From c3199f28e09496aa9fec9313b4f6e90e7dc913f0 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Mon, 25 Apr 2016 01:11:37 +0200 Subject: [PATCH] KVM: arm/arm64: vgic-new: Export register access interface 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 Signed-off-by: Andre Przywara --- virt/kvm/arm/vgic/vgic-mmio-v2.c | 36 ++++++++++++++++++++++++++++++++ virt/kvm/arm/vgic/vgic.h | 2 ++ 2 files changed, 38 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c index 71896900ad12..a25512212bc7 100644 --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c @@ -296,3 +296,39 @@ int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr) return -ENXIO; } + +/* + * 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. + */ +static int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev, + bool is_write, int offset, u32 *val) +{ + unsigned int len = 4; + u8 buf[4]; + int ret; + + 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; +} + +int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write, + int offset, u32 *val) +{ + struct vgic_io_device dev = { + .regions = vgic_v2_dist_registers, + .nr_regions = ARRAY_SIZE(vgic_v2_dist_registers), + }; + + return vgic_uaccess(vcpu, &dev, is_write, offset, val); +} diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index a264c5ff476e..f8260268dd24 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -38,6 +38,8 @@ 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_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr); +int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write, + int offset, u32 *val); int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address, enum vgic_type); -- 2.20.1