From: Borislav Petkov <bp@alien8.de>
To: Takahiro Itazuri <itazur@amazon.com>
Cc: dave.hansen@linux.intel.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, mingo@redhat.com,
pbonzini@redhat.com, seanjc@google.com, tglx@linutronix.de,
x86@kernel.org, zulinx86@gmail.com
Subject: Re: [PATCH 0/2] KVM: x86: Propagate AMD-specific IBRS bits to guests
Date: Tue, 28 Feb 2023 20:24:12 +0100 [thread overview]
Message-ID: <Y/5U3N0XfRaZ2KkX@zn.tnic> (raw)
In-Reply-To: <20230228181345.40837-1-itazur@amazon.com>
On Tue, Feb 28, 2023 at 06:13:45PM +0000, Takahiro Itazuri wrote:
> VMMs trust to some extent that KVM_GET_SUPPORTED_CPUID returns cpuid
> information consistent with hardware, although they should not for some
> leaves (like CPU topoligy). IMHO, propagating these bits without VMM
> actions would be helpful since guests come to know IBRS related
> information of processors by default and applies mitigations properly
> based on that information.
I'd prefer if VMMs did supply whatever they prefer to the guests
instead. None of those bits are used in the kernel for mitigations, as
you've realized.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2023-02-28 19:24 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-27 21:05 [PATCH 0/2] KVM: x86: Propagate AMD-specific IBRS bits to guests Takahiro Itazuri
2023-02-27 21:05 ` [PATCH 1/2] x86/cpufeatures: Add AMD-specific IBRS bits Takahiro Itazuri
2023-02-27 21:05 ` [PATCH 2/2] KVM: x86: Propagate AMD-specific IBRS related bits Takahiro Itazuri
2023-02-27 21:40 ` [PATCH 0/2] KVM: x86: Propagate AMD-specific IBRS bits to guests Borislav Petkov
2023-02-28 18:13 ` Takahiro Itazuri
2023-02-28 19:24 ` Borislav Petkov [this message]
2023-02-28 19:41 ` Takahiro Itazuri
2023-02-28 20:45 ` Borislav Petkov
2023-02-28 22:24 ` Takahiro Itazuri
2023-02-28 22:50 ` Borislav Petkov
2023-03-06 21:16 ` Sean Christopherson
2023-03-06 21:25 ` Paolo Bonzini
2023-03-06 21:44 ` Borislav Petkov
2023-03-06 21:47 ` Paolo Bonzini
2023-03-06 21:54 ` Borislav Petkov
2023-03-07 18:49 ` Sean Christopherson
2023-03-07 18:58 ` Borislav Petkov
2023-03-07 19:28 ` Sean Christopherson
2023-03-07 19:55 ` Borislav Petkov
2023-03-06 21:31 ` Paolo Bonzini
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