linux-kernel - Re: [PATCH 0/2] KVM: x86: Do runtime updates during KVM_SET

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <176494721851.296449.6639753862362613097.b4-ty@google.com>
Date: Fri,  5 Dec 2025 08:59:29 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Igor Mammedov <imammedo@...hat.com>
Subject: Re: [PATCH 0/2] KVM: x86: Do runtime updates during KVM_SET_CPUID2

On Mon, 01 Dec 2025 17:50:47 -0800, Sean Christopherson wrote:
> Do runtime updates (if necessary) when userspace sets CPUID to fix a bug
> where KVM drops a pending update (KVM will clear the dirty flag when doing
> updates on the new/incoming CPUID).  The bug most visibly manifests as an
> -EINVAL failure on KVM_SET_CPUID{,2} due to the old/current CPUID not
> matching the new/incoming CPUID, but if userspace were to continue running
> past the failure, the vCPU would run with stale CPUID/caps.
> 
> [...]

Applied to kvm-x86 fixes, thanks!

[1/2] KVM: x86: Apply runtime updates to current CPUID during KVM_SET_CPUID{,2}
      https://github.com/kvm-x86/linux/commit/e2b43fb25243
[2/2] KVM: selftests: Add a CPUID testcase for KVM_SET_CPUID2 with runtime updates
      https://github.com/kvm-x86/linux/commit/824d227324dc

--
https://github.com/kvm-x86/linux/tree/next