From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+bc0e18379a290e5edfe4@syzkaller.appspotmail.com,
Ethan Yang <ethan.yang.kernel@gmail.com>
Subject: Re: [PATCH v3 2/3] KVM: x86: Drop superfluous caching of KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT
Date: Tue, 7 Apr 2026 22:00:59 +0800 [thread overview]
Message-ID: <8799eb07-0641-402f-a856-eb1ac3098df9@intel.com> (raw)
In-Reply-To: <20260406225359.1245490-3-seanjc@google.com>
On 4/7/2026 6:53 AM, Sean Christopherson wrote:
> Drop kvm_vcpu_arch.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")
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
next prev parent reply other threads:[~2026-04-07 14:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-06 22:53 [PATCH v3 0/3] KVM: x86: Async #PF MSR fix and cleanups Sean Christopherson
2026-04-06 22:53 ` [PATCH v3 1/3] KVM: x86: Don't leave APF half-enabled on bad APF data GPA Sean Christopherson
2026-04-09 7:18 ` Binbin Wu
2026-04-06 22:53 ` [PATCH v3 2/3] KVM: x86: Drop superfluous caching of KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT Sean Christopherson
2026-04-07 14:00 ` Xiaoyao Li [this message]
2026-04-09 7:25 ` Binbin Wu
2026-04-06 22:53 ` [PATCH v3 3/3] KVM: x86: Drop superfluous caching of KVM_ASYNC_PF_SEND_ALWAYS Sean Christopherson
2026-04-07 14:06 ` Xiaoyao Li
2026-04-09 7:42 ` Binbin Wu
2026-04-09 3:14 ` [PATCH v3 0/3] KVM: x86: Async #PF MSR fix and cleanups ethan_yang_kernel
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