lkml.org 
[lkml]   [2020]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH 02/61] KVM: x86: Refactor loop around do_cpuid_func() to separate helper
Date
Sean Christopherson <sean.j.christopherson@intel.com> writes:

> Move the guts of kvm_dev_ioctl_get_cpuid()'s CPUID func loop to a
> separate helper to improve code readability and pave the way for future
> cleanup.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
> arch/x86/kvm/cpuid.c | 45 ++++++++++++++++++++++++++------------------
> 1 file changed, 27 insertions(+), 18 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 47ce04762c20..f49fdd06f511 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -839,6 +839,29 @@ static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
> return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
> }
>
> +static int get_cpuid_func(struct kvm_cpuid_entry2 *entries, u32 func,
> + int *nent, int maxnent, unsigned int type)
> +{
> + u32 limit;
> + int r;
> +
> + r = do_cpuid_func(&entries[*nent], func, nent, maxnent, type);
> + if (r)
> + return r;
> +
> + limit = entries[*nent - 1].eax;
> + for (func = func + 1; func <= limit; ++func) {
> + if (*nent >= maxnent)
> + return -E2BIG;
> +
> + r = do_cpuid_func(&entries[*nent], func, nent, maxnent, type);
> + if (r)
> + break;
> + }
> +
> + return r;
> +}
> +
> static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
> __u32 num_entries, unsigned int ioctl_type)
> {
> @@ -871,8 +894,8 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
> unsigned int type)
> {
> struct kvm_cpuid_entry2 *cpuid_entries;
> - int limit, nent = 0, r = -E2BIG, i;
> - u32 func;
> + int nent = 0, r = -E2BIG, i;

Not this patches fault, but I just noticed that '-E2BIG' initializer
here is only being used for

'if (cpuid->nent < 1)'

case so I have two suggestion:
1) Return directly without the 'goto' , drop the initializer.
2) Return -EINVAL instead.

> +
> static const struct kvm_cpuid_param param[] = {
> { .func = 0 },
> { .func = 0x80000000 },
> @@ -901,22 +924,8 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
> if (ent->qualifier && !ent->qualifier(ent))
> continue;
>
> - r = do_cpuid_func(&cpuid_entries[nent], ent->func,
> - &nent, cpuid->nent, type);
> -
> - if (r)
> - goto out_free;
> -
> - limit = cpuid_entries[nent - 1].eax;
> - for (func = ent->func + 1; func <= limit && r == 0; ++func) {
> - if (nent >= cpuid->nent) {
> - r = -E2BIG;
> - goto out_free;
> - }
> - r = do_cpuid_func(&cpuid_entries[nent], func,
> - &nent, cpuid->nent, type);
> - }
> -
> + r = get_cpuid_func(cpuid_entries, ent->func, &nent,
> + cpuid->nent, type);
> if (r)
> goto out_free;
> }

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

--
Vitaly

\
 
 \ /
  Last update: 2020-02-06 16:00    [W:1.033 / U:5.704 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site