On 25/09/19 20:17, Jim Mattson wrote:
> Don't return -E2BIG from __do_cpuid_func when processing function 0BH
> or 1FH and the last interesting subleaf occupies the last allocated
> entry in the result array.
>
> Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Fixes: 831bf664e9c1fc ("KVM: Refactor and simplify kvm_dev_ioctl_get_supported_cpuid")
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
> ---
> arch/x86/kvm/cpuid.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index dd5985eb61b4c..a3ee9e110ba82 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -612,16 +612,20 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
> */
> case 0x1f:
> case 0xb: {
> - int i, level_type;
> + int i;
>
> - /* read more entries until level_type is zero */
> - for (i = 1; ; ++i) {
> + /*
> + * We filled in entry[0] for CPUID(EAX=<function>,
> + * ECX=00H) above. If its level type (ECX[15:8]) is
> + * zero, then the leaf is unimplemented, and we're
> + * done. Otherwise, continue to populate entries
> + * until the level type (ECX[15:8]) of the previously
> + * added entry is zero.
> + */
> + for (i = 1; entry[i - 1].ecx & 0xff00; ++i) {
> if (*nent >= maxnent)
> goto out;
>
> - level_type = entry[i - 1].ecx & 0xff00;
> - if (!level_type)
> - break;
> do_host_cpuid(&entry[i], function, i);
> ++*nent;
> }
>
Queued, thanks.
Paolo
