diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/x86.c | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 58f517b5964..934b4c6b0bf 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2395,9 +2395,9 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, int i; entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; - for (i = 1; *nent < maxnent; ++i) { - if (entry[i - 1].eax == 0 && i != 2) - break; + for (i = 1; *nent < maxnent && i < 64; ++i) { + if (entry[i].eax == 0) + continue; do_cpuid_1_ent(&entry[i], function, i); entry[i].flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; @@ -4958,12 +4958,6 @@ struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, best = e; break; } - /* - * Both basic or both extended? - */ - if (((e->function ^ function) & 0x80000000) == 0) - if (!best || e->function > best->function) - best = e; } return best; } @@ -4983,6 +4977,27 @@ not_found: return 36; } +/* + * If no match is found, check whether we exceed the vCPU's limit + * and return the content of the highest valid _standard_ leaf instead. + * This is to satisfy the CPUID specification. + */ +static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, + u32 function, u32 index) +{ + struct kvm_cpuid_entry2 *maxlevel; + + maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); + if (!maxlevel || maxlevel->eax >= function) + return NULL; + if (function & 0x80000000) { + maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); + if (!maxlevel) + return NULL; + } + return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); +} + void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) { u32 function, index; @@ -4995,6 +5010,10 @@ void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) kvm_register_write(vcpu, VCPU_REGS_RCX, 0); kvm_register_write(vcpu, VCPU_REGS_RDX, 0); best = kvm_find_cpuid_entry(vcpu, function, index); + + if (!best) + best = check_cpuid_limit(vcpu, function, index); + if (best) { kvm_register_write(vcpu, VCPU_REGS_RAX, best->eax); kvm_register_write(vcpu, VCPU_REGS_RBX, best->ebx); |