| Message ID | 20180315203050.19791-3-andre.przywara@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | New VGIC(-v2) implementation | expand |
Hi Andre, On 15/03/18 20:30, Andre Przywara wrote: > If we change something in a vCPU that affects its runnability or > otherwise needs the vCPU's attention, we might need to tell the scheduler > about it. > We are using this in one place (vIRQ injection) at the moment, but will > need this at more places soon. > So let's factor out this functionality, using the already existing > vcpu_kick() prototype (used in x86 only so far), to make this available > to the rest of the Xen code. > Also adjust the perfcounter name to reflect the new usage. > > Signed-off-by: Andre Przywara <andre.przywara@linaro.org> Reviewed-by: Julien Grall <julien.grall@arm.com> Cheers, > --- > Changelog v1 ... v2: > - use vcpu_kick() name from x86 and existing prototype > - rename performance counter > > xen/arch/arm/domain.c | 12 ++++++++++++ > xen/arch/arm/vgic.c | 11 +++-------- > xen/include/asm-arm/perfc_defn.h | 3 ++- > 3 files changed, 17 insertions(+), 9 deletions(-) > > diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c > index bc10f412ba..4462e62599 100644 > --- a/xen/arch/arm/domain.c > +++ b/xen/arch/arm/domain.c > @@ -967,6 +967,18 @@ void vcpu_block_unless_event_pending(struct vcpu *v) > vcpu_unblock(current); > } > > +void vcpu_kick(struct vcpu *vcpu) > +{ > + bool running = vcpu->is_running; > + > + vcpu_unblock(vcpu); > + if ( running && vcpu != current ) > + { > + perfc_incr(vcpu_kick); > + smp_send_event_check_mask(cpumask_of(vcpu->processor)); > + } > +} > + > /* > * Local variables: > * mode: C > diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c > index eb09d9ca54..3fafdd0b66 100644 > --- a/xen/arch/arm/vgic.c > +++ b/xen/arch/arm/vgic.c > @@ -26,6 +26,7 @@ > #include <xen/sched.h> > #include <xen/perfc.h> > > +#include <asm/event.h> > #include <asm/current.h> > > #include <asm/mmio.h> > @@ -530,7 +531,6 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq, > uint8_t priority; > struct pending_irq *iter, *n; > unsigned long flags; > - bool running; > > /* > * For edge triggered interrupts we always ignore a "falling edge". > @@ -590,14 +590,9 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq, > list_add_tail(&n->inflight, &v->arch.vgic.inflight_irqs); > out: > spin_unlock_irqrestore(&v->arch.vgic.lock, flags); > + > /* we have a new higher priority irq, inject it into the guest */ > - running = v->is_running; > - vcpu_unblock(v); > - if ( running && v != current ) > - { > - perfc_incr(vgic_cross_cpu_intr_inject); > - smp_send_event_check_mask(cpumask_of(v->processor)); > - } > + vcpu_kick(v); > > return; > } > diff --git a/xen/include/asm-arm/perfc_defn.h b/xen/include/asm-arm/perfc_defn.h > index 87866264ca..8922e9525a 100644 > --- a/xen/include/asm-arm/perfc_defn.h > +++ b/xen/include/asm-arm/perfc_defn.h > @@ -33,6 +33,8 @@ PERFCOUNTER(vpsci_cpu_suspend, "vpsci: cpu_suspend") > PERFCOUNTER(vpsci_cpu_affinity_info, "vpsci: cpu_affinity_info") > PERFCOUNTER(vpsci_features, "vpsci: features") > > +PERFCOUNTER(vcpu_kick, "vcpu: notify other vcpu") > + > PERFCOUNTER(vgicd_reads, "vgicd: read") > PERFCOUNTER(vgicd_writes, "vgicd: write") > PERFCOUNTER(vgicr_reads, "vgicr: read") > @@ -44,7 +46,6 @@ PERFCOUNTER(vgic_sysreg_writes, "vgic: sysreg write") > PERFCOUNTER(vgic_sgi_list , "vgic: SGI send to list") > PERFCOUNTER(vgic_sgi_others, "vgic: SGI send to others") > PERFCOUNTER(vgic_sgi_self, "vgic: SGI send to self") > -PERFCOUNTER(vgic_cross_cpu_intr_inject, "vgic: cross-CPU irq inject") > PERFCOUNTER(vgic_irq_migrates, "vgic: irq migration") > > PERFCOUNTER(vuart_reads, "vuart: read") >
On Thu, 15 Mar 2018, Andre Przywara wrote: > If we change something in a vCPU that affects its runnability or > otherwise needs the vCPU's attention, we might need to tell the scheduler > about it. > We are using this in one place (vIRQ injection) at the moment, but will > need this at more places soon. > So let's factor out this functionality, using the already existing > vcpu_kick() prototype (used in x86 only so far), to make this available > to the rest of the Xen code. > Also adjust the perfcounter name to reflect the new usage. > > Signed-off-by: Andre Przywara <andre.przywara@linaro.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > Changelog v1 ... v2: > - use vcpu_kick() name from x86 and existing prototype > - rename performance counter > > xen/arch/arm/domain.c | 12 ++++++++++++ > xen/arch/arm/vgic.c | 11 +++-------- > xen/include/asm-arm/perfc_defn.h | 3 ++- > 3 files changed, 17 insertions(+), 9 deletions(-) > > diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c > index bc10f412ba..4462e62599 100644 > --- a/xen/arch/arm/domain.c > +++ b/xen/arch/arm/domain.c > @@ -967,6 +967,18 @@ void vcpu_block_unless_event_pending(struct vcpu *v) > vcpu_unblock(current); > } > > +void vcpu_kick(struct vcpu *vcpu) > +{ > + bool running = vcpu->is_running; > + > + vcpu_unblock(vcpu); > + if ( running && vcpu != current ) > + { > + perfc_incr(vcpu_kick); > + smp_send_event_check_mask(cpumask_of(vcpu->processor)); > + } > +} > + > /* > * Local variables: > * mode: C > diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c > index eb09d9ca54..3fafdd0b66 100644 > --- a/xen/arch/arm/vgic.c > +++ b/xen/arch/arm/vgic.c > @@ -26,6 +26,7 @@ > #include <xen/sched.h> > #include <xen/perfc.h> > > +#include <asm/event.h> > #include <asm/current.h> > > #include <asm/mmio.h> > @@ -530,7 +531,6 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq, > uint8_t priority; > struct pending_irq *iter, *n; > unsigned long flags; > - bool running; > > /* > * For edge triggered interrupts we always ignore a "falling edge". > @@ -590,14 +590,9 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq, > list_add_tail(&n->inflight, &v->arch.vgic.inflight_irqs); > out: > spin_unlock_irqrestore(&v->arch.vgic.lock, flags); > + > /* we have a new higher priority irq, inject it into the guest */ > - running = v->is_running; > - vcpu_unblock(v); > - if ( running && v != current ) > - { > - perfc_incr(vgic_cross_cpu_intr_inject); > - smp_send_event_check_mask(cpumask_of(v->processor)); > - } > + vcpu_kick(v); > > return; > } > diff --git a/xen/include/asm-arm/perfc_defn.h b/xen/include/asm-arm/perfc_defn.h > index 87866264ca..8922e9525a 100644 > --- a/xen/include/asm-arm/perfc_defn.h > +++ b/xen/include/asm-arm/perfc_defn.h > @@ -33,6 +33,8 @@ PERFCOUNTER(vpsci_cpu_suspend, "vpsci: cpu_suspend") > PERFCOUNTER(vpsci_cpu_affinity_info, "vpsci: cpu_affinity_info") > PERFCOUNTER(vpsci_features, "vpsci: features") > > +PERFCOUNTER(vcpu_kick, "vcpu: notify other vcpu") > + > PERFCOUNTER(vgicd_reads, "vgicd: read") > PERFCOUNTER(vgicd_writes, "vgicd: write") > PERFCOUNTER(vgicr_reads, "vgicr: read") > @@ -44,7 +46,6 @@ PERFCOUNTER(vgic_sysreg_writes, "vgic: sysreg write") > PERFCOUNTER(vgic_sgi_list , "vgic: SGI send to list") > PERFCOUNTER(vgic_sgi_others, "vgic: SGI send to others") > PERFCOUNTER(vgic_sgi_self, "vgic: SGI send to self") > -PERFCOUNTER(vgic_cross_cpu_intr_inject, "vgic: cross-CPU irq inject") > PERFCOUNTER(vgic_irq_migrates, "vgic: irq migration") > > PERFCOUNTER(vuart_reads, "vuart: read") > -- > 2.14.1 >
>>> On 15.03.18 at 21:30, <andre.przywara@linaro.org> wrote: > If we change something in a vCPU that affects its runnability or > otherwise needs the vCPU's attention, we might need to tell the scheduler > about it. > We are using this in one place (vIRQ injection) at the moment, but will > need this at more places soon. > So let's factor out this functionality, using the already existing > vcpu_kick() prototype (used in x86 only so far), to make this available > to the rest of the Xen code. Having just seen this among the commits having gone in recently - was it considered to make this a common function? The implementations currently differ, but I'm not sure I see why that needs to be. With x86's vcpu_kick_softirq() handler doing nothing I could see the ARM implementation be suitable for x86, just like I could see the x86 implementation be suitable for ARM. Jan
Hi Jan, On 03/20/2018 10:35 AM, Jan Beulich wrote: >>>> On 15.03.18 at 21:30, <andre.przywara@linaro.org> wrote: >> If we change something in a vCPU that affects its runnability or >> otherwise needs the vCPU's attention, we might need to tell the scheduler >> about it. >> We are using this in one place (vIRQ injection) at the moment, but will >> need this at more places soon. >> So let's factor out this functionality, using the already existing >> vcpu_kick() prototype (used in x86 only so far), to make this available >> to the rest of the Xen code. > > Having just seen this among the commits having gone in recently - > was it considered to make this a common function? The > implementations currently differ, but I'm not sure I see why that > needs to be. With x86's vcpu_kick_softirq() handler doing nothing > I could see the ARM implementation be suitable for x86, just like > I could see the x86 implementation be suitable for ARM. I considered it when reviewing the patch but discard it I wasn't entirely sure if it was possible to make it common and I wanted this series to move forward (it is 50 patches series)! I would be happy to consider any patch to make them common. My preference would tend to go towards the Arm solution as it has a slightly smaller overhead to kick a vCPU. Indeed the x86 version requires to raise a softirq and then send an IPI to the other CPU. Cheers,
>>> On 21.03.18 at 05:10, <julien.grall@arm.com> wrote: > On 03/20/2018 10:35 AM, Jan Beulich wrote: >>>>> On 15.03.18 at 21:30, <andre.przywara@linaro.org> wrote: >>> If we change something in a vCPU that affects its runnability or >>> otherwise needs the vCPU's attention, we might need to tell the scheduler >>> about it. >>> We are using this in one place (vIRQ injection) at the moment, but will >>> need this at more places soon. >>> So let's factor out this functionality, using the already existing >>> vcpu_kick() prototype (used in x86 only so far), to make this available >>> to the rest of the Xen code. >> >> Having just seen this among the commits having gone in recently - >> was it considered to make this a common function? The >> implementations currently differ, but I'm not sure I see why that >> needs to be. With x86's vcpu_kick_softirq() handler doing nothing >> I could see the ARM implementation be suitable for x86, just like >> I could see the x86 implementation be suitable for ARM. > I considered it when reviewing the patch but discard it I wasn't > entirely sure if it was possible to make it common and I wanted this > series to move forward (it is 50 patches series)! > > I would be happy to consider any patch to make them common. My > preference would tend to go towards the Arm solution as it has a > slightly smaller overhead to kick a vCPU. Indeed the x86 version > requires to raise a softirq and then send an IPI to the other CPU. Yes, that's my preference too. I'll send something after 4.11 has settled. Jan
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c index bc10f412ba..4462e62599 100644 --- a/xen/arch/arm/domain.c +++ b/xen/arch/arm/domain.c @@ -967,6 +967,18 @@ void vcpu_block_unless_event_pending(struct vcpu *v) vcpu_unblock(current); } +void vcpu_kick(struct vcpu *vcpu) +{ + bool running = vcpu->is_running; + + vcpu_unblock(vcpu); + if ( running && vcpu != current ) + { + perfc_incr(vcpu_kick); + smp_send_event_check_mask(cpumask_of(vcpu->processor)); + } +} + /* * Local variables: * mode: C diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c index eb09d9ca54..3fafdd0b66 100644 --- a/xen/arch/arm/vgic.c +++ b/xen/arch/arm/vgic.c @@ -26,6 +26,7 @@ #include <xen/sched.h> #include <xen/perfc.h> +#include <asm/event.h> #include <asm/current.h> #include <asm/mmio.h> @@ -530,7 +531,6 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq, uint8_t priority; struct pending_irq *iter, *n; unsigned long flags; - bool running; /* * For edge triggered interrupts we always ignore a "falling edge". @@ -590,14 +590,9 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq, list_add_tail(&n->inflight, &v->arch.vgic.inflight_irqs); out: spin_unlock_irqrestore(&v->arch.vgic.lock, flags); + /* we have a new higher priority irq, inject it into the guest */ - running = v->is_running; - vcpu_unblock(v); - if ( running && v != current ) - { - perfc_incr(vgic_cross_cpu_intr_inject); - smp_send_event_check_mask(cpumask_of(v->processor)); - } + vcpu_kick(v); return; } diff --git a/xen/include/asm-arm/perfc_defn.h b/xen/include/asm-arm/perfc_defn.h index 87866264ca..8922e9525a 100644 --- a/xen/include/asm-arm/perfc_defn.h +++ b/xen/include/asm-arm/perfc_defn.h @@ -33,6 +33,8 @@ PERFCOUNTER(vpsci_cpu_suspend, "vpsci: cpu_suspend") PERFCOUNTER(vpsci_cpu_affinity_info, "vpsci: cpu_affinity_info") PERFCOUNTER(vpsci_features, "vpsci: features") +PERFCOUNTER(vcpu_kick, "vcpu: notify other vcpu") + PERFCOUNTER(vgicd_reads, "vgicd: read") PERFCOUNTER(vgicd_writes, "vgicd: write") PERFCOUNTER(vgicr_reads, "vgicr: read") @@ -44,7 +46,6 @@ PERFCOUNTER(vgic_sysreg_writes, "vgic: sysreg write") PERFCOUNTER(vgic_sgi_list , "vgic: SGI send to list") PERFCOUNTER(vgic_sgi_others, "vgic: SGI send to others") PERFCOUNTER(vgic_sgi_self, "vgic: SGI send to self") -PERFCOUNTER(vgic_cross_cpu_intr_inject, "vgic: cross-CPU irq inject") PERFCOUNTER(vgic_irq_migrates, "vgic: irq migration") PERFCOUNTER(vuart_reads, "vuart: read")
If we change something in a vCPU that affects its runnability or otherwise needs the vCPU's attention, we might need to tell the scheduler about it. We are using this in one place (vIRQ injection) at the moment, but will need this at more places soon. So let's factor out this functionality, using the already existing vcpu_kick() prototype (used in x86 only so far), to make this available to the rest of the Xen code. Also adjust the perfcounter name to reflect the new usage. Signed-off-by: Andre Przywara <andre.przywara@linaro.org> --- Changelog v1 ... v2: - use vcpu_kick() name from x86 and existing prototype - rename performance counter xen/arch/arm/domain.c | 12 ++++++++++++ xen/arch/arm/vgic.c | 11 +++-------- xen/include/asm-arm/perfc_defn.h | 3 ++- 3 files changed, 17 insertions(+), 9 deletions(-)