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authorGreg Kurz <gkurz@linux.vnet.ibm.com>2016-05-09 18:13:37 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2016-05-11 22:37:54 +0200
commit0b1b1dfd52a67f4f09a18cb82337199bc90ad7fb (patch)
tree7d4ec00b96a96ef12fe3aeab042de758451e1bd4 /include/uapi
parent9b9e3fc4d5a31f6050508f2404369beac4356867 (diff)
kvm: introduce KVM_MAX_VCPU_ID
The KVM_MAX_VCPUS define provides the maximum number of vCPUs per guest, and also the upper limit for vCPU ids. This is okay for all archs except PowerPC which can have higher ids, depending on the cpu/core/thread topology. In the worst case (single threaded guest, host with 8 threads per core), it limits the maximum number of vCPUS to KVM_MAX_VCPUS / 8. This patch separates the vCPU numbering from the total number of vCPUs, with the introduction of KVM_MAX_VCPU_ID, as the maximal valid value for vCPU ids plus one. The corresponding KVM_CAP_MAX_VCPU_ID allows userspace to validate vCPU ids before passing them to KVM_CREATE_VCPU. This patch only implements KVM_MAX_VCPU_ID with a specific value for PowerPC. Other archs continue to return KVM_MAX_VCPUS instead. Suggested-by: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/uapi')
-rw-r--r--include/uapi/linux/kvm.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a7f1f8032ec1..05ebf475104c 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -865,6 +865,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_SPAPR_TCE_64 125
#define KVM_CAP_ARM_PMU_V3 126
#define KVM_CAP_VCPU_ATTRIBUTES 127
+#define KVM_CAP_MAX_VCPU_ID 128
#ifdef KVM_CAP_IRQ_ROUTING