[Qemu-devel] [PATCH] limit guest cpus for kvm enabled builds

[Bruce Rogers]

The x86 kvm kernel module limits guest cpu count to 16, but the userspace pc 
definition says 255 still.  When invoking qemu-kvm with -smp > 16, it prints 
some error messages, then segfaults.   One of the mistakes is that the error 
code from kvm_create_vcpu is ignored in ap_main_loop.
This patch will enforce the limit at initialization time and avoid these 
problems from the get go.

Bruce

Signed-off-by: Bruce Rogers <address@hidden>

--- a/hw/pc.c
+++ b/hw/pc.c
@@ -1162,7 +1162,11 @@ QEMUMachine pc_machine = {
     .desc = "Standard PC",
     .init = pc_init_pci,
     .ram_require = VGA_RAM_SIZE + PC_MAX_BIOS_SIZE,
+#ifdef CONFIG_KVM
+    .max_cpus = 16,
+#else
     .max_cpus = 255,
+#endif
 };