Commit 11d483ce authored by Christoffer Dall's avatar Christoffer Dall Committed by Sasha Levin

arm/arm64: KVM: Initialize the vgic on-demand when injecting IRQs

commit ca7d9c82 upstream.

Userspace assumes that it can wire up IRQ injections after having
created all VCPUs and after having created the VGIC, but potentially
before starting the first VCPU.  This can currently lead to lost IRQs
because the state of that IRQ injection is not stored anywhere and we
don't return an error to userspace.

We haven't seen this problem manifest itself yet, presumably because
guests reset the devices on boot, but this could cause issues with
migration and other non-standard startup configurations.
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarShannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent d4d53f72
...@@ -1693,16 +1693,26 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid, ...@@ -1693,16 +1693,26 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num, int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
bool level) bool level)
{ {
int ret = 0;
int vcpu_id; int vcpu_id;
if (likely(vgic_initialized(kvm))) { if (unlikely(!vgic_initialized(kvm))) {
mutex_lock(&kvm->lock);
ret = vgic_init(kvm);
mutex_unlock(&kvm->lock);
if (ret)
goto out;
}
vcpu_id = vgic_update_irq_pending(kvm, cpuid, irq_num, level); vcpu_id = vgic_update_irq_pending(kvm, cpuid, irq_num, level);
if (vcpu_id >= 0) if (vcpu_id >= 0) {
/* kick the specified vcpu */ /* kick the specified vcpu */
kvm_vcpu_kick(kvm_get_vcpu(kvm, vcpu_id)); kvm_vcpu_kick(kvm_get_vcpu(kvm, vcpu_id));
} }
return 0; out:
return ret;
} }
static irqreturn_t vgic_maintenance_handler(int irq, void *data) static irqreturn_t vgic_maintenance_handler(int irq, void *data)
......
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