Re: [PATCH] qemu: Add GTK display with OpenGL support

28 Apr 2025

On Mon, Apr 28, 2025 at 12:22:22 +0200, Kirill Shchetiniuk via Devel wrote:
...
From: Kirill Shchetiniuk <kshcheti@redhat.com>
Introduce GTK display support with OpenGL for the QEMU driver.
- Add new XML options for GTK display type.
 - Include capability flags for the QEMU driver.
Note: The `QEMU_CAPS_GTK_GL` flag cannot yet be checked, so device
definition validation is incomplete. A placeholder is left for
future implementation, when the GTK along with OpenGL capability
check would be available in QEMU.
Can you elaborate? WHy can't it be checked?
...
Resolves: https://gitlab.com/libvirt/libvirt/-/issues/570
Signed-off-by: Kirill Shchetiniuk <kshcheti@redhat.com>
---
You will need to split this patch.

At least the capability flag needs to be a separate commit that only
adds the capability flag.

I'm also missing qemuxmlconftest test cases and docs/formatdomain.rst
documentation changes.


[...]
...
36 files changed, 218 insertions(+), 2 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 542d6ade91..73550f7fcf 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -960,6 +960,7 @@ VIR_ENUM_IMPL(virDomainGraphics,
               "spice",
               "egl-headless",
               "dbus",
+              "gtk",
 );
VIR_ENUM_IMPL(virDomainGraphicsListen,
@@ -2054,6 +2055,12 @@ void virDomainGraphicsDefFree(virDomainGraphicsDef *def)
         g_free(def->data.dbus.rendernode);
         break;
+    case VIR_DOMAIN_GRAPHICS_TYPE_GTK:
+        g_free(def->data.gtk.display);
+        g_free(def->data.gtk.xauth);
+        g_free(def->data.gtk.rendernode);
+        break;
+
     case VIR_DOMAIN_GRAPHICS_TYPE_LAST:
         break;
     }
@@ -12199,6 +12206,39 @@ virDomainGraphicsDefParseXMLDBus(virDomainGraphicsDef *def,
 }
+static int
+virDomainGraphicsDefParseXMLGTK(virDomainGraphicsDef *def,
+                                xmlNodePtr node,
+                                xmlXPathContextPtr ctxt)
+{
+    VIR_XPATH_NODE_AUTORESTORE(ctxt)
+    xmlNodePtr glNode;
+    virTristateBool fullscreen;
+
+    ctxt->node = node;
+
+    if (virXMLPropTristateBool(node, "fullscreen", VIR_XML_PROP_NONE,
+                               &fullscreen) < 0)
You parse a tristate ...
...
+        return -1;
+
+    virTristateBoolToBool(fullscreen, &def->data.gtk.fullscreen);
... but store it only as boolean?
...
+    def->data.gtk.xauth = virXMLPropString(node, "xauth");
+    def->data.gtk.display = virXMLPropString(node, "display");
+
+    if ((glNode = virXPathNode("./gl", ctxt))) {
+        def->data.gtk.rendernode = virXMLPropString(glNode,
+                                                     "rendernode");
+
+        if (virXMLPropTristateBool(glNode, "enable",
+                                   VIR_XML_PROP_REQUIRED,
+                                   &def->data.gtk.gl) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+
 virDomainGraphicsDef *
 virDomainGraphicsDefNew(virDomainXMLOption *xmlopt)
 {
[...]
...
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index a804335c85..de7ce95499 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -732,6 +732,8 @@ VIR_ENUM_IMPL(virQEMUCaps,
/* 475 */
               "virtio-scsi.iothread-mapping", /* QEMU_CAPS_VIRTIO_SCSI_IOTHREAD_MAPPING */
+              "gtk", /* QEMU_CAPS_GTK */
+              "gtk-gl", /* QEMU_CAPS_GTK_GL */
     );
@@ -1602,6 +1604,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsQMPSchemaQueries[] = {
     { "set-numa-node/arg-type/+hmat-lb", QEMU_CAPS_NUMA_HMAT },
     { "query-cpu-model-expansion/ret-type/deprecated-props", QEMU_CAPS_QUERY_CPU_MODEL_EXPANSION_DEPRECATED_PROPS },
     { "migrate-incoming/arg-type/exit-on-error", QEMU_CAPS_MIGRATE_INCOMING_EXIT_ON_ERROR },
+    { "query-display-options/ret-type/type/^gtk", QEMU_CAPS_GTK },
 };
typedef struct _virQEMUCapsObjectTypeProps virQEMUCapsObjectTypeProps;
@@ -6499,6 +6502,8 @@ virQEMUCapsFillDomainDeviceGraphicsCaps(virQEMUDriverConfig *cfg,
                                      VIR_DOMAIN_GRAPHICS_TYPE_RDP);
         }
     }
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_GTK))
+        VIR_DOMAIN_CAPS_ENUM_SET(dev->type, VIR_DOMAIN_GRAPHICS_TYPE_GTK);
 }
[...]
...
diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
index b2c3c9e2f6..be92785d71 100644
--- a/src/qemu/qemu_validate.c
+++ b/src/qemu/qemu_validate.c
@@ -4523,6 +4523,17 @@ qemuValidateDomainDeviceDefRDPGraphics(const virDomainGraphicsDef *graphics)
 }
+static int
+qemuValidateDomainDeviceDefGTKGraphics(const virDomainGraphicsDef *graphics G_GNUC_UNUSED,
+                                       virQEMUCaps *qemuCaps G_GNUC_UNUSED)
+{
+    /* TODO: OpenGL check */
+    /* For now it's not possible to check if gtk-gl capability is available in QEMU */
+    /* Add cappability check later when will be possible to gather the capability from QEMU */
So why does the patch add the capability then? Or is this comment no
longer applicable?
...
+    return 0;
+}
+
+
 static int
 qemuValidateDomainDeviceDefGraphics(const virDomainGraphicsDef *graphics,
                                     const virDomainDef *def,

    

Re: [PATCH] qemu: Add GTK display with OpenGL support

Peter Krempa