Re: [uq/master patch 1/2] kvm-all.c: use recommended max vcpus limit

[Paolo Bonzini <pbonzini@redhat.com>]

Il 12/08/2013 21:56, Marcelo Tosatti ha scritto:
> Commit 8c3ba334f8588e1d5099f8602cf01897720e0eca, "KVM: x86: Raise the
> hard VCPU count limit", upstream introduced the notion of a recommended
> vcpu max limit.
> 
> Switch the order so the recommended vcpu max limit is used instead of
> the actual max vcpu limit.
> 
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
> 
> Index: qemu/kvm-all.c
> ===================================================================
> --- qemu.orig/kvm-all.c
> +++ qemu/kvm-all.c
> @@ -1321,11 +1321,11 @@ static int kvm_max_vcpus(KVMState *s)
>       * 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);
> +    ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS);
>      if (ret) {
>          return ret;
>      }
> -    ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS);
> +    ret = kvm_check_extension(s, KVM_CAP_MAX_VCPUS);
>      if (ret) {
>          return ret;
>      }
> 
> 

This would break "working" configurations.  Perhaps we should just warn
if the VCPU limit exceeds KVM_CAP_NR_VCPUS, and fail if the VCPU limit
exceeds KVM_CAP_MAX_VCPUS.

Patch 2 is fine, ok to apply it (since it fixes a real bug) and then you
can work on top of it?

Paolo