diff options
| author | Sean Christopherson <seanjc@google.com> | 2026-04-07 01:53:57 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-05-13 20:40:13 +0300 |
| commit | 3c0bf11dd41ffd4206c8ba76d485379e307080e0 (patch) | |
| tree | 92ac819e314b97f1c2287323ae62f0e7e847f054 | |
| parent | 923ca078f08cbdf526d1e8df9bbb824b14c8ed9d (diff) | |
| download | linux-3c0bf11dd41ffd4206c8ba76d485379e307080e0.tar.xz | |
KVM: x86: Drop superfluous caching of KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT
Drop kvm_vcpu_arch.apf.delivery_as_pf_vmexit and instead use msr_en_val as
the source of truth to reduce the probability of operating on stale data.
This fixes flaws where KVM fails to update delivery_as_pf_vmexit when APF
is explicitly disabled by the guest or implicitly disabled by KVM on INIT.
Absent other bugs, the flaws are benign as KVM *shouldn't* consume
delivery_as_pf_vmexit when PV APF support is disabled.
Simply delete the field, as there's zero benefit to maintaining a separate
"cache" of the state.
Fixes: 52a5c155cf79 ("KVM: async_pf: Let guest support delivery of async_pf from guest mode")
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://patch.msgid.link/20260406225359.1245490-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
2 files changed, 1 insertions, 3 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 8a53ca619570..5644dc9f08a4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1058,7 +1058,6 @@ struct kvm_vcpu_arch { u32 id; u32 host_apf_flags; bool send_always; - bool delivery_as_pf_vmexit; bool pageready_pending; } apf; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 82dce54ac505..4bffcea3ede9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3667,7 +3667,6 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data) } vcpu->arch.apf.send_always = (data & KVM_ASYNC_PF_SEND_ALWAYS); - vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT; kvm_async_pf_wakeup_all(vcpu); @@ -14018,7 +14017,7 @@ static bool kvm_can_deliver_async_pf(struct kvm_vcpu *vcpu) * L1 needs to opt into the special #PF vmexits that are * used to deliver async page faults. */ - return vcpu->arch.apf.delivery_as_pf_vmexit; + return vcpu->arch.apf.msr_en_val & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT; } else { /* * Play it safe in case the guest temporarily disables paging. |