linux-kernel - Re: [PATCH] KVM: X86: Allow userspace to define the microcode version

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 24 Apr 2018 10:56:46 +0800
From:   Wanpeng Li <kernellwp@...il.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Borislav Petkov <bp@...en8.de>,
        LKML <linux-kernel@...r.kernel.org>, kvm <kvm@...r.kernel.org>,
        Radim Krčmář <rkrcmar@...hat.com>
Subject: Re: [PATCH] KVM: X86: Allow userspace to define the microcode version

2018-02-26 20:41 GMT+08:00 Paolo Bonzini <pbonzini@...hat.com>:
> On 26/02/2018 13:22, Borislav Petkov wrote:
>> On Mon, Feb 26, 2018 at 01:18:07PM +0100, Paolo Bonzini wrote:
>>>> In this context, "host-initiated" write means written by KVM userspace
>>>> with ioctl(KVM_SET_MSR).  It generally happens only on VM startup, reset
>>>> or live migration.
>>>
>>> To be clear, the target of the write is still the vCPU's emulated MSR.
>>
>> So how am I to imagine this as a user:
>>
>> qemu-system-x86_64 --microcode-revision=0xdeadbeef...
>
> More like "-cpu foo,ucode_rev=0xdeadbeef".  But in practice what would
> happen is one of the following:
>
> 1) "-cpu host" sets ucode_rev to the same value of the host, everyone

I found vmware on my macbook will also do this. :)

Regards,
Wanpeng Li