[PATCH 4/4] KVM: arm/arm64: vgic: Allow VMs to configure interrupt groups

On Mon, Jun 25, 2018 at 09:19:07AM +0100, Marc Zyngier wrote:

quoted

On 24/06/18 23:11, Christoffer Dall wrote:

quoted

Implement the required MMIO accessors for GICv2 and GICv3 for the
IGROUPR distributor and redistributor registers.

This can allow guests to change behavior compared to running on previous
versions of KVM, but only to align with the architecture and hardware
implementations.

Signed-off-by: Christoffer Dall <redacted>
---
 virt/kvm/arm/vgic/vgic-mmio-v2.c |  2 +-
 virt/kvm/arm/vgic/vgic-mmio-v3.c |  2 +-
 virt/kvm/arm/vgic/vgic-mmio.c    | 38 ++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic-mmio.h    |  6 +++++
 4 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index 8d18f89397d3..ff3834d16ac9 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c

@@ -362,7 +362,7 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = {
 		vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, NULL, NULL, 1,
+		vgic_mmio_read_group, vgic_mmio_write_group, NULL, NULL, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
 		vgic_mmio_read_enable, vgic_mmio_write_senable, NULL, NULL, 1,

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 287784095b5b..76e422859745 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c

@@ -451,7 +451,7 @@ static const struct vgic_register_region vgic_v3_dist_registers[] = {
 		vgic_mmio_read_rao, vgic_mmio_write_wi, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IGROUPR,
-		vgic_mmio_read_rao, vgic_mmio_write_wi, NULL, NULL, 1,
+		vgic_mmio_read_group, vgic_mmio_write_group, NULL, NULL, 1,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISENABLER,
 		vgic_mmio_read_enable, vgic_mmio_write_senable, NULL, NULL, 1,

I think you're missing the GICR_IGROUPR accessor in the redistributor
(despite mentioning it in the commit message).

Indeed.  I fixed this up on my kernel.org branch (vgic-group-fixes), and
the fix is pretty trivial:

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 76e422859745..d2acad07dd30 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c

@@ -524,7 +524,7 @@ static const struct vgic_register_region vgic_v3_rdbase_registers[] = {
 
 static const struct vgic_register_region vgic_v3_sgibase_registers[] = {
 	REGISTER_DESC_WITH_LENGTH(GICR_IGROUPR0,
-		vgic_mmio_read_rao, vgic_mmio_write_wi, 4,
+		vgic_mmio_read_group, vgic_mmio_write_group, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GICR_ISENABLER0,
 		vgic_mmio_read_enable, vgic_mmio_write_senable, 4,

I did a test on the model using both GICv3 and GICv2-on-GICv3, seems
happy still.

Do you want me to send a v2, or do you prefer to fix this up locally?