From: Avi Kivity <avi@redhat.com>
To: "Roedel, Joerg" <Joerg.Roedel@amd.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>,
Sheng Yang <sheng@linux.intel.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Yaozu (Eddie) Dong" <eddie.dong@intel.com>
Subject: Re: [PATCH v5] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices
Date: Tue, 29 Jun 2010 15:37:53 +0300 [thread overview]
Message-ID: <4C29E921.90304@redhat.com> (raw)
In-Reply-To: <20100629123232.GD1788@amd.com>
On 06/29/2010 03:32 PM, Roedel, Joerg wrote:
> On Tue, Jun 29, 2010 at 06:42:57AM -0400, Avi Kivity wrote:
>
>> On 06/29/2010 01:32 PM, Jan Kiszka wrote:
>>
>
>> Correctness is more important than performance. Since we don't know
>> whether the guest needs it or not, we have to enable it. The user may
>> disable it if he likes.
>>
> Can't this code only be enabled if VT-d hardware is detected that does
> not support the snoop force bit? So the user does not have to struggle
> with configuration options that are hard to understand for a
> non-developer.
>
>
It's already this way, that's why we test for
KVM_IOMMU_CACHE_COHERENCY. Jan wants an override for older hardware
which doesn't support a coherent iommu (the wbinvd ipi on task
migrations, on processors that don't support wbinvd exits, is
particularly expensive).
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2010-06-29 12:38 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-28 3:36 [PATCH v3] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices Sheng Yang
2010-06-28 3:56 ` Avi Kivity
2010-06-28 6:42 ` Sheng Yang
2010-06-28 6:56 ` Avi Kivity
2010-06-28 6:56 ` Sheng Yang
2010-06-28 7:08 ` Avi Kivity
2010-06-28 7:41 ` Sheng Yang
2010-06-28 8:07 ` Avi Kivity
2010-06-28 8:42 ` [PATCH v4] " Sheng Yang
2010-06-28 9:27 ` Avi Kivity
2010-06-28 9:31 ` Gleb Natapov
2010-06-28 9:35 ` Avi Kivity
2010-06-29 3:16 ` [PATCH v5] " Sheng Yang
2010-06-29 9:39 ` Avi Kivity
2010-06-29 10:32 ` Jan Kiszka
2010-06-29 10:42 ` Avi Kivity
2010-06-29 12:32 ` Roedel, Joerg
2010-06-29 12:37 ` Avi Kivity [this message]
2010-06-29 10:14 ` Roedel, Joerg
2010-06-29 10:44 ` Avi Kivity
2010-06-29 12:28 ` Roedel, Joerg
2010-06-29 12:35 ` Avi Kivity
2010-06-29 13:34 ` Roedel, Joerg
2010-06-29 13:25 ` Marcelo Tosatti
2010-06-29 13:28 ` Avi Kivity
2010-06-29 13:35 ` Marcelo Tosatti
2010-06-29 13:50 ` Avi Kivity
2010-06-29 14:31 ` Marcelo Tosatti
2010-06-28 7:30 ` [PATCH v3] " Dong, Eddie
2010-06-28 8:04 ` Avi Kivity
2010-06-28 8:16 ` Dong, Eddie
2010-06-28 8:45 ` Jan Kiszka
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