[PATCH v4 04/12] KVM: arm64: handle ITS related GICv3 redistributor registers

Hi Christoffer,
On 04/03/2016 12:08 PM, Christoffer Dall wrote:

On Sat, Mar 26, 2016 at 02:14:02AM +0000, Andre Przywara wrote:

quoted

In the GICv3 redistributor there are the PENDBASER and PROPBASER
registers which we did not emulate so far, as they only make sense
when having an ITS. In preparation for that emulate those MMIO
accesses by storing the 64-bit data written into it into a variable
which we later read in the ITS emulation.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 include/kvm/vgic/vgic.h       |  8 ++++++++
 virt/kvm/arm/vgic/vgic_mmio.c | 26 ++++++++++++++++++++++----
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
index 11344e6..8ea5dd7 100644
--- a/include/kvm/vgic/vgic.h
+++ b/include/kvm/vgic/vgic.h

@@ -145,6 +145,14 @@ struct vgic_dist {
 
 	struct vgic_io_device	*dist_iodevs;
 	struct vgic_io_device	*redist_iodevs;
+
+	/* Address of LPI configuration table shared by all redistributors */
+	u64			propbaser;

is this an architectural requirement or an implementation decision?

Looks like it is an architectural requirement:
GIC archi spec, 4.8.9 Configuring the Configuration and Pending Tables
for  states:
"Each redistributor shares a table containing the LPI configuration
(group, priority and enables) and has a separate table containing the
pending state for each LPI."

Eric

quoted

+
+	/* Addresses of LPI pending tables per redistributor */
+	u64			*pendbaser;

have we considered having an array of redistributors and putting the
field in each one of those instead?

quoted

+
+	bool			lpis_enabled;
 };
 
 struct vgic_v2_cpu_if {

diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c
index 7d5d630..252b9aff 100644
--- a/virt/kvm/arm/vgic/vgic_mmio.c
+++ b/virt/kvm/arm/vgic/vgic_mmio.c

@@ -771,7 +771,9 @@ static int vgic_mmio_read_v3r_propbase(struct kvm_vcpu *vcpu,
 				       struct kvm_io_device *this,
 				       gpa_t addr, int len, void *val)
 {
-	/* TODO: implement */
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+	write_mask64(dist->propbaser, addr & 7, len, val);
 	return 0;
 }
 

@@ -779,7 +781,11 @@ static int vgic_mmio_write_v3r_propbase(struct kvm_vcpu *vcpu,
 				        struct kvm_io_device *this,
 				        gpa_t addr, int len, const void *val)
 {
-	/* TODO: implement */
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+	/* Storing a value with LPIs already enabled is undefined */
+	if (!dist->lpis_enabled)
+		dist->propbaser = mask64(dist->propbaser, addr & 7, len, val);
 	return 0;
 }
 

@@ -787,7 +793,12 @@ static int vgic_mmio_read_v3r_pendbase(struct kvm_vcpu *vcpu,
 				       struct kvm_io_device *this,
 				       gpa_t addr, int len, void *val)
 {
-	/* TODO: implement */
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	struct vgic_io_device *iodev = container_of(this,
+						    struct vgic_io_device, dev);
+	u64 pendbaser = dist->pendbaser[iodev->redist_vcpu->vcpu_id];
+
+	write_mask64(pendbaser, addr & 7, len, val);
 	return 0;
 }
 

@@ -795,7 +806,14 @@ static int vgic_mmio_write_v3r_pendbase(struct kvm_vcpu *vcpu,
 				        struct kvm_io_device *this,
 				        gpa_t addr, int len, const void *val)
 {
-	/* TODO: implement */
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	struct vgic_io_device *iodev = container_of(this,
+						    struct vgic_io_device, dev);
+	u64 *pendbaser = &dist->pendbaser[iodev->redist_vcpu->vcpu_id];
+
+	/* Storing a value with LPIs already enabled is undefined */
+	if (!dist->lpis_enabled)
+		*pendbaser = mask64(*pendbaser, addr & 7, len, val);
 	return 0;
 }
 

-- 
2.7.3