KVM: MMU: out of sync shadow core

Allow guest pagetables to go out of sync.  Instead of emulating write
accesses to guest pagetables, or unshadowing them, we un-write-protect
the page table and allow the guest to modify it at will.  We rely on
invlpg executions to synchronize individual ptes, and will synchronize
the entire pagetable on tlb flushes.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Marcelo Tosatti
2008-09-23 13:18:39 -03:00
committed by Avi Kivity
parent 6844dec694
commit 4731d4c7a0
5 changed files with 201 additions and 18 deletions

View File

@@ -101,6 +101,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "mmu_flooded", VM_STAT(mmu_flooded) },
{ "mmu_recycled", VM_STAT(mmu_recycled) },
{ "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
{ "mmu_unsync", VM_STAT(mmu_unsync) },
{ "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
{ "largepages", VM_STAT(lpages) },
{ NULL }
@@ -3120,6 +3121,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (vcpu->requests) {
if (test_and_clear_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests))
__kvm_migrate_timers(vcpu);
if (test_and_clear_bit(KVM_REQ_MMU_SYNC, &vcpu->requests))
kvm_mmu_sync_roots(vcpu);
if (test_and_clear_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
kvm_x86_ops->tlb_flush(vcpu);
if (test_and_clear_bit(KVM_REQ_REPORT_TPR_ACCESS,