linux-kernel - Re: [PATCH v2 0/2] Improve KVM_SET_TSC

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Message-ID: <175253196286.1789819.9618704444430239046.b4-ty@google.com>
Date: Mon, 14 Jul 2025 17:23:28 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, pbonzini@...hat.com, Kai Huang <kai.huang@...el.com>
Cc: kvm@...r.kernel.org, thomas.lendacky@....com, nikunj@....com, bp@...en8.de, 
	isaku.yamahata@...el.com, xiaoyao.li@...el.com, rick.p.edgecombe@...el.com, 
	chao.gao@...el.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 0/2] Improve KVM_SET_TSC_KHZ handling for CoCo VMs

On Mon, 14 Jul 2025 10:20:18 +1200, Kai Huang wrote:
> This series follows Sean's suggestions [1][2] to:
> 
>  - Reject vCPU scope KVM_SET_TSC_KHZ ioctl for TSC protected vCPU
>  - Reject VM scope KVM_SET_TSC_KHZ ioctl when vCPUs have been created
> 
> .. in the discussion of SEV-SNP Secure TSC support series.
> 
> [...]

Applied patch 2 to kvm-x86 fixes, with a tweaked changelog to call out that
TDX support hasn't yet been released, i.e. that there is no established ABI
to break.

Applied patch 1 to kvm-x86 misc, with tweaked documentation to not imply that
userspace "must" invoke the ioctl.  I think this is the last patch I'll throw
into misc for 6.17?  So in theory, if it breaks userspace, I can simply
truncate it from the pull request.

[1/2] KVM: x86: Reject KVM_SET_TSC_KHZ VM ioctl when vCPUs have been created
      https://github.com/kvm-x86/linux/commit/dcbe5a466c12
[2/2] KVM: x86: Reject KVM_SET_TSC_KHZ vCPU ioctl for TSC protected guest
      https://github.com/kvm-x86/linux/commit/e51cf184d90c

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