From: Marc Zyngier <maz@kernel.org>
To: Sean Christopherson <seanjc@google.com>
Cc: Oliver Upton <oupton@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Joey Gouly <joey.gouly@arm.com>,
Steffen Eiden <seiden@linux.ibm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: Never clear KVM_REQ_VM_DEAD from a vCPU's requests
Date: Fri, 07 Aug 2026 09:20:47 +0100 [thread overview]
Message-ID: <8633wqbau8.wl-maz@kernel.org> (raw)
In-Reply-To: <20260806214618.82180-1-seanjc@google.com>
On Thu, 06 Aug 2026 22:46:18 +0100,
Sean Christopherson <seanjc@google.com> wrote:
>
> Use kvm_test_request() instead of kvm_check_request() when querying
> KVM_REQ_VM_DEAD, i.e. don't clear KVM_REQ_VM_DEAD, as the entire purpose
> of KVM_REQ_VM_DEAD is to prevent the vCPU from enterring the guest ever
> again, even if userspace insists on redoing KVM_RUN.
>
> Ensuring KVM_REQ_VM_DEAD is never cleared will allow relaxing KVM's rule
> that ioctls can't be invoked on dead VMs, to only disallow ioctls if the
> VM is bugged, i.e. if KVM hit a KVM_BUG_ON().
>
> Opportunistically add compile-time assertions to guard against clearing
> KVM_REQ_VM_DEAD through the standard APIs.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
M.
--
Without deviation from the norm, progress is not possible.
prev parent reply other threads:[~2026-08-07 8:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-06 21:46 [PATCH] KVM: Never clear KVM_REQ_VM_DEAD from a vCPU's requests Sean Christopherson
2026-08-07 8:20 ` Marc Zyngier [this message]
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