From: Cédric Le Goater <c...@redhat.com>
When a protected VM is started with the maximum number of CPUs (248),
the service call providing information on the CPUs requires more
buffer space than allocated and QEMU disgracefully aborts :
LOADPARM=[........]
Using virtio-blk.
Using SCSI scheme.
...................................................................................
qemu-system-s390x: KVM_S390_MEM_OP failed: Argument list too long
Implement a test for this limitation in the ConfidentialGuestSupportClass
check handler and provide some valid information to the user before the
machine starts.
Signed-off-by: Cédric Le Goater <c...@redhat.com>
---
hw/s390x/pv.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c
index 8dfe92d8df..3a7ec70634 100644
--- a/hw/s390x/pv.c
+++ b/hw/s390x/pv.c
@@ -266,6 +266,26 @@ int s390_pv_kvm_init(ConfidentialGuestSupport *cgs, Error
**errp)
return 0;
}
+static bool s390_pv_check_cpus(Error **errp)
+{
+ MachineState *ms = MACHINE(qdev_get_machine());
+ MachineClass *mc = MACHINE_GET_CLASS(ms);
+ uint32_t pv_max_cpus = mc->max_cpus - 1;
+
+ if (ms->smp.max_cpus > pv_max_cpus) {
+ error_setg(errp, "Protected VMs support a maximum of %d CPUs",
+ pv_max_cpus);
+ return false;
+ }
+
+ return true;
+}
+
+static bool s390_pv_guest_check(const Object *obj, Error **errp)
+{
+ return s390_pv_check_cpus(errp);
+}
+
OBJECT_DEFINE_TYPE_WITH_INTERFACES(S390PVGuest,
s390_pv_guest,
S390_PV_GUEST,
@@ -275,6 +295,9 @@ OBJECT_DEFINE_TYPE_WITH_INTERFACES(S390PVGuest,
static void s390_pv_guest_class_init(ObjectClass *oc, void *data)
{
+ ConfidentialGuestSupportClass *cgsc = CONFIDENTIAL_GUEST_SUPPORT_CLASS(oc);
+
+ cgsc->check = s390_pv_guest_check;
}
static void s390_pv_guest_init(Object *obj)
--
2.38.1
