From 74fa0bc7f083fbcce1ee0b9c3c2716fcb068fce4 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 2 Mar 2020 15:56:17 -0800 Subject: [PATCH] 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 Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 37 +++++++++++++------------------------ 1 file changed, 13 insertions(+), 24 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 1ae3b25..5044a595 100644 --- 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=, * 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; -- 2.7.4