spice: detect if qemu can disable file transfer

spice-server offers an API to disable file transfer messages
on the agent channel between the client and the guest.
This is supported in qemu through the disable-agent-file-xfer option.

This patch detects if QEMU supports this option, and add
a capability if does.

Signed-off-by: Francesco Romani <fromani@redhat.com>

src/qemu/qemu_capabilities.c

@@ -247,6 +247,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "boot-strict", /* 160 */
               "pvpanic",
               "enable-fips",
+              "spice-file-xfer-disable"
     );
 
 struct _virQEMUCaps {
@@ -2286,6 +2287,7 @@ static struct virQEMUCapsCommandLineProps virQEMUCapsCommandLine[] = {
     { "realtime", "mlock", QEMU_CAPS_MLOCK },
     { "boot-opts", "strict", QEMU_CAPS_BOOT_STRICT },
     { "boot-opts", "reboot-timeout", QEMU_CAPS_REBOOT_TIMEOUT },
+    { "spice", "disable-agent-file-xfer", QEMU_CAPS_SPICE_FILE_XFER_DISABLE },
 };
 
 static int

src/qemu/qemu_capabilities.h

@@ -201,6 +201,7 @@ enum virQEMUCapsFlags {
     QEMU_CAPS_BOOT_STRICT        = 160, /* -boot strict */
     QEMU_CAPS_DEVICE_PANIC       = 161, /* -device pvpanic */
     QEMU_CAPS_ENABLE_FIPS        = 162, /* -enable-fips */
+    QEMU_CAPS_SPICE_FILE_XFER_DISABLE = 163, /* -spice disable-agent-file-xfer */
 
     QEMU_CAPS_LAST,                   /* this must always be the last item */
 };

tests/qemucapabilitiesdata/caps_1.6.0-1.caps

@@ -139,4 +139,5 @@
     <flag name='pvpanic'/>
     <flag name='reboot-timeout'/>
     <flag name='enable-fips'/>
+    <flag name='spice-file-xfer-disable'/>
   </qemuCaps>

tests/qemucapabilitiesdata/caps_1.6.50-1.caps

@@ -137,4 +137,5 @@
     <flag name='boot-strict'/>
     <flag name='pvpanic'/>
     <flag name='reboot-timeout'/>
+    <flag name='spice-file-xfer-disable'/>
   </qemuCaps>