Hi Dmitry, Thank you for the detailed explanation about your ideas on planes_layout and mem_layout. On Mon, Jan 13, 2020 at 6:50 PM Dmitry Sepp <dmitry.sepp@xxxxxxxxxxxxxxx> wrote: > > Hi Tomasz, > > On Samstag, 11. Januar 2020 17:06:46 CET Tomasz Figa wrote: > > On Sat, Jan 11, 2020 at 12:12 AM Dmitry Sepp > > > > <dmitry.sepp@xxxxxxxxxxxxxxx> wrote: > > > Hi Keiichi, > > > > > > On Freitag, 10. Januar 2020 14:53:01 CET Keiichi Watanabe wrote: > > > > Hi, > > > > > > > > On Fri, Jan 10, 2020 at 7:16 PM Dmitry Sepp > > > > <dmitry.sepp@xxxxxxxxxxxxxxx> > > > > > > wrote: > > > > > Hi, > > > > > > > > > > On Donnerstag, 9. Januar 2020 15:56:08 CET Dmitry Sepp wrote: > > > > > > Hi, > > > > > > > > > > > > On Dienstag, 7. Januar 2020 11:25:56 CET Keiichi Watanabe wrote: > > > > > > > Hi Dmitry, > > > > > > > > > > > > > > On Mon, Jan 6, 2020 at 8:28 PM Dmitry Sepp > > > > > > > <dmitry.sepp@xxxxxxxxxxxxxxx> > > > > > > > > > > > > wrote: > > > > > > > > Hi, > > > > > > > > > > > > > > > > On Montag, 6. Januar 2020 11:30:22 CET Keiichi Watanabe wrote: > > > > > > > > > Hi Dmitry, Tomasz, > > > > > > > > > > > > > > > > > > On Fri, Jan 3, 2020 at 10:05 PM Dmitry Sepp > > > > > > > > > <dmitry.sepp@xxxxxxxxxxxxxxx> > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > Hi Tomasz, Keiichi, > > > > > > > > > > > > > > > > > > > > On Samstag, 21. Dezember 2019 07:19:23 CET Tomasz Figa > wrote: > > > > > > > > > > > On Sat, Dec 21, 2019 at 3:18 PM Tomasz Figa > > > > > > > > > > > <tfiga@xxxxxxxxxxxx> > > > > > > > > > > > > wrote: > > > > > > > > > > > > On Sat, Dec 21, 2019 at 1:36 PM Keiichi Watanabe > > > > > > > > > > > > <keiichiw@xxxxxxxxxxxx> > > > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > Hi Dmitry, > > > > > > > > > > > > > > > > > > > > > > > > > > On Sat, Dec 21, 2019 at 12:59 AM Dmitry Sepp > > > > > > > > > > > > > > > > > > > > > > > > > > <dmitry.sepp@xxxxxxxxxxxxxxx> wrote: > > > > > > > > > > > > > > Hi Keiichi, > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Mittwoch, 18. Dezember 2019 14:02:13 CET Keiichi > > > > > > > > > > > > > > Watanabe > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > This is the 2nd version of virtio-video patch. The > > > > > > > > > > > > > > > PDF > > > > > > > > > > > > > > > is > > > > > > > > > > > > > > > available > > > > > > > > > > > > > > > in [1]. > > > > > > > > > > > > > > > The first version was sent at [2]. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Any feedback would be appreciated. Thank you. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Best, > > > > > > > > > > > > > > > Keiichi > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [1]: > > > > > > > > > > > > > > > https://drive.google.com/drive/folders/1eT5fEckBoo > > > > > > > > > > > > > > > r2iH > > > > > > > > > > > > > > > ZR4f > > > > > > > > > > > > > > > 4G > > > > > > > > > > > > > > > LxYz > > > > > > > > > > > > > > > FMVa > > > > > > > > > > > > > > > pOFx?us > > > > > > > > > > > > > > > p=sharing [2]: > > > > > > > > > > > > > > > https://markmail.org/message/gc6h25acct22niut > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Change log: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > v2: > > > > > > > > > > > > > > > * Removed functionalities except encoding and > > > > > > > > > > > > > > > decoding. > > > > > > > > > > > > > > > * Splited encoder and decoder into different > > > > > > > > > > > > > > > devices > > > > > > > > > > > > > > > that > > > > > > > > > > > > > > > use > > > > > > > > > > > > > > > the > > > > > > > > > > > > > > > same > > > > > > > > > > > > > > > protocol. * Replaced GET_FUNCS with > > > > > > > > > > > > > > > GET_CAPABILITY. > > > > > > > > > > > > > > > * Updated structs for capabilities. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - Defined new structs and enums such as image > > > > > > > > > > > > > > > formats, > > > > > > > > > > > > > > > profiles, > > > > > > > > > > > > > > > range > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > (min, max, step), etc > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > * For virtio_video_pixel_format, chose a > > > > > > > > > > > > > > > naming > > > > > > > > > > > > > > > convention > > > > > > > > > > > > > > > that > > > > > > > > > > > > > > > is used > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > in DRM. We removed XBGR, NV21 and I422, as > > > > > > > > > > > > > > > they > > > > > > > > > > > > > > > are > > > > > > > > > > > > > > > not > > > > > > > > > > > > > > > used > > > > > > > > > > > > > > > in the > > > > > > > > > > > > > > > current draft implementation. > > > > > > > > > > > > > > > https://lwn.net/Articles/806416/ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - Removed virtio_video_control, whose usage was > > > > > > > > > > > > > > > not > > > > > > > > > > > > > > > documented > > > > > > > > > > > > > > > yet > > > > > > > > > > > > > > > and > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > which is not necessary for the simplest decoding > > > > > > > > > > > > > > > scenario. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - Removed virtio_video_desc, as it is no longer > > > > > > > > > > > > > > > needed. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > * Updated struct virtio_video_config for changes > > > > > > > > > > > > > > > around > > > > > > > > > > > > > > > capabilities. > > > > > > > > > > > > > > > * Added a way to represent supported combinations > > > > > > > > > > > > > > > of > > > > > > > > > > > > > > > formats. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - A field "mask" in virtio_video_format_desc > > > > > > > > > > > > > > > plays > > > > > > > > > > > > > > > this > > > > > > > > > > > > > > > role. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > * Removed VIRTIO_VIDEO_T_STREAM_{START,STOP} > > > > > > > > > > > > > > > because > > > > > > > > > > > > > > > they > > > > > > > > > > > > > > > don't > > > > > > > > > > > > > > > play > > > > > > > > > > > > > > > any > > > > > > > > > > > > > > > meaningful roles. * Removed > > > > > > > > > > > > > > > VIRTIO_VIDEO_T_STREAM_{ATTACH, > > > > > > > > > > > > > > > DETACH}_BACKING > > > > > > > > > > > > > > > and merged them into RESOURCE_{CREATE, DESTROY}. * > > > > > > > > > > > > > > > Added a > > > > > > > > > > > > > > > way > > > > > > > > > > > > > > > to > > > > > > > > > > > > > > > notify/specify resource creation method. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - Added a feature flag. > > > > > > > > > > > > > > > - Defined enum virtio_video_mem_type. > > > > > > > > > > > > > > > - Added new fields in video_stream_create. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > * Modified fields in virtio_video_params. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - Added crop information. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > * Removed enum virtio_video_channel_type because > > > > > > > > > > > > > > > we > > > > > > > > > > > > > > > can > > > > > > > > > > > > > > > get > > > > > > > > > > > > > > > this > > > > > > > > > > > > > > > information by image format. > > > > > > > > > > > > > > > > > > > > > > > > > > > > Could you please explain this? How do you get the > > > > > > > > > > > > > > information? > > > > > > > > > > > > > > > > > > > > > > > > > > It means that if image formats are well-defined, > > > > > > > > > > > > > channel > > > > > > > > > > > > > information > > > > > > > > > > > > > (e.g. the order of channels) is uniquely determined. > > > > > > > > > > > > > > > > > > > > > > > > > > > Suppose you have some piece of HW on the host side > > > > > > > > > > > > > > that > > > > > > > > > > > > > > wants > > > > > > > > > > > > > > I420 > > > > > > > > > > > > > > as > > > > > > > > > > > > > > one > > > > > > > > > > > > > > contig buffer w/ some offsets. But on the driver > > > > > > > > > > > > > > side, > > > > > > > > > > > > > > say, > > > > > > > > > > > > > > gralloc > > > > > > > > > > > > > > gives you three separate buffers, one per channel. > > > > > > > > > > > > > > How > > > > > > > > > > > > > > do we > > > > > > > > > > > > > > pass > > > > > > > > > > > > > > those to the device then? > > > > > > > > > > > > > > > > > > > > > > > > > > You're talking about CrOS use case where buffers are > > > > > > > > > > > > > allocated > > > > > > > > > > > > > by > > > > > > > > > > > > > virtio-gpu, right? > > > > > > > > > > > > > In this case, virtio-gpu allocates one contiguous > > > > > > > > > > > > > host-side > > > > > > > > > > > > > buffer > > > > > > > > > > > > > and > > > > > > > > > > > > > the client regards a pair of (buffer FD, offset) as > > > > > > > > > > > > > one > > > > > > > > > > > > > channel. > > > > > > > > > > > > > And, we can register this pair to the device when the > > > > > > > > > > > > > buffer > > > > > > > > > > > > > is > > > > > > > > > > > > > imported. > > > > > > > > > > > > > In the virtio-vdec spec draft, this pair corresponds > > > > > > > > > > > > > to > > > > > > > > > > > > > struct > > > > > > > > > > > > > virtio_vdec_plane in struct virtio_vdec_plane. > > > > > > > > > > > > > > > > > > > > > > > > > > So, I suppose we will need similar structs when we add > > > > > > > > > > > > > a > > > > > > > > > > > > > control > > > > > > > > > > > > > to > > > > > > > > > > > > > import buffers. However, I don't think it's necessary > > > > > > > > > > > > > when > > > > > > > > > > > > > guest > > > > > > > > > > > > > pages > > > > > > > > > > > > > are used. > > > > > > > > > > > > > > > > > > > > > > > > I think we need some way for the guest to know whether > > > > > > > > > > > > it > > > > > > > > > > > > can > > > > > > > > > > > > allocate > > > > > > > > > > > > the planes in separate buffers, even when guest pages > > > > > > > > > > > > are > > > > > > > > > > > > used. > > > > > > > > > > > > This > > > > > > > > > > > > would be equivalent to V4L2 M and non-M formats, but > > > > > > > > > > > > mixing > > > > > > > > > > > > this > > > > > > > > > > > > into > > > > > > > > > > > > FourCC in V4L2 is an acknowledged mistake, so we should > > > > > > > > > > > > add > > > > > > > > > > > > a > > > > > > > > > > > > query or > > > > > > > > > > > > something. > > > > > > > > > > > > > > > > > > > > Yes, this is what I mean. In fact, we already do face the > > > > > > > > > > situation > > > > > > > > > > when > > > > > > > > > > the device side is not happy with the sgt and wants contig. > > > > > > > > > > I > > > > > > > > > > think > > > > > > > > > > we'll > > > > > > > > > > add a module parameter for now. > > > > > > > > > > > > > > > > > > Okay. So, I suppose we'll be able to update structs: > > > > > > > > > * Add a flag in virtio_video_format_desc that indicates > > > > > > > > > whether > > > > > > > > > planes > > > > > > > > > can be in separate buffers, and > > > > > > > > > * Add a flag in virtio_video_format_desc that indicates that > > > > > > > > > the > > > > > > > > > device requires contiguous buffers for this format. > > > > > > > > > > > > > > > > > > Does it make sense? > > > > > > > > > > > > > > > > Sorry, I don't understand the difference between the two above: > > > > > > > > isn't > > > > > > > > the > > > > > > > > first case is just when the flag is not set? > > > > > > > > > > > > > > Ah, I was confused and wrote something strange. Yeah, these two > > > > > > > are > > > > > > > the > > > > > > > same. Sorry for that. > > > > > > > > > > > > > > So, the suggestion is to add a field "planes_layout" in > > > > > > > virtio_video_format_desc, which is one of the following enums: > > > > > > > > > > > > > > enum virtio_video_planes_layout { > > > > > > > > > > > > > > VIRTIO_VIDEO_PLANES_LAYOUT_UNSPEC = 0, /* no special > > > > > > > requirement > > > > > > > */ > > > > > > > VIRTIO_VIDEO_PLANES_LAYOUT_CONTIGUOUS, > > > > > > > > > > > > > > }; > > > > > > > > > > > > > > If we have a better idea or naming, please let me know. > > > > > > > > > > > > The naming looks good for me, I might only change to CONTIG as we > > > > > > have > > > > > > UNSPEC. > > > > > > > > > > So here we are talking about plane layout in memory, am I correct? But > > > > > I > > > > > think we also need a way to communicate memory requirements of the > > > > > device: the device might require CMA buffers or it can be ok with SG > > > > > lists. What about adding something like this to > > > > > virtio_video_format_desc: > > > > > > > > > > enum virtio_video_mem_layout { > > > > > > > > > > VIRTIO_VIDEO_MEM_LAYOUT_UNDEFINED = 0, > > > > > > > > > > VIRTIO_VIDEO_MEM_LAYOUT_CONTIG = 0x100, > > > > > VIRTIO_VIDEO_MEM_LAYOUT_NON_CONTIG, > > > > > > > > > > }; > > > > > > > > > > struct virtio_video_format_desc { > > > > > > > > > > __le64 mask; > > > > > __le32 format; /* One of VIRTIO_VIDEO_FORMAT_* types */ > > > > > __le32 planes_layout; /* One of VIRTIO_VIDEO_PLANES_LAYOUT_* types > > > > > */ > > > > > __le32 mem_layout; /* One of VIRTIO_VIDEO_MEM_LAYOUT_* types */ > > > > > ... > > > > > > > > > > }; > > > > > > > > Good. > > > > I'd not like to call it NON_CONTIG, as it sounds like CMA buffers > > > > aren't allowed. > > > > Instead, how about this definition? > > > > > > > > enum virtio_video_mem_layout { > > > > > > > > VIRTIO_VIDEO_MEM_LAYOUT_UNSPEC = 0, /* no special requirement > > > > */ > > > > VIRTIO_VIDEO_MEM_LAYOUT_CONTIG = 1, > > > > > > > > }; > > > > > > Yes, I agree, that would be more correct. We just need an empty line to be > > > aligned with other enums. > > > > > > > With this enum, > > > > * the device can simply ignore this field if it doesn't have any > > > > requirement and the struct is zero-initialized, and > > > > * if we need to add other types of memory layout requirements, we can > > > > add them as 2, 4, 8, etc to represent combinations of requirements. > > > > > > > > Just to confirm, are the following combination of planes_layout and > > > > mem_layout valid? > > > > (1) (planes_layout, mem_layout) = (contig, not specified) > > > > (2) (planes_layout, mem_layout) = (not specified, contig) > > > > > > > > In my understanding, (1) means that each plane must be a contiguous > > > > buffer while different planes don't have to be in a contig memory, but > > > > (2) is invalid. > > > > Is it correct? > > > > > > Let me tell a bit more about my vision: > > > > > > mem_layout: device can handle SG lists (e.g. using iommu) or it cannot and > > > needs CMA. If it can handle SG, CMA is also ok. So it is ether 'I don't > > > care' or 'give me CMA'. > > > > > > planes_layout: some devices might want to see multiplanar data in one > > > buffer. So if we allocate two sets of mem entries (one per each plane) > > > and send them to the host, the device will fail to handle those. > > > > > > So from my perspective you example can be interpreted as follows: > > > (1) means all your planes are hosted by one buffer instance (we can see it > > > as one fd for all planes plus per-plane offsets inside the buffer), the > > > buffer itself consists of arbitrary pages (or can consist, as it can of > > > course also be CMA, because of UNSPEC). > > > (2) valid, means each plane has its own buffer, each buffer is contiguous > > > in memory (must be allocated from CMA), but planes are not necessarily > > > adjacent to each other in memory. > > > > > > This also means that we cannot have unspec for planes layout. Device > > > either > > > expects planes in separate buffers or in one buffer with some offsets, > > > there cannot be mixed cases. > > > > I might be misunderstanding the above, but just to make sure we're on > > the same page, here are the cases that we found to exist in practice > > with V4L2 stateful decoders: > > > > 1) device expects planes in one buffer laid out one after another > > without any padding; the device accepts only 1 pointer and no offsets > > - this corresponds to V4L2 non-M formats, such as NV12, which exactly > > specify the location of planes in the buffer, > > > > 2) device accepts separate pointers to all planes - the planes can be > > located anywhere in memory, which could be separate buffers, 1 buffer > > with planes laid out at arbitrary offsets or even exactly the same > > layout as required for 1). > > > > 3) device _requires_ planes to be located in separate buffers > > allocated from designated areas in memory, e.g. different physical > > memory banks, for performance purposes. This is actually a very rare > > case and observed only on old generations of Samsung Exynos SoCs. > > > > Please let me know if that matches your expectation, > > > > Thank you for the update! > > Yes, I think this matches our expectations, and this also does not contradict > the enums I provided in the previous email. > > Btw, you haven't mentioned anything regarding mem layout. Do you agree with > what was proposed? Tomasz, do you find any thought on mem layout Dmitry suggested? I have one question about mem layout. When the device reports VIRTIO_VIDEO_MEM_LAYOUT_UNSPEC, doesn't the driver want to tell whether it uses contiguous memory or not? In other words, I'm wondering if we should have a field "mem_layout" in virtio_video_resource_create to store one of enum virtio_video_mem_layout type. If so, we might want to add a new type like VIRTIO_VIDEO_MEM_LAYOUT_SG_LIST to tell that contiguous memories aren't used. Best regards, Keiichi Best regards, Keiichi > > Best regards, > Dmitry > > > Best regards, > > Tomasz > > > > > So it should look like this: > > > > > > enum virtio_video_planes_layout { > > > > > > VIRTIO_VIDEO_PLANES_LAYOUT_UNSPEC = 0, /* default, invalid */ > > > > > > VIRTIO_VIDEO_PLANES_LAYOUT_CONTIG = 0x100, > > > VIRTIO_VIDEO_PLANES_LAYOUT_NON_CONTIG, > > > > > > }; > > > > > > Best regards, > > > Dmitry > > > > > > > Best regards, > > > > Keiichi > > > > > > > > > Best regards, > > > > > Dmitry. > > > > > > > > > > > Best regards, > > > > > > Dmitry. > > > > > > > > > > > > > Best regards, > > > > > > > Keiichi > > > > > > > > > > > > > > > Regards, > > > > > > > > Dmitry. > > > > > > > > > > > > > > > > > Best regards, > > > > > > > > > Keiichi > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > Dmitry. > > > > > > > > > > > > > > > > > > > > > > For future V4L2 development we came up with the idea of > > > > > > > > > > > > a > > > > > > > > > > > > format > > > > > > > > > > > > flag > > > > > > > > > > > > which could mean that the hardware allows putting planes > > > > > > > > > > > > in > > > > > > > > > > > > separate > > > > > > > > > > > > buffers. We could have a similar per-format flag in the > > > > > > > > > > > > capabilities, > > > > > > > > > > > > as we already have a list of all the supported formats > > > > > > > > > > > > there. > > > > > > > > > > > > > > > > > > > > > > Sorry, forgot to paste the link from future V4L2 work > > > > > > > > > > > notes > > > > > > > > > > > from > > > > > > > > > > > this > > > > > > > > > > > year > > > > > > > > > > > ELCE: > > > > > > > > > > > https://www.spinics.net/lists/linux-media/msg159789.html > > > > > > > > > > > > > > > > > > > > > > > Best regards, > > > > > > > > > > > > Tomasz > > > > > > > > > > > > > > > > > > > > > > > > > Best regards, > > > > > > > > > > > > > Keiichi > > > > > > > > > > > > > > > > > > > > > > > > > > > Best regards, > > > > > > > > > > > > > > Dmitry. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > * Renamed virtio_video_pin to > > > > > > > > > > > > > > > virtio_video_buf_type. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - It's similar to V4L2_BUF_TYPE_VIDEO_{OUTPUT, > > > > > > > > > > > > > > > CAPTURE}. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > * Added an error event. > > > > > > > > > > > > > > > * Reordered some subsections. > > > > > > > > > > > > > > > * Changed styles to make it consistent with other > > > > > > > > > > > > > > > devices. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Dmitry Sepp (1): > > > > > > > > > > > > > > > virtio-video: Add virtio video device > > > > > > > > > > > > > > > specification > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > content.tex | 1 + > > > > > > > > > > > > > > > virtio-video.tex | 579 > > > > > > > > > > > > > > > +++++++++++++++++++++++++++++++++++++++++++++++ > > > > > > > > > > > > > > > 2 files changed, 580 insertions(+) > > > > > > > > > > > > > > > create mode 100644 virtio-video.tex > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > > > > > 2.24.1.735.g03f4e72817-goog > > > > > > > > > > > > -------------------------------------------------------------------- > > > > > > - > > > > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@xxxxxxxxxxxxxxxxxxxx > > > > > > For additional commands, e-mail: > > > > > > virtio-dev-help@xxxxxxxxxxxxxxxxxxxx > >
