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Diffstat (limited to 'arch/x86/kvm/paging_tmpl.h')
-rw-r--r--arch/x86/kvm/paging_tmpl.h249
1 files changed, 168 insertions, 81 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 4a814bf..613ec9a 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -25,11 +25,11 @@
#if PTTYPE == 64
#define pt_element_t u64
#define guest_walker guest_walker64
+ #define shadow_walker shadow_walker64
#define FNAME(name) paging##64_##name
#define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK
#define PT_DIR_BASE_ADDR_MASK PT64_DIR_BASE_ADDR_MASK
#define PT_INDEX(addr, level) PT64_INDEX(addr, level)
- #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
#define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level)
#define PT_LEVEL_BITS PT64_LEVEL_BITS
#ifdef CONFIG_X86_64
@@ -42,11 +42,11 @@
#elif PTTYPE == 32
#define pt_element_t u32
#define guest_walker guest_walker32
+ #define shadow_walker shadow_walker32
#define FNAME(name) paging##32_##name
#define PT_BASE_ADDR_MASK PT32_BASE_ADDR_MASK
#define PT_DIR_BASE_ADDR_MASK PT32_DIR_BASE_ADDR_MASK
#define PT_INDEX(addr, level) PT32_INDEX(addr, level)
- #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
#define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level)
#define PT_LEVEL_BITS PT32_LEVEL_BITS
#define PT_MAX_FULL_LEVELS 2
@@ -73,6 +73,17 @@ struct guest_walker {
u32 error_code;
};
+struct shadow_walker {
+ struct kvm_shadow_walk walker;
+ struct guest_walker *guest_walker;
+ int user_fault;
+ int write_fault;
+ int largepage;
+ int *ptwrite;
+ pfn_t pfn;
+ u64 *sptep;
+};
+
static gfn_t gpte_to_gfn(pt_element_t gpte)
{
return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
@@ -91,14 +102,10 @@ static bool FNAME(cmpxchg_gpte)(struct kvm *kvm,
pt_element_t *table;
struct page *page;
- down_read(&current->mm->mmap_sem);
page = gfn_to_page(kvm, table_gfn);
- up_read(&current->mm->mmap_sem);
table = kmap_atomic(page, KM_USER0);
-
ret = CMPXCHG(&table[index], orig_pte, new_pte);
-
kunmap_atomic(table, KM_USER0);
kvm_release_page_dirty(page);
@@ -274,86 +281,89 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
/*
* Fetch a shadow pte for a specific level in the paging hierarchy.
*/
-static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
- struct guest_walker *walker,
- int user_fault, int write_fault, int largepage,
- int *ptwrite, pfn_t pfn)
+static int FNAME(shadow_walk_entry)(struct kvm_shadow_walk *_sw,
+ struct kvm_vcpu *vcpu, u64 addr,
+ u64 *sptep, int level)
{
- hpa_t shadow_addr;
- int level;
- u64 *shadow_ent;
- unsigned access = walker->pt_access;
-
- if (!is_present_pte(walker->ptes[walker->level - 1]))
- return NULL;
-
- shadow_addr = vcpu->arch.mmu.root_hpa;
- level = vcpu->arch.mmu.shadow_root_level;
- if (level == PT32E_ROOT_LEVEL) {
- shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
- shadow_addr &= PT64_BASE_ADDR_MASK;
- --level;
+ struct shadow_walker *sw =
+ container_of(_sw, struct shadow_walker, walker);
+ struct guest_walker *gw = sw->guest_walker;
+ unsigned access = gw->pt_access;
+ struct kvm_mmu_page *shadow_page;
+ u64 spte;
+ int metaphysical;
+ gfn_t table_gfn;
+ int r;
+ pt_element_t curr_pte;
+
+ if (level == PT_PAGE_TABLE_LEVEL
+ || (sw->largepage && level == PT_DIRECTORY_LEVEL)) {
+ mmu_set_spte(vcpu, sptep, access, gw->pte_access & access,
+ sw->user_fault, sw->write_fault,
+ gw->ptes[gw->level-1] & PT_DIRTY_MASK,
+ sw->ptwrite, sw->largepage, gw->gfn, sw->pfn,
+ false);
+ sw->sptep = sptep;
+ return 1;
}
- for (; ; level--) {
- u32 index = SHADOW_PT_INDEX(addr, level);
- struct kvm_mmu_page *shadow_page;
- u64 shadow_pte;
- int metaphysical;
- gfn_t table_gfn;
-
- shadow_ent = ((u64 *)__va(shadow_addr)) + index;
- if (level == PT_PAGE_TABLE_LEVEL)
- break;
-
- if (largepage && level == PT_DIRECTORY_LEVEL)
- break;
+ if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep))
+ return 0;
- if (is_shadow_present_pte(*shadow_ent)
- && !is_large_pte(*shadow_ent)) {
- shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK;
- continue;
- }
+ if (is_large_pte(*sptep)) {
+ set_shadow_pte(sptep, shadow_trap_nonpresent_pte);
+ kvm_flush_remote_tlbs(vcpu->kvm);
+ rmap_remove(vcpu->kvm, sptep);
+ }
- if (is_large_pte(*shadow_ent))
- rmap_remove(vcpu->kvm, shadow_ent);
-
- if (level - 1 == PT_PAGE_TABLE_LEVEL
- && walker->level == PT_DIRECTORY_LEVEL) {
- metaphysical = 1;
- if (!is_dirty_pte(walker->ptes[level - 1]))
- access &= ~ACC_WRITE_MASK;
- table_gfn = gpte_to_gfn(walker->ptes[level - 1]);
- } else {
- metaphysical = 0;
- table_gfn = walker->table_gfn[level - 2];
- }
- shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
- metaphysical, access,
- shadow_ent);
- if (!metaphysical) {
- int r;
- pt_element_t curr_pte;
- r = kvm_read_guest_atomic(vcpu->kvm,
- walker->pte_gpa[level - 2],
- &curr_pte, sizeof(curr_pte));
- if (r || curr_pte != walker->ptes[level - 2]) {
- kvm_release_pfn_clean(pfn);
- return NULL;
- }
+ if (level == PT_DIRECTORY_LEVEL && gw->level == PT_DIRECTORY_LEVEL) {
+ metaphysical = 1;
+ if (!is_dirty_pte(gw->ptes[level - 1]))
+ access &= ~ACC_WRITE_MASK;
+ table_gfn = gpte_to_gfn(gw->ptes[level - 1]);
+ } else {
+ metaphysical = 0;
+ table_gfn = gw->table_gfn[level - 2];
+ }
+ shadow_page = kvm_mmu_get_page(vcpu, table_gfn, (gva_t)addr, level-1,
+ metaphysical, access, sptep);
+ if (!metaphysical) {
+ r = kvm_read_guest_atomic(vcpu->kvm, gw->pte_gpa[level - 2],
+ &curr_pte, sizeof(curr_pte));
+ if (r || curr_pte != gw->ptes[level - 2]) {
+ kvm_release_pfn_clean(sw->pfn);
+ sw->sptep = NULL;
+ return 1;
}
- shadow_addr = __pa(shadow_page->spt);
- shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
- | PT_WRITABLE_MASK | PT_USER_MASK;
- set_shadow_pte(shadow_ent, shadow_pte);
}
- mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access,
- user_fault, write_fault,
- walker->ptes[walker->level-1] & PT_DIRTY_MASK,
- ptwrite, largepage, walker->gfn, pfn, false);
+ spte = __pa(shadow_page->spt) | PT_PRESENT_MASK | PT_ACCESSED_MASK
+ | PT_WRITABLE_MASK | PT_USER_MASK;
+ *sptep = spte;
+ return 0;
+}
+
+static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
+ struct guest_walker *guest_walker,
+ int user_fault, int write_fault, int largepage,
+ int *ptwrite, pfn_t pfn)
+{
+ struct shadow_walker walker = {
+ .walker = { .entry = FNAME(shadow_walk_entry), },
+ .guest_walker = guest_walker,
+ .user_fault = user_fault,
+ .write_fault = write_fault,
+ .largepage = largepage,
+ .ptwrite = ptwrite,
+ .pfn = pfn,
+ };
+
+ if (!is_present_pte(guest_walker->ptes[guest_walker->level - 1]))
+ return NULL;
+
+ walk_shadow(&walker.walker, vcpu, addr);
- return shadow_ent;
+ return walker.sptep;
}
/*
@@ -407,7 +417,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
return 0;
}
- down_read(&current->mm->mmap_sem);
if (walker.level == PT_DIRECTORY_LEVEL) {
gfn_t large_gfn;
large_gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE-1);
@@ -417,9 +426,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
}
}
mmu_seq = vcpu->kvm->mmu_notifier_seq;
- /* implicit mb(), we'll read before PT lock is unlocked */
+ smp_rmb();
pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
- up_read(&current->mm->mmap_sem);
/* mmio */
if (is_error_pfn(pfn)) {
@@ -453,6 +461,31 @@ out_unlock:
return 0;
}
+static int FNAME(shadow_invlpg_entry)(struct kvm_shadow_walk *_sw,
+ struct kvm_vcpu *vcpu, u64 addr,
+ u64 *sptep, int level)
+{
+
+ if (level == PT_PAGE_TABLE_LEVEL) {
+ if (is_shadow_present_pte(*sptep))
+ rmap_remove(vcpu->kvm, sptep);
+ set_shadow_pte(sptep, shadow_trap_nonpresent_pte);
+ return 1;
+ }
+ if (!is_shadow_present_pte(*sptep))
+ return 1;
+ return 0;
+}
+
+static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
+{
+ struct shadow_walker walker = {
+ .walker = { .entry = FNAME(shadow_invlpg_entry), },
+ };
+
+ walk_shadow(&walker.walker, vcpu, gva);
+}
+
static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
{
struct guest_walker walker;
@@ -499,12 +532,66 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
}
}
+/*
+ * Using the cached information from sp->gfns is safe because:
+ * - The spte has a reference to the struct page, so the pfn for a given gfn
+ * can't change unless all sptes pointing to it are nuked first.
+ * - Alias changes zap the entire shadow cache.
+ */
+static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+ int i, offset, nr_present;
+
+ offset = nr_present = 0;
+
+ if (PTTYPE == 32)
+ offset = sp->role.quadrant << PT64_LEVEL_BITS;
+
+ for (i = 0; i < PT64_ENT_PER_PAGE; i++) {
+ unsigned pte_access;
+ pt_element_t gpte;
+ gpa_t pte_gpa;
+ gfn_t gfn = sp->gfns[i];
+
+ if (!is_shadow_present_pte(sp->spt[i]))
+ continue;
+
+ pte_gpa = gfn_to_gpa(sp->gfn);
+ pte_gpa += (i+offset) * sizeof(pt_element_t);
+
+ if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte,
+ sizeof(pt_element_t)))
+ return -EINVAL;
+
+ if (gpte_to_gfn(gpte) != gfn || !is_present_pte(gpte) ||
+ !(gpte & PT_ACCESSED_MASK)) {
+ u64 nonpresent;
+
+ rmap_remove(vcpu->kvm, &sp->spt[i]);
+ if (is_present_pte(gpte))
+ nonpresent = shadow_trap_nonpresent_pte;
+ else
+ nonpresent = shadow_notrap_nonpresent_pte;
+ set_shadow_pte(&sp->spt[i], nonpresent);
+ continue;
+ }
+
+ nr_present++;
+ pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
+ set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
+ is_dirty_pte(gpte), 0, gfn,
+ spte_to_pfn(sp->spt[i]), true, false);
+ }
+
+ return !nr_present;
+}
+
#undef pt_element_t
#undef guest_walker
+#undef shadow_walker
#undef FNAME
#undef PT_BASE_ADDR_MASK
#undef PT_INDEX
-#undef SHADOW_PT_INDEX
#undef PT_LEVEL_MASK
#undef PT_DIR_BASE_ADDR_MASK
#undef PT_LEVEL_BITS
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