From: Dave Hansen <dave.hansen@intel.com>
To: Jon Kohler <jon@nutanix.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
Peter Zijlstra <peterz@infradead.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Jonathan Corbet <corbet@lwn.net>, Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>, Brian Gerst <brgerst@gmail.com>,
Brendan Jackman <jackmanb@google.com>,
"Ahmed S. Darwish" <darwi@linutronix.de>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/its: use Sapphire Rapids+ feature to opt out
Date: Tue, 21 Oct 2025 07:01:33 -0700 [thread overview]
Message-ID: <73a22a19-c492-4a75-8352-a4cfac47d812@intel.com> (raw)
In-Reply-To: <1D952EBC-CA16-49FE-8AD0-48BCE038332B@nutanix.com>
On 10/21/25 06:40, Jon Kohler wrote:
> So to simplify it down:
> A guest VM that updates to a ITS-enabled guest kernel sees performance
> impacts on non-vulnerable hardware, when running on non-BHI_CTRL and/or
> non-ITS_NO hypervisors, which is a very easy situation to get into, especially
> on QEMU with live migration-enabled pools.
By non-$FEATURE, do you mean that they chose to not enumerate those
features, or that they are completely ignorant of them?
next prev parent reply other threads:[~2025-10-21 14:01 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-17 1:12 [PATCH] x86/its: use Sapphire Rapids+ feature to opt out Jon Kohler
2025-10-20 15:48 ` Sean Christopherson
2025-10-20 16:05 ` Jon Kohler
2025-10-20 16:21 ` Dave Hansen
2025-10-20 16:26 ` Jon Kohler
2025-10-20 19:26 ` Pawan Gupta
2025-10-20 19:38 ` Jon Kohler
2025-10-20 19:53 ` Pawan Gupta
2025-10-20 20:29 ` Jon Kohler
2025-10-20 19:44 ` Pawan Gupta
2025-10-20 19:54 ` Jon Kohler
2025-10-20 20:40 ` Pawan Gupta
2025-10-20 21:02 ` Jon Kohler
2025-10-20 22:09 ` Dave Hansen
2025-10-20 22:41 ` Pawan Gupta
2025-10-21 13:40 ` Jon Kohler
2025-10-21 14:01 ` Dave Hansen [this message]
2025-10-21 14:39 ` Jon Kohler
2025-10-21 15:21 ` Dave Hansen
2025-10-21 15:40 ` Jon Kohler
2025-10-21 15:27 ` Konrad Rzeszutek Wilk
2025-10-21 15:35 ` Jon Kohler
2025-10-21 15:46 ` Konrad Rzeszutek Wilk
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