From: Sean Christopherson <seanjc@google.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Amit Shah <amit@kernel.org>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
x86@kernel.org, linux-doc@vger.kernel.org,
thomas.lendacky@amd.com, bp@alien8.de, tglx@linutronix.de,
peterz@infradead.org, jpoimboe@kernel.org,
pawan.kumar.gupta@linux.intel.com, corbet@lwn.net,
mingo@redhat.com, dave.hansen@linux.intel.com, hpa@zytor.com,
pbonzini@redhat.com, daniel.sneddon@linux.intel.com,
kai.huang@intel.com, sandipan.das@amd.com,
boris.ostrovsky@oracle.com, Babu.Moger@amd.com,
david.kaplan@amd.com, dwmw@amazon.co.uk,
andrew.cooper3@citrix.com, Amit Shah <Amit.Shah@amd.com>
Subject: Re: [RFC PATCH v3 1/2] x86: cpu/bugs: add AMD ERAPS support; hardware flushes RSB
Date: Mon, 2 Dec 2024 10:36:05 -0800 [thread overview]
Message-ID: <Z03-FSa6nvVbFjwc@google.com> (raw)
In-Reply-To: <0dd91e39-c4b7-4740-b469-6f71e48b72de@intel.com>
On Mon, Dec 02, 2024, Dave Hansen wrote:
> On 12/2/24 10:09, Amit Shah wrote:
> > I can still include the summary of the discussion in this patch - I
> > just feel it isn't necessary with the rework.
>
> It's necessary.
>
> There's a new hardware feature. You want it to replace a software
> sequence in certain situations. You have to make an actual, coherent
> argument argument as to why the hardware feature is a suitable replacement.
>
> For instance (and I'm pretty sure we've gone over this more than once),
> the changelog here still makes the claim that a "context switch" and a
> "mov-to-CR3" are the same thing.
+1000. I want a crisp, precise description of the actual hardware behavior, so
that KVM can do the right thing when virtualizing ERAPS.
next prev parent reply other threads:[~2024-12-02 18:36 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-21 20:07 [PATCH v2 0/2] x86/bugs: RSB tweaks Josh Poimboeuf
2024-11-21 20:07 ` [PATCH v2 1/2] x86/bugs: Don't fill RSB on VMEXIT with eIBRS+retpoline Josh Poimboeuf
2024-11-30 15:31 ` Borislav Petkov
2024-12-02 11:15 ` Shah, Amit
2024-12-02 12:19 ` Borislav Petkov
2024-12-02 23:35 ` Pawan Gupta
2024-12-03 11:20 ` Borislav Petkov
2024-12-05 23:12 ` Josh Poimboeuf
2024-12-21 9:13 ` Borislav Petkov
2025-04-02 9:19 ` Shah, Amit
2025-04-02 14:16 ` Josh Poimboeuf
2025-04-02 14:19 ` Shah, Amit
2024-12-05 23:13 ` Josh Poimboeuf
2024-11-21 20:07 ` [PATCH v2 2/2] x86/bugs: Don't fill RSB on context switch with eIBRS Josh Poimboeuf
2024-12-03 11:42 ` Borislav Petkov
2024-12-05 23:32 ` Josh Poimboeuf
2024-12-06 0:53 ` Josh Poimboeuf
2024-12-06 23:02 ` Josh Poimboeuf
2024-12-30 14:54 ` Shah, Amit
2025-01-08 11:50 ` Shah, Amit
2024-12-06 10:10 ` Shah, Amit
2024-12-09 20:46 ` jpoimboe
2024-11-28 13:28 ` [RFC PATCH v3 0/2] Add support for the ERAPS feature Amit Shah
2024-11-28 13:28 ` [RFC PATCH v3 1/2] x86: cpu/bugs: add AMD ERAPS support; hardware flushes RSB Amit Shah
2024-12-02 17:26 ` Dave Hansen
2024-12-02 18:09 ` Amit Shah
2024-12-02 18:25 ` Dave Hansen
2024-12-02 18:36 ` Sean Christopherson [this message]
2024-11-28 13:28 ` [RFC PATCH v3 2/2] x86: kvm: svm: advertise ERAPS (larger RSB) support to guests Amit Shah
2024-12-02 18:30 ` Sean Christopherson
2025-03-27 11:10 ` Shah, Amit
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