[RFC PATCH v1 2/4] arm/arm64: vgic-new: Add distributor and redistributor access
Christoffer Dall
christoffer.dall at linaro.org
Tue Aug 2 07:43:49 PDT 2016
On Wed, Jul 20, 2016 at 06:32:26PM +0530, vijay.kilari at gmail.com wrote:
> From: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
>
> VGICv3 Distributor and Redistributor registers are accessed using
> KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_DIST_REGS
> with KVM_SET_DEVICE_ATTR and KVM_GET_DEVICE_ATTR ioctls.
> These registers are accessed as 32-bit and cpu mpidr
> value passed along with register offset is used to identify the
> cpu for redistributor registers access.
>
> The draft version of VGIC v3 specification is define here
> https://lists.cs.columbia.edu/pipermail/kvmarm/2016-May/020355.html
>
> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
> ---
> arch/arm64/include/uapi/asm/kvm.h | 3 +
> virt/kvm/arm/vgic/vgic-kvm-device.c | 72 ++++++++++++++++++++++--
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 105 +++++++++++++++++++++++++++++++++++
> virt/kvm/arm/vgic/vgic-mmio.c | 2 +-
> virt/kvm/arm/vgic/vgic.h | 8 +++
> 5 files changed, 183 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index f209ea1..a6b996e 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -199,10 +199,13 @@ struct kvm_arch_memory_slot {
> #define KVM_DEV_ARM_VGIC_GRP_CPU_REGS 2
> #define KVM_DEV_ARM_VGIC_CPUID_SHIFT 32
> #define KVM_DEV_ARM_VGIC_CPUID_MASK (0xffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT)
> +#define KVM_DEV_ARM_VGIC_V3_CPUID_MASK \
> + (0xffffffffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT)
> #define KVM_DEV_ARM_VGIC_OFFSET_SHIFT 0
> #define KVM_DEV_ARM_VGIC_OFFSET_MASK (0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT)
> #define KVM_DEV_ARM_VGIC_GRP_NR_IRQS 3
> #define KVM_DEV_ARM_VGIC_GRP_CTRL 4
> +#define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
> #define KVM_DEV_ARM_VGIC_CTRL_INIT 0
>
> /* Device Control API on vcpu fd */
> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
> index cace996..996a720 100644
> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c
> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
> @@ -266,10 +266,17 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
> int cpuid, ret, c;
> struct kvm_vcpu *vcpu, *tmp_vcpu;
> int vcpu_lock_idx = -1;
> + struct vgic_dist *vgic = &dev->kvm->arch.vgic;
>
> - cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
> - KVM_DEV_ARM_VGIC_CPUID_SHIFT;
> - vcpu = kvm_get_vcpu(dev->kvm, cpuid);
> + if (vgic->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2) {
> + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
> + KVM_DEV_ARM_VGIC_CPUID_SHIFT;
> + vcpu = kvm_get_vcpu(dev->kvm, cpuid);
> + } else {
> + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_V3_CPUID_MASK) >>
> + KVM_DEV_ARM_VGIC_CPUID_SHIFT;
> + vcpu = kvm_mpidr_to_vcpu(dev->kvm, cpuid);
> + }
> addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
>
> mutex_lock(&dev->kvm->lock);
> @@ -301,7 +308,19 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
> ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, ®->reg32);
> break;
> case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
> - ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, ®->reg32);
> + if (vgic->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
> + ret = vgic_v2_dist_uaccess(vcpu, is_write, addr,
> + ®->reg32);
> + else
> + ret = vgic_v3_dist_uaccess(vcpu, is_write, addr,
> + ®->reg32);
> + break;
> + case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
> + if (vgic->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
> + ret = vgic_v3_redist_uaccess(vcpu, is_write, addr,
> + ®->reg32);
> + else
> + ret = -EINVAL;
> break;
> default:
> ret = -EINVAL;
> @@ -411,13 +430,51 @@ struct kvm_device_ops kvm_arm_vgic_v2_ops = {
> static int vgic_v3_set_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> - return vgic_set_common_attr(dev, attr);
> + int ret;
> +
> + ret = vgic_set_common_attr(dev, attr);
> + if (ret != -ENXIO)
> + return ret;
> +
> + switch (attr->group) {
> + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
> + case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS: {
> + u32 __user *uaddr = (u32 __user *)(long)attr->addr;
> + union ureg reg;
> +
> + if (get_user(reg.reg32, uaddr))
> + return -EFAULT;
> +
> + return vgic_attr_regs_access(dev, attr, ®, true);
> + }
> + }
> + return -ENXIO;
> }
>
> static int vgic_v3_get_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> - return vgic_get_common_attr(dev, attr);
> + int ret;
> +
> + ret = vgic_get_common_attr(dev, attr);
> + if (ret != -ENXIO)
> + return ret;
> +
> + switch (attr->group) {
> + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
> + case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS: {
> + u32 __user *uaddr = (u32 __user *)(long)attr->addr;
> + union ureg reg;
> +
> + ret = vgic_attr_regs_access(dev, attr, ®, false);
> + if (ret)
> + return ret;
> + ret = put_user(reg.reg32, uaddr);
> + return ret;
> + }
> + }
> +
> + return -ENXIO;
> }
>
> static int vgic_v3_has_attr(struct kvm_device *dev,
> @@ -431,6 +488,9 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
> return 0;
> }
> break;
> + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
> + case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
> + return vgic_v3_has_attr_regs(dev, attr);
> case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
> return 0;
> case KVM_DEV_ARM_VGIC_GRP_CTRL:
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index a0c515a..f6a4e97 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -18,6 +18,8 @@
> #include <kvm/arm_vgic.h>
>
> #include <asm/kvm_emulate.h>
> +#include <asm/kvm_arm.h>
> +#include <asm/kvm_mmu.h>
>
> #include "vgic.h"
> #include "vgic-mmio.h"
> @@ -226,6 +228,9 @@ static const struct vgic_register_region vgic_v3_rdbase_registers[] = {
> REGISTER_DESC_WITH_LENGTH(GICR_TYPER,
> vgic_mmio_read_v3r_typer, vgic_mmio_write_wi, 8,
> VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
> + REGISTER_DESC_WITH_LENGTH(GICR_WAKER,
> + vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
> + VGIC_ACCESS_32bit),
> REGISTER_DESC_WITH_LENGTH(GICR_PROPBASER,
> vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
> VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
> @@ -348,6 +353,52 @@ int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t redist_base_address)
> return ret;
> }
>
> +int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
> +{
> + struct kvm_vcpu *vcpu;
> + int nr_irqs = dev->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
> + const struct vgic_register_region *regions;
> + gpa_t addr;
> + int nr_regions, i, len, cpuid;
> +
> + addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
> + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_V3_CPUID_MASK) >>
> + KVM_DEV_ARM_VGIC_CPUID_SHIFT;
> + vcpu = kvm_mpidr_to_vcpu(dev->kvm, cpuid);
> +
> + switch (attr->group) {
> + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
> + regions = vgic_v3_dist_registers;
> + nr_regions = ARRAY_SIZE(vgic_v3_dist_registers);
> + break;
> + case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:{
> + struct vgic_io_device *devices;
> + struct vgic_io_device *rd_dev;
> +
> + devices = dev->kvm->arch.vgic.redist_iodevs;
> + rd_dev = &devices[vcpu->vcpu_id * 2];
> +
> + regions = rd_dev->regions;
> + nr_regions = rd_dev->nr_regions;
> + break;
> + }
> + default:
> + return -ENXIO;
> + }
> +
> + for (i = 0; i < nr_regions; i++) {
> + if (regions[i].bits_per_irq)
> + len = (regions[i].bits_per_irq * nr_irqs) / 8;
> + else
> + len = regions[i].len;
> +
> + if (regions[i].reg_offset <= addr &&
> + regions[i].reg_offset + len > addr)
> + return 0;
> + }
> +
> + return -ENXIO;
> +}
> /*
> * Compare a given affinity (level 1-3 and a level 0 mask, from the SGI
> * generation register ICC_SGI1R_EL1) with a given VCPU.
> @@ -453,3 +504,57 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg)
> vgic_queue_irq_unlock(vcpu->kvm, irq);
> }
> }
> +
> +/*
> + * 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_v3_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,
> + dev->base_addr + offset, len, buf);
> + } else {
> + ret = kvm_io_gic_ops.read(vcpu, &dev->dev,
> + dev->base_addr + offset, len, buf);
> + if (!ret)
> + *val = vgic_data_mmio_bus_to_host(buf, len);
> + }
> +
> + return ret;
> +}
> +
> +int vgic_v3_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
> + int offset, u32 *val)
> +{
> + struct vgic_io_device *dev;
> +
> + dev = &vcpu->kvm->arch.vgic.dist_iodev;
You're not supposed to do this.
You're supposed to create a temporary vgic_io_device for this, just like
we do in vgic_v2_dist_uaccess().
This is why we went down the road of all the init sequence problems.
Any reason why you didn't just follow the lead from the v2
implementation?
Thanks,
-Christoffer
> + return vgic_v3_uaccess(vcpu, dev, is_write, offset, val);
> +}
> +
> +int vgic_v3_redist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
> + int offset, u32 *val)
> +{
> + struct vgic_io_device *devices;
> + struct vgic_io_device *rd_dev;
> + const struct vgic_register_region *region;
> +
> + devices = vcpu->kvm->arch.vgic.redist_iodevs;
> + rd_dev = &devices[(vcpu->vcpu_id * 2) + 1];
> +
> + region = vgic_find_mmio_region(rd_dev->regions, rd_dev->nr_regions,
> + offset);
> + if (region == NULL)
> + rd_dev = &devices[vcpu->vcpu_id * 2];
> +
> + return vgic_v3_uaccess(vcpu, rd_dev, is_write, offset, val);
> +}
> diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
> index 9f6fab7..f583959 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio.c
> @@ -363,7 +363,7 @@ static int match_region(const void *key, const void *elt)
> }
>
> /* Find the proper register handler entry given a certain address offset. */
> -static const struct vgic_register_region *
> +const struct vgic_register_region *
> vgic_find_mmio_region(const struct vgic_register_region *region, int nr_regions,
> unsigned int offset)
> {
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 7b300ca..8637690 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -59,6 +59,9 @@ int vgic_v2_map_resources(struct kvm *kvm);
> int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
> enum vgic_type);
>
> +const struct vgic_register_region *
> + vgic_find_mmio_region(const struct vgic_register_region *region,
> + int nr_regions, unsigned int offset);
> #ifdef CONFIG_KVM_ARM_VGIC_V3
> void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu);
> void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu);
> @@ -71,6 +74,11 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu);
> int vgic_v3_probe(const struct gic_kvm_info *info);
> int vgic_v3_map_resources(struct kvm *kvm);
> int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address);
> +int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr);
> +int vgic_v3_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
> + int offset, u32 *val);
> +int vgic_v3_redist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
> + int offset, u32 *val);
> #else
> static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
> {
> --
> 1.7.9.5
>
More information about the linux-arm-kernel
mailing list