KVM: x86: Refactor loop around do_cpuid_func() to separate helper

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.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 47ce047..f49fdd0 100644 (file)
--- 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;
+
        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;
        }