KVM: MMU: Move accessed/dirty bit checks from rmap_remove() to drop_spte()

Since we need to make the check atomic, move it to the place that will
set the new spte.

Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity 2010-06-06 14:38:12 +03:00
parent be38d276b0
commit ce061867aa

View File

@ -612,19 +612,11 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
struct kvm_rmap_desc *desc;
struct kvm_rmap_desc *prev_desc;
struct kvm_mmu_page *sp;
pfn_t pfn;
gfn_t gfn;
unsigned long *rmapp;
int i;
if (!is_rmap_spte(*spte))
return;
sp = page_header(__pa(spte));
pfn = spte_to_pfn(*spte);
if (*spte & shadow_accessed_mask)
kvm_set_pfn_accessed(pfn);
if (is_writable_pte(*spte))
kvm_set_pfn_dirty(pfn);
gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt);
rmapp = gfn_to_rmap(kvm, gfn, sp->role.level);
if (!*rmapp) {
@ -660,6 +652,17 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
static void drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte)
{
pfn_t pfn;
if (!is_rmap_spte(*sptep)) {
__set_spte(sptep, new_spte);
return;
}
pfn = spte_to_pfn(*sptep);
if (*sptep & shadow_accessed_mask)
kvm_set_pfn_accessed(pfn);
if (is_writable_pte(*sptep))
kvm_set_pfn_dirty(pfn);
rmap_remove(kvm, sptep);
__set_spte(sptep, new_spte);
}