From patchwork Mon Jul 30 18:22:38 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: kvm: Check if smp_cpus exceeds max cpus supported by kvm Date: Mon, 30 Jul 2012 08:22:38 -0000 From: dunrong huang X-Patchwork-Id: 174073 Message-Id: <1343672558-8560-1-git-send-email-riegamaths@gmail.com> To: qemu-devel Cc: Marcelo Tosatti , Dunrong Huang , Stefan Hajnoczi , kvm@vger.kernel.org, Avi Kivity From: Dunrong Huang 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 --- kvm-all.c | 25 +++++++++++++++++++++++++ 1 files changed, 25 insertions(+), 0 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 2148b20..8cb4b92 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -1207,6 +1207,23 @@ static int kvm_irqchip_create(KVMState *s) return 0; } +static int kvm_max_vcpus(KVMState *s) +{ + int max_vcpus = 4; + int ret; + ret = kvm_check_extension(s, KVM_CAP_MAX_VCPUS); + if (ret) { + max_vcpus = ret; + } else { + ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS); + if (ret) { + max_vcpus = ret; + } + } + + return max_vcpus; +} + int kvm_init(void) { static const char upgrade_note[] = @@ -1216,6 +1233,7 @@ int kvm_init(void) const KVMCapabilityInfo *missing_cap; int ret; int i; + int max_vcpus; s = g_malloc0(sizeof(KVMState)); @@ -1256,6 +1274,13 @@ int kvm_init(void) goto err; } + max_vcpus = kvm_max_vcpus(s); + if (smp_cpus > max_vcpus) { + fprintf(stderr, "Number of SMP cpus requested (%d) exceeds max cpus " + "supported by KVM (%d)\n", smp_cpus, max_vcpus); + exit(1); + } + s->vmfd = kvm_ioctl(s, KVM_CREATE_VM, 0); if (s->vmfd < 0) { #ifdef TARGET_S390X