![Avi Kivity](/assets/img/avatar_default.png)
While backporting 72dc67a696
, a gfn_to_page()
call was duplicated instead of moved (due to an unrelated patch not being
present in mainline). This caused a page reference leak, resulting in a
fairly massive memory leak.
Fix by removing the extraneous gfn_to_page() call.
Signed-off-by: Avi Kivity <avi@qumranet.com>
1908 lines
45 KiB
C
1908 lines
45 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 "vmx.h"
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#include "mmu.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 <asm/page.h>
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#include <asm/cmpxchg.h>
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#include <asm/io.h>
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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 = 1;
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#endif
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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 PT64_PT_BITS 9
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#define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
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#define PT32_PT_BITS 10
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#define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
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#define PT_WRITABLE_SHIFT 1
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#define PT_PRESENT_MASK (1ULL << 0)
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#define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
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#define PT_USER_MASK (1ULL << 2)
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#define PT_PWT_MASK (1ULL << 3)
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#define PT_PCD_MASK (1ULL << 4)
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#define PT_ACCESSED_MASK (1ULL << 5)
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#define PT_DIRTY_MASK (1ULL << 6)
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#define PT_PAGE_SIZE_MASK (1ULL << 7)
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#define PT_PAT_MASK (1ULL << 7)
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#define PT_GLOBAL_MASK (1ULL << 8)
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#define PT64_NX_SHIFT 63
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#define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
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#define PT_PAT_SHIFT 7
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#define PT_DIR_PAT_SHIFT 12
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#define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
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#define PT32_DIR_PSE36_SIZE 4
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#define PT32_DIR_PSE36_SHIFT 13
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#define PT32_DIR_PSE36_MASK \
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(((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
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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 PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
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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_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 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 PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
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| PT64_NX_MASK)
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#define PFERR_PRESENT_MASK (1U << 0)
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#define PFERR_WRITE_MASK (1U << 1)
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#define PFERR_USER_MASK (1U << 2)
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#define PFERR_FETCH_MASK (1U << 4)
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#define PT64_ROOT_LEVEL 4
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#define PT32_ROOT_LEVEL 2
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#define PT32E_ROOT_LEVEL 3
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#define PT_DIRECTORY_LEVEL 2
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#define PT_PAGE_TABLE_LEVEL 1
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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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struct kvm_rmap_desc {
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u64 *shadow_ptes[RMAP_EXT];
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struct kvm_rmap_desc *more;
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};
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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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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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static int is_write_protection(struct kvm_vcpu *vcpu)
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{
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return vcpu->arch.cr0 & 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.shadow_efer & EFER_NX;
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}
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static int is_present_pte(unsigned long pte)
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{
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return pte & PT_PRESENT_MASK;
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}
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static int is_shadow_present_pte(u64 pte)
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{
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pte &= ~PT_SHADOW_IO_MARK;
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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_writeble_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_pte(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_io_pte(unsigned long pte)
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{
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return pte & PT_SHADOW_IO_MARK;
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}
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static int is_rmap_pte(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 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_shadow_pte(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, 1);
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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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memset(p, 0, size);
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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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* Take gfn and return the reverse mapping to it.
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* Note: gfn must be unaliased before this function get called
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*/
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static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn)
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{
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struct kvm_memory_slot *slot;
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slot = gfn_to_memslot(kvm, gfn);
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return &slot->rmap[gfn - slot->base_gfn];
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}
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/*
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* Reverse mapping data structures:
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*
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* If rmapp bit zero is zero, then rmapp point to the shadw page table entry
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* that points to page_address(page).
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*
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* If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
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* containing more mappings.
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*/
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static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
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{
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struct kvm_mmu_page *sp;
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struct kvm_rmap_desc *desc;
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unsigned long *rmapp;
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int i;
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if (!is_rmap_pte(*spte))
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return;
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gfn = unalias_gfn(vcpu->kvm, gfn);
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sp = page_header(__pa(spte));
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sp->gfns[spte - sp->spt] = gfn;
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rmapp = gfn_to_rmap(vcpu->kvm, gfn);
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if (!*rmapp) {
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rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
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*rmapp = (unsigned long)spte;
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} else if (!(*rmapp & 1)) {
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rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
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desc = mmu_alloc_rmap_desc(vcpu);
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desc->shadow_ptes[0] = (u64 *)*rmapp;
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desc->shadow_ptes[1] = spte;
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*rmapp = (unsigned long)desc | 1;
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} else {
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rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
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desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
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while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
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desc = desc->more;
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if (desc->shadow_ptes[RMAP_EXT-1]) {
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desc->more = mmu_alloc_rmap_desc(vcpu);
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desc = desc->more;
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}
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for (i = 0; desc->shadow_ptes[i]; ++i)
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;
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desc->shadow_ptes[i] = spte;
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}
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}
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static void rmap_desc_remove_entry(unsigned long *rmapp,
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struct kvm_rmap_desc *desc,
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int i,
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struct kvm_rmap_desc *prev_desc)
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{
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int j;
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for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
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;
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desc->shadow_ptes[i] = desc->shadow_ptes[j];
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desc->shadow_ptes[j] = NULL;
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if (j != 0)
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return;
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if (!prev_desc && !desc->more)
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*rmapp = (unsigned long)desc->shadow_ptes[0];
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else
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if (prev_desc)
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prev_desc->more = desc->more;
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else
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*rmapp = (unsigned long)desc->more | 1;
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mmu_free_rmap_desc(desc);
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}
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static void rmap_remove(struct kvm *kvm, u64 *spte)
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{
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struct kvm_rmap_desc *desc;
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struct kvm_rmap_desc *prev_desc;
|
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struct kvm_mmu_page *sp;
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struct page *page;
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unsigned long *rmapp;
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int i;
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if (!is_rmap_pte(*spte))
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return;
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sp = page_header(__pa(spte));
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page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
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mark_page_accessed(page);
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if (is_writeble_pte(*spte))
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kvm_release_page_dirty(page);
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else
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kvm_release_page_clean(page);
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rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt]);
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if (!*rmapp) {
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printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
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BUG();
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} else if (!(*rmapp & 1)) {
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rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
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if ((u64 *)*rmapp != spte) {
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printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
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spte, *spte);
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BUG();
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}
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*rmapp = 0;
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} else {
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rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
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desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
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prev_desc = NULL;
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while (desc) {
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for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
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if (desc->shadow_ptes[i] == spte) {
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rmap_desc_remove_entry(rmapp,
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desc, i,
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prev_desc);
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return;
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}
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prev_desc = desc;
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desc = desc->more;
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}
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BUG();
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}
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}
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static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
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{
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struct kvm_rmap_desc *desc;
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struct kvm_rmap_desc *prev_desc;
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|
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->shadow_ptes[i]; ++i) {
|
|
if (prev_spte == spte)
|
|
return desc->shadow_ptes[i];
|
|
prev_spte = desc->shadow_ptes[i];
|
|
}
|
|
desc = desc->more;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void rmap_write_protect(struct kvm *kvm, u64 gfn)
|
|
{
|
|
unsigned long *rmapp;
|
|
u64 *spte;
|
|
int write_protected = 0;
|
|
|
|
gfn = unalias_gfn(kvm, gfn);
|
|
rmapp = gfn_to_rmap(kvm, gfn);
|
|
|
|
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_writeble_pte(*spte)) {
|
|
set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
|
|
write_protected = 1;
|
|
}
|
|
spte = rmap_next(kvm, rmapp, spte);
|
|
}
|
|
if (write_protected)
|
|
kvm_flush_remote_tlbs(kvm);
|
|
}
|
|
|
|
#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 ((*pos & ~PT_SHADOW_IO_MARK) != shadow_trap_nonpresent_pte) {
|
|
printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
|
|
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;
|
|
}
|
|
|
|
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);
|
|
ASSERT(is_empty_shadow_page(sp->spt));
|
|
sp->slot_bitmap = 0;
|
|
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 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", __FUNCTION__, gfn);
|
|
index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
|
|
bucket = &kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry(sp, node, bucket, hash_link)
|
|
if (sp->gfn == gfn && !sp->role.metaphysical) {
|
|
pgprintk("%s: found role %x\n",
|
|
__FUNCTION__, sp->role.word);
|
|
return sp;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
|
|
gfn_t gfn,
|
|
gva_t gaddr,
|
|
unsigned level,
|
|
int metaphysical,
|
|
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;
|
|
|
|
role.word = 0;
|
|
role.glevels = vcpu->arch.mmu.root_level;
|
|
role.level = level;
|
|
role.metaphysical = metaphysical;
|
|
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;
|
|
}
|
|
pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
|
|
gfn, role.word);
|
|
index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
|
|
bucket = &vcpu->kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry(sp, node, bucket, hash_link)
|
|
if (sp->gfn == gfn && sp->role.word == role.word) {
|
|
mmu_page_add_parent_pte(vcpu, sp, parent_pte);
|
|
pgprintk("%s: found\n", __FUNCTION__);
|
|
return sp;
|
|
}
|
|
++vcpu->kvm->stat.mmu_cache_miss;
|
|
sp = kvm_mmu_alloc_page(vcpu, parent_pte);
|
|
if (!sp)
|
|
return sp;
|
|
pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
|
|
sp->gfn = gfn;
|
|
sp->role = role;
|
|
hlist_add_head(&sp->hash_link, bucket);
|
|
vcpu->arch.mmu.prefetch_page(vcpu, sp);
|
|
if (!metaphysical)
|
|
rmap_write_protect(vcpu->kvm, gfn);
|
|
return sp;
|
|
}
|
|
|
|
static void kvm_mmu_page_unlink_children(struct kvm *kvm,
|
|
struct kvm_mmu_page *sp)
|
|
{
|
|
unsigned i;
|
|
u64 *pt;
|
|
u64 ent;
|
|
|
|
pt = sp->spt;
|
|
|
|
if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
|
|
if (is_shadow_present_pte(pt[i]))
|
|
rmap_remove(kvm, &pt[i]);
|
|
pt[i] = shadow_trap_nonpresent_pte;
|
|
}
|
|
kvm_flush_remote_tlbs(kvm);
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
|
|
ent = pt[i];
|
|
|
|
pt[i] = shadow_trap_nonpresent_pte;
|
|
if (!is_shadow_present_pte(ent))
|
|
continue;
|
|
ent &= PT64_BASE_ADDR_MASK;
|
|
mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
|
|
}
|
|
kvm_flush_remote_tlbs(kvm);
|
|
}
|
|
|
|
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;
|
|
|
|
for (i = 0; i < KVM_MAX_VCPUS; ++i)
|
|
if (kvm->vcpus[i])
|
|
kvm->vcpus[i]->arch.last_pte_updated = NULL;
|
|
}
|
|
|
|
static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
|
|
{
|
|
u64 *parent_pte;
|
|
|
|
++kvm->stat.mmu_shadow_zapped;
|
|
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_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
|
|
}
|
|
kvm_mmu_page_unlink_children(kvm, sp);
|
|
if (!sp->root_count) {
|
|
hlist_del(&sp->hash_link);
|
|
kvm_mmu_free_page(kvm, sp);
|
|
} else
|
|
list_move(&sp->link, &kvm->arch.active_mmu_pages);
|
|
kvm_mmu_reset_last_pte_updated(kvm);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
/*
|
|
* 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 ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
|
|
kvm_nr_mmu_pages) {
|
|
int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
|
|
- kvm->arch.n_free_mmu_pages;
|
|
|
|
while (n_used_mmu_pages > kvm_nr_mmu_pages) {
|
|
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);
|
|
n_used_mmu_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", __FUNCTION__, gfn);
|
|
r = 0;
|
|
index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
|
|
bucket = &kvm->arch.mmu_page_hash[index];
|
|
hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
|
|
if (sp->gfn == gfn && !sp->role.metaphysical) {
|
|
pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
|
|
sp->role.word);
|
|
kvm_mmu_zap_page(kvm, sp);
|
|
r = 1;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
|
|
while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
|
|
pgprintk("%s: zap %lx %x\n", __FUNCTION__, gfn, sp->role.word);
|
|
kvm_mmu_zap_page(kvm, sp);
|
|
}
|
|
}
|
|
|
|
static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
|
|
{
|
|
int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
|
|
struct kvm_mmu_page *sp = page_header(__pa(pte));
|
|
|
|
__set_bit(slot, &sp->slot_bitmap);
|
|
}
|
|
|
|
struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
|
|
{
|
|
struct page *page;
|
|
|
|
gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
|
|
|
|
if (gpa == UNMAPPED_GVA)
|
|
return NULL;
|
|
|
|
down_read(¤t->mm->mmap_sem);
|
|
page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
|
|
up_read(¤t->mm->mmap_sem);
|
|
|
|
return page;
|
|
}
|
|
|
|
static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
|
|
unsigned pt_access, unsigned pte_access,
|
|
int user_fault, int write_fault, int dirty,
|
|
int *ptwrite, gfn_t gfn, struct page *page)
|
|
{
|
|
u64 spte;
|
|
int was_rmapped = 0;
|
|
int was_writeble = is_writeble_pte(*shadow_pte);
|
|
hfn_t host_pfn = (*shadow_pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
|
|
|
|
pgprintk("%s: spte %llx access %x write_fault %d"
|
|
" user_fault %d gfn %lx\n",
|
|
__FUNCTION__, *shadow_pte, pt_access,
|
|
write_fault, user_fault, gfn);
|
|
|
|
if (is_rmap_pte(*shadow_pte)) {
|
|
if (host_pfn != page_to_pfn(page)) {
|
|
pgprintk("hfn old %lx new %lx\n",
|
|
host_pfn, page_to_pfn(page));
|
|
rmap_remove(vcpu->kvm, shadow_pte);
|
|
}
|
|
else
|
|
was_rmapped = 1;
|
|
}
|
|
|
|
/*
|
|
* 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 = PT_PRESENT_MASK | PT_DIRTY_MASK;
|
|
if (!dirty)
|
|
pte_access &= ~ACC_WRITE_MASK;
|
|
if (!(pte_access & ACC_EXEC_MASK))
|
|
spte |= PT64_NX_MASK;
|
|
|
|
spte |= PT_PRESENT_MASK;
|
|
if (pte_access & ACC_USER_MASK)
|
|
spte |= PT_USER_MASK;
|
|
|
|
if (is_error_page(page)) {
|
|
set_shadow_pte(shadow_pte,
|
|
shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
|
|
kvm_release_page_clean(page);
|
|
return;
|
|
}
|
|
|
|
spte |= page_to_phys(page);
|
|
|
|
if ((pte_access & ACC_WRITE_MASK)
|
|
|| (write_fault && !is_write_protection(vcpu) && !user_fault)) {
|
|
struct kvm_mmu_page *shadow;
|
|
|
|
spte |= PT_WRITABLE_MASK;
|
|
if (user_fault) {
|
|
mmu_unshadow(vcpu->kvm, gfn);
|
|
goto unshadowed;
|
|
}
|
|
|
|
shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
|
|
if (shadow) {
|
|
pgprintk("%s: found shadow page for %lx, marking ro\n",
|
|
__FUNCTION__, gfn);
|
|
pte_access &= ~ACC_WRITE_MASK;
|
|
if (is_writeble_pte(spte)) {
|
|
spte &= ~PT_WRITABLE_MASK;
|
|
kvm_x86_ops->tlb_flush(vcpu);
|
|
}
|
|
if (write_fault)
|
|
*ptwrite = 1;
|
|
}
|
|
}
|
|
|
|
unshadowed:
|
|
|
|
if (pte_access & ACC_WRITE_MASK)
|
|
mark_page_dirty(vcpu->kvm, gfn);
|
|
|
|
pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
|
|
set_shadow_pte(shadow_pte, spte);
|
|
page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
|
|
if (!was_rmapped) {
|
|
rmap_add(vcpu, shadow_pte, gfn);
|
|
if (!is_rmap_pte(*shadow_pte))
|
|
kvm_release_page_clean(page);
|
|
} else {
|
|
if (was_writeble)
|
|
kvm_release_page_dirty(page);
|
|
else
|
|
kvm_release_page_clean(page);
|
|
}
|
|
if (!ptwrite || !*ptwrite)
|
|
vcpu->arch.last_pte_updated = shadow_pte;
|
|
}
|
|
|
|
static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
|
|
{
|
|
}
|
|
|
|
static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write,
|
|
gfn_t gfn, struct page *page)
|
|
{
|
|
int level = PT32E_ROOT_LEVEL;
|
|
hpa_t table_addr = vcpu->arch.mmu.root_hpa;
|
|
int pt_write = 0;
|
|
|
|
for (; ; level--) {
|
|
u32 index = PT64_INDEX(v, level);
|
|
u64 *table;
|
|
|
|
ASSERT(VALID_PAGE(table_addr));
|
|
table = __va(table_addr);
|
|
|
|
if (level == 1) {
|
|
mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
|
|
0, write, 1, &pt_write, gfn, page);
|
|
return pt_write || is_io_pte(table[index]);
|
|
}
|
|
|
|
if (table[index] == shadow_trap_nonpresent_pte) {
|
|
struct kvm_mmu_page *new_table;
|
|
gfn_t pseudo_gfn;
|
|
|
|
pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
|
|
>> PAGE_SHIFT;
|
|
new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
|
|
v, level - 1,
|
|
1, ACC_ALL, &table[index]);
|
|
if (!new_table) {
|
|
pgprintk("nonpaging_map: ENOMEM\n");
|
|
kvm_release_page_clean(page);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
|
|
| PT_WRITABLE_MASK | PT_USER_MASK;
|
|
}
|
|
table_addr = table[index] & PT64_BASE_ADDR_MASK;
|
|
}
|
|
}
|
|
|
|
static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
|
|
{
|
|
int r;
|
|
|
|
struct page *page;
|
|
|
|
down_read(&vcpu->kvm->slots_lock);
|
|
|
|
down_read(¤t->mm->mmap_sem);
|
|
page = gfn_to_page(vcpu->kvm, gfn);
|
|
up_read(¤t->mm->mmap_sem);
|
|
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
kvm_mmu_free_some_pages(vcpu);
|
|
r = __nonpaging_map(vcpu, v, write, gfn, page);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
|
|
up_read(&vcpu->kvm->slots_lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
|
|
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 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);
|
|
#ifdef CONFIG_X86_64
|
|
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;
|
|
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
return;
|
|
}
|
|
#endif
|
|
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;
|
|
}
|
|
vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
|
|
}
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
|
|
}
|
|
|
|
static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
|
|
{
|
|
int i;
|
|
gfn_t root_gfn;
|
|
struct kvm_mmu_page *sp;
|
|
|
|
root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
|
|
|
|
#ifdef CONFIG_X86_64
|
|
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
|
|
hpa_t root = vcpu->arch.mmu.root_hpa;
|
|
|
|
ASSERT(!VALID_PAGE(root));
|
|
sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
|
|
PT64_ROOT_LEVEL, 0, ACC_ALL, NULL);
|
|
root = __pa(sp->spt);
|
|
++sp->root_count;
|
|
vcpu->arch.mmu.root_hpa = root;
|
|
return;
|
|
}
|
|
#endif
|
|
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) {
|
|
if (!is_present_pte(vcpu->arch.pdptrs[i])) {
|
|
vcpu->arch.mmu.pae_root[i] = 0;
|
|
continue;
|
|
}
|
|
root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
|
|
} else if (vcpu->arch.mmu.root_level == 0)
|
|
root_gfn = 0;
|
|
sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
|
|
PT32_ROOT_LEVEL, !is_paging(vcpu),
|
|
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);
|
|
}
|
|
|
|
static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
|
|
{
|
|
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", __FUNCTION__, 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 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->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", __FUNCTION__, 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);
|
|
}
|
|
|
|
#define PTTYPE 64
|
|
#include "paging_tmpl.h"
|
|
#undef PTTYPE
|
|
|
|
#define PTTYPE 32
|
|
#include "paging_tmpl.h"
|
|
#undef PTTYPE
|
|
|
|
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->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)
|
|
{
|
|
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;
|
|
|
|
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->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)
|
|
{
|
|
return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
|
|
}
|
|
|
|
static int init_kvm_mmu(struct kvm_vcpu *vcpu)
|
|
{
|
|
ASSERT(vcpu);
|
|
ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
|
|
|
|
if (!is_paging(vcpu))
|
|
return nonpaging_init_context(vcpu);
|
|
else if (is_long_mode(vcpu))
|
|
return paging64_init_context(vcpu);
|
|
else if (is_pae(vcpu))
|
|
return paging32E_init_context(vcpu);
|
|
else
|
|
return paging32_init_context(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);
|
|
mmu_alloc_roots(vcpu);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
|
|
kvm_mmu_flush_tlb(vcpu);
|
|
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 (sp->role.level == PT_PAGE_TABLE_LEVEL)
|
|
rmap_remove(vcpu->kvm, spte);
|
|
else {
|
|
child = page_header(pte & PT64_BASE_ADDR_MASK);
|
|
mmu_page_remove_parent_pte(child, spte);
|
|
}
|
|
}
|
|
set_shadow_pte(spte, shadow_trap_nonpresent_pte);
|
|
}
|
|
|
|
static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
|
|
struct kvm_mmu_page *sp,
|
|
u64 *spte,
|
|
const void *new, int bytes,
|
|
int offset_in_pte)
|
|
{
|
|
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, bytes, offset_in_pte);
|
|
else
|
|
paging64_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte);
|
|
}
|
|
|
|
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 & PT_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;
|
|
struct page *page;
|
|
|
|
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_pte(gpte))
|
|
return;
|
|
gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
|
|
|
|
down_read(¤t->mm->mmap_sem);
|
|
page = gfn_to_page(vcpu->kvm, gfn);
|
|
up_read(¤t->mm->mmap_sem);
|
|
|
|
vcpu->arch.update_pte.gfn = gfn;
|
|
vcpu->arch.update_pte.page = page;
|
|
}
|
|
|
|
void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
|
|
const u8 *new, int bytes)
|
|
{
|
|
gfn_t gfn = gpa >> PAGE_SHIFT;
|
|
struct kvm_mmu_page *sp;
|
|
struct hlist_node *node, *n;
|
|
struct hlist_head *bucket;
|
|
unsigned index;
|
|
u64 entry;
|
|
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;
|
|
|
|
pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
|
|
mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
kvm_mmu_free_some_pages(vcpu);
|
|
++vcpu->kvm->stat.mmu_pte_write;
|
|
kvm_mmu_audit(vcpu, "pre pte write");
|
|
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) % KVM_NUM_MMU_PAGES;
|
|
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.metaphysical)
|
|
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);
|
|
kvm_mmu_zap_page(vcpu->kvm, sp);
|
|
++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)];
|
|
while (npte--) {
|
|
entry = *spte;
|
|
mmu_pte_write_zap_pte(vcpu, sp, spte);
|
|
mmu_pte_write_new_pte(vcpu, sp, spte, new, bytes,
|
|
page_offset & (pte_size - 1));
|
|
mmu_pte_write_flush_tlb(vcpu, entry, *spte);
|
|
++spte;
|
|
}
|
|
}
|
|
kvm_mmu_audit(vcpu, "post pte write");
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
if (vcpu->arch.update_pte.page) {
|
|
kvm_release_page_clean(vcpu->arch.update_pte.page);
|
|
vcpu->arch.update_pte.page = NULL;
|
|
}
|
|
}
|
|
|
|
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
|
|
{
|
|
gpa_t gpa;
|
|
int r;
|
|
|
|
down_read(&vcpu->kvm->slots_lock);
|
|
gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
|
|
up_read(&vcpu->kvm->slots_lock);
|
|
|
|
spin_lock(&vcpu->kvm->mmu_lock);
|
|
r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
|
|
spin_unlock(&vcpu->kvm->mmu_lock);
|
|
return r;
|
|
}
|
|
|
|
void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
|
|
{
|
|
while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_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, vcpu->run, cr2, error_code, 0);
|
|
|
|
switch (er) {
|
|
case EMULATE_DONE:
|
|
return 1;
|
|
case EMULATE_DO_MMIO:
|
|
++vcpu->stat.mmio_exits;
|
|
return 0;
|
|
case EMULATE_FAIL:
|
|
kvm_report_emulation_failure(vcpu, "pagetable");
|
|
return 1;
|
|
default:
|
|
BUG();
|
|
}
|
|
out:
|
|
return r;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
|
|
|
|
static void free_mmu_pages(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
|
|
while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
|
|
sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
|
|
struct kvm_mmu_page, link);
|
|
kvm_mmu_zap_page(vcpu->kvm, sp);
|
|
}
|
|
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);
|
|
|
|
if (vcpu->kvm->arch.n_requested_mmu_pages)
|
|
vcpu->kvm->arch.n_free_mmu_pages =
|
|
vcpu->kvm->arch.n_requested_mmu_pages;
|
|
else
|
|
vcpu->kvm->arch.n_free_mmu_pages =
|
|
vcpu->kvm->arch.n_alloc_mmu_pages;
|
|
/*
|
|
* 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)
|
|
goto error_1;
|
|
vcpu->arch.mmu.pae_root = page_address(page);
|
|
for (i = 0; i < 4; ++i)
|
|
vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
|
|
|
|
return 0;
|
|
|
|
error_1:
|
|
free_mmu_pages(vcpu);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
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)
|
|
kvm_mmu_zap_page(kvm, sp);
|
|
spin_unlock(&kvm->mmu_lock);
|
|
|
|
kvm_flush_remote_tlbs(kvm);
|
|
}
|
|
|
|
void kvm_mmu_module_exit(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);
|
|
}
|
|
|
|
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;
|
|
|
|
return 0;
|
|
|
|
nomem:
|
|
kvm_mmu_module_exit();
|
|
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;
|
|
|
|
for (i = 0; i < kvm->nmemslots; i++)
|
|
nr_pages += kvm->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;
|
|
}
|
|
|
|
#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;
|
|
}
|
|
|
|
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 (level > 1) {
|
|
if (ent == shadow_notrap_nonpresent_pte)
|
|
printk(KERN_ERR "audit: (%s) nontrapping pte"
|
|
" in nonleaf level: levels %d gva %lx"
|
|
" level %d pte %llx\n", audit_msg,
|
|
vcpu->arch.mmu.root_level, va, level, ent);
|
|
|
|
audit_mappings_page(vcpu, ent, va, level - 1);
|
|
} else {
|
|
gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
|
|
struct page *page = gpa_to_page(vcpu, gpa);
|
|
hpa_t hpa = page_to_phys(page);
|
|
|
|
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_page_clean(page);
|
|
|
|
}
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
|
|
struct kvm_memory_slot *m = &vcpu->kvm->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->shadow_ptes[k])
|
|
++nmaps;
|
|
else
|
|
break;
|
|
d = d->more;
|
|
}
|
|
}
|
|
}
|
|
return nmaps;
|
|
}
|
|
|
|
static int count_writable_mappings(struct kvm_vcpu *vcpu)
|
|
{
|
|
int nmaps = 0;
|
|
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;
|
|
++nmaps;
|
|
}
|
|
}
|
|
return nmaps;
|
|
}
|
|
|
|
static void audit_rmap(struct kvm_vcpu *vcpu)
|
|
{
|
|
int n_rmap = count_rmaps(vcpu);
|
|
int n_actual = count_writable_mappings(vcpu);
|
|
|
|
if (n_rmap != n_actual)
|
|
printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
|
|
__FUNCTION__, audit_msg, n_rmap, n_actual);
|
|
}
|
|
|
|
static void audit_write_protection(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct kvm_mmu_page *sp;
|
|
struct kvm_memory_slot *slot;
|
|
unsigned long *rmapp;
|
|
gfn_t gfn;
|
|
|
|
list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
|
|
if (sp->role.metaphysical)
|
|
continue;
|
|
|
|
slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
|
|
gfn = unalias_gfn(vcpu->kvm, sp->gfn);
|
|
rmapp = &slot->rmap[gfn - slot->base_gfn];
|
|
if (*rmapp)
|
|
printk(KERN_ERR "%s: (%s) shadow page has writable"
|
|
" mappings: gfn %lx role %x\n",
|
|
__FUNCTION__, audit_msg, sp->gfn,
|
|
sp->role.word);
|
|
}
|
|
}
|
|
|
|
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);
|
|
audit_mappings(vcpu);
|
|
dbg = olddbg;
|
|
}
|
|
|
|
#endif
|