[PATCH 1/2] qemuBuildHostdevMediatedDevProps: Format 'ramfb' only when enabled

[Peter Krempa]

Before commit 73c352ab8c97d3 which converted the hostdev commandline
formatter to JSON the 'ramfb' property was formatted only if it was
enabled.

The main reason for that is that enabling 'ramfb' switches the device
model to 'vfio-pci-nohotplug' which actually has the property, while
'vfio-pci' (used when 'ramfb' is disabled or absent) doesn't have it.

Restore the logic to format 'ramfb' only when it's enabled and add a
comment that it's deliberate.

Fixes: 73c352ab8c97d3
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2024435
Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/qemu/qemu_command.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 713304dd22..d1b0205eb2 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -5329,6 +5329,8 @@ qemuBuildHostdevMediatedDevProps(const virDomainDef *def,
     g_autoptr(virJSONValue) props = NULL;
     virDomainHostdevSubsysMediatedDev *mdevsrc = &dev->source.subsys.u.mdev;
     g_autofree char *mdevPath = NULL;
+    /* 'ramfb' property must be omitted unless it's to be enabled */
+    bool ramfb = mdevsrc->ramfb == VIR_TRISTATE_SWITCH_ON;

     mdevPath = virMediatedDeviceGetSysfsPath(mdevsrc->uuidstr);

@@ -5337,7 +5339,7 @@ qemuBuildHostdevMediatedDevProps(const virDomainDef *def,
                               "s:id", dev->info->alias,
                               "s:sysfsdev", mdevPath,
                               "S:display", qemuOnOffAuto(mdevsrc->display),
-                              "T:ramfb", mdevsrc->ramfb,
+                              "B:ramfb", ramfb,
                               "p:bootindex", dev->info->bootIndex,
                               NULL) < 0)
         return NULL;
-- 
2.31.1