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/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 50c79b9..502e53f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -40,6 +40,8 @@
0xFFFFFF0000000000ULL)
#define INVALID_PAGE (~(hpa_t)0)
+#define VALID_PAGE(x) ((x) != INVALID_PAGE)
+
#define UNMAPPED_GVA (~(gpa_t)0)
/* KVM Hugepage definitions for x86 */
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a20fd61..70cdf68 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -92,8 +92,6 @@
#define PT_FIRST_AVAIL_BITS_SHIFT 9
#define PT64_SECOND_AVAIL_BITS_SHIFT 52
-#define VALID_PAGE(x) ((x) != INVALID_PAGE)
-
#define PT64_LEVEL_BITS 9
#define PT64_LEVEL_SHIFT(level) \
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)