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KVM: arm64: vgic: Split out mapping IRQs and setting irq_ops

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Prior to this change, the act of mapping a virtual IRQ to a physical
one also set the irq_ops. Unmapping then reset the irq_ops to NULL. So
far, this has been fine and hasn't caused any major issues.

Now, however, as GICv5 support is being added to KVM, it has become
apparent that conflating mapping/unmapping IRQs and setting/clearing
irq_ops can cause issues. The reason is that the upcoming GICv5
support introduces a set of default irq_ops for PPIs, and removing
this when unmapping will cause things to break rather horribly.

Split out the mapping/unmapping of IRQs from the setting/clearing of
irq_ops. The arch timer code is updated to set the irq_ops following a
successful map. The irq_ops are intentionally not removed again on an
unmap as the only irq_op introduced by the arch timer only takes
effect if the hw bit in struct vgic_irq is set. Therefore, it is safe
to leave this in place, and it avoids additional complexity when GICv5
support is introduced.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Link: https://patch.msgid.link/20260319154937.3619520-6-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Sascha Bischoff
2026-03-19 15:51:01 +00:00
committed by Marc Zyngier
parent cbd8c958be
commit 663594aafb
3 changed files with 36 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
arch/arm64/kvm/arch_timer.c
View File

@@ -740,13 +740,11 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
ret = kvm_vgic_map_phys_irq(vcpu,
map->direct_vtimer->host_timer_irq,
timer_irq(map->direct_vtimer),
&arch_timer_irq_ops);
timer_irq(map->direct_vtimer));
WARN_ON_ONCE(ret);
ret = kvm_vgic_map_phys_irq(vcpu,
map->direct_ptimer->host_timer_irq,
timer_irq(map->direct_ptimer),
&arch_timer_irq_ops);
timer_irq(map->direct_ptimer));
WARN_ON_ONCE(ret);
}
}
@@ -1543,6 +1541,7 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct timer_map map;
struct irq_ops *ops;
int ret;
if (timer->enabled)
@@ -1563,20 +1562,21 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
get_timer_map(vcpu, &map);
ops = &arch_timer_irq_ops;
for (int i = 0; i < nr_timers(vcpu); i++)
kvm_vgic_set_irq_ops(vcpu, timer_irq(vcpu_get_timer(vcpu, i)), ops);
ret = kvm_vgic_map_phys_irq(vcpu,
map.direct_vtimer->host_timer_irq,
timer_irq(map.direct_vtimer),
&arch_timer_irq_ops);
timer_irq(map.direct_vtimer));
if (ret)
return ret;
if (map.direct_ptimer) {
if (map.direct_ptimer)
ret = kvm_vgic_map_phys_irq(vcpu,
map.direct_ptimer->host_timer_irq,
timer_irq(map.direct_ptimer),
&arch_timer_irq_ops);
}
timer_irq(map.direct_ptimer));
if (ret)
return ret;