On Thu, Jul 25, 2019 at 11:12:40AM +0800, Yang Weijiang wrote:
> To make the code look clean, wrap CPUID(0xD,n>=1) enumeration
> code in a helper function now.
>
> Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
> ---
> arch/x86/kvm/cpuid.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 4992e7c99588..29cbde7538a3 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -313,6 +313,50 @@ static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
> return 0;
> }
>
> +static inline int __do_cpuid_dx_leaf(struct kvm_cpuid_entry2 *entry, int *nent,
'dx' makes me think of the generic reference to RDX vs EDX. Maybe
__do_cpuid_0xd_leaf()?
> + int maxnent, u64 xss_mask, u64 xcr0_mask,
> + u32 eax_mask)
> +{
> + int idx, i;
> + u64 mask;
> + u64 supported;
> +
> + for (idx = 1, i = 1; idx < 64; ++idx) {
Rather than loop here, I think it makes sense to loop in the caller to
make the code consistent with do_cpuid_7_mask() added by commit
54d360d41211 ("KVM: cpuid: extract do_cpuid_7_mask and support multiple subleafs")
> + mask = ((u64)1 << idx);
> + if (*nent >= maxnent)
> + return -EINVAL;
> +
> + do_cpuid_1_ent(&entry[i], 0xD, idx);
> + if (idx == 1) {
> + entry[i].eax &= eax_mask;
> + cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
> + supported = xcr0_mask | xss_mask;
> + entry[i].ebx = 0;
> + entry[i].edx = 0;
> + entry[i].ecx &= xss_mask;
> + if (entry[i].eax & (F(XSAVES) | F(XSAVEC))) {
> + entry[i].ebx =
> + xstate_required_size(supported,
> + true);
> + }
> + } else {
> + supported = (entry[i].ecx & 1) ? xss_mask :
> + xcr0_mask;
> + if (entry[i].eax == 0 || !(supported & mask))
> + continue;
> + entry[i].ecx &= 1;
> + entry[i].edx = 0;
> + if (entry[i].ecx)
> + entry[i].ebx = 0;
> + }
> + entry[i].flags |=
> + KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
> + ++*nent;
> + ++i;
> + }
> + return 0;
> +}
> +
Extracting code into a helper should be done in the same patch that the
existing code is replaced with a call to the helper, i.e. the chunk of the
next patch that invokes the helper should be squashed with this patch.
> static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
> u32 index, int *nent, int maxnent)
> {
> --
> 2.17.2
>
