diff mbox series

[v2] virtio-gpu: add VIRTIO_GPU_F_EDID feature

Message ID 20181005125154.19824-1-kraxel@redhat.com (mailing list archive)
State New, archived
Headers show
Series [v2] virtio-gpu: add VIRTIO_GPU_F_EDID feature | expand

Commit Message

Gerd Hoffmann Oct. 5, 2018, 12:51 p.m. UTC
The feature allows the guest request an EDID blob (describing monitor
capabilities) for a given scanout (aka virtual monitor connector).

It brings a new command message, which has just a scanout field (beside
the standard virtio-gpu header) and a response message which carries the
EDID data.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 include/uapi/linux/virtio_gpu.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

Comments

Christophe de Dinechin Oct. 5, 2018, 2:38 p.m. UTC | #1
> On 5 Oct 2018, at 14:51, Gerd Hoffmann <kraxel@redhat.com> wrote:
> 
> The feature allows the guest request an EDID blob (describing monitor
> capabilities) for a given scanout (aka virtual monitor connector).
> 
> It brings a new command message, which has just a scanout field (beside
> the standard virtio-gpu header) and a response message which carries the
> EDID data.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
> include/uapi/linux/virtio_gpu.h | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
> 
> diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
> index f43c3c6171..1cef1ff339 100644
> --- a/include/uapi/linux/virtio_gpu.h
> +++ b/include/uapi/linux/virtio_gpu.h
> @@ -41,6 +41,7 @@
> #include <linux/types.h>
> 
> #define VIRTIO_GPU_F_VIRGL 0
> +#define VIRTIO_GPU_F_EDID  1
> 
> enum virtio_gpu_ctrl_type {
> 	VIRTIO_GPU_UNDEFINED = 0,
> @@ -56,6 +57,7 @@ enum virtio_gpu_ctrl_type {
> 	VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING,
> 	VIRTIO_GPU_CMD_GET_CAPSET_INFO,
> 	VIRTIO_GPU_CMD_GET_CAPSET,
> +	VIRTIO_GPU_CMD_GET_EDID,
> 
> 	/* 3d commands */
> 	VIRTIO_GPU_CMD_CTX_CREATE = 0x0200,
> @@ -76,6 +78,7 @@ enum virtio_gpu_ctrl_type {
> 	VIRTIO_GPU_RESP_OK_DISPLAY_INFO,
> 	VIRTIO_GPU_RESP_OK_CAPSET_INFO,
> 	VIRTIO_GPU_RESP_OK_CAPSET,
> +	VIRTIO_GPU_RESP_OK_EDID,
> 
> 	/* error responses */
> 	VIRTIO_GPU_RESP_ERR_UNSPEC = 0x1200,
> @@ -291,6 +294,20 @@ struct virtio_gpu_resp_capset {
> 	__u8 capset_data[];
> };
> 
> +/* VIRTIO_GPU_CMD_GET_EDID */
> +struct virtio_gpu_get_edid {
> +	struct virtio_gpu_ctrl_hdr hdr;
> +	__le32 scanout;
> +};
> +
> +/* VIRTIO_GPU_RESP_OK_EDID */
> +struct virtio_gpu_resp_edid {
> +	struct virtio_gpu_ctrl_hdr hdr;
> +	__le32 scanout;
> +	__le32 size;
> +	__u8 edid[1024];

Wouldn’t it be enough to stick to EDID 2.0 (256 bytes)?

If not, maybe add comment to explain why you chose 1024.

> +};
> +
> #define VIRTIO_GPU_EVENT_DISPLAY (1 << 0)
> 
> struct virtio_gpu_config {
> -- 
> 2.9.3
>
Daniel Vetter Oct. 5, 2018, 2:41 p.m. UTC | #2
On Fri, Oct 05, 2018 at 04:38:11PM +0200, Christophe de Dinechin wrote:
> 
> 
> > On 5 Oct 2018, at 14:51, Gerd Hoffmann <kraxel@redhat.com> wrote:
> > 
> > The feature allows the guest request an EDID blob (describing monitor
> > capabilities) for a given scanout (aka virtual monitor connector).
> > 
> > It brings a new command message, which has just a scanout field (beside
> > the standard virtio-gpu header) and a response message which carries the
> > EDID data.
> > 
> > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> > ---
> > include/uapi/linux/virtio_gpu.h | 17 +++++++++++++++++
> > 1 file changed, 17 insertions(+)
> > 
> > diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
> > index f43c3c6171..1cef1ff339 100644
> > --- a/include/uapi/linux/virtio_gpu.h
> > +++ b/include/uapi/linux/virtio_gpu.h
> > @@ -41,6 +41,7 @@
> > #include <linux/types.h>
> > 
> > #define VIRTIO_GPU_F_VIRGL 0
> > +#define VIRTIO_GPU_F_EDID  1
> > 
> > enum virtio_gpu_ctrl_type {
> > 	VIRTIO_GPU_UNDEFINED = 0,
> > @@ -56,6 +57,7 @@ enum virtio_gpu_ctrl_type {
> > 	VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING,
> > 	VIRTIO_GPU_CMD_GET_CAPSET_INFO,
> > 	VIRTIO_GPU_CMD_GET_CAPSET,
> > +	VIRTIO_GPU_CMD_GET_EDID,
> > 
> > 	/* 3d commands */
> > 	VIRTIO_GPU_CMD_CTX_CREATE = 0x0200,
> > @@ -76,6 +78,7 @@ enum virtio_gpu_ctrl_type {
> > 	VIRTIO_GPU_RESP_OK_DISPLAY_INFO,
> > 	VIRTIO_GPU_RESP_OK_CAPSET_INFO,
> > 	VIRTIO_GPU_RESP_OK_CAPSET,
> > +	VIRTIO_GPU_RESP_OK_EDID,
> > 
> > 	/* error responses */
> > 	VIRTIO_GPU_RESP_ERR_UNSPEC = 0x1200,
> > @@ -291,6 +294,20 @@ struct virtio_gpu_resp_capset {
> > 	__u8 capset_data[];
> > };
> > 
> > +/* VIRTIO_GPU_CMD_GET_EDID */
> > +struct virtio_gpu_get_edid {
> > +	struct virtio_gpu_ctrl_hdr hdr;
> > +	__le32 scanout;
> > +};
> > +
> > +/* VIRTIO_GPU_RESP_OK_EDID */
> > +struct virtio_gpu_resp_edid {
> > +	struct virtio_gpu_ctrl_hdr hdr;
> > +	__le32 scanout;
> > +	__le32 size;
> > +	__u8 edid[1024];
> 
> Wouldn’t it be enough to stick to EDID 2.0 (256 bytes)?
> 
> If not, maybe add comment to explain why you chose 1024.

EDID in the wild can be up to 512 bytes.
-Daniel

> 
> > +};
> > +
> > #define VIRTIO_GPU_EVENT_DISPLAY (1 << 0)
> > 
> > struct virtio_gpu_config {
> > -- 
> > 2.9.3
> > 
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Christophe de Dinechin Oct. 5, 2018, 3:33 p.m. UTC | #3
> On 5 Oct 2018, at 16:41, Daniel Vetter <daniel@ffwll.ch> wrote:
> 
> On Fri, Oct 05, 2018 at 04:38:11PM +0200, Christophe de Dinechin wrote:
>> 
>> 
>>> On 5 Oct 2018, at 14:51, Gerd Hoffmann <kraxel@redhat.com> wrote:
>>> 
>>> The feature allows the guest request an EDID blob (describing monitor
>>> capabilities) for a given scanout (aka virtual monitor connector).
>>> 
>>> It brings a new command message, which has just a scanout field (beside
>>> the standard virtio-gpu header) and a response message which carries the
>>> EDID data.
>>> 
>>> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>>> ---
>>> include/uapi/linux/virtio_gpu.h | 17 +++++++++++++++++
>>> 1 file changed, 17 insertions(+)
>>> 
>>> diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
>>> index f43c3c6171..1cef1ff339 100644
>>> --- a/include/uapi/linux/virtio_gpu.h
>>> +++ b/include/uapi/linux/virtio_gpu.h
>>> @@ -41,6 +41,7 @@
>>> #include <linux/types.h>
>>> 
>>> #define VIRTIO_GPU_F_VIRGL 0
>>> +#define VIRTIO_GPU_F_EDID  1
>>> 
>>> enum virtio_gpu_ctrl_type {
>>> 	VIRTIO_GPU_UNDEFINED = 0,
>>> @@ -56,6 +57,7 @@ enum virtio_gpu_ctrl_type {
>>> 	VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING,
>>> 	VIRTIO_GPU_CMD_GET_CAPSET_INFO,
>>> 	VIRTIO_GPU_CMD_GET_CAPSET,
>>> +	VIRTIO_GPU_CMD_GET_EDID,
>>> 
>>> 	/* 3d commands */
>>> 	VIRTIO_GPU_CMD_CTX_CREATE = 0x0200,
>>> @@ -76,6 +78,7 @@ enum virtio_gpu_ctrl_type {
>>> 	VIRTIO_GPU_RESP_OK_DISPLAY_INFO,
>>> 	VIRTIO_GPU_RESP_OK_CAPSET_INFO,
>>> 	VIRTIO_GPU_RESP_OK_CAPSET,
>>> +	VIRTIO_GPU_RESP_OK_EDID,
>>> 
>>> 	/* error responses */
>>> 	VIRTIO_GPU_RESP_ERR_UNSPEC = 0x1200,
>>> @@ -291,6 +294,20 @@ struct virtio_gpu_resp_capset {
>>> 	__u8 capset_data[];
>>> };
>>> 
>>> +/* VIRTIO_GPU_CMD_GET_EDID */
>>> +struct virtio_gpu_get_edid {
>>> +	struct virtio_gpu_ctrl_hdr hdr;
>>> +	__le32 scanout;
>>> +};
>>> +
>>> +/* VIRTIO_GPU_RESP_OK_EDID */
>>> +struct virtio_gpu_resp_edid {
>>> +	struct virtio_gpu_ctrl_hdr hdr;
>>> +	__le32 scanout;
>>> +	__le32 size;
>>> +	__u8 edid[1024];
>> 
>> Wouldn’t it be enough to stick to EDID 2.0 (256 bytes)?
>> 
>> If not, maybe add comment to explain why you chose 1024.
> 
> EDID in the wild can be up to 512 bytes.

Does this return a physical EDID? I thought it would be made-up by virtio-gpu.

Thanks,
Christophe

> 
>> 
>>> +};
>>> +
>>> #define VIRTIO_GPU_EVENT_DISPLAY (1 << 0)
>>> 
>>> struct virtio_gpu_config {
>>> -- 
>>> 2.9.3
>>> 
>> 
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
Gerd Hoffmann Oct. 5, 2018, 3:55 p.m. UTC | #4
Hi,

> >>> +/* VIRTIO_GPU_RESP_OK_EDID */
> >>> +struct virtio_gpu_resp_edid {
> >>> +	struct virtio_gpu_ctrl_hdr hdr;
> >>> +	__le32 scanout;
> >>> +	__le32 size;
> >>> +	__u8 edid[1024];
> >> 
> >> Wouldn’t it be enough to stick to EDID 2.0 (256 bytes)?
> >> 
> >> If not, maybe add comment to explain why you chose 1024.
> > 
> > EDID in the wild can be up to 512 bytes.
> 
> Does this return a physical EDID? I thought it would be made-up by virtio-gpu.

Well, edid has extensions, so it can become pretty large in theory, and
I've figured it would be a good idea to leave some room just in case.
It should be a rather infrequent operation, so the unused buffer space
should not hurt much.

Yes, it will be a edid generated by qemu.  The current generator code will
use at most 256 bytes.

cheers,
  Gerd
Dave Airlie Oct. 18, 2018, 1:17 a.m. UTC | #5
Reviewed-by: Dave Airlie <airlied@redhat.com>
On Fri, 5 Oct 2018 at 22:52, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> The feature allows the guest request an EDID blob (describing monitor
> capabilities) for a given scanout (aka virtual monitor connector).
>
> It brings a new command message, which has just a scanout field (beside
> the standard virtio-gpu header) and a response message which carries the
> EDID data.
>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  include/uapi/linux/virtio_gpu.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
> index f43c3c6171..1cef1ff339 100644
> --- a/include/uapi/linux/virtio_gpu.h
> +++ b/include/uapi/linux/virtio_gpu.h
> @@ -41,6 +41,7 @@
>  #include <linux/types.h>
>
>  #define VIRTIO_GPU_F_VIRGL 0
> +#define VIRTIO_GPU_F_EDID  1
>
>  enum virtio_gpu_ctrl_type {
>         VIRTIO_GPU_UNDEFINED = 0,
> @@ -56,6 +57,7 @@ enum virtio_gpu_ctrl_type {
>         VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING,
>         VIRTIO_GPU_CMD_GET_CAPSET_INFO,
>         VIRTIO_GPU_CMD_GET_CAPSET,
> +       VIRTIO_GPU_CMD_GET_EDID,
>
>         /* 3d commands */
>         VIRTIO_GPU_CMD_CTX_CREATE = 0x0200,
> @@ -76,6 +78,7 @@ enum virtio_gpu_ctrl_type {
>         VIRTIO_GPU_RESP_OK_DISPLAY_INFO,
>         VIRTIO_GPU_RESP_OK_CAPSET_INFO,
>         VIRTIO_GPU_RESP_OK_CAPSET,
> +       VIRTIO_GPU_RESP_OK_EDID,
>
>         /* error responses */
>         VIRTIO_GPU_RESP_ERR_UNSPEC = 0x1200,
> @@ -291,6 +294,20 @@ struct virtio_gpu_resp_capset {
>         __u8 capset_data[];
>  };
>
> +/* VIRTIO_GPU_CMD_GET_EDID */
> +struct virtio_gpu_get_edid {
> +       struct virtio_gpu_ctrl_hdr hdr;
> +       __le32 scanout;
> +};
> +
> +/* VIRTIO_GPU_RESP_OK_EDID */
> +struct virtio_gpu_resp_edid {
> +       struct virtio_gpu_ctrl_hdr hdr;
> +       __le32 scanout;
> +       __le32 size;
> +       __u8 edid[1024];
> +};
> +
>  #define VIRTIO_GPU_EVENT_DISPLAY (1 << 0)
>
>  struct virtio_gpu_config {
> --
> 2.9.3
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff mbox series

Patch

diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
index f43c3c6171..1cef1ff339 100644
--- a/include/uapi/linux/virtio_gpu.h
+++ b/include/uapi/linux/virtio_gpu.h
@@ -41,6 +41,7 @@ 
 #include <linux/types.h>
 
 #define VIRTIO_GPU_F_VIRGL 0
+#define VIRTIO_GPU_F_EDID  1
 
 enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_UNDEFINED = 0,
@@ -56,6 +57,7 @@  enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING,
 	VIRTIO_GPU_CMD_GET_CAPSET_INFO,
 	VIRTIO_GPU_CMD_GET_CAPSET,
+	VIRTIO_GPU_CMD_GET_EDID,
 
 	/* 3d commands */
 	VIRTIO_GPU_CMD_CTX_CREATE = 0x0200,
@@ -76,6 +78,7 @@  enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_RESP_OK_DISPLAY_INFO,
 	VIRTIO_GPU_RESP_OK_CAPSET_INFO,
 	VIRTIO_GPU_RESP_OK_CAPSET,
+	VIRTIO_GPU_RESP_OK_EDID,
 
 	/* error responses */
 	VIRTIO_GPU_RESP_ERR_UNSPEC = 0x1200,
@@ -291,6 +294,20 @@  struct virtio_gpu_resp_capset {
 	__u8 capset_data[];
 };
 
+/* VIRTIO_GPU_CMD_GET_EDID */
+struct virtio_gpu_get_edid {
+	struct virtio_gpu_ctrl_hdr hdr;
+	__le32 scanout;
+};
+
+/* VIRTIO_GPU_RESP_OK_EDID */
+struct virtio_gpu_resp_edid {
+	struct virtio_gpu_ctrl_hdr hdr;
+	__le32 scanout;
+	__le32 size;
+	__u8 edid[1024];
+};
+
 #define VIRTIO_GPU_EVENT_DISPLAY (1 << 0)
 
 struct virtio_gpu_config {