Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-09-05 Thread Michael S. Tsirkin
On Mon, Aug 12, 2019 at 02:15:32PM +0200, Christoph Hellwig wrote: > On Sun, Aug 11, 2019 at 04:55:27AM -0400, Michael S. Tsirkin wrote: > > On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > > > So we need a flag on the virtio device, exposed by the > > > hypervisor (or hardware

RE: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-26 Thread Ram Pai
On Tue, Aug 13, 2019 at 08:45:37AM -0700, Ram Pai wrote: > On Wed, Aug 14, 2019 at 12:24:39AM +1000, David Gibson wrote: > > On Tue, Aug 13, 2019 at 03:26:17PM +0200, Christoph Hellwig wrote: > > > On Mon, Aug 12, 2019 at 07:51:56PM +1000, David Gibson wrote: > > > > AFAICT we already kind of

RE: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-13 Thread Ram Pai
On Wed, Aug 14, 2019 at 12:24:39AM +1000, David Gibson wrote: > On Tue, Aug 13, 2019 at 03:26:17PM +0200, Christoph Hellwig wrote: > > On Mon, Aug 12, 2019 at 07:51:56PM +1000, David Gibson wrote: > > > AFAICT we already kind of abuse this for the VIRTIO_F_IOMMU_PLATFORM, > > > because to handle

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-13 Thread David Gibson
On Tue, Aug 13, 2019 at 03:26:17PM +0200, Christoph Hellwig wrote: > On Mon, Aug 12, 2019 at 07:51:56PM +1000, David Gibson wrote: > > AFAICT we already kind of abuse this for the VIRTIO_F_IOMMU_PLATFORM, > > because to handle for cases where it *is* a device limitation, we > > assume that if the

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-13 Thread Christoph Hellwig
On Mon, Aug 12, 2019 at 07:51:56PM +1000, David Gibson wrote: > AFAICT we already kind of abuse this for the VIRTIO_F_IOMMU_PLATFORM, > because to handle for cases where it *is* a device limitation, we > assume that if the hypervisor presents VIRTIO_F_IOMMU_PLATFORM then > the guest *must* select

RE: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-12 Thread Ram Pai
On Mon, Aug 12, 2019 at 02:13:24PM +0200, Christoph Hellwig wrote: > On Sat, Aug 10, 2019 at 11:46:21PM -0700, Ram Pai wrote: > > If the hypervisor (hardware for hw virtio devices) does not mandate a > > DMA API, why is it illegal for the driver to request, special handling > > of its i/o buffers?

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-12 Thread David Gibson
On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > sev_active() is gone now in linux-next, at least as a global API. > > And once again this is entirely going in the wrong direction. The only > way using the DMA API is going to work at all is if the device is ready > for it.

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-12 Thread Christoph Hellwig
On Sun, Aug 11, 2019 at 04:55:27AM -0400, Michael S. Tsirkin wrote: > On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > > So we need a flag on the virtio device, exposed by the > > hypervisor (or hardware for hw virtio devices) that says: hey, I'm real, > > don't take a

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-12 Thread Christoph Hellwig
On Sat, Aug 10, 2019 at 11:46:21PM -0700, Ram Pai wrote: > If the hypervisor (hardware for hw virtio devices) does not mandate a > DMA API, why is it illegal for the driver to request, special handling > of its i/o buffers? Why are we associating this special handling to > always mean, some DMA

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-11 Thread Michael S. Tsirkin
On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > So we need a flag on the virtio device, exposed by the > hypervisor (or hardware for hw virtio devices) that says: hey, I'm real, > don't take a shortcut. The point here is that it's actually still not real. So we would still

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-11 Thread Michael S. Tsirkin
On Sat, Aug 10, 2019 at 11:46:21PM -0700, Ram Pai wrote: > On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > > sev_active() is gone now in linux-next, at least as a global API. > > > > And once again this is entirely going in the wrong direction. The only > > way using the DMA

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-11 Thread Michael S. Tsirkin
On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > And once again this is entirely going in the wrong direction. The only > way using the DMA API is going to work at all is if the device is ready > for it. So the point made is that if DMA addresses are also physical addresses

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-11 Thread Michael S. Tsirkin
do you think? > > > > > > >From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 > > > From: Thiago Jung Bauermann > > > Date: Thu, 24 Jan 2019 22:08:02 -0200 > > > Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encr

RE: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-11 Thread Ram Pai
On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > sev_active() is gone now in linux-next, at least as a global API. > > And once again this is entirely going in the wrong direction. The only > way using the DMA API is going to work at all is if the device is ready > for it.

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-10 Thread Christoph Hellwig
sev_active() is gone now in linux-next, at least as a global API. And once again this is entirely going in the wrong direction. The only way using the DMA API is going to work at all is if the device is ready for it. So we need a flag on the virtio device, exposed by the hypervisor (or hardware

RE: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-10 Thread Ram Pai
; > Of course, I also have patches (soon to be posted as RFC) which hook up > > to the powerpc secure guest support code. > > > > What do you think? > > > > >From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 > > From: Thiago Jung Baue

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-08-10 Thread Michael S. Tsirkin
ode. > > What do you think? > > >From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 > From: Thiago Jung Bauermann > Date: Thu, 24 Jan 2019 22:08:02 -0200 > Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted > > The host can't access

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-17 Thread Thiago Jung Bauermann
Hello, Just going back to this question which I wasn't able to answer. Thiago Jung Bauermann writes: > Michael S. Tsirkin writes: > >> So far so good, but now a question: >> >> how are we handling guest address width limitations? >> Is VIRTIO_F_ACCESS_PLATFORM_IDENTITY_ADDRESS subject to >>

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-15 Thread Benjamin Herrenschmidt
On Mon, 2019-07-15 at 19:03 -0300, Thiago Jung Bauermann wrote: > > > Indeed. The idea is that QEMU can offer the flag, old guests can > > > reject > > > it (or even new guests can reject it, if they decide not to > > > convert into > > > secure VMs) and the feature negotiation will succeed with

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-15 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Mon, Jul 15, 2019 at 07:03:03PM -0300, Thiago Jung Bauermann wrote: >> >> Michael S. Tsirkin writes: >> >> > On Mon, Jul 15, 2019 at 05:29:06PM -0300, Thiago Jung Bauermann wrote: >> >> >> >> Michael S. Tsirkin writes: >> >> >> >> > On Sun, Jul 14, 2019 at

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-15 Thread Michael S. Tsirkin
On Mon, Jul 15, 2019 at 07:03:03PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: > > > On Mon, Jul 15, 2019 at 05:29:06PM -0300, Thiago Jung Bauermann wrote: > >> > >> Michael S. Tsirkin writes: > >> > >> > On Sun, Jul 14, 2019 at 02:51:18AM -0300, Thiago Jung Bauermann

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-15 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Mon, Jul 15, 2019 at 05:29:06PM -0300, Thiago Jung Bauermann wrote: >> >> Michael S. Tsirkin writes: >> >> > On Sun, Jul 14, 2019 at 02:51:18AM -0300, Thiago Jung Bauermann wrote: >> >> >> >> >> >> Michael S. Tsirkin writes: >> >> >> >> > So this is what I

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-15 Thread Michael S. Tsirkin
On Mon, Jul 15, 2019 at 05:29:06PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: > > > On Sun, Jul 14, 2019 at 02:51:18AM -0300, Thiago Jung Bauermann wrote: > >> > >> > >> Michael S. Tsirkin writes: > >> > >> > So this is what I would call this option: > >> > > >> >

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-15 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Sun, Jul 14, 2019 at 02:51:18AM -0300, Thiago Jung Bauermann wrote: >> >> >> Michael S. Tsirkin writes: >> >> > So this is what I would call this option: >> > >> > VIRTIO_F_ACCESS_PLATFORM_IDENTITY_ADDRESS >> > >> > and the explanation should state that all

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-15 Thread Michael S. Tsirkin
On Sun, Jul 14, 2019 at 02:51:18AM -0300, Thiago Jung Bauermann wrote: > > > Michael S. Tsirkin writes: > > > On Thu, Jun 27, 2019 at 10:58:40PM -0300, Thiago Jung Bauermann wrote: > >> > >> Michael S. Tsirkin writes: > >> > >> > On Mon, Jun 03, 2019 at 10:13:59PM -0300, Thiago Jung Bauermann

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-14 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Thu, Jun 27, 2019 at 10:58:40PM -0300, Thiago Jung Bauermann wrote: >> >> Michael S. Tsirkin writes: >> >> > On Mon, Jun 03, 2019 at 10:13:59PM -0300, Thiago Jung Bauermann wrote: >> >> >> >> >> >> Michael S. Tsirkin writes: >> >> >> >> > On Wed, Apr 17, 2019

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-07-01 Thread Michael S. Tsirkin
On Thu, Jun 27, 2019 at 10:58:40PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: > > > On Mon, Jun 03, 2019 at 10:13:59PM -0300, Thiago Jung Bauermann wrote: > >> > >> > >> Michael S. Tsirkin writes: > >> > >> > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-06-27 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Mon, Jun 03, 2019 at 10:13:59PM -0300, Thiago Jung Bauermann wrote: >> >> >> Michael S. Tsirkin writes: >> >> > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: >> >> I rephrased it in terms of address translation. What do you think of >>

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-06-03 Thread Michael S. Tsirkin
On Mon, Jun 03, 2019 at 10:13:59PM -0300, Thiago Jung Bauermann wrote: > > > Michael S. Tsirkin writes: > > > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: > >> I rephrased it in terms of address translation. What do you think of > >> this version? The flag name is

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-06-03 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: >> I rephrased it in terms of address translation. What do you think of >> this version? The flag name is slightly different too: >> >> >> VIRTIO_F_ACCESS_PLATFORM_NO_TRANSLATION This feature

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-05-20 Thread Michael S. Tsirkin
On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: > I rephrased it in terms of address translation. What do you think of > this version? The flag name is slightly different too: > > > VIRTIO_F_ACCESS_PLATFORM_NO_TRANSLATION This feature has the same > meaning as

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-05-20 Thread Michael S. Tsirkin
On Fri, Apr 26, 2019 at 08:56:43PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: > > > On Wed, Apr 24, 2019 at 10:01:56PM -0300, Thiago Jung Bauermann wrote: > >> > >> Michael S. Tsirkin writes: > >> > >> > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-26 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Wed, Apr 24, 2019 at 10:01:56PM -0300, Thiago Jung Bauermann wrote: >> >> Michael S. Tsirkin writes: >> >> > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: >> >> >> >> Michael S. Tsirkin writes: >> >> >> >> > On Thu, Mar 21, 2019 at

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-24 Thread Michael S. Tsirkin
On Wed, Apr 24, 2019 at 10:01:56PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: > > > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: > >> > >> Michael S. Tsirkin writes: > >> > >> > On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-24 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: >> >> Michael S. Tsirkin writes: >> >> > On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann wrote: >> >> >> >> Michael S. Tsirkin writes: >> >> >> >> > On Wed, Mar 20, 2019 at

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-19 Thread Thiago Jung Bauermann
think? >> > >> > From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 >> > From: Thiago Jung Bauermann >> > Date: Thu, 24 Jan 2019 22:08:02 -0200 >> > Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted &

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-19 Thread Thiago Jung Bauermann
Christoph Hellwig writes: > On Tue, Jan 29, 2019 at 09:36:08PM -0500, Michael S. Tsirkin wrote: >> This has been discussed ad nauseum. virtio is all about compatibility. >> Losing a couple of lines of code isn't worth breaking working setups. >> People that want "just use DMA API no tricks"

[RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-19 Thread Thiago Jung Bauermann
Jan 2019 22:08:02 -0200 Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted The host can't access the guest memory when it's encrypted, so using regular memory pages for the ring isn't an option. Go through the DMA API. Signed-off-by: Thiago Jung Bauermann --- drivers/vir

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-19 Thread Thiago Jung Bauermann
ode. > > What do you think? > > From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 > From: Thiago Jung Bauermann > Date: Thu, 24 Jan 2019 22:08:02 -0200 > Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted > > The host can't access the gu

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-19 Thread Michael S. Tsirkin
On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: > > > On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann wrote: > >> > >> Michael S. Tsirkin writes: > >> > >> > On Wed, Mar 20, 2019 at 01:13:41PM -0300, Thiago Jung Bauermann

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-17 Thread Thiago Jung Bauermann
David Gibson writes: > On Sat, Mar 23, 2019 at 05:01:35PM -0400, Michael S. Tsirkin wrote: >> On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann wrote: >> > Michael S. Tsirkin writes: > [snip] >> > >> > Is there any justification to doing that beyond someone putting >> > >> > out

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-04-17 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann wrote: >> >> Michael S. Tsirkin writes: >> >> > On Wed, Mar 20, 2019 at 01:13:41PM -0300, Thiago Jung Bauermann wrote: >> >> >From what I understand of the ACCESS_PLATFORM definition, the host will >>

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-03-26 Thread Michael S. Tsirkin
On Wed, Jan 30, 2019 at 08:44:27AM +0100, Christoph Hellwig wrote: > On Tue, Jan 29, 2019 at 09:36:08PM -0500, Michael S. Tsirkin wrote: > > This has been discussed ad nauseum. virtio is all about compatibility. > > Losing a couple of lines of code isn't worth breaking working setups. > > People

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-03-24 Thread David Gibson
On Sat, Mar 23, 2019 at 05:01:35PM -0400, Michael S. Tsirkin wrote: > On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: [snip] > > >> > Is there any justification to doing that beyond someone putting > > >> > out slow code in the past? > > >> >

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-03-23 Thread Michael S. Tsirkin
On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann wrote: > > Michael S. Tsirkin writes: > > > On Wed, Mar 20, 2019 at 01:13:41PM -0300, Thiago Jung Bauermann wrote: > >> >> Another way of looking at this issue which also explains our reluctance > >> >> is that the only difference

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-03-21 Thread Thiago Jung Bauermann
Michael S. Tsirkin writes: > On Wed, Mar 20, 2019 at 01:13:41PM -0300, Thiago Jung Bauermann wrote: >> >> Another way of looking at this issue which also explains our reluctance >> >> is that the only difference between a secure guest and a regular guest >> >> (at least regarding virtio) is

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-03-20 Thread Michael S. Tsirkin
On Wed, Mar 20, 2019 at 01:13:41PM -0300, Thiago Jung Bauermann wrote: > >> Another way of looking at this issue which also explains our reluctance > >> is that the only difference between a secure guest and a regular guest > >> (at least regarding virtio) is that the former uses swiotlb while the

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-03-20 Thread Thiago Jung Bauermann
Hello Michael, Sorry for the delay in responding. We had some internal discussions on this. Michael S. Tsirkin writes: > On Mon, Feb 04, 2019 at 04:14:20PM -0200, Thiago Jung Bauermann wrote: >> >> Hello Michael, >> >> Michael S. Tsirkin writes: >> >> > On Tue, Jan 29, 2019 at 03:42:44PM

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-02-05 Thread Michael S. Tsirkin
On Tue, Feb 05, 2019 at 08:24:07AM +0100, Christoph Hellwig wrote: > On Mon, Feb 04, 2019 at 04:38:21PM -0500, Michael S. Tsirkin wrote: > > It was designed to make, when set, as many guests as we can work > > correctly, and it seems to be successful in doing exactly that. > > > > Unfortunately

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-02-05 Thread Christoph Hellwig
On Mon, Feb 04, 2019 at 04:38:21PM -0500, Michael S. Tsirkin wrote: > It was designed to make, when set, as many guests as we can work > correctly, and it seems to be successful in doing exactly that. > > Unfortunately there could be legacy guests that do work correctly but > become slow. Whether

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-02-04 Thread Michael S. Tsirkin
On Mon, Feb 04, 2019 at 04:15:41PM -0200, Thiago Jung Bauermann wrote: > > Christoph Hellwig writes: > > > On Tue, Jan 29, 2019 at 09:36:08PM -0500, Michael S. Tsirkin wrote: > >> This has been discussed ad nauseum. virtio is all about compatibility. > >> Losing a couple of lines of code isn't

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-02-04 Thread Michael S. Tsirkin
> > >> > Of course, I also have patches (soon to be posted as RFC) which hook up > >> > to the powerpc secure guest support code. > >> > > >> > What do you think? > >> > > >> > From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-01-30 Thread Christoph Hellwig
On Tue, Jan 29, 2019 at 09:36:08PM -0500, Michael S. Tsirkin wrote: > This has been discussed ad nauseum. virtio is all about compatibility. > Losing a couple of lines of code isn't worth breaking working setups. > People that want "just use DMA API no tricks" now have the option. > Setting a flag

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-01-29 Thread Michael S. Tsirkin
> > > > > > > > > > Of course, I also have patches (soon to be posted as RFC) which > > > > > > hook up > > > > > > to the powerpc secure guest support code. > > > > > > > > > > > > What do you thi

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-01-29 Thread Michael S. Tsirkin
f course, I also have patches (soon to be posted as RFC) which hook up > > > > to the powerpc secure guest support code. > > > > > > > > What do you think? > > > > > > > > From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-01-29 Thread Jason Wang
Jan 2019 22:08:02 -0200 Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted The host can't access the guest memory when it's encrypted, so using regular memory pages for the ring isn't an option. Go through the DMA API. Signed-off-by: Thiago Jung Bauermann Well I think

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-01-29 Thread Jason Wang
hook up to the powerpc secure guest support code. What do you think? From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Thu, 24 Jan 2019 22:08:02 -0200 Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted The host

Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

2019-01-29 Thread Michael S. Tsirkin
t; > > > Of course, I also have patches (soon to be posted as RFC) which hook up > > to the powerpc secure guest support code. > > > > What do you think? > > > > From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 > > From: Thiago