Re: [PATCH v3 03/12] KVM: arm/arm64: Replace the single rdist region by a list

Christoffer Dall
2018-04-24T21:06:45Z

On Fri, Apr 13, 2018 at 10:20:49AM +0200, Eric Auger wrote:
> At the moment KVM supports a single rdist region. We want to
> support several separate rdist regions so let's introduce a list
> of them. This patch currently only cares about a single
> entry in this list as the functionality to register several redist
> regions is not yet there. So this only translates the existing code
> into something functionally similar using that new data struct.
>
> The redistributor region handle is stored in the vgic_cpu structure
> to allow later computation of the TYPER last bit.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>

Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>

> ---
> include/kvm/arm_vgic.h | 14 +++++++++----
> virt/kvm/arm/vgic/vgic-init.c | 16 ++++++++++++--
> virt/kvm/arm/vgic/vgic-kvm-device.c | 13 ++++++++++--
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 42 ++++++++++++++++++++++++++++---------
> virt/kvm/arm/vgic/vgic-v3.c | 20 +++++++++++-------
> 5 files changed, 79 insertions(+), 26 deletions(-)
>
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 24f0394..e5c16d1 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -200,6 +200,14 @@ struct vgic_its {
>
> struct vgic_state_iter;
>
> +struct vgic_redist_region {
> + uint32_t index;
> + gpa_t base;
> + uint32_t count; /* number of redistributors or 0 if single region */
> + uint32_t free_index; /* index of the next free redistributor */
> + struct list_head list;
> +};
> +
> struct vgic_dist {
> bool in_kernel;
> bool ready;
> @@ -219,10 +227,7 @@ struct vgic_dist {
> /* either a GICv2 CPU interface */
> gpa_t vgic_cpu_base;
> /* or a number of GICv3 redistributor regions */
> - struct {
> - gpa_t vgic_redist_base;
> - gpa_t vgic_redist_free_offset;
> - };
> + struct list_head rd_regions;
> };
>
> /* distributor enabled */
> @@ -310,6 +315,7 @@ struct vgic_cpu {
> */
> struct vgic_io_device rd_iodev;
> struct vgic_io_device sgi_iodev;
> + struct vgic_redist_region *rdreg;
>
> /* Contains the attributes and gpa of the LPI pending tables. */
> u64 pendbaser;
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index c52f03d..6456371 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -167,8 +167,11 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
> kvm->arch.vgic.vgic_model = type;
>
> kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
> - kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
> - kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
> +
> + if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
> + kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
> + else
> + INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
>
> out_unlock:
> for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
> @@ -303,6 +306,7 @@ int vgic_init(struct kvm *kvm)
> static void kvm_vgic_dist_destroy(struct kvm *kvm)
> {
> struct vgic_dist *dist = &kvm->arch.vgic;
> + struct vgic_redist_region *rdreg, *next;
>
> dist->ready = false;
> dist->initialized = false;
> @@ -311,6 +315,14 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
> dist->spis = NULL;
> dist->nr_spis = 0;
>
> + if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
> + list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list) {
> + list_del(&rdreg->list);
> + kfree(rdreg);
> + }
> + INIT_LIST_HEAD(&dist->rd_regions);
> + }
> +
> if (vgic_supports_direct_msis(kvm))
> vgic_v4_teardown(kvm);
> }
> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
> index 10ae6f3..e7b5a86 100644
> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c
> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
> @@ -66,6 +66,7 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> int r = 0;
> struct vgic_dist *vgic = &kvm->arch.vgic;
> phys_addr_t *addr_ptr, alignment;
> + uint64_t undef_value = VGIC_ADDR_UNDEF;
>
> mutex_lock(&kvm->lock);
> switch (type) {
> @@ -84,7 +85,9 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> addr_ptr = &vgic->vgic_dist_base;
> alignment = SZ_64K;
> break;
> - case KVM_VGIC_V3_ADDR_TYPE_REDIST:
> + case KVM_VGIC_V3_ADDR_TYPE_REDIST: {
> + struct vgic_redist_region *rdreg;
> +
> r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V3);
> if (r)
> break;
> @@ -92,8 +95,14 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> r = vgic_v3_set_redist_base(kvm, *addr);
> goto out;
> }
> - addr_ptr = &vgic->vgic_redist_base;
> + rdreg = list_first_entry(&vgic->rd_regions,
> + struct vgic_redist_region, list);
> + if (!rdreg)
> + addr_ptr = &undef_value;
> + else
> + addr_ptr = &rdreg->base;
> break;
> + }
> default:
> r = -ENODEV;
> }
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index 671fe81..d1aab18 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -580,8 +580,10 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
> {
> struct kvm *kvm = vcpu->kvm;
> struct vgic_dist *vgic = &kvm->arch.vgic;
> + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
> struct vgic_io_device *rd_dev = &vcpu->arch.vgic_cpu.rd_iodev;
> struct vgic_io_device *sgi_dev = &vcpu->arch.vgic_cpu.sgi_iodev;
> + struct vgic_redist_region *rdreg;
> gpa_t rd_base, sgi_base;
> int ret;
>
> @@ -591,13 +593,17 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
> * function for all VCPUs when the base address is set. Just return
> * without doing any work for now.
> */
> - if (IS_VGIC_ADDR_UNDEF(vgic->vgic_redist_base))
> + rdreg = list_first_entry(&vgic->rd_regions,
> + struct vgic_redist_region, list);
> + if (!rdreg)
> return 0;
>
> if (!vgic_v3_check_base(kvm))
> return -EINVAL;
>
> - rd_base = vgic->vgic_redist_base + vgic->vgic_redist_free_offset;
> + vgic_cpu->rdreg = rdreg;
> +
> + rd_base = rdreg->base + rdreg->free_index * KVM_VGIC_V3_REDIST_SIZE;
> sgi_base = rd_base + SZ_64K;
>
> kvm_iodevice_init(&rd_dev->dev, &kvm_io_gic_ops);
> @@ -631,7 +637,7 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
> goto out;
> }
>
> - vgic->vgic_redist_free_offset += 2 * SZ_64K;
> + rdreg->free_index++;
> out:
> mutex_unlock(&kvm->slots_lock);
> return ret;
> @@ -673,19 +679,31 @@ static int vgic_register_all_redist_iodevs(struct kvm *kvm)
> int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
> {
> struct vgic_dist *vgic = &kvm->arch.vgic;
> + struct vgic_redist_region *rdreg;
> int ret;
>
> /* vgic_check_ioaddr makes sure we don't do this twice */
> - ret = vgic_check_ioaddr(kvm, &vgic->vgic_redist_base, addr, SZ_64K);
> - if (ret)
> - return ret;
> -
> - vgic->vgic_redist_base = addr;
> - if (!vgic_v3_check_base(kvm)) {
> - vgic->vgic_redist_base = VGIC_ADDR_UNDEF;
> + if (!list_empty(&vgic->rd_regions))
> return -EINVAL;
> +
> + rdreg = kzalloc(sizeof(*rdreg), GFP_KERNEL);
> + if (!rdreg)
> + return -ENOMEM;
> +
> + rdreg->base = VGIC_ADDR_UNDEF;
> +
> + ret = vgic_check_ioaddr(kvm, &rdreg->base, addr, SZ_64K);
> + if (ret)
> + goto out;
> +
> + rdreg->base = addr;
> + if (!vgic_v3_check_base(kvm)) {
> + ret = -EINVAL;
> + goto out;
> }
>
> + list_add(&rdreg->list, &vgic->rd_regions);
> +
> /*
> * Register iodevs for each existing VCPU. Adding more VCPUs
> * afterwards will register the iodevs when needed.
> @@ -695,6 +713,10 @@ int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
> return ret;
>
> return 0;
> +
> +out:
> + kfree(rdreg);
> + return ret;
> }
>
> int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 8195f52..94de6cd 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -418,6 +418,9 @@ bool vgic_v3_check_base(struct kvm *kvm)
> {
> struct vgic_dist *d = &kvm->arch.vgic;
> gpa_t redist_size = KVM_VGIC_V3_REDIST_SIZE;
> + struct vgic_redist_region *rdreg =
> + list_first_entry(&d->rd_regions,
> + struct vgic_redist_region, list);
>
> redist_size *= atomic_read(&kvm->online_vcpus);
>
> @@ -425,18 +428,17 @@ bool vgic_v3_check_base(struct kvm *kvm)
> d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE < d->vgic_dist_base)
> return false;
>
> - if (!IS_VGIC_ADDR_UNDEF(d->vgic_redist_base) &&
> - d->vgic_redist_base + redist_size < d->vgic_redist_base)
> + if (rdreg && (rdreg->base + redist_size < rdreg->base))
> return false;
>
> /* Both base addresses must be set to check if they overlap */
> - if (IS_VGIC_ADDR_UNDEF(d->vgic_dist_base) ||
> - IS_VGIC_ADDR_UNDEF(d->vgic_redist_base))
> + if (IS_VGIC_ADDR_UNDEF(d->vgic_dist_base) || !rdreg)
> return true;
>
> - if (d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE <= d->vgic_redist_base)
> + if (d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE <= rdreg->base)
> return true;
> - if (d->vgic_redist_base + redist_size <= d->vgic_dist_base)
> +
> + if (rdreg->base + redist_size <= d->vgic_dist_base)
> return true;
>
> return false;
> @@ -446,12 +448,14 @@ int vgic_v3_map_resources(struct kvm *kvm)
> {
> int ret = 0;
> struct vgic_dist *dist = &kvm->arch.vgic;
> + struct vgic_redist_region *rdreg =
> + list_first_entry(&dist->rd_regions,
> + struct vgic_redist_region, list);
>
> if (vgic_ready(kvm))
> goto out;
>
> - if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) ||
> - IS_VGIC_ADDR_UNDEF(dist->vgic_redist_base)) {
> + if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) || !rdreg) {
> kvm_err("Need to set vgic distributor addresses first\n");
> ret = -ENXIO;
> goto out;
> --
> 2.5.5
>