[PATCH v5 0/1] Support per-head resolutions with virtio-gpu

[PATCH v5 0/1] Support per-head resolutions with virtio-gpu

[Andrew Keesler]

In 454f4b0f, we started down the path of supporting separate
configurations per display head (e.g., you have 2 heads - one with
EDID name "AAA" and the other with EDID name "BBB").

In this change, we add resolution to this configuration surface (e.g.,
you have 2 heads - one with resolution 111x222 and the other with
resolution 333x444).

  -display vnc=localhost:0,id=aaa,display=vga,head=0 \
  -display vnc=localhost:1,id=bbb,display=vga,head=1 \
  -device '{"driver":"virtio-vga",
            "max_outputs":2,
            "id":"vga",
            "outputs":[
              {
                 "name":"AAA",
                 "xres":111,
                 "yres":222
              },
              {
                 "name":"BBB",
                 "xres":333,
                 "yres":444
              }
            ]}'

Here is the behavior matrix of the current resolution configuration
surface (xres/yres) with the new resolution configuration surface
(outputs[i].xres/yres).

Note - we use "xres" and "yres" (instead of, say, "width" and "height")
to match analogous virtio_gpu_base_conf.xres/yres.

Case: !(xres || yres) && !(outputs[i].has_xres && outputs[i].has_yres)
Behavior: current behavior - outputs[0] enabled with default xres/yres

Case: (xres || yres) && !(outputs[i].has_xres && outputs[i].has_yres)
Behavior: current behavior - outputs[0] enabled with xres/yres

Case: outputs[i].has_xres && outputs[i].has_yres
Behavior: new behavior - outputs[i] enabled with outputs[i].xres/yres

Case: outputs[i].has_xres != outputs[i].has_yres
Behavior: error

Changelist:
* v5: changes after v4 review
  * since 10.2 -> since 11.0
  * setting only one of xres and yres is an error
* v4: changes after dropped from pull request
  * rebase against master (3b5fe75e2c)
  * use @NAME (@xres/@yres) in qapi/virtio.json docs
  * documented behavior when only one or none of @xres/@yres is set
* v3: changes after v2 review
  * fix new resolution configuration logic (&& instead of ||)
  * correct use of api machinery (has_*)
  * move documentation to QMP API
* v2: changes after v1 review + 10.2 rebase
  * updated code, commit message, and cover letter to match new res config logic
  * marked new VirtIOGPUOutput fields as optional and since 10.2
* v1: initial patch

Andrew Keesler (1):
  Support per-head resolutions with virtio-gpu

 hw/display/virtio-gpu-base.c | 16 ++++++++++++++++
 qapi/virtio.json             | 13 +++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

-- 
2.53.0.rc2.204.g2597b5adb4-goog

[PATCH v5 1/1] Support per-head resolutions with virtio-gpu

[Andrew Keesler]

In 454f4b0f, we started down the path of supporting separate
configurations per display head (e.g., you have 2 heads - one with
EDID name "AAA" and the other with EDID name "BBB").

In this change, we add resolution to this configuration surface (e.g.,
you have 2 heads - one with resolution 111x222 and the other with
resolution 333x444).

  -display vnc=localhost:0,id=aaa,display=vga,head=0 \
  -display vnc=localhost:1,id=bbb,display=vga,head=1 \
  -device '{"driver":"virtio-vga",
            "max_outputs":2,
            "id":"vga",
            "outputs":[
              {
                 "name":"AAA",
                 "xres":111,
                 "yres":222
              },
              {
                 "name":"BBB",
                 "xres":333,
                 "yres":444
              }
            ]}'

Here is the behavior matrix of the current resolution configuration
surface (xres/yres) with the new resolution configuration surface
(outputs[i].xres/yres).

Note - we use "xres" and "yres" (instead of, say, "width" and "height")
to match analogous virtio_gpu_base_conf.xres/yres.

Case: !(xres || yres) && !(outputs[i].has_xres && outputs[i].has_yres)
Behavior: current behavior - outputs[0] enabled with default xres/yres

Case: (xres || yres) && !(outputs[i].has_xres && outputs[i].has_yres)
Behavior: current behavior - outputs[0] enabled with xres/yres

Case: outputs[i].has_xres && outputs[i].has_yres
Behavior: new behavior - outputs[i] enabled with outputs[i].xres/yres

Case: outputs[i].has_xres != outputs[i].has_yres
Behavior: error

Signed-off-by: Andrew Keesler <ankeesler@google.com>
---
 hw/display/virtio-gpu-base.c | 16 ++++++++++++++++
 qapi/virtio.json             | 13 +++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c
index 7269477a1c..4bd2311182 100644
--- a/hw/display/virtio-gpu-base.c
+++ b/hw/display/virtio-gpu-base.c
@@ -233,6 +233,22 @@ virtio_gpu_base_device_realize(DeviceState *qdev,
     g->req_state[0].width = g->conf.xres;
     g->req_state[0].height = g->conf.yres;
 
+    for (output_idx = 0, node = g->conf.outputs;
+         node && output_idx < g->conf.max_outputs;
+         output_idx++, node = node->next) {
+        if (node->value->has_xres != node->value->has_yres) {
+            error_setg(errp,
+                       "must set both outputs[%lu].xres and outputs[%lu].yres",
+                       output_idx, output_idx);
+            return false;
+        }
+        if (node->value->has_xres && node->value->has_yres) {
+            g->enabled_output_bitmask |= (1 << output_idx);
+            g->req_state[output_idx].width = node->value->xres;
+            g->req_state[output_idx].height = node->value->yres;
+        }
+    }
+
     g->hw_ops = &virtio_gpu_ops;
     for (i = 0; i < g->conf.max_outputs; i++) {
         g->scanout[i].con =
diff --git a/qapi/virtio.json b/qapi/virtio.json
index cd67c4f52e..09dd0e6d05 100644
--- a/qapi/virtio.json
+++ b/qapi/virtio.json
@@ -970,15 +970,24 @@
 ##
 # @VirtIOGPUOutput:
 #
-# Describes configuration of a VirtIO GPU output.
+# Describes configuration of a VirtIO GPU output.  If both @xres and
+# @yres are set, they take precedence over root virtio-gpu resolution
+# configuration and enable the corresponding output.  If none of @xres
+# and @yres are set, root virtio-gpu resolution configuration takes
+# precedence and only the first output is enabled.  Only setting one
+# of @xres or @yres is an error.
 #
 # @name: the name of the output
 #
+# @xres: horizontal resolution of the output in pixels (since 11.0)
+#
+# @yres: vertical resolution of the output in pixels (since 11.0)
+#
 # Since: 10.1
 ##
 
 { 'struct': 'VirtIOGPUOutput',
-  'data': { 'name': 'str' } }
+  'data': { 'name': 'str', '*xres': 'uint16', '*yres': 'uint16' } }
 
 ##
 # @DummyVirtioForceArrays:
-- 
2.53.0.rc2.204.g2597b5adb4-goog

Re: [PATCH v5 1/1] Support per-head resolutions with virtio-gpu

[Markus Armbruster]

Andrew Keesler <ankeesler@google.com> writes:

> In 454f4b0f, we started down the path of supporting separate
> configurations per display head (e.g., you have 2 heads - one with
> EDID name "AAA" and the other with EDID name "BBB").
>
> In this change, we add resolution to this configuration surface (e.g.,
> you have 2 heads - one with resolution 111x222 and the other with
> resolution 333x444).
>
>   -display vnc=localhost:0,id=aaa,display=vga,head=0 \
>   -display vnc=localhost:1,id=bbb,display=vga,head=1 \
>   -device '{"driver":"virtio-vga",
>             "max_outputs":2,
>             "id":"vga",
>             "outputs":[
>               {
>                  "name":"AAA",
>                  "xres":111,
>                  "yres":222
>               },
>               {
>                  "name":"BBB",
>                  "xres":333,
>                  "yres":444
>               }
>             ]}'
>
> Here is the behavior matrix of the current resolution configuration
> surface (xres/yres) with the new resolution configuration surface
> (outputs[i].xres/yres).
>
> Note - we use "xres" and "yres" (instead of, say, "width" and "height")
> to match analogous virtio_gpu_base_conf.xres/yres.
>
> Case: !(xres || yres) && !(outputs[i].has_xres && outputs[i].has_yres)
> Behavior: current behavior - outputs[0] enabled with default xres/yres
>
> Case: (xres || yres) && !(outputs[i].has_xres && outputs[i].has_yres)
> Behavior: current behavior - outputs[0] enabled with xres/yres
>
> Case: outputs[i].has_xres && outputs[i].has_yres
> Behavior: new behavior - outputs[i] enabled with outputs[i].xres/yres
>
> Case: outputs[i].has_xres != outputs[i].has_yres
> Behavior: error
>
> Signed-off-by: Andrew Keesler <ankeesler@google.com>

[...]

> diff --git a/qapi/virtio.json b/qapi/virtio.json
> index cd67c4f52e..09dd0e6d05 100644
> --- a/qapi/virtio.json
> +++ b/qapi/virtio.json
> @@ -970,15 +970,24 @@
>  ##
>  # @VirtIOGPUOutput:
>  #
> -# Describes configuration of a VirtIO GPU output.
> +# Describes configuration of a VirtIO GPU output.  If both @xres and
> +# @yres are set, they take precedence over root virtio-gpu resolution
> +# configuration and enable the corresponding output.  If none of @xres
> +# and @yres are set, root virtio-gpu resolution configuration takes
> +# precedence and only the first output is enabled.  Only setting one
> +# of @xres or @yres is an error.
>  #
>  # @name: the name of the output
>  #
> +# @xres: horizontal resolution of the output in pixels (since 11.0)
> +#
> +# @yres: vertical resolution of the output in pixels (since 11.0)
> +#
>  # Since: 10.1
>  ##
>  
>  { 'struct': 'VirtIOGPUOutput',
> -  'data': { 'name': 'str' } }
> +  'data': { 'name': 'str', '*xres': 'uint16', '*yres': 'uint16' } }
>  
>  ##
>  # @DummyVirtioForceArrays:

Acked-by: Markus Armbruster <armbru@redhat.com>

Re: [PATCH v5 0/1] Support per-head resolutions with virtio-gpu

[Alex Bennée]

Andrew Keesler <ankeesler@google.com> writes:

> In 454f4b0f, we started down the path of supporting separate
> configurations per display head (e.g., you have 2 heads - one with
> EDID name "AAA" and the other with EDID name "BBB").

Queued to virtio-gpu/next, thanks.

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro