On 07/03/2012 08:34 PM, Marcelo Tosatti wrote:
> On Wed, Jun 27, 2012 at 06:24:50PM +0300, Avi Kivity wrote:
>> Introduce kvm_cpuid() to perform the leaf limit check and calculate
>> register values, and let kvm_emulate_cpuid() just handle reading and
>> writing the registers from/to the vcpu. This allows us to reuse
>> kvm_cpuid() in a context where directly reading and writing registers
>> is not desired.
>>
>> Signed-off-by: Avi Kivity <a...@redhat.com>
>> ---
>> arch/x86/kvm/cpuid.c | 38 ++++++++++++++++++++++++--------------
>> arch/x86/kvm/cpuid.h | 1 +
>> 2 files changed, 25 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
>> index 7df1c6d..44476fb 100644
>> --- a/arch/x86/kvm/cpuid.c
>> +++ b/arch/x86/kvm/cpuid.c
>> @@ -639,33 +639,43 @@ static struct kvm_cpuid_entry2*
>> check_cpuid_limit(struct kvm_vcpu *vcpu,
>> return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
>> }
>>
>> -void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
>> +void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32
>> *edx)
>> {
>> - u32 function, index;
>> + u32 function = *eax, index = *ecx;
>> struct kvm_cpuid_entry2 *best;
>>
>> - function = kvm_register_read(vcpu, VCPU_REGS_RAX);
>> - index = kvm_register_read(vcpu, VCPU_REGS_RCX);
>> - kvm_register_write(vcpu, VCPU_REGS_RAX, 0);
>> - kvm_register_write(vcpu, VCPU_REGS_RBX, 0);
>> - 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);
>> - kvm_register_write(vcpu, VCPU_REGS_RCX, best->ecx);
>> - kvm_register_write(vcpu, VCPU_REGS_RDX, best->edx);
>> - }
>> - kvm_x86_ops->skip_emulated_instruction(vcpu);
>> + *eax = best->eax;
>> + *ebx = best->ebx;
>> + *ecx = best->ecx;
>> + *edx = best->edx;
>> + } else
>> + *eax = *ebx = *ecx = *edx = 0;
>> +
>> trace_kvm_cpuid(function,
>> kvm_register_read(vcpu, VCPU_REGS_RAX),
>> kvm_register_read(vcpu, VCPU_REGS_RBX),
>> kvm_register_read(vcpu, VCPU_REGS_RCX),
>> kvm_register_read(vcpu, VCPU_REGS_RDX));
>> }
>> +
>> +void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
>> +{
>> + u32 function, eax, ebx, ecx, edx;
>> +
>> + function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
>> + ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
>> + kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
>> + kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
>> + kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
>> + kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
>> + kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
>> + kvm_x86_ops->skip_emulated_instruction(vcpu);
>> + trace_kvm_cpuid(function, eax, ebx, ecx, edx);
>> +}
>
> Tracing is duplicated. Is that intented?
The first instance is bogus, since it's reading vcpu registers which
might not have been the input to the function. I'll remove it.
--
error compiling committee.c: too many arguments to function
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