Hi,

On 11/05/16 14:13, Marc Zyngier wrote:

On 11/05/16 13:34, Christoffer Dall wrote:

quoted

On Fri, May 06, 2016 at 11:45:37AM +0100, Andre Przywara wrote:

quoted

As the enable register handlers are shared between the v2 and v3
emulation, their implementation goes into vgic-mmio.c, to be easily
referenced from the v3 emulation as well later.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
Changelog RFC..v1:
- use lower bits of address to determine IRQ number
- remove TODO, confirmed to be fine

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

 virt/kvm/arm/vgic/vgic-mmio-v2.c |  4 +--
 virt/kvm/arm/vgic/vgic-mmio.c    | 56 ++++++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic-mmio.h    | 11 ++++++++
 3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index 69e96f7..448d1da 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c

@@ -72,9 +72,9 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = {
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
 		vgic_mmio_read_rao, vgic_mmio_write_wi, 1),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, 1),
+		vgic_mmio_read_enable, vgic_mmio_write_senable, 1),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, 1),
+		vgic_mmio_read_enable, vgic_mmio_write_cenable, 1),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
 		vgic_mmio_read_raz, vgic_mmio_write_wi, 1),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,

diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index 41cf4f4..077ae86 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c

@@ -46,6 +46,62 @@ void vgic_mmio_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
 	/* Ignore */
 }
 
+/*
+ * Read accesses to both GICD_ICENABLER and GICD_ISENABLER return the value
+ * of the enabled bit, so there is only one function for both here.
+ */
+unsigned long vgic_mmio_read_enable(struct kvm_vcpu *vcpu,
+				    gpa_t addr, unsigned int len)
+{
+	u32 intid = (addr & 0x7f) * 8;

is there anything we can do about this to make it more intuitive?  A
macro to generate the mask/offset based on bits per interrupt or
something?

Untested (and thus probably wrong):

#define VGIC_ADDR_IRQ_MASK(bits) ((1024 - 1) >> (4 - (bits))
#define VGIC_ADDR_IRQ_MULT(bits) (8 / (bits))
#define VGIC_ADDR_TO_INTID(addr, bits)  (((addr) & VGIC_ADDR_IRQ_MASK(bits)) * \
					 VGIC_ADDR_IRQ_MULT(bits))

Would:

#define VGIC_ADDR_IRQ_MASK(bits) GENMASK_ULL((bits) + 10 - 1 - 1, 0)
#define VGIC_ADDR_TO_INTID(addr, bits) (((addr) &		\
			VGIC_ADDR_IRQ_MASK(bits)) * 64 / (bits) / 8)

work for all bitnesses?

Cheers,
Andre.