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Diffstat (limited to 'arch/x86/kvm/mmu.c')
-rw-r--r--arch/x86/kvm/mmu.c137
1 files changed, 64 insertions, 73 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 89a49fb46a2..741373e8ca7 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -18,6 +18,7 @@
*/
#include "mmu.h"
+#include "x86.h"
#include "kvm_cache_regs.h"
#include <linux/kvm_host.h>
@@ -29,6 +30,7 @@
#include <linux/swap.h>
#include <linux/hugetlb.h>
#include <linux/compiler.h>
+#include <linux/srcu.h>
#include <asm/page.h>
#include <asm/cmpxchg.h>
@@ -136,16 +138,6 @@ module_param(oos_shadow, bool, 0644);
#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
| PT64_NX_MASK)
-#define PFERR_PRESENT_MASK (1U << 0)
-#define PFERR_WRITE_MASK (1U << 1)
-#define PFERR_USER_MASK (1U << 2)
-#define PFERR_RSVD_MASK (1U << 3)
-#define PFERR_FETCH_MASK (1U << 4)
-
-#define PT_PDPE_LEVEL 3
-#define PT_DIRECTORY_LEVEL 2
-#define PT_PAGE_TABLE_LEVEL 1
-
#define RMAP_EXT 4
#define ACC_EXEC_MASK 1
@@ -153,6 +145,9 @@ module_param(oos_shadow, bool, 0644);
#define ACC_USER_MASK PT_USER_MASK
#define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
+#include <trace/events/kvm.h>
+
+#undef TRACE_INCLUDE_FILE
#define CREATE_TRACE_POINTS
#include "mmutrace.h"
@@ -229,7 +224,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
static int is_write_protection(struct kvm_vcpu *vcpu)
{
- return vcpu->arch.cr0 & X86_CR0_WP;
+ return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
}
static int is_cpuid_PSE36(void)
@@ -239,7 +234,7 @@ static int is_cpuid_PSE36(void)
static int is_nx(struct kvm_vcpu *vcpu)
{
- return vcpu->arch.shadow_efer & EFER_NX;
+ return vcpu->arch.efer & EFER_NX;
}
static int is_shadow_present_pte(u64 pte)
@@ -253,7 +248,7 @@ static int is_large_pte(u64 pte)
return pte & PT_PAGE_SIZE_MASK;
}
-static int is_writeble_pte(unsigned long pte)
+static int is_writable_pte(unsigned long pte)
{
return pte & PT_WRITABLE_MASK;
}
@@ -470,24 +465,10 @@ static int has_wrprotected_page(struct kvm *kvm,
static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
{
- unsigned long page_size = PAGE_SIZE;
- struct vm_area_struct *vma;
- unsigned long addr;
+ unsigned long page_size;
int i, ret = 0;
- addr = gfn_to_hva(kvm, gfn);
- if (kvm_is_error_hva(addr))
- return PT_PAGE_TABLE_LEVEL;
-
- down_read(&current->mm->mmap_sem);
- vma = find_vma(current->mm, addr);
- if (!vma)
- goto out;
-
- page_size = vma_kernel_pagesize(vma);
-
-out:
- up_read(&current->mm->mmap_sem);
+ page_size = kvm_host_page_size(kvm, gfn);
for (i = PT_PAGE_TABLE_LEVEL;
i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
@@ -503,8 +484,7 @@ out:
static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
{
struct kvm_memory_slot *slot;
- int host_level;
- int level = PT_PAGE_TABLE_LEVEL;
+ int host_level, level, max_level;
slot = gfn_to_memslot(vcpu->kvm, large_gfn);
if (slot && slot->dirty_bitmap)
@@ -515,7 +495,10 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
if (host_level == PT_PAGE_TABLE_LEVEL)
return host_level;
- for (level = PT_DIRECTORY_LEVEL; level <= host_level; ++level)
+ max_level = kvm_x86_ops->get_lpage_level() < host_level ?
+ kvm_x86_ops->get_lpage_level() : host_level;
+
+ for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
break;
@@ -633,7 +616,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
pfn = spte_to_pfn(*spte);
if (*spte & shadow_accessed_mask)
kvm_set_pfn_accessed(pfn);
- if (is_writeble_pte(*spte))
+ if (is_writable_pte(*spte))
kvm_set_pfn_dirty(pfn);
rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], sp->role.level);
if (!*rmapp) {
@@ -662,6 +645,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
prev_desc = desc;
desc = desc->more;
}
+ pr_err("rmap_remove: %p %llx many->many\n", spte, *spte);
BUG();
}
}
@@ -708,7 +692,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
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)) {
+ if (is_writable_pte(*spte)) {
__set_spte(spte, *spte & ~PT_WRITABLE_MASK);
write_protected = 1;
}
@@ -732,7 +716,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
BUG_ON(!(*spte & PT_PRESENT_MASK));
BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
- if (is_writeble_pte(*spte)) {
+ if (is_writable_pte(*spte)) {
rmap_remove(kvm, spte);
--kvm->stat.lpages;
__set_spte(spte, shadow_trap_nonpresent_pte);
@@ -787,7 +771,7 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
new_spte &= ~PT_WRITABLE_MASK;
new_spte &= ~SPTE_HOST_WRITEABLE;
- if (is_writeble_pte(*spte))
+ if (is_writable_pte(*spte))
kvm_set_pfn_dirty(spte_to_pfn(*spte));
__set_spte(spte, new_spte);
spte = rmap_next(kvm, rmapp, spte);
@@ -805,35 +789,32 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
unsigned long data))
{
int i, j;
+ int ret;
int retval = 0;
+ struct kvm_memslots *slots;
- /*
- * If mmap_sem isn't taken, we can look the memslots with only
- * the mmu_lock by skipping over the slots with userspace_addr == 0.
- */
- for (i = 0; i < kvm->nmemslots; i++) {
- struct kvm_memory_slot *memslot = &kvm->memslots[i];
+ slots = rcu_dereference(kvm->memslots);
+
+ for (i = 0; i < slots->nmemslots; i++) {
+ struct kvm_memory_slot *memslot = &slots->memslots[i];
unsigned long start = memslot->userspace_addr;
unsigned long end;
- /* mmu_lock protects userspace_addr */
- if (!start)
- continue;
-
end = start + (memslot->npages << PAGE_SHIFT);
if (hva >= start && hva < end) {
gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
- retval |= handler(kvm, &memslot->rmap[gfn_offset],
- data);
+ ret = handler(kvm, &memslot->rmap[gfn_offset], data);
for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
int idx = gfn_offset;
idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j);
- retval |= handler(kvm,
+ ret |= handler(kvm,
&memslot->lpage_info[j][idx].rmap_pde,
data);
}
+ trace_kvm_age_page(hva, memslot, ret);
+ retval |= ret;
}
}
@@ -856,9 +837,15 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
u64 *spte;
int young = 0;
- /* always return old for EPT */
+ /*
+ * Emulate the accessed bit for EPT, by checking if this page has
+ * an EPT mapping, and clearing it if it does. On the next access,
+ * a new EPT mapping will be established.
+ * This has some overhead, but not as much as the cost of swapping
+ * out actively used pages or breaking up actively used hugepages.
+ */
if (!shadow_accessed_mask)
- return 0;
+ return kvm_unmap_rmapp(kvm, rmapp, data);
spte = rmap_next(kvm, rmapp, NULL);
while (spte) {
@@ -1615,7 +1602,7 @@ static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
{
- int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
+ int slot = memslot_id(kvm, gfn);
struct kvm_mmu_page *sp = page_header(__pa(pte));
__set_bit(slot, sp->slot_bitmap);
@@ -1639,7 +1626,7 @@ 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);
+ gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
if (gpa == UNMAPPED_GVA)
return NULL;
@@ -1852,7 +1839,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
* is responsibility of mmu_get_page / kvm_sync_page.
* Same reasoning can be applied to dirty page accounting.
*/
- if (!can_unsync && is_writeble_pte(*sptep))
+ if (!can_unsync && is_writable_pte(*sptep))
goto set_pte;
if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
@@ -1860,7 +1847,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
__func__, gfn);
ret = 1;
pte_access &= ~ACC_WRITE_MASK;
- if (is_writeble_pte(spte))
+ if (is_writable_pte(spte))
spte &= ~PT_WRITABLE_MASK;
}
}
@@ -1881,7 +1868,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
bool reset_host_protection)
{
int was_rmapped = 0;
- int was_writeble = is_writeble_pte(*sptep);
+ int was_writable = is_writable_pte(*sptep);
int rmap_count;
pgprintk("%s: spte %llx access %x write_fault %d"
@@ -1932,7 +1919,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
if (rmap_count > RMAP_RECYCLE_THRESHOLD)
rmap_recycle(vcpu, sptep, gfn);
} else {
- if (was_writeble)
+ if (was_writable)
kvm_release_pfn_dirty(pfn);
else
kvm_release_pfn_clean(pfn);
@@ -2162,8 +2149,11 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
spin_unlock(&vcpu->kvm->mmu_lock);
}
-static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
+static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr,
+ u32 access, u32 *error)
{
+ if (error)
+ *error = 0;
return vaddr;
}
@@ -2747,7 +2737,7 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
if (tdp_enabled)
return 0;
- gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
+ gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
spin_lock(&vcpu->kvm->mmu_lock);
r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
@@ -2847,16 +2837,13 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
*/
page = alloc_page(GFP_KERNEL | __GFP_DMA32);
if (!page)
- goto error_1;
+ return -ENOMEM;
+
vcpu->arch.mmu.pae_root = page_address(page);
for (i = 0; i < 4; ++i)
vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
return 0;
-
-error_1:
- free_mmu_pages(vcpu);
- return -ENOMEM;
}
int kvm_mmu_create(struct kvm_vcpu *vcpu)
@@ -2936,10 +2923,9 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
spin_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list) {
- int npages;
+ int npages, idx;
- if (!down_read_trylock(&kvm->slots_lock))
- continue;
+ idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
npages = kvm->arch.n_alloc_mmu_pages -
kvm->arch.n_free_mmu_pages;
@@ -2952,7 +2938,7 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
nr_to_scan--;
spin_unlock(&kvm->mmu_lock);
- up_read(&kvm->slots_lock);
+ srcu_read_unlock(&kvm->srcu, idx);
}
if (kvm_freed)
list_move_tail(&kvm_freed->vm_list, &vm_list);
@@ -3019,9 +3005,11 @@ unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
int i;
unsigned int nr_mmu_pages;
unsigned int nr_pages = 0;
+ struct kvm_memslots *slots;
- for (i = 0; i < kvm->nmemslots; i++)
- nr_pages += kvm->memslots[i].npages;
+ slots = rcu_dereference(kvm->memslots);
+ for (i = 0; i < slots->nmemslots; i++)
+ nr_pages += slots->memslots[i].npages;
nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
nr_mmu_pages = max(nr_mmu_pages,
@@ -3246,7 +3234,7 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
if (is_shadow_present_pte(ent) && !is_last_spte(ent, level))
audit_mappings_page(vcpu, ent, va, level - 1);
else {
- gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
+ gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, va, NULL);
gfn_t gfn = gpa >> PAGE_SHIFT;
pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
@@ -3291,10 +3279,12 @@ static void audit_mappings(struct kvm_vcpu *vcpu)
static int count_rmaps(struct kvm_vcpu *vcpu)
{
int nmaps = 0;
- int i, j, k;
+ int i, j, k, idx;
+ idx = srcu_read_lock(&kvm->srcu);
+ slots = rcu_dereference(kvm->memslots);
for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
- struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
+ struct kvm_memory_slot *m = &slots->memslots[i];
struct kvm_rmap_desc *d;
for (j = 0; j < m->npages; ++j) {
@@ -3317,6 +3307,7 @@ static int count_rmaps(struct kvm_vcpu *vcpu)
}
}
}
+ srcu_read_unlock(&kvm->srcu, idx);
return nmaps;
}