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From: Vincent Bernat <vincent@bernat.im>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>,
	Richard Henderson <rth@twiddle.net>,
	qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] target-i386: add pcid to both Sandy Bridge and Ivy Bridge
Date: Tue, 09 Jan 2018 07:40:26 +0100	[thread overview]
Message-ID: <m34lnva61x.fsf@luffy.cx> (raw)
In-Reply-To: <242287261.31733448.1515451036017.JavaMail.zimbra@redhat.com> (Paolo Bonzini's message of "Mon, 8 Jan 2018 17:37:16 -0500 (EST)")

 ❦  8 janvier 2018 17:37 -0500, Paolo Bonzini <pbonzini@redhat.com> :

>> One possible way to work around this problem is to declare that
>> QEMU 2.12 with KVM will require Linux v3.6 and newer (because we
>> need Linux kernel commit ad756a1603c5 "KVM: VMX: Implement
>> PCID/INVPCID for guests with EPT").
>
> Note that PCID is still not supported for guests without EPT, so
> this would break ept=0 with recent "-cpu" models.  I'm not sure of
> a way to fix it; probably it just has to be documented.

>From the above patch, it seems only INVPCID needs EPT. KVM exposes PCID
whenever it is present on the host.
-- 
When you are about to die, a wombat is better than no company at all.
		-- Roger Zelazny, "Doorways in the Sand"

      parent reply	other threads:[~2018-01-09  6:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-08 20:50 [Qemu-devel] [PATCH] target-i386: add pcid to both Sandy Bridge and Ivy Bridge Vincent Bernat
2018-01-08 21:16 ` Eduardo Habkost
2018-01-08 21:51   ` Vincent Bernat
2018-01-08 22:14     ` Eduardo Habkost
2018-01-08 22:22       ` Vincent Bernat
2018-01-08 22:28         ` Eduardo Habkost
2018-01-08 22:37   ` Paolo Bonzini
2018-01-08 22:56     ` Eduardo Habkost
2018-01-08 23:09       ` Paolo Bonzini
2018-01-08 23:19         ` Eduardo Habkost
2018-01-09  7:04           ` Vincent Bernat
2018-01-09  6:41       ` Vincent Bernat
2018-01-09  6:40     ` Vincent Bernat [this message]

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