[RFC PATCH 19/45] KVM: arm/arm64: vgic-new: Add CONFIG registers handlers

Andre Przywara
2016-03-25T02:04:54Z

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
virt/kvm/arm/vgic/vgic_mmio.c | 63 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 62 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c
index bfc530c..76657ce 100644
--- a/virt/kvm/arm/vgic/vgic_mmio.c
+++ b/virt/kvm/arm/vgic/vgic_mmio.c
@@ -410,6 +410,67 @@ static int vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
return 0;
}

+static int vgic_mmio_read_config(struct kvm_vcpu *vcpu,
+ struct kvm_io_device *this,
+ gpa_t addr, int len, void *val)
+{
+ struct vgic_io_device *iodev = container_of(this,
+ struct vgic_io_device, dev);
+ u32 intid = (addr - iodev->base_addr) * 4;
+ u32 value = 0;
+ int i;
+
+ if (iodev->redist_vcpu)
+ vcpu = iodev->redist_vcpu;
+
+ for (i = 0; i < len * 4; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ if (irq->config == VGIC_CONFIG_EDGE)
+ value |= (2U << (i * 2));
+ }
+
+ write_mask32(value, addr & 3, len, val);
+ return 0;
+}
+
+static int vgic_mmio_write_config(struct kvm_vcpu *vcpu,
+ struct kvm_io_device *this,
+ gpa_t addr, int len, const void *val)
+{
+ struct vgic_io_device *iodev = container_of(this,
+ struct vgic_io_device, dev);
+ u32 intid = (addr - iodev->base_addr) * 4;
+ int i;
+
+ if (iodev->redist_vcpu)
+ vcpu = iodev->redist_vcpu;
+
+ for (i = 0; i < len * 4; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ if (intid + i < 16)
+ continue;
+
+ /*
+ * The spec says that interrupts must be disabled before
+ * changing the configuration to avoid UNDEFINED behaviour.
+ * Is this sufficient in our case? Do we quickly enough remove
+ * the IRQ from the ap_list to safely do the config change?
+ * Will even a disabled interrupt in an ap_list cause us
+ * headaches if we change the configuration?
+ */
+ spin_lock(&irq->irq_lock);
+ if (test_bit(i * 2 + 1, val))
+ irq->config = VGIC_CONFIG_EDGE;
+ else
+ irq->config = VGIC_CONFIG_LEVEL;
+ spin_unlock(&irq->irq_lock);
+ }
+
+ return 0;
+}
+
struct vgic_register_region vgic_v2_dist_registers[] = {
REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL,
vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12),
@@ -432,7 +493,7 @@ struct vgic_register_region vgic_v2_dist_registers[] = {
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
- vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8),
+ vgic_mmio_read_config, vgic_mmio_write_config, 2),
REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT,
vgic_mmio_read_nyi, vgic_mmio_write_nyi, 4),
REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
--
2.7.3