Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-06 Thread Michael S. Tsirkin
On Wed, Oct 06, 2021 at 12:13:14PM +0200, Cornelia Huck wrote: > On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > > > On Mon, Oct 04, 2021 at 05:50:44PM +0200, Cornelia Huck wrote: > >> On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > >> > >> > On Mon, Oct 04, 2021 at 04:33:21PM +0200,

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-06 Thread Cornelia Huck
On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > On Mon, Oct 04, 2021 at 05:50:44PM +0200, Cornelia Huck wrote: >> On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: >> >> > On Mon, Oct 04, 2021 at 04:33:21PM +0200, Cornelia Huck wrote: >> >> On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote:

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Cornelia Huck
On Tue, Oct 05 2021, Halil Pasic wrote: > On Tue, 05 Oct 2021 13:13:31 +0200 > Cornelia Huck wrote: >> Or am I misunderstanding what you're getting at? >> > > Probably. I'm talking about pre- "do transport specific legacy detection > in the device instead of looking at VERSION_1" you are

Re: [virtio-dev] Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Cornelia Huck
On Tue, Oct 05 2021, "Michael S. Tsirkin" wrote: > On Tue, Oct 05, 2021 at 01:17:51PM +0200, Halil Pasic wrote: >> On Mon, 4 Oct 2021 16:01:12 -0400 >> "Michael S. Tsirkin" wrote: >> >> > > >> > > Ok, so what about something like >> > > >> > > "If FEATURES_OK is not set, the driver MAY

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Halil Pasic
On Tue, 05 Oct 2021 13:13:31 +0200 Cornelia Huck wrote: > On Tue, Oct 05 2021, Halil Pasic wrote: > > > On Mon, 4 Oct 2021 05:07:13 -0400 > > "Michael S. Tsirkin" wrote: > >> Well we established that we can know. Here's an alternative explanation: > > > > > > I thin we established how

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Michael S. Tsirkin
On Tue, Oct 05, 2021 at 01:13:31PM +0200, Cornelia Huck wrote: > On Tue, Oct 05 2021, Halil Pasic wrote: > > > On Mon, 4 Oct 2021 05:07:13 -0400 > > "Michael S. Tsirkin" wrote: > >> Well we established that we can know. Here's an alternative explanation: > > > > > > I thin we established how

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Michael S. Tsirkin
On Tue, Oct 05, 2021 at 12:46:34PM +0200, Halil Pasic wrote: > On Tue, 5 Oct 2021 03:53:17 -0400 > "Michael S. Tsirkin" wrote: > > > > Wouldn't a call from transport code into virtio core > > > be more handy? What I have in mind is stuff like vhost-user and vdpa. My > > > understanding is, that

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Michael S. Tsirkin
On Tue, Oct 05, 2021 at 12:43:03PM +0200, Halil Pasic wrote: > On Mon, 4 Oct 2021 05:07:13 -0400 > "Michael S. Tsirkin" wrote: > > > On Mon, Oct 04, 2021 at 04:23:23AM +0200, Halil Pasic wrote: > > > On Sat, 2 Oct 2021 14:13:37 -0400 > > > "Michael S. Tsirkin" wrote: > > > > > > > > Anyone

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Cornelia Huck
On Tue, Oct 05 2021, Halil Pasic wrote: > On Mon, 4 Oct 2021 05:07:13 -0400 > "Michael S. Tsirkin" wrote: >> Well we established that we can know. Here's an alternative explanation: > > > I thin we established how this should be in the future, where a transport > specific mechanism is used to

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Halil Pasic
On Tue, 5 Oct 2021 03:53:17 -0400 "Michael S. Tsirkin" wrote: > > Wouldn't a call from transport code into virtio core > > be more handy? What I have in mind is stuff like vhost-user and vdpa. My > > understanding is, that for vhost setups where the config is outside qemu, > > we probably need a

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Halil Pasic
On Mon, 4 Oct 2021 05:07:13 -0400 "Michael S. Tsirkin" wrote: > On Mon, Oct 04, 2021 at 04:23:23AM +0200, Halil Pasic wrote: > > On Sat, 2 Oct 2021 14:13:37 -0400 > > "Michael S. Tsirkin" wrote: > > > > > > Anyone else have an idea? This is a nasty regression; we could revert > > > > the >

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Cornelia Huck
On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > On Mon, Oct 04, 2021 at 04:23:23AM +0200, Halil Pasic wrote: >> --8<- >> >> From: Halil Pasic >> Date: Thu, 30 Sep 2021 02:38:47 +0200 >> Subject: [PATCH] virtio: write back feature VERSION_1 before

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Michael S. Tsirkin
On Tue, Oct 05, 2021 at 09:25:39AM +0200, Halil Pasic wrote: > On Mon, 4 Oct 2021 09:11:04 -0400 > "Michael S. Tsirkin" wrote: > > > > >> static inline bool virtio_access_is_big_endian(VirtIODevice *vdev) > > > >> { > > > >> #if defined(LEGACY_VIRTIO_IS_BIENDIAN) > > > >> return

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-05 Thread Halil Pasic
On Mon, 4 Oct 2021 09:11:04 -0400 "Michael S. Tsirkin" wrote: > > >> static inline bool virtio_access_is_big_endian(VirtIODevice *vdev) > > >> { > > >> #if defined(LEGACY_VIRTIO_IS_BIENDIAN) > > >> return virtio_is_big_endian(vdev); > > >> #elif defined(TARGET_WORDS_BIGENDIAN) > > >> if

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-04 Thread Michael S. Tsirkin
On Mon, Oct 04, 2021 at 05:50:44PM +0200, Cornelia Huck wrote: > On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > > > On Mon, Oct 04, 2021 at 04:33:21PM +0200, Cornelia Huck wrote: > >> On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > >> > >> > On Mon, Oct 04, 2021 at 02:19:55PM +0200,

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-04 Thread Cornelia Huck
On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > On Mon, Oct 04, 2021 at 04:33:21PM +0200, Cornelia Huck wrote: >> On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: >> >> > On Mon, Oct 04, 2021 at 02:19:55PM +0200, Cornelia Huck wrote: >> >> >> >> [cc:qemu-devel] >> >> >> >> On Sat, Oct 02

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-04 Thread Michael S. Tsirkin
On Mon, Oct 04, 2021 at 04:33:21PM +0200, Cornelia Huck wrote: > On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > > > On Mon, Oct 04, 2021 at 02:19:55PM +0200, Cornelia Huck wrote: > >> > >> [cc:qemu-devel] > >> > >> On Sat, Oct 02 2021, "Michael S. Tsirkin" wrote: > >> > >> > On Fri, Oct

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-04 Thread Cornelia Huck
On Mon, Oct 04 2021, "Michael S. Tsirkin" wrote: > On Mon, Oct 04, 2021 at 02:19:55PM +0200, Cornelia Huck wrote: >> >> [cc:qemu-devel] >> >> On Sat, Oct 02 2021, "Michael S. Tsirkin" wrote: >> >> > On Fri, Oct 01, 2021 at 09:21:25AM +0200, Halil Pasic wrote: >> >> On Thu, 30 Sep 2021

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-04 Thread Michael S. Tsirkin
On Mon, Oct 04, 2021 at 02:19:55PM +0200, Cornelia Huck wrote: > > [cc:qemu-devel] > > On Sat, Oct 02 2021, "Michael S. Tsirkin" wrote: > > > On Fri, Oct 01, 2021 at 09:21:25AM +0200, Halil Pasic wrote: > >> On Thu, 30 Sep 2021 07:12:21 -0400 > >> "Michael S. Tsirkin" wrote: > >> > >> > On

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-04 Thread Cornelia Huck
[cc:qemu-devel] On Sat, Oct 02 2021, "Michael S. Tsirkin" wrote: > On Fri, Oct 01, 2021 at 09:21:25AM +0200, Halil Pasic wrote: >> On Thu, 30 Sep 2021 07:12:21 -0400 >> "Michael S. Tsirkin" wrote: >> >> > On Thu, Sep 30, 2021 at 03:20:49AM +0200, Halil Pasic wrote: >> > > This patch fixes a

Re: [RFC PATCH 1/1] virtio: write back features before verify

2021-10-04 Thread Michael S. Tsirkin
On Mon, Oct 04, 2021 at 04:23:23AM +0200, Halil Pasic wrote: > On Sat, 2 Oct 2021 14:13:37 -0400 > "Michael S. Tsirkin" wrote: > > > > Anyone else have an idea? This is a nasty regression; we could revert the > > > patch, which would remove the symptoms and give us some time, but that > > >