From: Dunrong Huang <riegama...@gmail.com>
The VCPU count limit in kernel now is 254, defined by KVM_MAX_VCPUS
in kernel's header files. But the count limit in QEMU is 255,
so QEMU will failed to start if user passes "-enable-kvm" and "-smp 255"
to it.
Exit QEMU with an error if KVM is enabled and number of SMP cpus requested
exceeds KVM_MAX_VCPUS.
Signed-off-by: Dunrong Huang <riegama...@gmail.com>
---
v1 -> v2:
Checking if the number of smp cpus requested exceeds KVM limit count
if and only if kvm is enabled.
vl.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/vl.c b/vl.c
index 8904db1..cdd1c96 100644
--- a/vl.c
+++ b/vl.c
@@ -169,6 +169,11 @@ int main(int argc, char **argv)
#define MAX_VIRTIO_CONSOLES 1
+/* KVM_MAX_VCPUS defined in kernel's header files */
+#ifndef KVM_MAX_VCPUS
+#define KVM_MAX_VCPUS 254
+#endif
+
static const char *data_dir;
const char *bios_name = NULL;
enum vga_retrace_method vga_retrace_method = VGA_RETRACE_DUMB;
@@ -3348,6 +3353,12 @@ int main(int argc, char **argv, char **envp)
configure_accelerator();
+ if (kvm_enabled() && smp_cpus > KVM_MAX_VCPUS) {
+ fprintf(stderr, "Number of SMP cpus requested (%d) exceeds max cpus "
+ "supported by KVM (%d)\n", smp_cpus, KVM_MAX_VCPUS);
+ exit(1);
+ }
+
qemu_init_cpu_loop();
if (qemu_init_main_loop()) {
fprintf(stderr, "qemu_init_main_loop failed\n");
--
1.7.8.6
