search for: msr_kvm_steal_tim

...+- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt > index 2a71c8f..3376f13 100644 > --- a/Documentation/virtual/kvm/msr.txt > +++ b/Documentation/virtual/kvm/msr.txt > @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 > __u64 steal; > __u32 version; > __u32 flags; > - __u32 pad[12]; > + __u8 preempted; > + __u32 pad[11]; > } I think I'd be explicit about the 3 pad bytes you've left. David

...+- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt > index 2a71c8f..3376f13 100644 > --- a/Documentation/virtual/kvm/msr.txt > +++ b/Documentation/virtual/kvm/msr.txt > @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 > __u64 steal; > __u32 version; > __u32 flags; > - __u32 pad[12]; > + __u8 preempted; > + __u32 pad[11]; > } I think I'd be explicit about the 3 pad bytes you've left. David

...+- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt > index 2a71c8f..3376f13 100644 > --- a/Documentation/virtual/kvm/msr.txt > +++ b/Documentation/virtual/kvm/msr.txt > @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 > __u64 steal; > __u32 version; > __u32 flags; > - __u32 pad[12]; > + __u8 preempted; > + __u32 pad[11]; > } > > whose data will be filled in by the hypervisor periodically. Only one > @@ -232,6 +233,11 @@ MSR_KVM_STEAL_TIME: 0x4b564d03...

...+- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt > index 2a71c8f..3376f13 100644 > --- a/Documentation/virtual/kvm/msr.txt > +++ b/Documentation/virtual/kvm/msr.txt > @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 > __u64 steal; > __u32 version; > __u32 flags; > - __u32 pad[12]; > + __u8 preempted; > + __u32 pad[11]; > } > > whose data will be filled in by the hypervisor periodically. Only one > @@ -232,6 +233,11 @@ MSR_KVM_STEAL_TIME: 0x4b564d03...

...tion/virtual/kvm/msr.txt | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt index 2a71c8f..3376f13 100644 --- a/Documentation/virtual/kvm/msr.txt +++ b/Documentation/virtual/kvm/msr.txt @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 __u64 steal; __u32 version; __u32 flags; - __u32 pad[12]; + __u8 preempted; + __u32 pad[11]; } whose data will be filled in by the hypervisor periodically. Only one @@ -232,6 +233,11 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 nanoseconds. Time during which the vcpu is idle...

...etion(-) >>> >>> diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt >>> index 2a71c8f..3376f13 100644 >>> --- a/Documentation/virtual/kvm/msr.txt >>> +++ b/Documentation/virtual/kvm/msr.txt >>> @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 >>> __u64 steal; >>> __u32 version; >>> __u32 flags; >>> - __u32 pad[12]; >>> + __u8 preempted; >>> + __u32 pad[11]; >>> } >> >> I think I'd be explicit about the 3 pad bytes you've left....

...etion(-) >>> >>> diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt >>> index 2a71c8f..3376f13 100644 >>> --- a/Documentation/virtual/kvm/msr.txt >>> +++ b/Documentation/virtual/kvm/msr.txt >>> @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 >>> __u64 steal; >>> __u32 version; >>> __u32 flags; >>> - __u32 pad[12]; >>> + __u8 preempted; >>> + __u32 pad[11]; >>> } >> >> I think I'd be explicit about the 3 pad bytes you've left....

change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc,

change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc,

...gt;>> Paolo, could you help out with an (x86) KVM interface for this? >> >> If it's just for spin loops, you can check if the version field in the >> steal time structure has changed. > > Steal time will not be updated until ahead of next vmentry except > wrmsr MSR_KVM_STEAL_TIME. So it can't represent it is preempted > currently, right? Hmm, you're right. We can use bit 0 of struct kvm_steal_time's flags to indicate that pad[0] is a "VCPU preempted" field; if pad[0] is 1, the VCPU has been scheduled out since the last time the guest reset the bi...

...gt;>> Paolo, could you help out with an (x86) KVM interface for this? >> >> If it's just for spin loops, you can check if the version field in the >> steal time structure has changed. > > Steal time will not be updated until ahead of next vmentry except > wrmsr MSR_KVM_STEAL_TIME. So it can't represent it is preempted > currently, right? Hmm, you're right. We can use bit 0 of struct kvm_steal_time's flags to indicate that pad[0] is a "VCPU preempted" field; if pad[0] is 1, the VCPU has been scheduled out since the last time the guest reset the bi...

On 06/07/2016 08:52, Peter Zijlstra wrote: > On Tue, Jun 28, 2016 at 10:43:07AM -0400, Pan Xinhui wrote: >> change fomr v1: >> a simplier definition of default vcpu_is_preempted >> skip mahcine type check on ppc, and add config. remove dedicated macro. >> add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. >> add more comments

On 06/07/2016 08:52, Peter Zijlstra wrote: > On Tue, Jun 28, 2016 at 10:43:07AM -0400, Pan Xinhui wrote: >> change fomr v1: >> a simplier definition of default vcpu_is_preempted >> skip mahcine type check on ppc, and add config. remove dedicated macro. >> add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. >> add more comments

The 6-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. one MSR is added to aid live migration. Changes

The 6-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. one MSR is added to aid live migration. Changes

...kvm_para.h > @@ -45,7 +45,8 @@ struct kvm_steal_time { > __u64 steal; > __u32 version; > __u32 flags; > - __u32 pad[12]; > + __u32 preempted; Why __u32 instead of __u8? > + __u32 pad[11]; > }; Please document the change in Documentation/virtual/kvm/msr.txt, section MSR_KVM_STEAL_TIME. > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > @@ -415,6 +415,15 @@ void kvm_disable_steal_time(void) > +static bool kvm_vcpu_is_preempted(int cpu) > +{ > + struct kvm_steal_time *src; > + > + src = &per_cpu(steal_time, cpu); > + > + return !!src-&g...

...kvm_para.h > @@ -45,7 +45,8 @@ struct kvm_steal_time { > __u64 steal; > __u32 version; > __u32 flags; > - __u32 pad[12]; > + __u32 preempted; Why __u32 instead of __u8? > + __u32 pad[11]; > }; Please document the change in Documentation/virtual/kvm/msr.txt, section MSR_KVM_STEAL_TIME. > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > @@ -415,6 +415,15 @@ void kvm_disable_steal_time(void) > +static bool kvm_vcpu_is_preempted(int cpu) > +{ > + struct kvm_steal_time *src; > + > + src = &per_cpu(steal_time, cpu); > + > + return !!src-&g...

...tch set >>> >> >> Paolo, could you help out with an (x86) KVM interface for this? > > If it's just for spin loops, you can check if the version field in the > steal time structure has changed. Steal time will not be updated until ahead of next vmentry except wrmsr MSR_KVM_STEAL_TIME. So it can't represent it is preempted currently, right? Regards, Wanpeng Li

...7 insertions(+), 1 deletion(-) >> >> diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt >> index 2a71c8f..3376f13 100644 >> --- a/Documentation/virtual/kvm/msr.txt >> +++ b/Documentation/virtual/kvm/msr.txt >> @@ -208,7 +208,8 @@ MSR_KVM_STEAL_TIME: 0x4b564d03 >> __u64 steal; >> __u32 version; >> __u32 flags; >> - __u32 pad[12]; >> + __u8 preempted; >> + __u32 pad[11]; >> } > > I think I'd be explicit about the 3 pad bytes you've left. Seconded. With that change are al...

...d you help out with an (x86) KVM interface for this? >>> >>> If it's just for spin loops, you can check if the version field in the >>> steal time structure has changed. >> >> Steal time will not be updated until ahead of next vmentry except >> wrmsr MSR_KVM_STEAL_TIME. So it can't represent it is preempted >> currently, right? > > Hmm, you're right. We can use bit 0 of struct kvm_steal_time's flags to > indicate that pad[0] is a "VCPU preempted" field; if pad[0] is 1, the > VCPU has been scheduled out since the last time...