[PATCH] virtio-rng-pci: fix migration compat for vectors

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Fixup the migration compatibility for existing machine types
so that they do not enable msi-x.

Symptom:

(qemu) qemu: get_pci_config_device: Bad config data: i=0x34 read: 84 device: 98 cmask: ff wmask: 0 w1cmask:0
qemu: Failed to load PCIDevice:config
qemu: Failed to load virtio-rng:virtio
qemu: error while loading state for instance 0x0 of device '0000:00:03.0/virtio-rng'
qemu: load of migration failed: Invalid argument

Note: This fix will break migration from 7.2->7.2-fixed with this patch

bz: https://bugzilla.redhat.com/show_bug.cgi?id=2155749
Fixes: 9ea02e8f1 ("virtio-rng-pci: Allow setting nvectors, so we can use MSI-X")

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/core/machine.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index f589b92909..45459d1cef 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -45,6 +45,7 @@ const size_t hw_compat_7_2_len = G_N_ELEMENTS(hw_compat_7_2);
 
 GlobalProperty hw_compat_7_1[] = {
     { "virtio-device", "queue_reset", "false" },
+    { "virtio-rng-pci", "vectors", "0" },
 };
 const size_t hw_compat_7_1_len = G_N_ELEMENTS(hw_compat_7_1);
 
-- 
2.39.0