[Qemu-devel] [PATCH] hw/arm/virt: fix cmdline parsing bug with CPU options and smp > 1

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

The recently introduced feature that allows 32 bit guests to be
executed under KVM on a 64-bit host incorrectly handles the case
where more than 1 cpu is specified using '-smp N'

For instance, this invocation of qemu

  qemu-system-aarch64 -M virt -cpu cortex-a57,aarch64=off -smp 2

produces the following error

  qemu-system-aarch64: Expected key=value format, found aarch64

which is caused by the destructive parsing performed by
cpu_common_parse_features(), resulting in subsequent attempts
to parse the CPU option string (for each additional CPU) to fail.

So duplicate the string before parsing it, and free it directly
afterwards.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 hw/arm/virt.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 69f51ac0da58..f8a6c46323dc 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -758,6 +758,7 @@ static void machvirt_init(MachineState *machine)
         CPUClass *cc = CPU_CLASS(oc);
         Object *cpuobj;
         Error *err = NULL;
+        char *cpuopts = g_strdup(cpustr[1]);
 
         if (!oc) {
             fprintf(stderr, "Unable to find CPU definition\n");
@@ -766,7 +767,8 @@ static void machvirt_init(MachineState *machine)
         cpuobj = object_new(object_class_get_name(oc));
 
         /* Handle any CPU options specified by the user */
-        cc->parse_features(CPU(cpuobj), cpustr[1], &err);
+        cc->parse_features(CPU(cpuobj), cpuopts, &err);
+        g_free(cpuopts);
         if (err) {
             error_report("%s", error_get_pretty(err));
             exit(1);
-- 
1.8.3.2