From: Yosry Ahmed <yosry.ahmed@linux.dev>
To: Borislav Petkov <bp@alien8.de>
Cc: Patrick Bellasi <derkling@google.com>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org,
Patrick Bellasi <derkling@matbug.net>,
Brendan Jackman <jackmanb@google.com>
Subject: Re: Re: Re: Re: [PATCH] x86/bugs: KVM: Add support for SRSO_MSR_FIX
Date: Sat, 15 Feb 2025 00:57:07 +0000 [thread overview]
Message-ID: <Z6_mY3a_FH-Zw4MC@google.com> (raw)
In-Reply-To: <20250214201005.GBZ6-jHUff99tmkyBK@fat_crate.local>
On Fri, Feb 14, 2025 at 09:10:05PM +0100, Borislav Petkov wrote:
> On Thu, Feb 13, 2025 at 05:50:57PM +0000, Patrick Bellasi wrote:
> > The "should be set identically across all processors in the system" makes me
> > wondering if using the "KVM's user_return approach" proposed here is robust
> > enough. Could this not lead to the bit being possibly set only on some CPU
> > but not others?
>
> That's fine, we should update that paper.
>
> > If BpSpecReduce does not prevent training, but only the training from being
> > used, should not we keep it consistently set after a guest has run, or until an
> > IBPB is executed?
>
> After talking with folks internally, you're probably right. We should slap an
> IBPB before clearing. Which means, I cannot use the MSR return slots anymore.
> I will have to resurrect some of the other solutions we had lined up...
>
> Stay tuned.
Thanks for working on this!
Should this patch (and the two previously merged patches) be backported
to stable? I noticed they did not have CC:stable.
>
> Thx.
>
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2025-02-15 0:57 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-02 12:04 [PATCH v2 0/4] x86/bugs: Adjust SRSO mitigation to new features Borislav Petkov
2024-12-02 12:04 ` [PATCH v2 1/4] x86/bugs: Add SRSO_USER_KERNEL_NO support Borislav Petkov
2024-12-10 6:53 ` Josh Poimboeuf
2024-12-10 15:37 ` Borislav Petkov
2024-12-11 7:53 ` Josh Poimboeuf
2024-12-11 20:38 ` Borislav Petkov
2024-12-11 22:35 ` Sean Christopherson
2024-12-16 17:21 ` Borislav Petkov
2024-12-30 17:02 ` [tip: x86/bugs] " tip-bot2 for Borislav Petkov (AMD)
2024-12-02 12:04 ` [PATCH v2 2/4] KVM: x86: Advertise SRSO_USER_KERNEL_NO to userspace Borislav Petkov
2024-12-30 17:02 ` [tip: x86/bugs] " tip-bot2 for Borislav Petkov (AMD)
2024-12-02 12:04 ` [PATCH v2 3/4] x86/bugs: KVM: Add support for SRSO_MSR_FIX Borislav Petkov
2024-12-11 22:27 ` Sean Christopherson
2024-12-16 17:31 ` Borislav Petkov
2024-12-16 18:51 ` Sean Christopherson
2024-12-17 9:34 ` Borislav Petkov
2024-12-30 11:14 ` Borislav Petkov
2025-01-08 13:38 ` Sean Christopherson
2025-01-08 15:49 ` Borislav Petkov
2025-01-08 17:18 ` Sean Christopherson
2025-01-08 18:14 ` Borislav Petkov
2025-01-08 18:37 ` Jim Mattson
2025-01-08 19:14 ` Borislav Petkov
2025-01-08 19:43 ` Jim Mattson
2025-01-08 19:45 ` Borislav Petkov
2025-01-11 12:52 ` [PATCH] " Borislav Petkov
2025-01-17 18:56 ` Sean Christopherson
2025-01-18 15:26 ` Borislav Petkov
2025-01-23 16:25 ` Sean Christopherson
2025-01-23 17:01 ` Borislav Petkov
2025-01-23 18:04 ` Sean Christopherson
2025-01-24 12:58 ` Borislav Petkov
2025-02-11 19:19 ` Jim Mattson
2025-02-11 20:51 ` Borislav Petkov
2025-02-13 10:53 ` Patrick Bellasi
2025-02-13 13:44 ` Patrick Bellasi
2025-02-13 14:28 ` Borislav Petkov
2025-02-13 17:50 ` Patrick Bellasi
2025-02-14 20:10 ` Borislav Petkov
2025-02-15 0:57 ` Yosry Ahmed [this message]
2025-02-15 9:15 ` Borislav Petkov
2025-02-17 5:47 ` Yosry Ahmed
2025-02-17 15:26 ` Borislav Petkov
2025-02-15 12:53 ` Borislav Petkov
2025-02-17 5:59 ` Yosry Ahmed
2025-02-17 16:07 ` Borislav Petkov
2025-02-17 19:56 ` Yosry Ahmed
2025-02-17 20:20 ` Borislav Petkov
2025-02-17 20:32 ` Yosry Ahmed
2025-02-18 11:13 ` [PATCH final?] " Borislav Petkov
2025-02-18 14:42 ` Patrick Bellasi
2025-02-18 15:34 ` Borislav Petkov
2025-04-29 13:25 ` x86/bugs: KVM: Add support for SRSO_MSR_FIX, back for moar Borislav Petkov
2025-04-30 23:33 ` Sean Christopherson
2025-05-01 0:42 ` Michael Larabel
2025-05-01 8:19 ` Borislav Petkov
2025-05-01 16:56 ` Sean Christopherson
2025-05-05 15:25 ` Borislav Petkov
2025-05-05 15:40 ` Kaplan, David
2025-05-05 15:47 ` Borislav Petkov
2025-05-05 16:30 ` Sean Christopherson
2025-05-05 16:42 ` Kaplan, David
2025-05-05 18:03 ` Sean Christopherson
2025-05-05 18:25 ` Kaplan, David
2024-12-02 12:04 ` [PATCH v2 4/4] Documentation/kernel-parameters: Fix a typo in kvm.enable_virt_at_load text Borislav Petkov
2024-12-30 17:21 ` [tip: x86/cleanups] " tip-bot2 for Borislav Petkov (AMD)
2024-12-03 14:30 ` [PATCH v2 0/4] x86/bugs: Adjust SRSO mitigation to new features Nikolay Borisov
2025-02-26 14:32 ` [tip: x86/bugs] x86/bugs: KVM: Add support for SRSO_MSR_FIX tip-bot2 for Borislav Petkov
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