Re: [PATCH 15/61] KVM: x86: Refactor CPUID 0x4 and 0x8000001d handling

From: Vitaly Kuznetsov
Date: Fri Feb 21 2020 - 09:40:16 EST


Sean Christopherson <sean.j.christopherson@xxxxxxxxx> writes:

> Refactoring the sub-leaf handling for CPUID 0x4/0x8000001d to eliminate
> a one-off variable and its associated brackets.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> ---
> arch/x86/kvm/cpuid.c | 16 ++++++----------
> 1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 5044a595799f..d75d539da759 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -545,20 +545,16 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
> break;
> /* functions 4 and 0x8000001d have additional index. */
> case 4:
> - case 0x8000001d: {
> - int cache_type;
> -
> - /* read more entries until cache_type is zero */
> - for (i = 1; ; ++i) {
> - cache_type = entry[i - 1].eax & 0x1f;
> - if (!cache_type)
> - break;
> -
> + case 0x8000001d:
> + /*
> + * Read entries until the cache type in the previous entry is
> + * zero, i.e. indicates an invalid entry.
> + */
> + for (i = 1; entry[i - 1].eax & 0x1f; ++i) {
> if (!do_host_cpuid(&entry[i], nent, maxnent, function, i))
> goto out;
> }
> break;
> - }
> case 6: /* Thermal management */
> entry->eax = 0x4; /* allow ARAT */
> entry->ebx = 0;

Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

--
Vitaly