arch.lpid);
pgd_free(kvm->mm, kvm->arch.pgtable);
kvm->arch.pgtable = NULL;
}
}
static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
unsigned long gpa, unsigned int lpid)
{
pte_t *pte = pte_offset_kernel(pmd, 0);
/*
* Clearing the pmd entry then flushing the PWC ensures that the pte
* page no longer be cached by the MMU, so can be freed without
* flushing the PWC again.
*/
pmd_clear(pmd);
kvmppc_radix_flush_pwc(kvm, lpid);
kvmppc_unmap_free_pte(kvm, pte, false, lpid);
}
static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
unsigned long gpa, unsigned int lpid)
{
pmd_t *pmd = pmd_offset(pud, 0);
/*
* Clearing the pud entry then flushing the PWC ensures that the pmd
* page and any children pte pages will no longer be cached by the MMU,
* so can be freed without flushing the PWC again.
*/
pud_clear(pud);
kvmppc_radix_flush_pwc(kvm, lpid);
kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
}
/*
* There are a number of bits which may differ between different faults to
* the same partition scope entry. RC bits, in the course of cleaning and
* aging. And the write bit can change, either the access could have been
* upgraded, or a read fault could happen concurrently with a write fault
* that sets those bits first.
*/
#define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
unsigned long gpa, unsigned int level,
unsigned long mmu_seq, unsigned int lpid,
unsigned long *rmapp, struct rmap_nested **n_rmap)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud, *new_pud = NULL;
pmd_t *pmd, *new_pmd = NULL;
pte_t *ptep, *new_ptep = NULL;
int ret;
/* Traverse the guest's 2nd-level tree, allocate new levels needed */
pgd = pgtable + pgd_index(gpa);
p4d = p4d_offset(pgd, gpa);
pud = NULL;
if (p4d_present(*p4d))
pud = pud_offset(p4d, gpa);
else
new_pud = pud_alloc_one(kvm->mm, gpa);
pmd = NULL;
if (pud && pud_present(*pud) && !pud_is_leaf(*pud))
pmd = pmd_offset(pud, gpa);
else if (level <= 1)
new_pmd = kvmppc_pmd_alloc();
if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
new_ptep = kvmppc_pte_alloc();
/* Check if we might have been invalidated; let the guest retry if so */
spin_lock(&kvm->mmu_lock);
ret = -EAGAIN;
if (mmu_notifier_retry(kvm, mmu_seq))
goto out_unlock;
/* Now traverse again under the lock and change the tree */
ret = -ENOMEM;
if (p4d_none(*p4d)) {
if (!new_pud)
goto out_unlock;
p4d_populate(kvm->mm, p4d, new_pud);
new_pud = NULL;
}
pud = pud_offset(p4d, gpa);
if (pud_is_leaf(*pud)) {
unsigned long hgpa = gpa & PUD_MASK;
/* Check if we raced and someone else has set the same thing */
if (level == 2) {
if (pud_raw(*pud) == pte_raw(pte)) {
ret = 0;
goto out_unlock;
}
/* Valid 1GB page here already, add our extra bits */
WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
PTE_BITS_MUST_MATCH);
kvmppc_radix_update_pte(kvm, (pte_t *)pud,
0, pte_val(pte), hgpa, PUD_SHIFT);
ret = 0;
goto out_unlock;
}
/*
* If we raced with another CPU which has just put
* a 1GB pte in after we saw a pmd page, try again.
*/
if (!new_pmd) {
ret = -EAGAIN;
goto out_unlock;
}
/* Valid 1GB page here already, remove it */
kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
lpid);
}
if (level == 2) {
if (!pud_none(*pud)) {
/*
* There's a page table page here, but we wanted to
* install a large page, so remove and free the page
* table page.
*/
kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
}
kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
if (rmapp && n_rmap)
kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
ret = 0;
goto out_unlock;
}
if (pud_none(*pud)) {
if (!new_pmd)
goto out_unlock;
pud_populate(kvm->mm, pud, new_pmd);
new_pmd = NULL;
}
pmd = pmd_offset(pud, gpa);
if (pmd_is_leaf(*pmd)) {
unsigned long lgpa = gpa & PMD_MASK;
/* Check if we raced and someone else has set the same thing */
if (level == 1) {
if (pmd_raw(*pmd) == pte_raw(pte)) {
ret = 0;
goto out_unlock;
}
/* Valid 2MB page here already, add our extra bits */
WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
PTE_BITS_MUST_MATCH);
kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
0, pte_val(pte), lgpa, PMD_SHIFT);
ret = 0;
goto out_unlock;
}
/*
* If we raced with another CPU which has just put
* a 2MB pte in after we saw a pte page, try again.
*/
if (!new_ptep) {
ret = -EAGAIN;
goto out_unlock;
}
/* Valid 2MB page here already, remove it */
kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
lpid);
}
if (level == 1) {
if (!pmd_none(*pmd)) {
/*
* There's a page table page here, but we wanted to
* install a large page, so remove and free the page
* table page.
*/
kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
}
kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
if (rmapp && n_rmap)
kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
ret = 0;
goto out_unlock;
}
if (pmd_none(*pmd)) {
if (!new_ptep)
goto out_unlock;
pmd_populate(kvm->mm, pmd, new_ptep);
new_ptep = NULL;
}
ptep = pte_offset_kernel(pmd, gpa);
if (pte_present(*ptep)) {
/* Check if someone else set the same thing */
if (pte_raw(*ptep) == pte_raw(pte)) {
ret = 0;
goto out_unlock;
}
/* Valid page here already, add our extra bits */
WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) &
PTE_BITS_MUST_MATCH);
kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0);
ret = 0;
goto out_unlock;
}
kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
if (rmapp && n_rmap)
kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
ret = 0;
out_unlock:
spin_unlock(&kvm->mmu_lock);
if (new_pud)
pud_free(kvm->mm, new_pud);
if (new_pmd)
kvmppc_pmd_free(new_pmd);
if (new_ptep)
kvmppc_pte_free(new_ptep);
return ret;
}
bool kvmppc_hv_handle_set_rc(struct kvm *kvm, bool nested, bool writing,
unsigned long gpa, unsigned int lpid)
{
unsigned long pgflags;
unsigned int shift;
pte_t *ptep;
/*
* Need to set an R or C bit in the 2nd-level tables;
* since we are just helping out the hardware here,
* it is sufficient to do what the hardware does.
*/
pgflags = _PAGE_ACCESSED;
if (writing)
pgflags |= _PAGE_DIRTY;
if (nested)
ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
else
ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
return true;
}
return false;
}
int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
unsigned long gpa,
struct kvm_memory_slot *memslot,
bool writing, bool kvm_ro,
pte_t *inserted_pte, unsigned int *levelp)
{
struct kvm *kvm = vcpu->kvm;
struct page *page = NULL;
unsigned long mmu_seq;
unsigned long hva, gfn = gpa >> PAGE_SHIFT;
bool upgrade_write = false;
bool *upgrade_p = &upgrade_write;
pte_t pte, *ptep;
unsigned int shift, level;
int ret;
bool large_enable;
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
/*
* Do a fast check first, since __gfn_to_pfn_memslot doesn't
* do it with !atomic && !async, which is how we call it.
* We always ask for write permission since the common case
* is that the page is writable.
*/
hva = gfn_to_hva_memslot(memslot, gfn);
if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
upgrade_write = true;
} else {
unsigned long pfn;
/* Call KVM generic code to do the slow-path check */
pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL,
writing, upgrade_p, NULL);
if (is_error_noslot_pfn(pfn))
return -EFAULT;
page = NULL;
if (pfn_valid(pfn)) {
page = pfn_to_page(pfn);
if (PageReserved(page))
page = NULL;
}
}
/*
* Read the PTE from the process' radix tree and use that
* so we get the shift and attribute bits.
*/
spin_lock(&kvm->mmu_lock);
ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
pte = __pte(0);
if (ptep)
pte = READ_ONCE(*ptep);
spin_unlock(&kvm->mmu_lock);
/*
* If the PTE disappeared temporarily due to a THP
* collapse, just return and let the guest try again.
*/
if (!pte_present(pte)) {
if (page)
put_page(page);
return RESUME_GUEST;
}
/* If we're logging dirty pages, always map single pages */
large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);
/* Get pte level from shift/size */
if (large_enable && shift == PUD_SHIFT &&
(gpa & (PUD_SIZE - PAGE_SIZE)) ==
(hva & (PUD_SIZE - PAGE_SIZE))) {
level = 2;
} else if (large_enable && shift == PMD_SHIFT &&
(gpa & (PMD_SIZE - PAGE_SIZE)) ==
(hva & (PMD_SIZE - PAGE_SIZE))) {
level = 1;
} else {
level = 0;
if (shift > PAGE_SHIFT) {
/*
* If the pte maps more than one page, bring over
* bits from the virtual address to get the real
* address of the specific single page we want.
*/
unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
pte = __pte(pte_val(pte) | (hva & rpnmask));
}
}
pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
if (writing || upgrade_write) {
if (pte_val(pte) & _PAGE_WRITE)
pte = __pte(pte_val(pte) | _PAGE_DIRTY);
} else {
pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
}
/* Allocate space in the tree and write the PTE */
ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
mmu_seq, kvm->arch.lpid, NULL, NULL);
if (inserted_pte)
*inserted_pte = pte;
if (levelp)
*levelp = level;
if (page) {
if (!ret && (pte_val(pte) & _PAGE_WRITE))
set_page_dirty_lock(page);
put_page(page);
}
/* Increment number of large pages if we (successfully) inserted one */
if (!ret) {
if (level == 1)
kvm->stat.num_2M_pages++;
else if (level == 2)
kvm->stat.num_1G_pages++;
}
return ret;
}
int kvmppc_book3s_radix_page_fault(struct kvm_vcpu *vcpu,
unsigned long ea, unsigned long dsisr)
{
struct kvm *kvm = vcpu->kvm;
unsigned long gpa, gfn;
struct kvm_memory_slot *memslot;
long ret;
bool writing = !!(dsisr & DSISR_ISSTORE);
bool kvm_ro = false;
/* Check for unusual errors */
if (dsisr & DSISR_UNSUPP_MMU) {
pr_err("KVM: Got unsupported MMU fault\n");
return -EFAULT;
}
if (dsisr & DSISR_BADACCESS) {
/* Reflect to the guest as DSI */
pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
return RESUME_GUEST;
}
/* Translate the logical address */
gpa = vcpu->arch.fault_gpa & ~0xfffUL;
gpa &= ~0xF000000000000000ul;
gfn = gpa >> PAGE_SHIFT;
if (!(dsisr & DSISR_PRTABLE_FAULT))
gpa |= ea & 0xfff;
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return kvmppc_send_page_to_uv(kvm, gfn);
/* Get the corresponding memslot */
memslot = gfn_to_memslot(kvm, gfn);
/* No memslot means it's an emulated MMIO region */
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
DSISR_SET_RC)) {
/*
* Bad address in guest page table tree, or other
* unusual error - reflect it to the guest as DSI.
*/
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
return RESUME_GUEST;
}
return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
}
if (memslot->flags & KVM_MEM_READONLY) {
if (writing) {
/* give the guest a DSI */
kvmppc_core_queue_data_storage(vcpu, ea, DSISR_ISSTORE |
DSISR_PROTFAULT);
return RESUME_GUEST;
}
kvm_ro = true;
}
/* Failed to set the reference/change bits */
if (dsisr & DSISR_SET_RC) {
spin_lock(&kvm->mmu_lock);
if (kvmppc_hv_handle_set_rc(kvm, false, writing,
gpa, kvm->arch.lpid))
dsisr &= ~DSISR_SET_RC;
spin_unlock(&kvm->mmu_lock);
if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
DSISR_PROTFAULT | DSISR_SET_RC)))
return RESUME_GUEST;
}
/* Try to insert a pte */
ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
kvm_ro, NULL, NULL);
if (ret == 0 || ret == -EAGAIN)
ret = RESUME_GUEST;
return ret;
}
/* Called with kvm->mmu_lock held */
bool kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn)
{
pte_t *ptep;
unsigned long gpa = gfn << PAGE_SHIFT;
unsigned int shift;
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
return false;
}
ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep))
kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
kvm->arch.lpid);
return false;
}
/* Called with kvm->mmu_lock held */
bool kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn)
{
pte_t *ptep;
unsigned long gpa = gfn << PAGE_SHIFT;
unsigned int shift;
bool ref = false;
unsigned long old, *rmapp;
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return ref;
ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
gpa, shift);
/* XXX need to flush tlb here? */
/* Also clear bit in ptes in shadow pgtable for nested guests */
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0,
old & PTE_RPN_MASK,
1UL << shift);
ref = true;
}
return ref;
}
/* Called with kvm->mmu_lock held */
bool kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn)
{
pte_t *ptep;
unsigned long gpa = gfn << PAGE_SHIFT;
unsigned int shift;
bool ref = false;
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return ref;
ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep) && pte_young(*ptep))
ref = true;
return ref;
}
/* Returns the number of PAGE_SIZE pages that are dirty */
static int kvm_radix_test_clear_dirty(struct kvm *kvm,
struct kvm_memory_slot *memslot, int pagenum)
{
unsigned long gfn = memslot->base_gfn + pagenum;
unsigned long gpa = gfn << PAGE_SHIFT;
pte_t *ptep, pte;
unsigned int shift;
int ret = 0;
unsigned long old, *rmapp;
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return ret;
/*
* For performance reasons we don't hold kvm->mmu_lock while walking the
* partition scoped table.
*/
ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift);
if (!ptep)
return 0;
pte = READ_ONCE(*ptep);
if (pte_present(pte) && pte_dirty(pte)) {
spin_lock(&kvm->mmu_lock);
/*
* Recheck the pte again
*/
if (pte_val(pte) != pte_val(*ptep)) {
/*
* We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can
* only find PAGE_SIZE pte entries here. We can continue
* to use the pte addr returned by above page table
* walk.
*/
if (!pte_present(*ptep) || !pte_dirty(*ptep)) {
spin_unlock(&kvm->mmu_lock);
return 0;
}
}
ret = 1;
VM_BUG_ON(shift);
old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
gpa, shift);
kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
/* Also clear bit in ptes in shadow pgtable for nested guests */
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0,
old & PTE_RPN_MASK,
1UL << shift);
spin_unlock(&kvm->mmu_lock);
}
return ret;
}
long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
struct kvm_memory_slot *memslot, unsigned long *map)
{
unsigned long i, j;
int npages;
for (i = 0; i < memslot->npages; i = j) {
npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
/*
* Note that if npages > 0 then i must be a multiple of npages,
* since huge pages are only used to back the guest at guest
* real addresses that are a multiple of their size.
* Since we have at most one PTE covering any given guest
* real address, if npages > 1 we can skip to i + npages.
*/
j = i + 1;
if (npages) {
set_dirty_bits(map, i, npages);
j = i + npages;
}
}
return 0;
}
void kvmppc_radix_flush_memslot(struct kvm *kvm,
const struct kvm_memory_slot *memslot)
{
unsigned long n;
pte_t *ptep;
unsigned long gpa;
unsigned int shift;
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
kvmppc_uvmem_drop_pages(memslot, kvm, true);
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return;
gpa = memslot->base_gfn << PAGE_SHIFT;
spin_lock(&kvm->mmu_lock);
for (n = memslot->npages; n; --n) {
ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep))
kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
kvm->arch.lpid);
gpa += PAGE_SIZE;
}
/*
* Increase the mmu notifier sequence number to prevent any page
* fault that read the memslot earlier from writing a PTE.
*/
kvm->mmu_notifier_seq++;
spin_unlock(&kvm->mmu_lock);
}
static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
int psize, int *indexp)
{
if (!mmu_psize_defs[psize].shift)
return;
info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
(mmu_psize_defs[psize].ap << 29);
++(*indexp);
}
int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
{
int i;
if (!radix_enabled())
return -EINVAL;
memset(info, 0, sizeof(*info));
/* 4k page size */
info->geometries[0].page_shift = 12;
info->geometries[0].level_bits[0] = 9;
for (i = 1; i < 4; ++i)
info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
/* 64k page size */
info->geometries[1].page_shift = 16;
for (i = 0; i < 4; ++i)
info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
i = 0;
add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
return 0;
}
int kvmppc_init_vm_radix(struct kvm *kvm)
{
kvm->arch.pgtable = pgd_alloc(kvm->mm);
if (!kvm->arch.pgtable)
return -ENOMEM;
return 0;
}
static void pte_ctor(void *addr)
{
memset(addr, 0, RADIX_PTE_TABLE_SIZE);
}
static void pmd_ctor(void *addr)
{
memset(addr, 0, RADIX_PMD_TABLE_SIZE);
}
struct debugfs_radix_state {
struct kvm *kvm;
struct mutex mutex;
unsigned long gpa;
int lpid;
int chars_left;
int buf_index;
char buf[128];
u8 hdr;
};
static int debugfs_radix_open(struct inode *inode, struct file *file)
{
struct kvm *kvm = inode->i_private;
struct debugfs_radix_state *p;
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
kvm_get_kvm(kvm);
p->kvm = kvm;
mutex_init(&p->mutex);
file->private_data = p;
return nonseekable_open(inode, file);
}
static int debugfs_radix_release(struct inode *inode, struct file *file)
{
struct debugfs_radix_state *p = file->private_data;
kvm_put_kvm(p->kvm);
kfree(p);
return 0;
}
static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos)
{
struct debugfs_radix_state *p = file->private_data;
ssize_t ret, r;
unsigned long n;
struct kvm *kvm;
unsigned long gpa;
pgd_t *pgt;
struct kvm_nested_guest *nested;
pgd_t *pgdp;
p4d_t p4d, *p4dp;
pud_t pud, *pudp;
pmd_t pmd, *pmdp;
pte_t *ptep;
int shift;
unsigned long pte;
kvm = p->kvm;
if (!kvm_is_radix(kvm))
return 0;
ret = mutex_lock_interruptible(&p->mutex);
if (ret)
return ret;
if (p->chars_left) {
n = p->chars_left;
if (n > len)
n = len;
r = copy_to_user(buf, p->buf + p->buf_index, n);
n -= r;
p->chars_left -= n;
p->buf_index += n;
buf += n;
len -= n;
ret = n;
if (r) {
if (!n)
ret = -EFAULT;
goto out;
}
}
gpa = p->gpa;
nested = NULL;
pgt = NULL;
while (len != 0 && p->lpid >= 0) {
if (gpa >= RADIX_PGTABLE_RANGE) {
gpa = 0;
pgt = NULL;
if (nested) {
kvmhv_put_nested(nested);
nested = NULL;
}
p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
p->hdr = 0;
if (p->lpid < 0)
break;
}
if (!pgt) {
if (p->lpid == 0) {
pgt = kvm->arch.pgtable;
} else {
nested = kvmhv_get_nested(kvm, p->lpid, false);
if (!nested) {
gpa = RADIX_PGTABLE_RANGE;
continue;
}
pgt = nested->shadow_pgtable;
}
}
n = 0;
if (!p->hdr) {
if (p->lpid > 0)
n = scnprintf(p->buf, sizeof(p->buf),
"\nNested LPID %d: ", p->lpid);
n += scnprintf(p->buf + n, sizeof(p->buf) - n,
"pgdir: %lx\n", (unsigned long)pgt);
p->hdr = 1;
goto copy;
}
pgdp = pgt + pgd_index(gpa);
p4dp = p4d_offset(pgdp, gpa);
p4d = READ_ONCE(*p4dp);
if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
gpa = (gpa & P4D_MASK) + P4D_SIZE;
continue;
}
pudp = pud_offset(&p4d, gpa);
pud = READ_ONCE(*pudp);
if (!(pud_val(pud) & _PAGE_PRESENT)) {
gpa = (gpa & PUD_MASK) + PUD_SIZE;
continue;
}
if (pud_val(pud) & _PAGE_PTE) {
pte = pud_val(pud);
shift = PUD_SHIFT;
goto leaf;
}
pmdp = pmd_offset(&pud, gpa);
pmd = READ_ONCE(*pmdp);
if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
gpa = (gpa & PMD_MASK) + PMD_SIZE;
continue;
}
if (pmd_val(pmd) & _PAGE_PTE) {
pte = pmd_val(pmd);
shift = PMD_SHIFT;
goto leaf;
}
ptep = pte_offset_kernel(&pmd, gpa);
pte = pte_val(READ_ONCE(*ptep));
if (!(pte & _PAGE_PRESENT)) {
gpa += PAGE_SIZE;
continue;
}
shift = PAGE_SHIFT;
leaf:
n = scnprintf(p->buf, sizeof(p->buf),
" %lx: %lx %d\n", gpa, pte, shift);
gpa += 1ul << shift;
copy:
p->chars_left = n;
if (n > len)
n = len;
r = copy_to_user(buf, p->buf, n);
n -= r;
p->chars_left -= n;
p->buf_index = n;
buf += n;
len -= n;
ret += n;
if (r) {
if (!ret)
ret = -EFAULT;
break;
}
}
p->gpa = gpa;
if (nested)
kvmhv_put_nested(nested);
out:
mutex_unlock(&p->mutex);
return ret;
}
static ssize_t debugfs_radix_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
return -EACCES;
}
static const struct file_operations debugfs_radix_fops = {
.owner = THIS_MODULE,
.open = debugfs_radix_open,
.release = debugfs_radix_release,
.read = debugfs_radix_read,
.write = debugfs_radix_write,
.llseek = generic_file_llseek,
};
void kvmhv_radix_debugfs_init(struct kvm *kvm)
{
debugfs_create_file("radix", 0400, kvm->arch.debugfs_dir, kvm,
&debugfs_radix_fops);
}
int kvmppc_radix_init(void)
{
unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE;
kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
if (!kvm_pte_cache)
return -ENOMEM;
size = sizeof(void *) << RADIX_PMD_INDEX_SIZE;
kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor);
if (!kvm_pmd_cache) {
kmem_cache_destroy(kvm_pte_cache);
return -ENOMEM;
}
return 0;
}
void kvmppc_radix_exit(void)
{
kmem_cache_destroy(kvm_pte_cache);
kmem_cache_destroy(kvm_pmd_cache);
}