For pCPU/core and VCPUS/logical cpu mapping, It should be 8 multiple. 254 is reasonable. Or something I miss? -----Original Message----- From: kvm-owner@xxxxxxxxxxxxxxx [mailto:kvm-owner@xxxxxxxxxxxxxxx] On Behalf Of Vinod, Chegu Sent: Sunday, October 14, 2012 9:43 PM To: Gleb Natapov Cc: Sasha Levin; KVM Subject: Re: KVM_MAX_VCPUS On 10/14/2012 2:08 AM, Gleb Natapov wrote: > On Sat, Oct 13, 2012 at 10:32:13PM -0400, Sasha Levin wrote: >> On 10/13/2012 06:29 PM, Chegu Vinod wrote: >>> Hello, >>> >>> Wanted to get a clarification about KVM_MAX_VCPUS(currently set to 254) >>> in kvm_host.h file. The kvm_vcpu *vcpus array is sized based on KVM_MAX_VCPUS. >>> (i.e. a max of 254 elements in the array). >>> >>> An 8bit APIC id should allow for 256 ID's. Reserving one for Broadcast should >>> leave 255 ID's. Is there one more ID reserved for some other purpose ? (hence >>> leading to KVM_MAX_VCPUS being set to 254 and not 255). >> Another ID goes to the IO-APIC. >> > This is not really needed on KVM. We can enlarge KVM_MAX_VCPUS to 255. Thanks for clarification! ( We did suspect the IO-APIC...but weren't quite sure). Vinod > > -- > Gleb. > . > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
