Increase KVM_MAX_VCPUS to 4096 when the maximum number of supported CPUs (NR_CPUS) is greater than 1024. The Hyper-V TLFS doesn't allow more than 64 sparse banks, which allows a maximum of 4096 virtual CPUs. Limit KVM's maximum number of virtual CPUs to 4096 to avoid exceeding that limit. Notable changes: * KVM_MAX_VCPU_IDS will increase from 4096 to 16384. * KVM_HV_MAX_SPARSE_VCPU_SET_BITS will increase from 16 to 64. * CPUID[HYPERV_CPUID_IMPLEMENT_LIMITS (00x40000005)].EAX will now be 4096. * struct kvm will increase from 40336 B to 40720 B. * struct kvm_ioapic will increase from 5240 B to 19064 B. * vcpu_mask in kvm_hv_flush_tlb will increase from 128 B to 512 B. * vcpu_bitmap in ioapic_write_indirect will increase from 128 B to 512 B. * vp_bitmap in sparse_set_to_vcpu_mask will increase from 128 B to 512 B. Signed-off-by: Kyle Meyer <kyle.meyer@xxxxxxx> --- arch/x86/include/asm/kvm_host.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 9217bd6cf0d1..867a945f0152 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -38,7 +38,11 @@ #define __KVM_HAVE_ARCH_VCPU_DEBUGFS +#if NR_CPUS < 1024 #define KVM_MAX_VCPUS 1024 +#else +#define KVM_MAX_VCPUS 4096 +#endif /* * In x86, the VCPU ID corresponds to the APIC ID, and APIC IDs -- 2.26.2
