Messages in this thread | | | Date | Wed, 22 Feb 2017 14:16:29 +0100 | From | Christoffer Dall <> | Subject | Re: [RFC 30/55] KVM: arm/arm64: Inject irqs to the guest hypervisor |
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On Mon, Jan 09, 2017 at 01:24:26AM -0500, Jintack Lim wrote: > If we have a pending IRQ for the guest and the guest expects IRQs > to be handled in its virtual EL2 mode (the virtual IMO bit is set) > and it is not already running in virtual EL2 mode, then we have to > emulate an IRQ exception. > > Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > --- > virt/kvm/arm/vgic/vgic.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c > index 6440b56..4a98654 100644 > --- a/virt/kvm/arm/vgic/vgic.c > +++ b/virt/kvm/arm/vgic/vgic.c > @@ -17,6 +17,7 @@ > #include <linux/kvm.h> > #include <linux/kvm_host.h> > #include <linux/list_sort.h> > +#include <asm/kvm_emulate.h> > > #include "vgic.h" > > @@ -652,6 +653,28 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu) > /* Nuke remaining LRs */ > for ( ; count < kvm_vgic_global_state.nr_lr; count++) > vgic_clear_lr(vcpu, count); > + > + /* > + * If we have any pending IRQ for the guest and the guest expects IRQs > + * to be handled in its virtual EL2 mode (the virtual IMO bit is set) > + * and it is not already running in virtual EL2 mode, then we have to > + * emulate an IRQ exception to virtual IRQ. Note that a pending IRQ > + * means an irq of which state is pending but not active. > + */ > + if (vcpu_el2_imo_is_set(vcpu) && !vcpu_mode_el2(vcpu)) {
Is this correct?
Shouldn't you also inject this to virtual EL2 even when virtual EL2 is already running as long as the PSTATE.I bit is clear?
> + bool pending = false; > + > + list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
You need to take a lock when iterating over this list.
> + spin_lock(&irq->irq_lock); > + pending = irq->pending && irq->enabled && !irq->active; > + spin_unlock(&irq->irq_lock); > + > + if (pending) { > + kvm_inject_nested_irq(vcpu); > + break; > + } > + }
I would prefer to see this check that loops over the AP list as a separate function that you call, like vgic_vcpu_has_pending_irq.
> + } > } > > /* Sync back the hardware VGIC state into our emulation after a guest's run. */ > -- > 1.9.1 > >
Thanks, -Christoffer
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