From: Paolo Bonzini <pbonzini@redhat.com>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: "Borislav Petkov" <bp@alien8.de>, "Jörg Rödel" <joro@8bytes.org>,
"Andre Przywara" <andre.przywara@arm.com>,
"kvm ML" <kvm@vger.kernel.org>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: kvm: RDTSCP on AMD
Date: Wed, 6 Jul 2016 23:27:16 +0200 [thread overview]
Message-ID: <0b830bbe-182a-3bd3-bab0-0c2fd823edd4@redhat.com> (raw)
In-Reply-To: <20160706173440.GU4131@thinpad.lan.raisama.net>
On 06/07/2016 19:34, Eduardo Habkost wrote:
>> > Nothing is needed in the kernel actually. You can skip the intercept
>> > by running the guest with MSR_TSC_AUX set to the guest's expected value.
>> > Which KVM does, except that it's botched so I need to apply the
>> > patch in https://lkml.org/lkml/2016/4/13/802.
> Do you mean -cpu Opteron_G*,+rdtscp will be buggy on Linux v4.5?
> (v4.5 reports rdtscp as supported in GET_SUPPORTED_CPUID)
>
> Can we do something to make QEMU detect the buggy kernel before
> allowing rdtscp to be enabled, or should we just tell people to
> upgrade their kernel?
We usually just tell people to use the latest stable kernel.
Adding new CPU models is not a big deal, in fact it's almost easier than
getting compat properties right. :)
Paolo
next prev parent reply other threads:[~2016-07-06 21:27 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-06 12:44 kvm: RDTSCP on AMD Borislav Petkov
2016-07-06 13:01 ` Paolo Bonzini
2016-07-06 17:34 ` Eduardo Habkost
2016-07-06 21:27 ` Paolo Bonzini [this message]
2018-12-10 18:13 Borislav Petkov
2018-12-10 18:37 ` Eduardo Habkost
2018-12-10 18:41 ` Borislav Petkov
2018-12-10 19:06 ` Eduardo Habkost
2018-12-10 19:42 ` Borislav Petkov
2018-12-10 20:08 ` Eduardo Habkost
2018-12-10 20:39 ` Borislav Petkov
2018-12-11 10:38 ` Daniel P. Berrangé
2018-12-11 11:55 ` Eduardo Habkost
2018-12-11 14:35 ` Daniel P. Berrangé
2018-12-11 15:23 ` Paolo Bonzini
2018-12-11 15:30 ` Daniel P. Berrangé
2018-12-10 19:47 ` Eduardo Habkost
2018-12-10 20:16 ` Borislav Petkov
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