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 12e101b8fd527fd40e8688b4db47a46246d60d65..d564a3068fcdb39ca80bf21d628fae45509bf0b2 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
@@ -90,7 +90,7 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = {
                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 79a4622dad04bfe8805d946137590bc5987ff247..6f4e05bada170d5dd460fe458736e001f0f24cda 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -236,6 +236,46 @@ void vgic_mmio_write_sactive(struct kvm_vcpu *vcpu,
        }
 }
 
+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 50b4464a073006817bc0ad3324a723789df4cee4..7e73f10bf646664ab55d8cbdf70fe7384f705214 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-mmio.h
+++ b/virt/kvm/arm/vgic/vgic-mmio.h
@@ -129,6 +129,13 @@ void vgic_mmio_write_sactive(struct kvm_vcpu *vcpu,
                             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 cf620157e1e4aec6c86a68eb6778494aea07fc8e..e57f8d54c79261b743a0d086746666b3c7671997 100644 (file)
--- 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,