Re: [kvm-devel] [PATCH 4/8] X86: export information about NPT to generic x86 code

Anthony Liguori
2008-01-25T21:40:27Z

Anthony Liguori wrote:
> Joerg Roedel wrote:
>> The generic x86 code has to know if the specific implementation uses
>> Nested
>> Paging. In the generic code Nested Paging is called Hardware Assisted
>> Paging
>> (HAP) to avoid confusion with (future) HAP implementations of other
>> vendors.
>> This patch exports the availability of HAP to the generic x86 code.
>>
>> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
>> ---
>> arch/x86/kvm/svm.c | 7 +++++++
>> arch/x86/kvm/vmx.c | 7 +++++++
>> include/asm-x86/kvm_host.h | 2 ++
>> 3 files changed, 16 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
>> index 2e718ff..d0bfdd8 100644
>> --- a/arch/x86/kvm/svm.c
>> +++ b/arch/x86/kvm/svm.c
>> @@ -1678,6 +1678,11 @@ static bool svm_cpu_has_accelerated_tpr(void)
>> return false;
>> }
>>
>> +static bool svm_hap_enabled(void)
>> +{
>> + return npt_enabled;
>> +}
>> +
>>
>
> To help with bisecting, you should probably return false here until
> the patch that actually implements NPT support. Otherwise, the 7th
> patch in this series breaks KVM for SVM.

Ignore this, you're already doing the right thing :-)

Regards,

Anthony Liguori

> Regards,
>
> Anthony Liguori
>
>> static struct kvm_x86_ops svm_x86_ops = {
>> .cpu_has_kvm_support = has_svm,
>> .disabled_by_bios = is_disabled,
>> @@ -1734,6 +1739,8 @@ static struct kvm_x86_ops svm_x86_ops = {
>> .inject_pending_vectors = do_interrupt_requests,
>>
>> .set_tss_addr = svm_set_tss_addr,
>> +
>> + .hap_enabled = svm_hap_enabled,
>> };
>>
>> static int __init svm_init(void)
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index 00a00e4..8feb775 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -2631,6 +2631,11 @@ static void __init
>> vmx_check_processor_compat(void *rtn)
>> }
>> }
>>
>> +static bool vmx_hap_enabled(void)
>> +{
>> + return false;
>> +}
>> +
>> static struct kvm_x86_ops vmx_x86_ops = {
>> .cpu_has_kvm_support = cpu_has_kvm_support,
>> .disabled_by_bios = vmx_disabled_by_bios,
>> @@ -2688,6 +2693,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
>> .inject_pending_vectors = do_interrupt_requests,
>>
>> .set_tss_addr = vmx_set_tss_addr,
>> +
>> + .hap_enabled = vmx_hap_enabled,
>> };
>>
>> static int __init vmx_init(void)
>> diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
>> index 67ae307..45a9d05 100644
>> --- a/include/asm-x86/kvm_host.h
>> +++ b/include/asm-x86/kvm_host.h
>> @@ -392,6 +392,8 @@ struct kvm_x86_ops {
>> struct kvm_run *run);
>>
>> int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
>> +
>> + bool (*hap_enabled)(void);
>> };
>>
>> extern struct kvm_x86_ops *kvm_x86_ops;
>>
>