Messages in this thread | | | Date | Tue, 18 Feb 2020 09:41:21 +0000 | From | Marc Zyngier <> | Subject | Re: [PATCH v4 15/20] KVM: arm64: GICv4.1: Add direct injection capability to SGI registers |
| |
On 2020-02-18 08:46, Zenghui Yu wrote: > Hi Marc, > > On 2020/2/14 22:57, Marc Zyngier wrote: >> Most of the GICv3 emulation code that deals with SGIs now has to be >> aware of the v4.1 capabilities in order to benefit from it. >> >> Add such support, keyed on the interrupt having the hw flag set and >> being a SGI. >> >> Signed-off-by: Marc Zyngier <maz@kernel.org> >> --- >> virt/kvm/arm/vgic/vgic-mmio-v3.c | 15 +++++- >> virt/kvm/arm/vgic/vgic-mmio.c | 88 >> ++++++++++++++++++++++++++++++-- >> 2 files changed, 96 insertions(+), 7 deletions(-) >> >> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c >> b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> index ebc218840fc2..de89da76a379 100644 >> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c >> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> @@ -6,6 +6,7 @@ >> #include <linux/irqchip/arm-gic-v3.h> >> #include <linux/kvm.h> >> #include <linux/kvm_host.h> >> +#include <linux/interrupt.h> >> #include <kvm/iodev.h> >> #include <kvm/arm_vgic.h> >> @@ -942,8 +943,18 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu >> *vcpu, u64 reg, bool allow_group1) >> * generate interrupts of either group. >> */ >> if (!irq->group || allow_group1) { >> - irq->pending_latch = true; >> - vgic_queue_irq_unlock(vcpu->kvm, irq, flags); >> + if (!irq->hw) { >> + irq->pending_latch = true; >> + vgic_queue_irq_unlock(vcpu->kvm, irq, flags); >> + } else { >> + /* HW SGI? Ask the GIC to inject it */ >> + int err; >> + err = irq_set_irqchip_state(irq->host_irq, >> + IRQCHIP_STATE_PENDING, >> + true); >> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq); >> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); >> + } >> } else { >> raw_spin_unlock_irqrestore(&irq->irq_lock, flags); >> } >> diff --git a/virt/kvm/arm/vgic/vgic-mmio.c >> b/virt/kvm/arm/vgic/vgic-mmio.c >> index d656ebd5f9d4..0a1fb61e5b89 100644 >> --- a/virt/kvm/arm/vgic/vgic-mmio.c >> +++ b/virt/kvm/arm/vgic/vgic-mmio.c >> @@ -5,6 +5,8 @@ >> #include <linux/bitops.h> >> #include <linux/bsearch.h> >> +#include <linux/interrupt.h> >> +#include <linux/irq.h> >> #include <linux/kvm.h> >> #include <linux/kvm_host.h> >> #include <kvm/iodev.h> >> @@ -59,6 +61,11 @@ unsigned long vgic_mmio_read_group(struct kvm_vcpu >> *vcpu, >> return value; >> } >> +static void vgic_update_vsgi(struct vgic_irq *irq) >> +{ >> + WARN_ON(its_prop_update_vsgi(irq->host_irq, irq->priority, >> irq->group)); >> +} >> + >> void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr, >> unsigned int len, unsigned long val) >> { >> @@ -71,7 +78,12 @@ void vgic_mmio_write_group(struct kvm_vcpu *vcpu, >> gpa_t addr, >> raw_spin_lock_irqsave(&irq->irq_lock, flags); >> irq->group = !!(val & BIT(i)); >> - vgic_queue_irq_unlock(vcpu->kvm, irq, flags); >> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) { >> + vgic_update_vsgi(irq); >> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); >> + } else { >> + vgic_queue_irq_unlock(vcpu->kvm, irq, flags); >> + } >> vgic_put_irq(vcpu->kvm, irq); >> } >> @@ -113,7 +125,21 @@ void vgic_mmio_write_senable(struct kvm_vcpu >> *vcpu, >> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); >> raw_spin_lock_irqsave(&irq->irq_lock, flags); >> - if (vgic_irq_is_mapped_level(irq)) { >> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) { >> + if (!irq->enabled) { >> + struct irq_data *data; >> + >> + irq->enabled = true; >> + data = &irq_to_desc(irq->host_irq)->irq_data; >> + while (irqd_irq_disabled(data)) >> + enable_irq(irq->host_irq); >> + } >> + >> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); >> + vgic_put_irq(vcpu->kvm, irq); >> + >> + continue; >> + } else if (vgic_irq_is_mapped_level(irq)) { >> bool was_high = irq->line_level; >> /* >> @@ -148,6 +174,8 @@ void vgic_mmio_write_cenable(struct kvm_vcpu >> *vcpu, >> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); >> raw_spin_lock_irqsave(&irq->irq_lock, flags); >> + if (irq->hw && vgic_irq_is_sgi(irq->intid) && irq->enabled) >> + disable_irq_nosync(irq->host_irq); >> irq->enabled = false; >> @@ -167,10 +195,22 @@ unsigned long vgic_mmio_read_pending(struct >> kvm_vcpu *vcpu, >> for (i = 0; i < len * 8; i++) { >> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); >> unsigned long flags; >> + bool val; >> raw_spin_lock_irqsave(&irq->irq_lock, flags); >> - if (irq_is_pending(irq)) >> - value |= (1U << i); >> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) { >> + int err; >> + >> + val = false; >> + err = irq_get_irqchip_state(irq->host_irq, >> + IRQCHIP_STATE_PENDING, >> + &val); >> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq); >> + } else { >> + val = irq_is_pending(irq); >> + } >> + >> + value |= ((u32)val << i); >> raw_spin_unlock_irqrestore(&irq->irq_lock, flags); >> vgic_put_irq(vcpu->kvm, irq); >> @@ -227,6 +267,21 @@ void vgic_mmio_write_spending(struct kvm_vcpu >> *vcpu, >> } >> raw_spin_lock_irqsave(&irq->irq_lock, flags); >> + >> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) { >> + /* HW SGI? Ask the GIC to inject it */ >> + int err; >> + err = irq_set_irqchip_state(irq->host_irq, >> + IRQCHIP_STATE_PENDING, >> + true); >> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq); >> + >> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); >> + vgic_put_irq(vcpu->kvm, irq); >> + >> + continue; >> + } >> + >> if (irq->hw) >> vgic_hw_irq_spending(vcpu, irq, is_uaccess); >> else > > Should we consider taking the GICv4.1 support into uaccess_{read/write} > callbacks for GICR_ISPENDR0 so that userspace can properly save/restore > the pending state of GICv4.1 vSGIs? > > I *think* we can do it because on restoration, GICD_CTLR(.nASSGIreq) is > restored before GICR_ISPENDR0. So we know whether we're restoring > pending for vSGIs, and we can restore it to the HW level if v4.1 is > supported by GIC. Otherwise restore it by the normal way. > > And saving is easy with the get_irqchip_state callback, right?
Yes, this should be pretty easy to do, but I haven't completely worked out the ordering dependencies (you're way ahead of me here!).
There is still a chance that userspace will play with us trying to set and reset nASSGIreq, so we need to define what is acceptable...
> >> @@ -281,6 +336,20 @@ void vgic_mmio_write_cpending(struct kvm_vcpu >> *vcpu, >> raw_spin_lock_irqsave(&irq->irq_lock, flags); >> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) { >> + /* HW SGI? Ask the GIC to inject it */ > > "Ask the GIC to clear its pending state" :-)
One day, I'll ban copy/paste from my editor... ;-)
M. -- Jazz is not dead. It just smells funny...
| |