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KVM: MMU: Use mmu_set_spte() for real-mode shadows

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In addition to removing some duplicated code, this also handles the unlikely
case of real-mode code updating a guest page table.  This can happen when
one vcpu (in real mode) touches a second vcpu's (in protected mode) page
tables, or if a vcpu switches to real mode, touches page tables, and switches
back.

Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Avi Kivity 2007-12-09 18:43:00 +02:00
parent bc750ba860
commit e833240f3c
1 changed files with 10 additions and 31 deletions
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41
drivers/kvm/mmu.c
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@ -966,40 +966,23 @@ static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
{
}
static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, struct page *page)
static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
{
int level = PT32E_ROOT_LEVEL;
hpa_t table_addr = vcpu->mmu.root_hpa;
int pt_write = 0;
for (; ; level--) {
u32 index = PT64_INDEX(v, level);
u64 *table;
u64 pte;
ASSERT(VALID_PAGE(table_addr));
table = __va(table_addr);
if (level == 1) {
int was_rmapped;
pte = table[index];
was_rmapped = is_rmap_pte(pte);
if (is_shadow_present_pte(pte) && is_writeble_pte(pte)) {
kvm_release_page_clean(page);
return 0;
}
mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
page_header_update_slot(vcpu->kvm, table,
v >> PAGE_SHIFT);
table[index] = page_to_phys(page)
| PT_PRESENT_MASK | PT_WRITABLE_MASK
| PT_USER_MASK;
if (!was_rmapped)
rmap_add(vcpu, &table[index], v >> PAGE_SHIFT);
else
kvm_release_page_clean(page);
return 0;
mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
0, write, 1, &pt_write, gfn);
return pt_write || is_io_pte(table[index]);
}
if (table[index] == shadow_trap_nonpresent_pte) {
@ -1013,7 +996,6 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, struct page *page)
1, ACC_ALL, &table[index]);
if (!new_table) {
pgprintk("nonpaging_map: ENOMEM\n");
kvm_release_page_clean(page);
return -ENOMEM;
}
@ -1114,9 +1096,10 @@ static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
u32 error_code)
{
struct page *page;
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;
@ -1124,14 +1107,10 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
ASSERT(vcpu);
ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
page = gfn_to_page(vcpu->kvm, gva >> PAGE_SHIFT);
gfn = gva >> PAGE_SHIFT;
if (is_error_page(page)) {
kvm_release_page_clean(page);
return 1;
}
return nonpaging_map(vcpu, gva & PAGE_MASK, page);
return nonpaging_map(vcpu, gva & PAGE_MASK,
error_code & PFERR_WRITE_MASK, gfn);
}
static void nonpaging_free(struct kvm_vcpu *vcpu)