KVM: arm/arm64: vgic-new: Add PRIORITY registers handlers
The priority register handlers are shared between the v2 and v3
emulation, so their implementation goes into vgic-mmio.c, to be
easily referenced from the v3 emulation as well later.
There is a corner case when we change the priority of a pending
interrupt which we don't handle at the moment.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index 12e101b..d564a30 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
@@ -90,7 +90,7 @@
vgic_mmio_read_active, vgic_mmio_write_cactive, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI,
- vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
+ vgic_mmio_read_priority, vgic_mmio_write_priority, 8,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index 79a4622..6f4e05b 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -236,6 +236,46 @@
}
}
+unsigned long vgic_mmio_read_priority(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
+ int i;
+ u64 val = 0;
+
+ for (i = 0; i < len; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ val |= (u64)irq->priority << (i * 8);
+ }
+
+ return val;
+}
+
+/*
+ * We currently don't handle changing the priority of an interrupt that
+ * is already pending on a VCPU. If there is a need for this, we would
+ * need to make this VCPU exit and re-evaluate the priorities, potentially
+ * leading to this interrupt getting presented now to the guest (if it has
+ * been masked by the priority mask before).
+ */
+void vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val)
+{
+ u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
+ int i;
+
+ for (i = 0; i < len; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ spin_lock(&irq->irq_lock);
+ /* Narrow the priority range to what we actually support */
+ irq->priority = (val >> (i * 8)) & GENMASK(7, 8 - VGIC_PRI_BITS);
+ spin_unlock(&irq->irq_lock);
+ }
+}
+
static int match_region(const void *key, const void *elt)
{
const unsigned int offset = (unsigned long)key;
diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
index 50b4464..7e73f10 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.h
+++ b/virt/kvm/arm/vgic/vgic-mmio.h
@@ -129,6 +129,13 @@
gpa_t addr, unsigned int len,
unsigned long val);
+unsigned long vgic_mmio_read_priority(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len);
+
+void vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val);
+
unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev);
#endif
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index cf62015..e57f8d5 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -19,6 +19,8 @@
#define PRODUCT_ID_KVM 0x4b /* ASCII code K */
#define IMPLEMENTER_ARM 0x43b
+#define VGIC_PRI_BITS 5
+
#define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)
struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,