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From: Christoph Egger <Christoph.Egger@amd.com>
To: Keir Fraser <keir@xen.org>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: [PATCH] nestedhvm: ASID emulation
Date: Fri, 15 Apr 2011 10:20:22 +0200	[thread overview]
Message-ID: <4DA7FFC6.3080702@amd.com> (raw)
In-Reply-To: <C9CCC6BD.2CA5F%keir@xen.org>

On 04/14/11 16:43, Keir Fraser wrote:
> On 14/04/2011 15:01, "Christoph Egger"<Christoph.Egger@amd.com>  wrote:
>
>>> What if some other vcpu's nv_n1asid or nv_n2asid got assigned the same HW
>>> asid in this generation as this vcpu's (now stale, as it's from a previous
>>> generation's) nv_n2asid? This PCPU can be interleaving execution of other
>>> HVM VCPUs after all.
>>
>> I am not sure if I got you right. You mean what if two vcpus run on one
>> physical cpu? In this case svm_do_resume() calls hvm_asid_flush_vcpu()
>> before so that asid_generation and core_asid_generation do not match and
>> a new asid is always assigned.
>
> No, it only does that if a given VCPU gets scheduled onto a *different* PCPU
> than last time it ran.
>
> I've attached a mostly rewritten version of your patch that is about half
> the size and I believe has a fighting chance of being correct (however it is
> only build tested). Give it a look and a spin.

Yes, it is correct. I like the idea to maintain a generation per asid.
Please apply it. Thanks for this work.

Christoph


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  reply	other threads:[~2011-04-15  8:20 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-13 10:37 [PATCH] nestedhvm: ASID emulation Christoph Egger
2011-04-13 13:27 ` Keir Fraser
2011-04-13 14:26   ` Christoph Egger
2011-04-13 15:05     ` Keir Fraser
2011-04-13 15:19       ` Christoph Egger
2011-04-13 16:22         ` Keir Fraser
2011-04-14  9:26           ` Christoph Egger
2011-04-14 10:28             ` Keir Fraser
2011-04-14 14:01               ` Christoph Egger
2011-04-14 14:43                 ` Keir Fraser
2011-04-15  8:20                   ` Christoph Egger [this message]
2011-04-15  9:05                     ` Keir Fraser
2011-04-15  9:08                       ` Christoph Egger
2011-04-15  9:24                         ` Keir Fraser
2011-04-15  9:57                           ` Christoph Egger
2011-04-15 12:53                             ` Keir Fraser
2011-04-15 12:49                               ` Christoph Egger
2011-04-15 13:40                               ` Christoph Egger
2011-04-13 13:51 ` Christoph Egger
2011-04-13 14:48   ` Christoph Egger
  -- strict thread matches above, loose matches on Subject: below --
2011-04-13  8:57 Christoph Egger
2011-04-13  9:18 ` Keir Fraser

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