arm/arm64: KVM: vgic: delay vgic allocation until init time
It is now quite easy to delay the allocation of the vgic tables
until we actually require it to be up and running (when the first
vcpu is kicking around, or someones tries to access the GIC registers).
This allow us to allocate memory for the exact number of CPUs we
have. As nobody configures the number of interrupts just yet,
use a fallback to VGIC_NR_IRQS_LEGACY.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 725d829..ac2b44d 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1729,15 +1729,12 @@
* Initialize the vgic_cpu struct and vgic_dist struct fields pertaining to
* this vcpu and enable the VGIC for this VCPU
*/
-int kvm_vgic_vcpu_init(struct kvm_vcpu *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;
- if (vcpu->vcpu_id >= dist->nr_cpus)
- return -EBUSY;
-
for (i = 0; i < dist->nr_irqs; i++) {
if (i < VGIC_NR_PPIS)
vgic_bitmap_set_irq_val(&dist->irq_enabled,
@@ -1757,8 +1754,6 @@
vgic_cpu->nr_lr = vgic->nr_lr;
vgic_enable(vcpu);
-
- return 0;
}
void kvm_vgic_destroy(struct kvm *kvm)
@@ -1802,8 +1797,17 @@
int nr_cpus, nr_irqs;
int ret, i;
- nr_cpus = dist->nr_cpus = KVM_MAX_VCPUS;
+ if (dist->nr_cpus) /* Already allocated */
+ return 0;
+ nr_cpus = dist->nr_cpus = atomic_read(&kvm->online_vcpus);
+ if (!nr_cpus) /* No vcpus? Can't be good... */
+ return -EINVAL;
+
+ /*
+ * If nobody configured the number of interrupts, use the
+ * legacy one.
+ */
if (!dist->nr_irqs)
dist->nr_irqs = VGIC_NR_IRQS_LEGACY;
@@ -1849,6 +1853,9 @@
}
}
+ for (i = VGIC_NR_PRIVATE_IRQS; i < dist->nr_irqs; i += 4)
+ vgic_set_target_reg(kvm, 0, i);
+
out:
if (ret)
kvm_vgic_destroy(kvm);
@@ -1867,6 +1874,7 @@
*/
int kvm_vgic_init(struct kvm *kvm)
{
+ struct kvm_vcpu *vcpu;
int ret = 0, i;
if (!irqchip_in_kernel(kvm))
@@ -1884,6 +1892,12 @@
goto out;
}
+ ret = vgic_init_maps(kvm);
+ if (ret) {
+ kvm_err("Unable to allocate maps\n");
+ goto out;
+ }
+
ret = kvm_phys_addr_ioremap(kvm, kvm->arch.vgic.vgic_cpu_base,
vgic->vcpu_base, KVM_VGIC_V2_CPU_SIZE);
if (ret) {
@@ -1891,11 +1905,13 @@
goto out;
}
- for (i = VGIC_NR_PRIVATE_IRQS; i < kvm->arch.vgic.nr_irqs; i += 4)
- vgic_set_target_reg(kvm, 0, i);
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ kvm_vgic_vcpu_init(vcpu);
kvm->arch.vgic.ready = true;
out:
+ if (ret)
+ kvm_vgic_destroy(kvm);
mutex_unlock(&kvm->lock);
return ret;
}
@@ -1936,10 +1952,6 @@
kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
- ret = vgic_init_maps(kvm);
- if (ret)
- kvm_err("Unable to allocate maps\n");
-
out_unlock:
for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
@@ -2140,6 +2152,10 @@
mutex_lock(&dev->kvm->lock);
+ ret = vgic_init_maps(dev->kvm);
+ if (ret)
+ goto out;
+
if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) {
ret = -EINVAL;
goto out;