KVM: VMX: fix tlb flush with invalid root
Commit 341d9b535b6c simplify reload logic while entry guest mode, it
can avoid unnecessary sync-root if KVM_REQ_MMU_RELOAD and
KVM_REQ_MMU_SYNC both set.
But, it cause a issue that when we handle 'KVM_REQ_TLB_FLUSH', the
root is invalid, it is triggered during my test:
Kernel BUG at ffffffffa00212b8 [verbose debug info unavailable]
......
Fixed by directly return if the root is not ready.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4dfb1dc..2fdcc98 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1828,8 +1828,11 @@
static void vmx_flush_tlb(struct kvm_vcpu *vcpu)
{
vpid_sync_context(to_vmx(vcpu));
- if (enable_ept)
+ if (enable_ept) {
+ if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
+ return;
ept_sync_context(construct_eptp(vcpu->arch.mmu.root_hpa));
+ }
}
static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
