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authorVitaly Kuznetsov2020-05-07 16:36:02 +0200
committerPaolo Bonzini2020-07-08 16:21:35 -0400
commit9ce372b33a2ebbd0b965148879ae169a0015d3f3 (patch)
tree52fa2906966ab56f900249ee6e762d82f00f6e27
parent6c6165f83ba7cee1997303115ffea9d5aa646188 (diff)
KVM: x86: drop KVM_PV_REASON_PAGE_READY case from kvm_handle_page_fault()
KVM guest code in Linux enables APF only when KVM_FEATURE_ASYNC_PF_INT is supported, this means we will never see KVM_PV_REASON_PAGE_READY when handling page fault vmexit in KVM. While on it, make sure we only follow genuine page fault path when APF reason is zero. If we happen to see something else this means that the underlying hypervisor is misbehaving. Leave WARN_ON_ONCE() to catch that. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/mmu.c17
1 files changed, 6 insertions, 11 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6d6a0ae7800c..3ca70554d5f1 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4156,6 +4156,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
u64 fault_address, char *insn, int insn_len)
{
int r = 1;
+ u32 flags = vcpu->arch.apf.host_apf_flags;
#ifndef CONFIG_X86_64
/* A 64-bit CR2 should be impossible on 32-bit KVM. */
@@ -4164,28 +4165,22 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
#endif
vcpu->arch.l1tf_flush_l1d = true;
- switch (vcpu->arch.apf.host_apf_flags) {
- default:
+ if (!flags) {
trace_kvm_page_fault(fault_address, error_code);
if (kvm_event_needs_reinjection(vcpu))
kvm_mmu_unprotect_page_virt(vcpu, fault_address);
r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn,
insn_len);
- break;
- case KVM_PV_REASON_PAGE_NOT_PRESENT:
+ } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) {
vcpu->arch.apf.host_apf_flags = 0;
local_irq_disable();
kvm_async_pf_task_wait_schedule(fault_address);
local_irq_enable();
- break;
- case KVM_PV_REASON_PAGE_READY:
- vcpu->arch.apf.host_apf_flags = 0;
- local_irq_disable();
- kvm_async_pf_task_wake(fault_address);
- local_irq_enable();
- break;
+ } else {
+ WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags);
}
+
return r;
}
EXPORT_SYMBOL_GPL(kvm_handle_page_fault);