| Message ID | 1407594349-9291-9-git-send-email-eric.auger@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 09.08.14 16:25, Eric Auger wrote: > set kvm_irqfds_allowed > > Signed-off-by: Eric Auger <eric.auger@linaro.org> > --- > hw/intc/arm_gic_kvm.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c > index 5038885..08b7bf9 100644 > --- a/hw/intc/arm_gic_kvm.c > +++ b/hw/intc/arm_gic_kvm.c > @@ -576,6 +576,8 @@ static void kvm_arm_gic_realize(DeviceState *dev, Error **errp) > KVM_DEV_ARM_VGIC_GRP_ADDR, > KVM_VGIC_V2_ADDR_TYPE_CPU, > s->dev_fd); > + > + kvm_irqfds_allowed = true; Is this always true? If it is, why not enable it separately while making vhost-net work for example? Alex
On 08/11/2014 11:37 AM, Alexander Graf wrote: > > On 09.08.14 16:25, Eric Auger wrote: >> set kvm_irqfds_allowed >> >> Signed-off-by: Eric Auger <eric.auger@linaro.org> >> --- >> hw/intc/arm_gic_kvm.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c >> index 5038885..08b7bf9 100644 >> --- a/hw/intc/arm_gic_kvm.c >> +++ b/hw/intc/arm_gic_kvm.c >> @@ -576,6 +576,8 @@ static void kvm_arm_gic_realize(DeviceState *dev, >> Error **errp) >> KVM_DEV_ARM_VGIC_GRP_ADDR, >> KVM_VGIC_V2_ADDR_TYPE_CPU, >> s->dev_fd); >> + >> + kvm_irqfds_allowed = true; > > Is this always true? If it is, why not enable it separately while making > vhost-net work for example? Hi Alex, yes I think so. As soon as KVM is enabled, KVM/arm would enable injection though irqfd. Defintively makes sense to test it with vhost-net too. Well a matter of priority ;-) Best Regards Eric > > Alex >
On 11.08.14 14:04, Eric Auger wrote: > On 08/11/2014 11:37 AM, Alexander Graf wrote: >> On 09.08.14 16:25, Eric Auger wrote: >>> set kvm_irqfds_allowed >>> >>> Signed-off-by: Eric Auger <eric.auger@linaro.org> >>> --- >>> hw/intc/arm_gic_kvm.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c >>> index 5038885..08b7bf9 100644 >>> --- a/hw/intc/arm_gic_kvm.c >>> +++ b/hw/intc/arm_gic_kvm.c >>> @@ -576,6 +576,8 @@ static void kvm_arm_gic_realize(DeviceState *dev, >>> Error **errp) >>> KVM_DEV_ARM_VGIC_GRP_ADDR, >>> KVM_VGIC_V2_ADDR_TYPE_CPU, >>> s->dev_fd); >>> + >>> + kvm_irqfds_allowed = true; >> Is this always true? If it is, why not enable it separately while making >> vhost-net work for example? > Hi Alex, > > yes I think so. As soon as KVM is enabled, KVM/arm would enable > injection though irqfd. Defintively makes sense to test it with > vhost-net too. Well a matter of priority ;-) More a matter of accuracy. What if you use new QEMU on old KVM which does have in-kernel GIC support, but no irqfd support? Alex
On 08/11/2014 02:05 PM, Alexander Graf wrote: > > On 11.08.14 14:04, Eric Auger wrote: >> On 08/11/2014 11:37 AM, Alexander Graf wrote: >>> On 09.08.14 16:25, Eric Auger wrote: >>>> set kvm_irqfds_allowed >>>> >>>> Signed-off-by: Eric Auger <eric.auger@linaro.org> >>>> --- >>>> hw/intc/arm_gic_kvm.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c >>>> index 5038885..08b7bf9 100644 >>>> --- a/hw/intc/arm_gic_kvm.c >>>> +++ b/hw/intc/arm_gic_kvm.c >>>> @@ -576,6 +576,8 @@ static void kvm_arm_gic_realize(DeviceState *dev, >>>> Error **errp) >>>> KVM_DEV_ARM_VGIC_GRP_ADDR, >>>> KVM_VGIC_V2_ADDR_TYPE_CPU, >>>> s->dev_fd); >>>> + >>>> + kvm_irqfds_allowed = true; >>> Is this always true? If it is, why not enable it separately while making >>> vhost-net work for example? >> Hi Alex, >> >> yes I think so. As soon as KVM is enabled, KVM/arm would enable >> injection though irqfd. Defintively makes sense to test it with >> vhost-net too. Well a matter of priority ;-) > > More a matter of accuracy. What if you use new QEMU on old KVM which > does have in-kernel GIC support, but no irqfd support? Hi Alex, VFIO device code also calls kvm_check_extension(kvm_state, KVM_CAP_IRQFD_RESAMPLE) which would return false if IRQFD is not enabled in old kernels. But with respect to vhost-net irqfd usage I cannot comment yet and you may be right ;-) Best Regards Eric > > > Alex >
On 11.08.14 14:27, Eric Auger wrote: > On 08/11/2014 02:05 PM, Alexander Graf wrote: >> On 11.08.14 14:04, Eric Auger wrote: >>> On 08/11/2014 11:37 AM, Alexander Graf wrote: >>>> On 09.08.14 16:25, Eric Auger wrote: >>>>> set kvm_irqfds_allowed >>>>> >>>>> Signed-off-by: Eric Auger <eric.auger@linaro.org> >>>>> --- >>>>> hw/intc/arm_gic_kvm.c | 2 ++ >>>>> 1 file changed, 2 insertions(+) >>>>> >>>>> diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c >>>>> index 5038885..08b7bf9 100644 >>>>> --- a/hw/intc/arm_gic_kvm.c >>>>> +++ b/hw/intc/arm_gic_kvm.c >>>>> @@ -576,6 +576,8 @@ static void kvm_arm_gic_realize(DeviceState *dev, >>>>> Error **errp) >>>>> KVM_DEV_ARM_VGIC_GRP_ADDR, >>>>> KVM_VGIC_V2_ADDR_TYPE_CPU, >>>>> s->dev_fd); >>>>> + >>>>> + kvm_irqfds_allowed = true; >>>> Is this always true? If it is, why not enable it separately while making >>>> vhost-net work for example? >>> Hi Alex, >>> >>> yes I think so. As soon as KVM is enabled, KVM/arm would enable >>> injection though irqfd. Defintively makes sense to test it with >>> vhost-net too. Well a matter of priority ;-) >> More a matter of accuracy. What if you use new QEMU on old KVM which >> does have in-kernel GIC support, but no irqfd support? > Hi Alex, > > VFIO device code also calls kvm_check_extension(kvm_state, > KVM_CAP_IRQFD_RESAMPLE) which would return false if IRQFD is not enabled > in old kernels. But with respect to vhost-net irqfd usage I cannot > comment yet and you may be right ;-) Yeah, please only set it when the kernel exposes that it supports irqfd ;). Alex
diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c index 5038885..08b7bf9 100644 --- a/hw/intc/arm_gic_kvm.c +++ b/hw/intc/arm_gic_kvm.c @@ -576,6 +576,8 @@ static void kvm_arm_gic_realize(DeviceState *dev, Error **errp) KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V2_ADDR_TYPE_CPU, s->dev_fd); + + kvm_irqfds_allowed = true; } static void kvm_arm_gic_class_init(ObjectClass *klass, void *data)
set kvm_irqfds_allowed Signed-off-by: Eric Auger <eric.auger@linaro.org> --- hw/intc/arm_gic_kvm.c | 2 ++ 1 file changed, 2 insertions(+)