[PATCH v2] qemu: fix qemuMigrationCapability enum

[Dmitry Frolov via Devel]

Enum variable of type qemuMigrationCapability is checked for zero in
src/qemu/qemu_migration_params.c:729.

"if (item->optional) { ..."

Actualy, QEMU_MIGRATION_CAP_XBZRLE enum constant has value 0.
So, at least, the condition is incorrect.

v1: introducing a separate enum for optional capabilities
v2: another approach: fix only the incorrect condition

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Dmitry Frolov <fro...@swemel.ru>
---
 src/qemu/qemu_migration_params.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_migration_params.c b/src/qemu/qemu_migration_params.c
index c10660d6f2..98d314cf2d 100644
--- a/src/qemu/qemu_migration_params.c
+++ b/src/qemu/qemu_migration_params.c
@@ -700,6 +700,12 @@ 
qemuMigrationParamsSetBlockDirtyBitmapMapping(qemuMigrationParams *migParams,
         ignore_value(virBitmapClearBit(migParams->caps, 
QEMU_MIGRATION_CAP_BLOCK_DIRTY_BITMAPS));
 }
 
+static bool
+qemuMigrationCapabilityIsOptional(qemuMigrationCapability cap)
+{
+    return cap == QEMU_MIGRATION_CAP_POSTCOPY_PREEMPT ||
+           cap == QEMU_MIGRATION_CAP_SWITCHOVER_ACK;
+}
 
 qemuMigrationParams *
 qemuMigrationParamsFromFlags(virTypedParameterPtr params,
@@ -725,7 +731,7 @@ qemuMigrationParamsFromFlags(virTypedParameterPtr params,
                       qemuMigrationCapabilityTypeToString(item->cap));
             ignore_value(virBitmapSetBit(migParams->caps, item->cap));
 
-            if (item->optional) {
+            if (qemuMigrationCapabilityIsOptional(item->optional)) {
                 qemuMigrationCapability opt = item->optional;
                 ignore_value(virBitmapSetBit(migParams->optional, opt));
                 if (item->party != party)
-- 
2.34.1