[RFC PATCH 13/45] KVM: arm/arm64: vgic-new: Export register access interface
From: Christoffer Dall <hidden>
Date: 2016-03-31 09:24:46
Also in:
kvm, kvmarm
On Fri, Mar 25, 2016 at 02:04:36AM +0000, Andre Przywara wrote:
quoted hunk ↗ jump to hunk
Userland can access the emulated GIC to save and restore its state for initialization or migration purposes. The kvm_io_bus API requires an absolute gpa, which does not fit the KVM_DEV_ARM_VGIC_GRP_DIST_REGS user API, that only provides relative offsets. So we explicitly iterate our register list to connect userland to the VGIC. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <redacted> --- virt/kvm/arm/vgic/vgic.h | 2 ++ virt/kvm/arm/vgic/vgic_mmio.c | 45 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+)diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index 53730ba..a462e2b 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h@@ -25,6 +25,8 @@ void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu); void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu); void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr); void vgic_v2_set_underflow(struct kvm_vcpu *vcpu); +int vgic_v2_dist_access(struct kvm_vcpu *vcpu, bool is_write, + int offset, int len, void *val); #ifdef CONFIG_KVM_ARM_VGIC_V3 void vgic_v3_irq_change_affinity(struct kvm *kvm, u32 intid, u64 mpidr);diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c index 26c46e7..e1fd17f 100644 --- a/virt/kvm/arm/vgic/vgic_mmio.c +++ b/virt/kvm/arm/vgic/vgic_mmio.c@@ -113,6 +113,51 @@ struct vgic_register_region vgic_v2_dist_registers[] = { vgic_mmio_read_nyi, vgic_mmio_write_nyi, 16), }; +/* + * Using kvm_io_bus_* to access GIC registers directly from userspace does + * not work, since we would need the absolute IPA address of the register + * in question, but the userland interface only provides relative offsets. + * So we provide our own dispatcher function for that purpose here. + */ +static int vgic_mmio_access(struct kvm_vcpu *vcpu, + struct vgic_register_region *region, int nr_regions, + bool is_write, int offset, int len, void *val) +{
I suspect this is going to get rewored based on previous discussions with the IO api...
+ int i;
+ struct vgic_io_device dev;
+
+ for (i = 0; i < nr_regions; i++) {
+ int reg_size = region[i].len;
+
+ if (!reg_size)
+ reg_size = (region[i].bits_per_irq * 1024) / 8;
+
+ if ((offset < region[i].reg_offset) ||
+ (offset + len > region[i].reg_offset + reg_size))
+ continue;
+
+ dev.base_addr = region[i].reg_offset;
+ dev.redist_vcpu = vcpu;
+
+ if (is_write)
+ return region[i].ops.write(vcpu, &dev.dev,
+ offset, len, val);
+ else
+ return region[i].ops.read(vcpu, &dev.dev,
+ offset, len, val);
+ }
+
+ return -ENODEV;
+}
+
+int vgic_v2_dist_access(struct kvm_vcpu *vcpu, bool is_write,
+ int offset, int len, void *val)
+{
+ return vgic_mmio_access(vcpu, vgic_v2_dist_registers,
+ ARRAY_SIZE(vgic_v2_dist_registers),
+ is_write, offset, len, val);
+}
+this makes me wonder if the v2 region declarations and functions like this should go in a separate file? vgic/mmio-v2.c ?
int kvm_vgic_register_mmio_region(struct kvm *kvm, struct kvm_vcpu *vcpu, struct vgic_register_region *reg_desc, struct vgic_io_device *region, -- 2.7.3