From: Avi Kivity <avi@redhat.com>
To: "Han, Weidong" <weidong.han@intel.com>
Cc: kvm@vger.kernel.org, Amit Shah <amit.shah@redhat.com>,
"Kay, Allen M" <allen.m.kay@intel.com>,
benami@il.ibm.com
Subject: Re: [PATCH] VT-d: Fix iommu map page for mmio pages
Date: Thu, 25 Sep 2008 16:58:21 +0300 [thread overview]
Message-ID: <48DB98FD.3000307@redhat.com> (raw)
In-Reply-To: <0122C7C995D32147B66BF4F440D3016301C7D0EB@pdsmsx415.ccr.corp.intel.com>
Han, Weidong wrote:
> Avi Kivity wrote:
>
>> Han, Weidong wrote:
>>
>>> Don't need to map mmio pages for iommu. When find mmio pages in
>>> kvm_iommu_map_pages(), don't map them, and shouldn't return error
>>> due to it's not an error. If return error (such as -EINVAL), device
>>> assigment will fail.
>>>
>>>
>>>
>> I don't understand. Why don't we need to map mmio pages? We
>> certainly don't want them emulated.
>>
>
> mmio pages need not to be mapped in VT-d page table, which only
> translate DMA addresses.
Right, I forgot the iommu is only for dma, not cpu accesses.
I suppose one could DMA into an mmio page. Is there a reason not to map?
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2008-09-25 14:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-19 7:15 [PATCH] VT-d: Fix iommu map page for mmio pages Han, Weidong
2008-09-25 10:27 ` Avi Kivity
2008-09-25 13:44 ` Han, Weidong
2008-09-25 13:58 ` Avi Kivity [this message]
2008-09-25 14:07 ` Han, Weidong
2008-09-25 14:45 ` Avi Kivity
2008-09-25 15:04 ` Anthony Liguori
2008-09-25 15:19 ` Han, Weidong
2008-09-25 21:14 ` Muli Ben-Yehuda
2008-09-25 21:51 ` Anthony Liguori
2008-09-26 23:57 ` Muli Ben-Yehuda
2008-09-27 10:24 ` Avi Kivity
2008-09-28 6:07 ` Muli Ben-Yehuda
2008-09-28 8:45 ` Avi Kivity
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