linux-kernel - Re: [PATCH v3 00/10] KVM: VMX: Fix APICv activation bugs

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: <176532631966.885296.9645749172580580884.b4-ty@google.com>
Date: Tue,  9 Dec 2025 16:25:54 -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, 
	Dongli Zhang <dongli.zhang@...cle.com>, Chao Gao <chao.gao@...el.com>
Subject: Re: [PATCH v3 00/10] KVM: VMX: Fix APICv activation bugs

On Fri, 05 Dec 2025 15:19:03 -0800, Sean Christopherson wrote:
> Fix two bugs related to updating APICv state, add a regression test, and
> then rip out the "defer updates until nested VM-Exit" that contributed to
> bug #2, and eliminated a number ideas for fixing bug #1 (ignoring that my
> ideas weren't all that great).
> 
> The only thing that gives me pause is the TLB flushing logic in
> vmx_set_virtual_apic_mode(), mainly because I don't love open coding things
> like that.  But for me, it's a much lesser evil than the mounting pile of
> booleans related to tracking deferred updates, and the mental gymnastics
> needed to understanding the interactions and ordering.
> 
> [...]

Applied 1 and 2 to kvm-x86 fixes.

[01/10] KVM: VMX: Update SVI during runtime APICv activation
        https://github.com/kvm-x86/linux/commit/b2849bec936b
[02/10] KVM: nVMX: Immediately refresh APICv controls as needed on nested VM-Exit
        https://github.com/kvm-x86/linux/commit/297631388309

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