[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v3] kvm: Check if smp_cpus exceeds max cpus supporte
From: |
riegamaths |
Subject: |
[Qemu-devel] [PATCH v3] kvm: Check if smp_cpus exceeds max cpus supported by kvm |
Date: |
Tue, 31 Jul 2012 19:18:17 +0800 |
From: Dunrong Huang <address@hidden>
Add a helper function for fetching max cpus supported by kvm.
Make QEMU exit with an error message if smp_cpus exceeds limit
of VCPU count retrieved by invoking this helper function.
Signed-off-by: Dunrong Huang <address@hidden>
---
v1 -> v2:
* Fix indentation(thanks to Stefan Hajnoczi for his review)
v2 -> v3(Thanks to Peter Maydell for this hint)
* Add a comment for helper function
* Use "goto err" instead of "exit(1)"
kvm-all.c | 29 +++++++++++++++++++++++++++++
1 files changed, 29 insertions(+), 0 deletions(-)
diff --git a/kvm-all.c b/kvm-all.c
index 2148b20..bf64761 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1207,6 +1207,26 @@ static int kvm_irqchip_create(KVMState *s)
return 0;
}
+static int kvm_max_vcpus(KVMState *s)
+{
+ int ret;
+
+ /* Find number of supported CPUs using the recommended
+ * procedure from the kernel API documentation to cope with
+ * older kernels that may be missing capabilities.
+ */
+ ret = kvm_check_extension(s, KVM_CAP_MAX_VCPUS);
+ if (ret) {
+ return ret;
+ }
+ ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS);
+ if (ret) {
+ return ret;
+ }
+
+ return 4;
+}
+
int kvm_init(void)
{
static const char upgrade_note[] =
@@ -1216,6 +1236,7 @@ int kvm_init(void)
const KVMCapabilityInfo *missing_cap;
int ret;
int i;
+ int max_vcpus;
s = g_malloc0(sizeof(KVMState));
@@ -1256,6 +1277,14 @@ int kvm_init(void)
goto err;
}
+ max_vcpus = kvm_max_vcpus(s);
+ if (smp_cpus > max_vcpus) {
+ ret = -EINVAL;
+ fprintf(stderr, "Number of SMP cpus requested (%d) exceeds max cpus "
+ "supported by KVM (%d)\n", smp_cpus, max_vcpus);
+ goto err;
+ }
+
s->vmfd = kvm_ioctl(s, KVM_CREATE_VM, 0);
if (s->vmfd < 0) {
#ifdef TARGET_S390X
--
1.7.8.6
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Qemu-devel] [PATCH v3] kvm: Check if smp_cpus exceeds max cpus supported by kvm,
riegamaths <=