From: Wanpeng Li <kernellwp@gmail.com>
To: Borislav Petkov <bp@alien8.de>
Cc: LKML <linux-kernel@vger.kernel.org>, kvm <kvm@vger.kernel.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Subject: Re: [PATCH] KVM: X86: Allow userspace to define the microcode version
Date: Mon, 26 Feb 2018 19:25:28 +0800 [thread overview]
Message-ID: <CANRm+Cxw2-8Cf+6cg_yZC+SD66uNA5RO+ZaoHHmkpHLzjCih=A@mail.gmail.com> (raw)
In-Reply-To: <20180226111630.GB4377@pd.tnic>
2018-02-26 19:16 GMT+08:00 Borislav Petkov <bp@alien8.de>:
> On Mon, Feb 26, 2018 at 07:02:29PM +0800, Wanpeng Li wrote:
>> > So a guest will have *two* microcode revisions - both of which are most
>> > likely wrong?!
>>
>> Just one revision.
>
> So what does "the non-sensical value which is written by the guest will
> not reflect to guest-visible microcode revision" even mean then?
>
> cat /proc/cpuinfo
>
> in the guest shows what exactly?
>
> And what would RDMSR 0x8b show then?
Both are the same values set by kvm userspace.
>
>> https://lkml.org/lkml/2017/12/9/29 The original discussion explain in
>> more details.
>
> approach. Instead, the kernel should not look at microcode revisions if
> it runs virtualized.
This is correct. The link explains why the userspace sets microcode
revision is still needed.
Regards,
Wanpeng Li
next prev parent reply other threads:[~2018-02-26 11:25 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-26 7:23 [PATCH] KVM: X86: Allow userspace to define the microcode version Wanpeng Li
2018-02-26 9:41 ` Borislav Petkov
2018-02-26 10:06 ` Wanpeng Li
2018-02-26 10:49 ` Borislav Petkov
2018-02-26 11:02 ` Wanpeng Li
2018-02-26 11:16 ` Borislav Petkov
2018-02-26 11:25 ` Wanpeng Li [this message]
2018-02-26 11:30 ` Borislav Petkov
2018-02-26 11:37 ` Wanpeng Li
2018-02-26 11:44 ` Borislav Petkov
2018-02-26 11:52 ` Wanpeng Li
2018-02-26 11:54 ` Paolo Bonzini
2018-02-26 12:15 ` Borislav Petkov
2018-02-26 12:16 ` Paolo Bonzini
2018-02-26 12:18 ` Paolo Bonzini
2018-02-26 12:22 ` Borislav Petkov
2018-02-26 12:41 ` Paolo Bonzini
2018-02-26 13:05 ` Borislav Petkov
2018-02-26 14:39 ` Konrad Rzeszutek Wilk
2018-02-26 14:46 ` Paolo Bonzini
2018-02-26 19:37 ` Borislav Petkov
2018-02-26 20:51 ` Konrad Rzeszutek Wilk
2018-02-26 21:30 ` Konrad Rzeszutek Wilk
2018-02-27 8:33 ` Paolo Bonzini
2018-03-08 9:24 ` [tip:x86/pti] x86/spectre_v2: Don't check microcode versions when running under hypervisors tip-bot for Konrad Rzeszutek Wilk
2018-04-17 10:40 ` [PATCH] KVM: X86: Allow userspace to define the microcode version Wanpeng Li
2018-04-17 20:24 ` Eduardo Habkost
2018-04-18 3:24 ` Wanpeng Li
2018-04-18 9:03 ` Eduardo Habkost
2018-04-18 10:36 ` Paolo Bonzini
2018-04-23 12:58 ` Borislav Petkov
2018-04-23 13:08 ` Eduardo Habkost
2018-04-23 13:23 ` Borislav Petkov
2018-04-23 16:03 ` Paolo Bonzini
2018-04-24 2:59 ` Wanpeng Li
2018-04-24 3:14 ` Konrad Rzeszutek Wilk
2018-04-24 5:09 ` Paolo Bonzini
2018-04-24 13:44 ` Konrad Rzeszutek Wilk
2018-04-24 2:56 ` Wanpeng Li
2018-02-26 11:47 ` Paolo Bonzini
2018-02-26 12:20 ` Borislav Petkov
2018-02-26 9:26 Liran Alon
2018-02-26 10:08 ` Wanpeng Li
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