From: Chao Gao <chao.gao@intel.com>
To: Kai Huang <kai.huang@intel.com>
Cc: <seanjc@google.com>, <pbonzini@redhat.com>, <kvm@vger.kernel.org>,
<thomas.lendacky@amd.com>, <nikunj@amd.com>, <bp@alien8.de>,
<isaku.yamahata@intel.com>, <xiaoyao.li@intel.com>,
<rick.p.edgecombe@intel.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] KVM: x86: Reject KVM_SET_TSC_KHZ VM ioctl when vCPUs have been created
Date: Mon, 14 Jul 2025 16:44:15 +0800 [thread overview]
Message-ID: <aHTDX1IQuyWYUwL+@intel.com> (raw)
In-Reply-To: <135a35223ce8d01cea06b6cef30bfe494ec85827.1752444335.git.kai.huang@intel.com>
On Mon, Jul 14, 2025 at 10:20:19AM +1200, Kai Huang wrote:
>Reject the KVM_SET_TSC_KHZ VM ioctl when vCPUs have been created and
>update the documentation to reflect it.
>
>The VM scope KVM_SET_TSC_KHZ ioctl is used to set up the default TSC
>frequency that all subsequently created vCPUs can use. It is only
>intended to be called before any vCPU is created. Allowing it to be
>called after that only results in confusion but nothing good.
>
>Note this is an ABI change. But currently in Qemu (the de facto
>userspace VMM) only TDX uses this VM ioctl, and it is only called once
>before creating any vCPU, therefore the risk of breaking userspace is
>pretty low.
>
>Suggested-by: Sean Christopherson <seanjc@google.com>
>Signed-off-by: Kai Huang <kai.huang@intel.com>
>Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Chao Gao <chao.gao@intel.com>
next prev parent reply other threads:[~2025-07-14 8:44 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-13 22:20 [PATCH v2 0/2] Improve KVM_SET_TSC_KHZ handling for CoCo VMs Kai Huang
2025-07-13 22:20 ` [PATCH v2 1/2] KVM: x86: Reject KVM_SET_TSC_KHZ VM ioctl when vCPUs have been created Kai Huang
2025-07-14 5:43 ` Nikunj A. Dadhania
2025-07-14 8:44 ` Chao Gao [this message]
2025-07-13 22:20 ` [PATCH v2 2/2] KVM: x86: Reject KVM_SET_TSC_KHZ vCPU ioctl for TSC protected guest Kai Huang
2025-07-15 0:23 ` [PATCH v2 0/2] Improve KVM_SET_TSC_KHZ handling for CoCo VMs Sean Christopherson
2025-07-15 0:54 ` Huang, Kai
2025-07-15 14:07 ` Sean Christopherson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aHTDX1IQuyWYUwL+@intel.com \
--to=chao.gao@intel.com \
--cc=bp@alien8.de \
--cc=isaku.yamahata@intel.com \
--cc=kai.huang@intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=nikunj@amd.com \
--cc=pbonzini@redhat.com \
--cc=rick.p.edgecombe@intel.com \
--cc=seanjc@google.com \
--cc=thomas.lendacky@amd.com \
--cc=xiaoyao.li@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.