From: David Woodhouse <dwmw@xxxxxxxxxxxx>
Even on x86_64 the default protocol is the x86-32 one if the guest doesn't
specifically ask for x86-64.
Cc: qemu-stable@xxxxxxxxxx
Fixes: b6af8926fb85 ("xen: add implementations of xen-block connect and disconnect functions...")
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Reviewed-by: Paul Durrant <paul@xxxxxxx>
---
hw/block/xen-block.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index a07cd7eb5d..bfa53960c3 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -115,9 +115,13 @@ static void xen_block_connect(XenDevice *xendev, Error **errp)
return;
}
- if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
- &str) != 1) {
- protocol = BLKIF_PROTOCOL_NATIVE;
+ if (xen_device_frontend_scanf(xendev, "protocol", "%ms", &str) != 1) {
+ /* x86 defaults to the 32-bit protocol even for 64-bit guests. */
+ if (object_dynamic_cast(OBJECT(qdev_get_machine()), "x86-machine")) {
+ protocol = BLKIF_PROTOCOL_X86_32;
+ } else {
+ protocol = BLKIF_PROTOCOL_NATIVE;
+ }
} else {
if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
protocol = BLKIF_PROTOCOL_X86_32;
--
2.41.0
