Remove spte and sptep initialization assignments, add sptep assignment
check and processing.
Signed-off-by: Li zeming <zeming@xxxxxxxxxxxx>
---
v2:
1. Remove spte initialization assignment.
2. Add sptep assignment check.
arch/x86/kvm/mmu/mmu.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ec169f5c7dce..0d11bfeae2f8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3456,8 +3456,8 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
{
struct kvm_mmu_page *sp;
int ret = RET_PF_INVALID;
- u64 spte = 0ull;
- u64 *sptep = NULL;
+ u64 spte;
+ u64 *sptep;
uint retry_count = 0;
if (!page_fault_can_be_fast(fault))
@@ -3473,6 +3473,14 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
else
sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte);
+ /*
+ * It's entirely possible for the mapping to have been zapped
+ * by a different task, but the root page is should always be
+ * available as the vCPU holds a reference to its root(s).
+ */
+ if (WARN_ON_ONCE(!sptep))
+ spte = REMOVED_SPTE;
+
if (!is_shadow_present_pte(spte))
break;
--
2.18.2
