On 2013-12-05 10:52, Paolo Bonzini wrote:
> Il 04/12/2013 08:58, Jan Kiszka ha scritto:
>> We can easily emulate the HLT activity state for L1: If it decides that
>> L2 shall be halted on entry, just invoke the normal emulation of halt
>> after switching to L2. We do not depend on specific host features to
>> provide this, so we can expose the capability unconditionally.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>> ---
>>
>> Jailhouse would like to use this. Experimental code works fine so far,
>> both on patched KVM and real HW.
>
> Nice. :)
>
> Do you have a testcase for kvm-unit-tests?
Not yet. Maybe I will find a little time these days.
Jan
>
> Paolo
>
>> arch/x86/include/asm/vmx.h | 1 +
>> arch/x86/kvm/vmx.c | 7 ++++++-
>> 2 files changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
>> index 966502d..2067264 100644
>> --- a/arch/x86/include/asm/vmx.h
>> +++ b/arch/x86/include/asm/vmx.h
>> @@ -100,6 +100,7 @@
>>
>> #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK 0x0000001f
>> #define VMX_MISC_SAVE_EFER_LMA 0x00000020
>> +#define VMX_MISC_ACTIVITY_HLT 0x00000040
>>
>> /* VMCS Encodings */
>> enum vmcs_field {
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index b2fe1c2..00faf1f 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -2279,6 +2279,7 @@ static __init void nested_vmx_setup_ctls_msrs(void)
>> rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
>> nested_vmx_misc_low &= VMX_MISC_PREEMPTION_TIMER_RATE_MASK |
>> VMX_MISC_SAVE_EFER_LMA;
>> + nested_vmx_misc_low |= VMX_MISC_ACTIVITY_HLT;
>> nested_vmx_misc_high = 0;
>> }
>>
>> @@ -7882,7 +7883,8 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
>> return 1;
>> }
>>
>> - if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE) {
>> + if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE &&
>> + vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT) {
>> nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
>> return 1;
>> }
>> @@ -8011,6 +8013,9 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
>>
>> prepare_vmcs02(vcpu, vmcs12);
>>
>> + if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT)
>> + return kvm_emulate_halt(vcpu);
>> +
>> /*
>> * Note no nested_vmx_succeed or nested_vmx_fail here. At this point
>> * we are no longer running L1, and VMLAUNCH/VMRESUME has not yet
>>
>
--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux
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