[PATCH v4 26/56] KVM: arm/arm64: vgic-new: Add PENDING registers handlers

[Andre Przywara]

The pending 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.
For level triggered interrupts the real line level is unaffected by
this write, so we keep this state separate and combine it with the
device's level to get the actual pending state.

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>
---
Changelog RFC..v1:
- remove IRQ lock from read handler
- remove TODO from clear pending handler

Changelog v1 .. v2:
- adapt to new MMIO framework

Changelog v3 .. v4:
- specify accessor width
- use IRQ number accessor macro
- replace extract_bytes() with simple return

 virt/kvm/arm/vgic/vgic-mmio-v2.c |  4 +--
 virt/kvm/arm/vgic/vgic-mmio.c    | 60 ++++++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic-mmio.h    | 12 ++++++++
 3 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index d5355b5..c13a708 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
@@ -78,10 +78,10 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = {
 		vgic_mmio_read_enable, vgic_mmio_write_cenable, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, 1,
+		vgic_mmio_read_pending, vgic_mmio_write_spending, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, 1,
+		vgic_mmio_read_pending, vgic_mmio_write_cpending, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET,
 		vgic_mmio_read_raz, vgic_mmio_write_wi, 1,
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index 32ed8db..d8dc8f6 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -95,6 +95,66 @@ void vgic_mmio_write_cenable(struct kvm_vcpu *vcpu,
 	}
 }
 
+unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu,
+				     gpa_t addr, unsigned int len)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	u32 value = 0;
+	int i;
+
+	/* Loop over all IRQs affected by this read */
+	for (i = 0; i < len * 8; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		if (irq->pending)
+			value |= (1U << i);
+	}
+
+	return value;
+}
+
+void vgic_mmio_write_spending(struct kvm_vcpu *vcpu,
+			      gpa_t addr, unsigned int len,
+			      unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		spin_lock(&irq->irq_lock);
+		irq->pending = true;
+		if (irq->config == VGIC_CONFIG_LEVEL)
+			irq->soft_pending = true;
+
+		vgic_queue_irq_unlock(vcpu->kvm, irq);
+	}
+}
+
+void vgic_mmio_write_cpending(struct kvm_vcpu *vcpu,
+			      gpa_t addr, unsigned int len,
+			      unsigned long val)
+{
+	u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+	int i;
+
+	for_each_set_bit(i, &val, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		spin_lock(&irq->irq_lock);
+
+		if (irq->config == VGIC_CONFIG_LEVEL) {
+			irq->soft_pending = false;
+			irq->pending = irq->line_level;
+		} else {
+			irq->pending = false;
+		}
+
+		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 66fd6fa..01db98a 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.h
+++ b/virt/kvm/arm/vgic/vgic-mmio.h
@@ -95,6 +95,18 @@ void vgic_mmio_write_cenable(struct kvm_vcpu *vcpu,
 			     gpa_t addr, unsigned int len,
 			     unsigned long val);
 
+unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu,
+				     gpa_t addr, unsigned int len);
+
+void vgic_mmio_write_spending(struct kvm_vcpu *vcpu,
+			      gpa_t addr, unsigned int len,
+			      unsigned long val);
+
+void vgic_mmio_write_cpending(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
-- 
2.8.2