From: Borislav Petkov <bp@alien8.de>
To: Dimitri John Ledkov <dimitri.ledkov@canonical.com>,
Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] x86/bugs: Do not enable IBPB at firmware entry when IBPB is not available
Date: Thu, 28 Jul 2022 17:18:31 +0200 [thread overview]
Message-ID: <YuKoxyUdAWsTfKez@zn.tnic> (raw)
In-Reply-To: <CADWks+aosM99jv9WwLvFo3LPEnsqts+2bJPzMnRqJX70qz51cg@mail.gmail.com>
On Thu, Jul 28, 2022 at 03:33:35PM +0100, Dimitri John Ledkov wrote:
> Azure public cloud (so it is Azure custom hyper-v hypervisor) these
> instance types https://docs.microsoft.com/en-us/azure/virtual-machines/dav4-dasv4-series
Thank you both for the info.
Virt is an awful piece of sh*t when it goes and emulates all kinds of
imaginary CPUs. And AMD machine *without* an IBPB which is affected by
retbleed. Well, f*ck that.
Does that say somewhere on azure that those guests need to even enable
the mitigation or does the HV mitigate it for them?
Because I wouldn't mind to simply disable the mitigation when on a
hypervisor which doesn't support IBPB.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-07-28 15:18 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-28 12:26 [PATCH] x86/bugs: Do not enable IBPB at firmware entry when IBPB is not available Thadeu Lima de Souza Cascardo
2022-07-28 12:35 ` Borislav Petkov
2022-07-28 12:39 ` Thadeu Lima de Souza Cascardo
2022-07-28 14:33 ` Dimitri John Ledkov
2022-07-28 15:18 ` Borislav Petkov [this message]
2022-07-28 15:50 ` Borislav Petkov
2022-07-28 17:01 ` Thadeu Lima de Souza Cascardo
2022-07-29 18:22 ` Borislav Petkov
2022-07-28 15:16 ` Peter Zijlstra
2022-07-29 8:11 ` [tip: x86/urgent] " tip-bot2 for Thadeu Lima de Souza Cascardo
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