From: Borislav Petkov <bp@alien8.de>
To: Takahiro Itazuri <itazur@amazon.com>
Cc: kvm@vger.kernel.org, x86@kernel.org,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
linux-kernel@vger.kernel.org,
Takahiro Itazuri <zulinx86@gmail.com>
Subject: Re: [PATCH 0/2] KVM: x86: Propagate AMD-specific IBRS bits to guests
Date: Mon, 27 Feb 2023 22:40:21 +0100 [thread overview]
Message-ID: <Y/0jRXzbcbxTjqSS@zn.tnic> (raw)
In-Reply-To: <20230227210526.83182-1-itazur@amazon.com>
On Mon, Feb 27, 2023 at 09:05:24PM +0000, Takahiro Itazuri wrote:
> VMMs retrieve supported CPUID features via KVM_GET_SUPPORTED_CPUID to
> construct CPUID information to be passed to KVM_SET_CPUID2. Most CPUID
> feature bits related to speculative attacks are propagated from host
> CPUID. But AMD processors have AMD-specific IBRS related bits in CPUID
> Fn8000_0008_EBX (ref: AMD64 Architecture Programmer's Manual Volume 3:
> General-Purpose and System Instructions) and some bits are not
> propagated to guests.
>
> Enable propagation of these bits to guests, so that VMMs don't have to
> enable them explicitly based on host CPUID.
How hard is it for the VMMs to enable them?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2023-02-27 21:40 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 ` Borislav Petkov [this message]
2023-02-28 18:13 ` [PATCH 0/2] KVM: x86: Propagate AMD-specific IBRS bits to guests Takahiro Itazuri
2023-02-28 19:24 ` Borislav Petkov
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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