KVM: MMU: handle invalid root_hpa at __direct_map
commit 989c6b34f6a9480e397b170cc62237e89bf4fdb9 upstream.
It is possible for __direct_map to be called on invalid root_hpa
(-1), two examples:
1) try_async_pf -> can_do_async_pf
-> vmx_interrupt_allowed -> nested_vmx_vmexit
2) vmx_handle_exit -> vmx_interrupt_allowed -> nested_vmx_vmexit
Then to load_vmcs12_host_state and kvm_mmu_reset_context.
Check for this possibility, let fault exception be regenerated.
BZ: https://bugzilla.redhat.com/show_bug.cgi?id=924916
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 4cb1642..fd6dec6 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2451,6 +2451,9 @@
int emulate = 0;
gfn_t pseudo_gfn;
+ if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
+ return 0;
+
for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
if (iterator.level == level) {
unsigned pte_access = ACC_ALL;