From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
To: Jon Kohler <jon@nutanix.com>
Cc: Dave Hansen <dave.hansen@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>, Tony Luck <tony.luck@intel.com>,
Andi Kleen <ak@linux.intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Borislav Petkov <bp@suse.de>,
Neelima Krishnan <neelima.krishnan@intel.com>,
"kvm @ vger . kernel . org" <kvm@vger.kernel.org>
Subject: Re: [PATCH] x86/tsx: fix KVM guest live migration for tsx=on
Date: Tue, 12 Apr 2022 11:04:52 -0700 [thread overview]
Message-ID: <20220412180452.ityo3o3eoxh3iul7@guptapa-desk> (raw)
In-Reply-To: <28C45B75-7FE3-4C79-9A29-F929AF9BC5A8@nutanix.com>
On Tue, Apr 12, 2022 at 04:08:32PM +0000, Jon Kohler wrote:
>
>
>> On Apr 12, 2022, at 11:54 AM, Dave Hansen <dave.hansen@intel.com> wrote:
>>
>> On 4/12/22 06:36, Jon Kohler wrote:
>>> So my theory here is to extend the logical effort of the microcode driven
>>> automatic disablement as well as the tsx=auto automatic disablement and
>>> have tsx=on force abort all transactions on X86_BUG_TAA SKUs, but leave
>>> the CPU features enumerated to maintain live migration.
>>>
>>> This would still leave TSX totally good on Ice Lake / non-buggy systems.
>>>
>>> If it would help, I'm working up an RFC patch, and we could discuss there?
>>
>> Sure. But, it sounds like you really want a new tdx=something rather
>> than to muck with tsx=on behavior. Surely someone else will come along
>> and complain that we broke their TDX setup if we change its behavior.
>
>Good point, there will always be a squeaky wheel. I’ll work that into the RFC,
>I’ll do something like tsx=compat and see how it shapes up.
FYI, the original series had tsx=fake, that would have taken care of
this breakage.
https://lore.kernel.org/lkml/de6b97a567e273adff1f5268998692bad548aa10.1623272033.git-series.pawan.kumar.gupta@linux.intel.com/
For the lack of real world use-cases at that time, this patch was dropped.
Thanks,
Pawan
next prev parent reply other threads:[~2022-04-12 18:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-11 18:01 [PATCH] x86/tsx: fix KVM guest live migration for tsx=on Jon Kohler
2022-04-11 19:26 ` Dave Hansen
2022-04-11 19:35 ` Jon Kohler
2022-04-11 23:45 ` Dave Hansen
2022-04-12 13:36 ` Jon Kohler
2022-04-12 15:54 ` Dave Hansen
2022-04-12 16:08 ` Jon Kohler
2022-04-12 18:04 ` Pawan Gupta [this message]
2022-04-12 18:12 ` Jon Kohler
2022-04-12 20:40 ` Pawan Gupta
2022-04-13 12:43 ` Jon Kohler
2022-04-11 20:07 ` [PATCH v2] " Jon Kohler
2022-04-12 19:55 ` Pawan Gupta
2022-04-12 20:54 ` Pawan Gupta
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