KVM: x86: Hoist loop counter and terminator to top of __do_cpuid_func()

Declare "i" and "max_idx" at the top of __do_cpuid_func() to consolidate
a handful of declarations in various case statements.

More importantly, establish the pattern of using max_idx instead of e.g.
entry->eax as the loop terminator in preparation for refactoring how
entry is handled in __do_cpuid_func().

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 1ae3b25..5044a59 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -439,7 +439,7 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry)
 static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
                                  int *nent, int maxnent)
 {
-       int r;
+       int r, i, max_idx;
        unsigned f_nx = is_efer_nx() ? F(NX) : 0;
 #ifdef CONFIG_X86_64
        unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
@@ -535,20 +535,18 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
         * may return different values. This forces us to get_cpu() before
         * issuing the first command, and also to emulate this annoying behavior
         * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
-       case 2: {
-               int t, times = entry->eax & 0xff;
-
+       case 2:
                entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
-               for (t = 1; t < times; ++t) {
-                       if (!do_host_cpuid(&entry[t], nent, maxnent, function, 0))
+
+               for (i = 1, max_idx = entry->eax & 0xff; i < max_idx; ++i) {
+                       if (!do_host_cpuid(&entry[i], nent, maxnent, function, 0))
                                goto out;
                }
                break;
-       }
        /* functions 4 and 0x8000001d have additional index. */
        case 4:
        case 0x8000001d: {
-               int i, cache_type;
+               int cache_type;
 
                /* read more entries until cache_type is zero */
                for (i = 1; ; ++i) {
@@ -568,19 +566,16 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
                entry->edx = 0;
                break;
        /* function 7 has additional index. */
-       case 7: {
-               int i;
-
+       case 7:
                do_cpuid_7_mask(entry);
 
-               for (i = 1; i <= entry->eax; i++) {
+               for (i = 1, max_idx = entry->eax; i <= max_idx; i++) {
                        if (!do_host_cpuid(&entry[i], nent, maxnent, function, i))
                                goto out;
 
                        do_cpuid_7_mask(&entry[i]);
                }
                break;
-       }
        case 9:
                break;
        case 0xa: { /* Architectural Performance Monitoring */
@@ -617,9 +612,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
         * thus they can be handled by common code.
         */
        case 0x1f:
-       case 0xb: {
-               int i;
-
+       case 0xb:
                /*
                 * We filled in entry[0] for CPUID(EAX=<function>,
                 * ECX=00H) above.  If its level type (ECX[15:8]) is
@@ -633,9 +626,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
                                goto out;
                }
                break;
-       }
        case 0xd: {
-               int idx, i;
+               int idx;
                u64 supported = kvm_supported_xcr0();
 
                entry->eax &= supported;
@@ -684,18 +676,15 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
                break;
        }
        /* Intel PT */
-       case 0x14: {
-               int t, times = entry->eax;
-
+       case 0x14:
                if (!f_intel_pt)
                        break;
 
-               for (t = 1; t <= times; ++t) {
-                       if (!do_host_cpuid(&entry[t], nent, maxnent, function, t))
+               for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) {
+                       if (!do_host_cpuid(&entry[i], nent, maxnent, function, i))
                                goto out;
                }
                break;
-       }
        case KVM_CPUID_SIGNATURE: {
                static const char signature[12] = "KVMKVMKVM\0\0";
                const u32 *sigptr = (const u32 *)signature;