linux-stable/arch/x86/include/asm/mmu.h
Kirill A. Shutemov 23e5d9ec2b x86/mm/iommu/sva: Make LAM and SVA mutually exclusive
IOMMU and SVA-capable devices know nothing about LAM and only expect
canonical addresses. An attempt to pass down tagged pointer will lead
to address translation failure.

By default do not allow to enable both LAM and use SVA in the same
process.

The new ARCH_FORCE_TAGGED_SVA arch_prctl() overrides the limitation.
By using the arch_prctl() userspace takes responsibility to never pass
tagged address to the device.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230312112612.31869-12-kirill.shutemov%40linux.intel.com
2023-03-16 13:08:40 -07:00

81 lines
2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_MMU_H
#define _ASM_X86_MMU_H
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/mutex.h>
#include <linux/atomic.h>
#include <linux/bits.h>
/* Uprobes on this MM assume 32-bit code */
#define MM_CONTEXT_UPROBE_IA32 0
/* vsyscall page is accessible on this MM */
#define MM_CONTEXT_HAS_VSYSCALL 1
/* Do not allow changing LAM mode */
#define MM_CONTEXT_LOCK_LAM 2
/* Allow LAM and SVA coexisting */
#define MM_CONTEXT_FORCE_TAGGED_SVA 3
/*
* x86 has arch-specific MMU state beyond what lives in mm_struct.
*/
typedef struct {
/*
* ctx_id uniquely identifies this mm_struct. A ctx_id will never
* be reused, and zero is not a valid ctx_id.
*/
u64 ctx_id;
/*
* Any code that needs to do any sort of TLB flushing for this
* mm will first make its changes to the page tables, then
* increment tlb_gen, then flush. This lets the low-level
* flushing code keep track of what needs flushing.
*
* This is not used on Xen PV.
*/
atomic64_t tlb_gen;
#ifdef CONFIG_MODIFY_LDT_SYSCALL
struct rw_semaphore ldt_usr_sem;
struct ldt_struct *ldt;
#endif
#ifdef CONFIG_X86_64
unsigned long flags;
#endif
#ifdef CONFIG_ADDRESS_MASKING
/* Active LAM mode: X86_CR3_LAM_U48 or X86_CR3_LAM_U57 or 0 (disabled) */
unsigned long lam_cr3_mask;
/* Significant bits of the virtual address. Excludes tag bits. */
u64 untag_mask;
#endif
struct mutex lock;
void __user *vdso; /* vdso base address */
const struct vdso_image *vdso_image; /* vdso image in use */
atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */
#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
/*
* One bit per protection key says whether userspace can
* use it or not. protected by mmap_lock.
*/
u16 pkey_allocation_map;
s16 execute_only_pkey;
#endif
} mm_context_t;
#define INIT_MM_CONTEXT(mm) \
.context = { \
.ctx_id = 1, \
.lock = __MUTEX_INITIALIZER(mm.context.lock), \
}
void leave_mm(int cpu);
#define leave_mm leave_mm
#endif /* _ASM_X86_MMU_H */