From: Christoffer Dall <christoffer.dall@xxxxxxxxxx> 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 provide a wrapper to plug into our MMIO framework and find the respective register handler. Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> --- Changelog v1 .. v2: - adapt to new MMIO framework - handle endianess explicitly virt/kvm/arm/vgic/vgic-mmio-v2.c | 30 ++++++++++++++++++++++++++++++ virt/kvm/arm/vgic/vgic.h | 2 ++ 2 files changed, 32 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c index afee778..02814a0 100644 --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c @@ -60,3 +60,33 @@ unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev) return SZ_4K; } + +/* + * When userland tries to access the VGIC register handlers, we need to + * create a usable struct vgic_io_device to be passed to the handlers and we + * have to set up a buffer similar to what would have happened if a guest MMIO + * access occurred, including doing endian conversions on BE systems. + */ +int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write, + int offset, u32 *val) +{ + unsigned int len = 4; + u8 buf[4]; + int ret; + + struct vgic_io_device dev = { + .regions = vgic_v2_dist_registers, + .nr_regions = ARRAY_SIZE(vgic_v2_dist_registers), + }; + + if (is_write) { + vgic_data_host_to_mmio_bus(buf, len, *val); + ret = kvm_io_gic_ops.write(vcpu, &dev.dev, offset, len, buf); + } else { + ret = kvm_io_gic_ops.read(vcpu, &dev.dev, offset, len, buf); + if (!ret) + *val = vgic_data_mmio_bus_to_host(buf, len); + } + + return ret; +} diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index 0c92cda..008588b 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -28,6 +28,8 @@ 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_clear_lr(struct kvm_vcpu *vcpu, int lr); void vgic_v2_set_underflow(struct kvm_vcpu *vcpu); +int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write, + int offset, u32 *val); #ifdef CONFIG_KVM_ARM_VGIC_V3 void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu); -- 2.7.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html