Re: [PATCH v6 9/9] KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET

Christoffer Dall
2017-10-30T06:11:33Z

On Thu, Oct 26, 2017 at 05:23:11PM +0200, Eric Auger wrote:
> On reset we clear the valid bits of GITS_CBASER and GITS_BASER<n>.
> We also clear command queue registers and free the cache (device,
> collection, and lpi lists).
>
> As we need to take the same locks as save/restore functions, we
> create a vgic_its_ctrl() wrapper that handles KVM_DEV_ARM_VGIC_GRP_CTRL
> group functions.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>

> ---
>
> v5 -> v6:
> - Rework the locking and create vgic_its_ctrl
>
> v2 -> v3:
> - added Christoffer's R-b
> ---
> arch/arm/include/uapi/asm/kvm.h | 1 +
> arch/arm64/include/uapi/asm/kvm.h | 1 +
> virt/kvm/arm/vgic/vgic-its.c | 105 ++++++++++++++++++++------------------
> 3 files changed, 58 insertions(+), 49 deletions(-)
>
> diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
> index 5db2d4c..7ef0c06 100644
> --- a/arch/arm/include/uapi/asm/kvm.h
> +++ b/arch/arm/include/uapi/asm/kvm.h
> @@ -215,6 +215,7 @@ struct kvm_arch_memory_slot {
> #define KVM_DEV_ARM_ITS_SAVE_TABLES 1
> #define KVM_DEV_ARM_ITS_RESTORE_TABLES 2
> #define KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES 3
> +#define KVM_DEV_ARM_ITS_CTRL_RESET 4
>
> /* KVM_IRQ_LINE irq field index values */
> #define KVM_ARM_IRQ_TYPE_SHIFT 24
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 9f3ca24..b5306ce 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -227,6 +227,7 @@ struct kvm_arch_memory_slot {
> #define KVM_DEV_ARM_ITS_SAVE_TABLES 1
> #define KVM_DEV_ARM_ITS_RESTORE_TABLES 2
> #define KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES 3
> +#define KVM_DEV_ARM_ITS_CTRL_RESET 4
>
> /* Device Control API on vcpu fd */
> #define KVM_ARM_VCPU_PMU_V3_CTRL 0
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 2a92d4d..09a459b 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -2301,29 +2301,13 @@ static int vgic_its_restore_collection_table(struct vgic_its *its)
> */
> static int vgic_its_save_tables_v0(struct vgic_its *its)
> {
> - struct kvm *kvm = its->dev->kvm;
> int ret;
>
> - mutex_lock(&kvm->lock);
> - mutex_lock(&its->its_lock);
> -
> - if (!lock_all_vcpus(kvm)) {
> - mutex_unlock(&its->its_lock);
> - mutex_unlock(&kvm->lock);
> - return -EBUSY;
> - }
> -
> ret = vgic_its_save_device_tables(its);
> if (ret)
> - goto out;
> -
> - ret = vgic_its_save_collection_table(its);
> + return ret;
>
> -out:
> - unlock_all_vcpus(kvm);
> - mutex_unlock(&its->its_lock);
> - mutex_unlock(&kvm->lock);
> - return ret;
> + return vgic_its_save_collection_table(its);
> }
>
> /**
> @@ -2333,29 +2317,13 @@ static int vgic_its_save_tables_v0(struct vgic_its *its)
> */
> static int vgic_its_restore_tables_v0(struct vgic_its *its)
> {
> - struct kvm *kvm = its->dev->kvm;
> int ret;
>
> - mutex_lock(&kvm->lock);
> - mutex_lock(&its->its_lock);
> -
> - if (!lock_all_vcpus(kvm)) {
> - mutex_unlock(&its->its_lock);
> - mutex_unlock(&kvm->lock);
> - return -EBUSY;
> - }
> -
> ret = vgic_its_restore_collection_table(its);
> if (ret)
> - goto out;
> -
> - ret = vgic_its_restore_device_tables(its);
> -out:
> - unlock_all_vcpus(kvm);
> - mutex_unlock(&its->its_lock);
> - mutex_unlock(&kvm->lock);
> + return ret;
>
> - return ret;
> + return vgic_its_restore_device_tables(its);
> }
>
> static int vgic_its_commit_v0(struct vgic_its *its)
> @@ -2374,6 +2342,19 @@ static int vgic_its_commit_v0(struct vgic_its *its)
> return 0;
> }
>
> +static void vgic_its_reset(struct kvm *kvm, struct vgic_its *its)
> +{
> + /* We need to keep the ABI specific field values */
> + its->baser_coll_table &= ~GITS_BASER_VALID;
> + its->baser_device_table &= ~GITS_BASER_VALID;
> + its->cbaser = 0;
> + its->creadr = 0;
> + its->cwriter = 0;
> + its->enabled = 0;
> + vgic_its_free_device_list(kvm, its);
> + vgic_its_free_collection_list(kvm, its);
> +}
> +
> static int vgic_its_has_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> @@ -2388,6 +2369,8 @@ static int vgic_its_has_attr(struct kvm_device *dev,
> switch (attr->attr) {
> case KVM_DEV_ARM_VGIC_CTRL_INIT:
> return 0;
> + case KVM_DEV_ARM_ITS_CTRL_RESET:
> + return 0;
> case KVM_DEV_ARM_ITS_SAVE_TABLES:
> return 0;
> case KVM_DEV_ARM_ITS_RESTORE_TABLES:
> @@ -2400,6 +2383,41 @@ static int vgic_its_has_attr(struct kvm_device *dev,
> return -ENXIO;
> }
>
> +static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr)
> +{
> + const struct vgic_its_abi *abi = vgic_its_get_abi(its);
> + int ret = 0;
> +
> + if (attr == KVM_DEV_ARM_VGIC_CTRL_INIT) /* Nothing to do */
> + return 0;
> +
> + mutex_lock(&kvm->lock);
> + mutex_lock(&its->its_lock);
> +
> + if (!lock_all_vcpus(kvm)) {
> + mutex_unlock(&its->its_lock);
> + mutex_unlock(&kvm->lock);
> + return -EBUSY;
> + }
> +
> + switch (attr) {
> + case KVM_DEV_ARM_ITS_CTRL_RESET:
> + vgic_its_reset(kvm, its);
> + break;
> + case KVM_DEV_ARM_ITS_SAVE_TABLES:
> + ret = abi->save_tables(its);
> + break;
> + case KVM_DEV_ARM_ITS_RESTORE_TABLES:
> + ret = abi->restore_tables(its);
> + break;
> + }
> +
> + unlock_all_vcpus(kvm);
> + mutex_unlock(&its->its_lock);
> + mutex_unlock(&kvm->lock);
> + return ret;
> +}
> +
> static int vgic_its_set_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> @@ -2425,19 +2443,8 @@ static int vgic_its_set_attr(struct kvm_device *dev,
>
> return vgic_register_its_iodev(dev->kvm, its, addr);
> }
> - case KVM_DEV_ARM_VGIC_GRP_CTRL: {
> - const struct vgic_its_abi *abi = vgic_its_get_abi(its);
> -
> - switch (attr->attr) {
> - case KVM_DEV_ARM_VGIC_CTRL_INIT:
> - /* Nothing to do */
> - return 0;
> - case KVM_DEV_ARM_ITS_SAVE_TABLES:
> - return abi->save_tables(its);
> - case KVM_DEV_ARM_ITS_RESTORE_TABLES:
> - return abi->restore_tables(its);
> - }
> - }
> + case KVM_DEV_ARM_VGIC_GRP_CTRL:
> + return vgic_its_ctrl(dev->kvm, its, attr->attr);
> case KVM_DEV_ARM_VGIC_GRP_ITS_REGS: {
> u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> u64 reg;
> --
> 2.5.5
>