VGIC initialization currently happens in three phases:
(1) kvm_vgic_create() (triggered by userspace GIC creation)
(2) vgic_init_maps() (triggered by userspace GIC register read/write
requests, or from kvm_vgic_init() if not already run)
(3) kvm_vgic_init() (triggered by first VM run)
We were doing initialization of some state to correspond with the
state of a freshly-reset GIC in kvm_vgic_init(); this is too late,
since it will overwrite changes made by userspace using the
register access APIs before the VM is run. Move this initialization
earlier, into the vgic_init_maps() phase.
This fixes a bug where QEMU could successfully restore a saved
VM state snapshot into a VM that had already been run, but could
not restore it "from cold" using the -loadvm command line option
(the symptoms being that the restored VM would run but interrupts
were ignored).
Signed-off-by: Peter Maydell <peter.maydell@xxxxxxxxxx>
---
You could make a good argument for renaming vgic_init_maps() and
kvm_vgic_init() (eg vgic_init() and vgic_first_run() ?)...
virt/kvm/arm/vgic.c | 49 ++++++++++++++++---------------------------------
1 file changed, 16 insertions(+), 33 deletions(-)
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 3aaca49..d2bc745 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1726,39 +1726,14 @@ static int vgic_vcpu_init_maps(struct kvm_vcpu *vcpu, int nr_irqs)
int sz = (nr_irqs - VGIC_NR_PRIVATE_IRQS) / 8;
vgic_cpu->pending_shared = kzalloc(sz, GFP_KERNEL);
- vgic_cpu->vgic_irq_lr_map = kzalloc(nr_irqs, GFP_KERNEL);
+ vgic_cpu->vgic_irq_lr_map = kmalloc(nr_irqs, GFP_KERNEL);
if (!vgic_cpu->pending_shared || !vgic_cpu->vgic_irq_lr_map) {
kvm_vgic_vcpu_destroy(vcpu);
return -ENOMEM;
}
- return 0;
-}
-
-/**
- * kvm_vgic_vcpu_init - Initialize per-vcpu VGIC state
- * @vcpu: pointer to the vcpu struct
- *
- * Initialize the vgic_cpu struct and vgic_dist struct fields pertaining to
- * this vcpu and enable the VGIC for this VCPU
- */
-static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
-{
- struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
- struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
- int i;
-
- for (i = 0; i < dist->nr_irqs; i++) {
- if (i < VGIC_NR_PPIS)
- vgic_bitmap_set_irq_val(&dist->irq_enabled,
- vcpu->vcpu_id, i, 1);
- if (i < VGIC_NR_PRIVATE_IRQS)
- vgic_bitmap_set_irq_val(&dist->irq_cfg,
- vcpu->vcpu_id, i, VGIC_CFG_EDGE);
-
- vgic_cpu->vgic_irq_lr_map[i] = LR_EMPTY;
- }
+ memset(vgic_cpu->vgic_irq_lr_map, LR_EMPTY, nr_irqs);
/*
* Store the number of LRs per vcpu, so we don't have to go
@@ -1767,7 +1742,7 @@ static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
*/
vgic_cpu->nr_lr = vgic->nr_lr;
- vgic_enable(vcpu);
+ return 0;
}
void kvm_vgic_destroy(struct kvm *kvm)
@@ -1865,11 +1840,23 @@ static int vgic_init_maps(struct kvm *kvm)
kvm_err("VGIC: Failed to allocate vcpu memory\n");
break;
}
+ for (i = 0; i < dist->nr_irqs; i++) {
+ if (i < VGIC_NR_PPIS)
+ vgic_bitmap_set_irq_val(&dist->irq_enabled,
+ vcpu->vcpu_id, i, 1);
+ if (i < VGIC_NR_PRIVATE_IRQS)
+ vgic_bitmap_set_irq_val(&dist->irq_cfg,
+ vcpu->vcpu_id, i,
+ VGIC_CFG_EDGE);
+ }
}
for (i = VGIC_NR_PRIVATE_IRQS; i < dist->nr_irqs; i += 4)
vgic_set_target_reg(kvm, 0, i);
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ vgic_enable(vcpu);
+
out:
if (ret)
kvm_vgic_destroy(kvm);
@@ -1888,8 +1875,7 @@ out:
*/
int kvm_vgic_init(struct kvm *kvm)
{
- struct kvm_vcpu *vcpu;
- int ret = 0, i;
+ int ret = 0;
if (!irqchip_in_kernel(kvm))
return 0;
@@ -1920,9 +1906,6 @@ int kvm_vgic_init(struct kvm *kvm)
goto out;
}
- kvm_for_each_vcpu(i, vcpu, kvm)
- kvm_vgic_vcpu_init(vcpu);
-
kvm->arch.vgic.ready = true;
out:
if (ret)
--
2.1.1
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