From aa10a7dc8858f6cbd1ef5cb86693592896ee27c7 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 2 Mar 2020 15:56:16 -0800 Subject: [PATCH] KVM: x86: Consolidate CPUID array max num entries checking Move the nent vs. maxnent check and nent increment into do_host_cpuid() to consolidate what is now identical code. To signal success vs. failure, return the entry and NULL respectively. A future patch will build on this to also move the entry retrieval into do_host_cpuid(). No functional change intended. Reviewed-by: Vitaly Kuznetsov Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 49 +++++++++++++++++-------------------------------- 1 file changed, 17 insertions(+), 32 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 52f0af4..1ae3b25 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -287,9 +287,14 @@ static __always_inline void cpuid_mask(u32 *word, int wordnum) *word &= boot_cpu_data.x86_capability[wordnum]; } -static void do_host_cpuid(struct kvm_cpuid_entry2 *entry, u32 function, - u32 index) +static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_entry2 *entry, + int *nent, int maxnent, + u32 function, u32 index) { + if (*nent >= maxnent) + return NULL; + ++*nent; + entry->function = function; entry->index = index; entry->flags = 0; @@ -316,6 +321,8 @@ static void do_host_cpuid(struct kvm_cpuid_entry2 *entry, u32 function, entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; break; } + + return entry; } static int __do_cpuid_func_emulated(struct kvm_cpuid_entry2 *entry, @@ -507,12 +514,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, r = -E2BIG; - if (WARN_ON(*nent >= maxnent)) + if (WARN_ON(!do_host_cpuid(entry, nent, maxnent, function, 0))) goto out; - do_host_cpuid(entry, function, 0); - ++*nent; - switch (function) { case 0: /* Limited to the highest leaf implemented in KVM. */ @@ -536,11 +540,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; for (t = 1; t < times; ++t) { - if (*nent >= maxnent) + if (!do_host_cpuid(&entry[t], nent, maxnent, function, 0)) goto out; - - do_host_cpuid(&entry[t], function, 0); - ++*nent; } break; } @@ -555,10 +556,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, if (!cache_type) break; - if (*nent >= maxnent) + if (!do_host_cpuid(&entry[i], nent, maxnent, function, i)) goto out; - do_host_cpuid(&entry[i], function, i); - ++*nent; } break; } @@ -575,12 +574,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, do_cpuid_7_mask(entry); for (i = 1; i <= entry->eax; i++) { - if (*nent >= maxnent) + if (!do_host_cpuid(&entry[i], nent, maxnent, function, i)) goto out; - do_host_cpuid(&entry[i], function, i); - ++*nent; - do_cpuid_7_mask(&entry[i]); } break; @@ -633,11 +629,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, * added entry is zero. */ for (i = 1; entry[i - 1].ecx & 0xff00; ++i) { - if (*nent >= maxnent) + if (!do_host_cpuid(&entry[i], nent, maxnent, function, i)) goto out; - - do_host_cpuid(&entry[i], function, i); - ++*nent; } break; } @@ -652,12 +645,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, if (!supported) break; - if (*nent >= maxnent) + if (!do_host_cpuid(&entry[1], nent, maxnent, function, 1)) goto out; - do_host_cpuid(&entry[1], function, 1); - ++*nent; - entry[1].eax &= kvm_cpuid_D_1_eax_x86_features; cpuid_mask(&entry[1].eax, CPUID_D_1_EAX); if (entry[1].eax & (F(XSAVES)|F(XSAVEC))) @@ -672,12 +662,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, if (!(supported & BIT_ULL(idx))) continue; - if (*nent >= maxnent) + if (!do_host_cpuid(&entry[i], nent, maxnent, function, idx)) goto out; - do_host_cpuid(&entry[i], function, idx); - ++*nent; - /* * The @supported check above should have filtered out * invalid sub-leafs as well as sub-leafs managed by @@ -704,10 +691,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, break; for (t = 1; t <= times; ++t) { - if (*nent >= maxnent) + if (!do_host_cpuid(&entry[t], nent, maxnent, function, t)) goto out; - do_host_cpuid(&entry[t], function, t); - ++*nent; } break; } -- 2.7.4