On Tue, Jan 15, 2019 at 02:20:19PM +0100, Christoph Hellwig wrote:
> On Tue, Jan 15, 2019 at 09:37:42AM +0100, Joerg Roedel wrote:
> > On Mon, Jan 14, 2019 at 01:20:45PM -0500, Michael S. Tsirkin wrote:
> > > Which would be fine especially if we can manage not to introduce a bunch
> > > of
On Mon, Jan 14, 2019 at 01:20:45PM -0500, Michael S. Tsirkin wrote:
> Which would be fine especially if we can manage not to introduce a bunch
> of indirect calls all over the place and hurt performance.
Which indirect calls? In case of unset dma_ops the DMA-API functions
call directly into the
On Mon, Jan 14, 2019 at 09:19:35PM +0100, Christoph Hellwig wrote:
> > Christoph is saying that !IOMMU_PLATFORM devices should hide the
> > compatibility code in a special per-device DMA API implementation.
> > Which would be fine especially if we can manage not to introduce a bunch
> > of
On Mon, Jan 14, 2019 at 07:12:08PM +, Robin Murphy wrote:
> On 14/01/2019 18:20, Michael S. Tsirkin wrote:
> > On Mon, Jan 14, 2019 at 08:41:37PM +0800, Jason Wang wrote:
> > >
> > > On 2019/1/14 下午5:50, Christoph Hellwig wrote:
> > > > On Mon, Jan 14, 2019 at 05:41:56PM +0800, Jason Wang
On Mon, Jan 14, 2019 at 07:12:08PM +, Robin Murphy wrote:
> Now, in theory, yes, the real issue at hand is not unique to virtio-blk nor
> SEV - any driver whose device has a sufficiently large DMA segment size and
> who manages to get sufficient physically-contiguous memory could
>
On Mon, Jan 14, 2019 at 01:20:45PM -0500, Michael S. Tsirkin wrote:
> I don't think so - the issue is really that DMA API does not yet handle
> the SEV case 100% correctly. I suspect passthrough devices would have
> the same issue.
The DMA API handles the SEV case perfectly. Its just that
On 1/14/19 12:20 PM, Michael S. Tsirkin wrote:
> On Mon, Jan 14, 2019 at 08:41:37PM +0800, Jason Wang wrote:
>>
>> On 2019/1/14 下午5:50, Christoph Hellwig wrote:
>>> On Mon, Jan 14, 2019 at 05:41:56PM +0800, Jason Wang wrote:
On 2019/1/11 下午5:15, Joerg Roedel wrote:
> On Fri, Jan 11,
On Mon, Jan 14, 2019 at 08:41:37PM +0800, Jason Wang wrote:
>
> On 2019/1/14 下午5:50, Christoph Hellwig wrote:
> > On Mon, Jan 14, 2019 at 05:41:56PM +0800, Jason Wang wrote:
> > > On 2019/1/11 下午5:15, Joerg Roedel wrote:
> > > > On Fri, Jan 11, 2019 at 11:29:31AM +0800, Jason Wang wrote:
> > > >
On Mon, Jan 14, 2019 at 05:41:56PM +0800, Jason Wang wrote:
>
> On 2019/1/11 下午5:15, Joerg Roedel wrote:
>> On Fri, Jan 11, 2019 at 11:29:31AM +0800, Jason Wang wrote:
>>> Just wonder if my understanding is correct IOMMU_PLATFORM must be set for
>>> all virtio devices under AMD-SEV guests?
>> Yes,
On 2019/1/11 下午5:15, Joerg Roedel wrote:
On Fri, Jan 11, 2019 at 11:29:31AM +0800, Jason Wang wrote:
Just wonder if my understanding is correct IOMMU_PLATFORM must be set for
all virtio devices under AMD-SEV guests?
Yes, that is correct. Emulated DMA can only happen on the SWIOTLB
aperture,
On Fri, Jan 11, 2019 at 11:29:31AM +0800, Jason Wang wrote:
> Just wonder if my understanding is correct IOMMU_PLATFORM must be set for
> all virtio devices under AMD-SEV guests?
Yes, that is correct. Emulated DMA can only happen on the SWIOTLB
aperture, because that memory is not encrypted. The
On 2019/1/10 下午9:44, Joerg Roedel wrote:
Hi,
there is a problem with virtio-blk driven devices when
virtio-ring uses SWIOTLB through the DMA-API. This happens
for example in AMD-SEV enabled guests, where the guest RAM
is mostly encrypted and all emulated DMA has to happen
to/from the SWIOTLB
Hi Christoph,
On Thu, Jan 10, 2019 at 02:59:52PM +0100, Christoph Hellwig wrote:
> On Thu, Jan 10, 2019 at 02:44:30PM +0100, Joerg Roedel wrote:
> > The problem is a limitation of the SWIOTLB implementation,
> > which does not support allocations larger than 256kb. When
> > the virtio-blk driver
On Thu, Jan 10, 2019 at 02:44:30PM +0100, Joerg Roedel wrote:
> Hi,
>
> there is a problem with virtio-blk driven devices when
> virtio-ring uses SWIOTLB through the DMA-API. This happens
> for example in AMD-SEV enabled guests, where the guest RAM
> is mostly encrypted and all emulated DMA has
Hi,
there is a problem with virtio-blk driven devices when
virtio-ring uses SWIOTLB through the DMA-API. This happens
for example in AMD-SEV enabled guests, where the guest RAM
is mostly encrypted and all emulated DMA has to happen
to/from the SWIOTLB aperture.
The problem is a limitation of the
15 matches
Mail list logo
