linux-kernel - Re: [PATCH v3 0/8] x86, KVM: Optimize SEV cache flushing

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Message-ID: <175218114710.1488061.16698832498491480621.b4-ty@google.com>
Date: Thu, 10 Jul 2025 16:08:54 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Thomas Gleixner <tglx@...utronix.de>, 
	Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, 
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org, 
	Paolo Bonzini <pbonzini@...hat.com>, Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
	Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
Cc: linux-kernel@...r.kernel.org, kvm@...r.kernel.org, 
	dri-devel@...ts.freedesktop.org, Kevin Loughlin <kevinloughlin@...gle.com>, 
	Tom Lendacky <thomas.lendacky@....com>, Kai Huang <kai.huang@...el.com>, 
	Ingo Molnar <mingo@...nel.org>, Zheyun Shen <szy0127@...u.edu.cn>, 
	Mingwei Zhang <mizhang@...gle.com>, Francesco Lavra <francescolavra.fl@...il.com>
Subject: Re: [PATCH v3 0/8] x86, KVM: Optimize SEV cache flushing

On Thu, 22 May 2025 16:37:24 -0700, Sean Christopherson wrote:
> This is the combination of Kevin's WBNOINVD series[1] with Zheyun's targeted
> flushing series[2].  The combined goal is to use WBNOINVD instead of WBINVD
> when doing cached maintenance to prevent data corruption due to C-bit aliasing,
> and to reduce the number of cache invalidations by only performing flushes on
> CPUs that have entered the relevant VM since the last cache flush.
> 
> All of the non-KVM patches are frontloaded and based on v6.15-rc7, so that
> they can go through the tip tree (in a stable branch, please :-) ).
> 
> [...]

Applied 5-8 to kvm-x86 sev (which is built on tip/x86_core_for_kvm).

[5/8] KVM: x86: Use wbinvd_on_cpu() instead of an open-coded equivalent
      https://github.com/kvm-x86/linux/commit/55aed8c2dbc4
[6/8] KVM: SVM: Remove wbinvd in sev_vm_destroy()
      https://github.com/kvm-x86/linux/commit/7e00013bd339
[7/8] KVM: SEV: Prefer WBNOINVD over WBINVD for cache maintenance efficiency
      https://github.com/kvm-x86/linux/commit/a77896eea33d
[8/8] KVM: SVM: Flush cache only on CPUs running SEV guest
      https://github.com/kvm-x86/linux/commit/d6581b6f2e26

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