KVM: MMU: Use mmu_set_spte() for real-mode shadows
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>
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index b4dd726..ba71e8d 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -966,40 +966,23 @@
{
}
-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 @@
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 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 @@
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)