[libvirt PATCH 1/4] qemu: prevent use of <bios useserial='yes'> on non-x86 arches

[Daniel P. Berrangé]

The <bios useserial='yes'> config results in use of the '-device sga'
QEMU options. This in turn causes QEMU go load the sgabios.bin option
ROM, which contains x86 machine code. This cannot work on non-x86
arches, thus we should block the bad config.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/qemu/qemu_validate.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
index d8f39b6bdd..3789361b57 100644
--- a/src/qemu/qemu_validate.c
+++ b/src/qemu/qemu_validate.c
@@ -1194,6 +1194,14 @@ qemuValidateDomainDef(const virDomainDef *def,
 
     /* Serial graphics adapter */
     if (def->os.bios.useserial == VIR_TRISTATE_BOOL_YES) {
+        /* -device sga is only sane on x86, since the option ROM it
+         * loads contains x86 machine code.
+         */
+        if (!ARCH_IS_X86(def->os.arch)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("BIOS serial console only supported on x86 architectures"));
+            return -1;
+        }
         if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_SGA)) {
             virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                            _("qemu does not support SGA"));
-- 
2.31.1