* [PATCH] KVM: nVMX: Add support for activity state HLT
@ 2013-12-04 7:58 Jan Kiszka
2013-12-05 9:52 ` Paolo Bonzini
0 siblings, 1 reply; 4+ messages in thread
From: Jan Kiszka @ 2013-12-04 7:58 UTC (permalink / raw)
To: Gleb Natapov, Paolo Bonzini; +Cc: kvm
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@siemens.com>
---
Jailhouse would like to use this. Experimental code works fine so far,
both on patched KVM and real HW.
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
--
1.8.1.1.298.ge7eed54
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] KVM: nVMX: Add support for activity state HLT
2013-12-04 7:58 [PATCH] KVM: nVMX: Add support for activity state HLT Jan Kiszka
@ 2013-12-05 9:52 ` Paolo Bonzini
2013-12-06 12:49 ` Jan Kiszka
0 siblings, 1 reply; 4+ messages in thread
From: Paolo Bonzini @ 2013-12-05 9:52 UTC (permalink / raw)
To: Jan Kiszka; +Cc: Gleb Natapov, kvm
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@siemens.com>
> ---
>
> 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?
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
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] KVM: nVMX: Add support for activity state HLT
2013-12-05 9:52 ` Paolo Bonzini
@ 2013-12-06 12:49 ` Jan Kiszka
2013-12-10 7:45 ` Jan Kiszka
0 siblings, 1 reply; 4+ messages in thread
From: Jan Kiszka @ 2013-12-06 12:49 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: Gleb Natapov, kvm
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@siemens.com>
>> ---
>>
>> 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
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] KVM: nVMX: Add support for activity state HLT
2013-12-06 12:49 ` Jan Kiszka
@ 2013-12-10 7:45 ` Jan Kiszka
0 siblings, 0 replies; 4+ messages in thread
From: Jan Kiszka @ 2013-12-10 7:45 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: Gleb Natapov, kvm
[-- Attachment #1: Type: text/plain, Size: 2058 bytes --]
On 2013-12-06 13:49, Jan Kiszka wrote:
> 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@siemens.com>
>>> ---
>>>
>>> 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.
Test are still ongoing, but it seems there are problems remaining with
halting in L2 in general, i.e. with unintercepted hlt. I'm currently
applying this to get beyond some hangups, but I'm still experiencing
some delayed IRQ delivery to L2:
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 31eb577..fad04ce 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4684,6 +4684,7 @@ static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu)
vmcs12->vm_exit_reason =
EXIT_REASON_EXTERNAL_INTERRUPT;
vmcs12->vm_exit_intr_info = 0;
+ kvm_make_request(KVM_REQ_UNHALT, vcpu);
/*
* fall through to normal code, but now in L1, not L2
*/
@@ -8057,8 +8058,6 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
enter_guest_mode(vcpu);
- vmx->nested.nested_run_pending = 1;
-
vmx->nested.vmcs01_tsc_offset = vmcs_read64(TSC_OFFSET);
cpu = get_cpu();
@@ -8077,6 +8076,8 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT)
return kvm_emulate_halt(vcpu);
+ vmx->nested.nested_run_pending = 1;
+
/*
* 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
Jan
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 263 bytes --]
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-12-10 7:46 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-12-04 7:58 [PATCH] KVM: nVMX: Add support for activity state HLT Jan Kiszka
2013-12-05 9:52 ` Paolo Bonzini
2013-12-06 12:49 ` Jan Kiszka
2013-12-10 7:45 ` Jan Kiszka
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox