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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 18:06:42 +0800	[thread overview]
Message-ID: <CANRm+CzODxLQ4UHgFCnpjABmBUvi9sbw=uyO1xk1dyWgnH86ig@mail.gmail.com> (raw)
In-Reply-To: <20180226094148.GA15539@pd.tnic>

2018-02-26 17:41 GMT+08:00 Borislav Petkov <bp@alien8.de>:
> On Mon, Feb 26, 2018 at 03:23:58PM +0800, Wanpeng Li wrote:
>> From: Wanpeng Li <wanpengli@tencent.com>
>>
>> Linux (among the others) has checks to make sure that certain features
>> aren't enabled on a certain family/model/stepping if the microcode version
>> isn't greater than or equal to a known good version.
>>
>> By exposing the real microcode version, we're preventing buggy guests that
>
> Where do we prevent userspace from coming up with some non-sensical
> microcode revision?

I think it is the host admin(e.g. cloud provider)'s responsibility to
set an expected microcode revision. In addition, the non-sensical
value which is written by the guest will not reflect to guest-visible
microcode revision and just be ignored in this implementation.

Regards,
Wanpeng Li

  reply	other threads:[~2018-02-26 10:06 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 [this message]
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
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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