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Message-ID: <028ebad8-2106-0ea9-4092-4c14f1e2fdfe@redhat.com>
Date: Fri, 9 Oct 2020 11:51:44 +0800
From: Jason Wang <jasowang@...hat.com>
To: Eli Cohen <elic@...dia.com>
Cc: mst@...hat.com, lulu@...hat.com, kvm@...r.kernel.org,
virtualization@...ts.linux-foundation.org, netdev@...r.kernel.org,
linux-kernel@...r.kernel.org, rob.miller@...adcom.com,
lingshan.zhu@...el.com, eperezma@...hat.com, hanand@...inx.com,
mhabets@...arflare.com, amorenoz@...hat.com,
maxime.coquelin@...hat.com, stefanha@...hat.com,
sgarzare@...hat.com
Subject: Re: [RFC PATCH 09/24] vdpa: multiple address spaces support
On 2020/10/1 下午9:21, Eli Cohen wrote:
> On Thu, Sep 24, 2020 at 11:21:10AM +0800, Jason Wang wrote:
>> This patches introduces the multiple address spaces support for vDPA
>> device. This idea is to identify a specific address space via an
>> dedicated identifier - ASID.
>>
>> During vDPA device allocation, vDPA device driver needs to report the
>> number of address spaces supported by the device then the DMA mapping
>> ops of the vDPA device needs to be extended to support ASID.
>>
>> This helps to isolate the DMA among the virtqueues. E.g in the case of
>> virtio-net, the control virtqueue will not be assigned directly to
>> guest.
>>
>> This RFC patch only converts for the device that wants its own
>> IOMMU/DMA translation logic. So it will rejects the device with more
>> that 1 address space that depends on platform IOMMU. The plan to
> This is not apparent from the code. Instead you enforce number of groups
> to 1.
Yes, will fix.
>
>> moving all the DMA mapping logic to the vDPA device driver instead of
>> doing it in vhost-vDPA (otherwise it could result a very complicated
>> APIs and actually vhost-vDPA doesn't care about how the actual
>> composition/emulation were done in the device driver).
>>
>> Signed-off-by: Jason Wang <jasowang@...hat.com>
>> ---
>> drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
>> drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +++--
>> drivers/vdpa/vdpa.c | 4 +++-
>> drivers/vdpa/vdpa_sim/vdpa_sim.c | 10 ++++++----
>> drivers/vhost/vdpa.c | 14 +++++++++-----
>> include/linux/vdpa.h | 23 ++++++++++++++++-------
>> 6 files changed, 38 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
>> index e6a0be374e51..86cdf5f8bcae 100644
>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
>> @@ -440,7 +440,7 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>>
>> adapter = vdpa_alloc_device(struct ifcvf_adapter, vdpa,
>> dev, &ifc_vdpa_ops,
>> - IFCVF_MAX_QUEUE_PAIRS * 2, 1);
>> + IFCVF_MAX_QUEUE_PAIRS * 2, 1, 1);
>>
>> if (adapter == NULL) {
>> IFCVF_ERR(pdev, "Failed to allocate vDPA structure");
>> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> index 4e480f4f754e..db7404e121bf 100644
>> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> @@ -1788,7 +1788,8 @@ static u32 mlx5_vdpa_get_generation(struct vdpa_device *vdev)
>> return mvdev->generation;
>> }
>>
>> -static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb)
>> +static int mlx5_vdpa_set_map(struct vdpa_device *vdev, unsigned int asid,
>> + struct vhost_iotlb *iotlb)
>> {
>> struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
>> struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
>> @@ -1931,7 +1932,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev *mdev)
>> max_vqs = min_t(u32, max_vqs, MLX5_MAX_SUPPORTED_VQS);
>>
>> ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev, mdev->device, &mlx5_vdpa_ops,
>> - 2 * mlx5_vdpa_max_qps(max_vqs), 1);
>> + 2 * mlx5_vdpa_max_qps(max_vqs), 1, 1);
>> if (IS_ERR(ndev))
>> return ndev;
>>
>> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
>> index 46399746ec7c..05195fa7865d 100644
>> --- a/drivers/vdpa/vdpa.c
>> +++ b/drivers/vdpa/vdpa.c
>> @@ -63,6 +63,7 @@ static void vdpa_release_dev(struct device *d)
>> * @config: the bus operations that is supported by this device
>> * @nvqs: number of virtqueues supported by this device
>> * @ngroups: number of groups supported by this device
>> + * @nas: number of address spaces supported by this device
>> * @size: size of the parent structure that contains private data
>> *
>> * Driver should use vdpa_alloc_device() wrapper macro instead of
>> @@ -74,7 +75,7 @@ static void vdpa_release_dev(struct device *d)
>> struct vdpa_device *__vdpa_alloc_device(struct device *parent,
>> const struct vdpa_config_ops *config,
>> int nvqs, unsigned int ngroups,
>> - size_t size)
>> + unsigned int nas, size_t size)
>> {
>> struct vdpa_device *vdev;
>> int err = -EINVAL;
>> @@ -102,6 +103,7 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
>> vdev->features_valid = false;
>> vdev->nvqs = nvqs;
>> vdev->ngroups = ngroups;
>> + vdev->nas = nas;
>>
>> err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index);
>> if (err)
>> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>> index 6669c561bc6e..5dc04ec271bb 100644
>> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
>> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>> @@ -354,7 +354,7 @@ static struct vdpasim *vdpasim_create(void)
>> ops = &vdpasim_net_config_ops;
>>
>> vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
>> - VDPASIM_VQ_NUM, 1);
>> + VDPASIM_VQ_NUM, 1, 1);
>> if (!vdpasim)
>> goto err_alloc;
>>
>> @@ -581,7 +581,7 @@ static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
>> return vdpasim->generation;
>> }
>>
>> -static int vdpasim_set_map(struct vdpa_device *vdpa,
>> +static int vdpasim_set_map(struct vdpa_device *vdpa, unsigned int asid,
>> struct vhost_iotlb *iotlb)
>> {
>> struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
>> @@ -608,7 +608,8 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
>> return ret;
>> }
>>
>> -static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
>> +static int vdpasim_dma_map(struct vdpa_device *vdpa, unsigned int asid,
>> + u64 iova, u64 size,
>> u64 pa, u32 perm)
>> {
>> struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
>> @@ -622,7 +623,8 @@ static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
>> return ret;
>> }
>>
>> -static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size)
>> +static int vdpasim_dma_unmap(struct vdpa_device *vdpa, unsigned int asid,
>> + u64 iova, u64 size)
>> {
>> struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
>>
>> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
>> index ec3c94f706c1..eeefcd971e3f 100644
>> --- a/drivers/vhost/vdpa.c
>> +++ b/drivers/vhost/vdpa.c
>> @@ -557,10 +557,10 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
>> return r;
>>
>> if (ops->dma_map) {
>> - r = ops->dma_map(vdpa, iova, size, pa, perm);
>> + r = ops->dma_map(vdpa, 0, iova, size, pa, perm);
>> } else if (ops->set_map) {
>> if (!v->in_batch)
>> - r = ops->set_map(vdpa, iotlb);
>> + r = ops->set_map(vdpa, 0, iotlb);
>> } else {
>> r = iommu_map(v->domain, iova, pa, size,
>> perm_to_iommu_flags(perm));
>> @@ -579,10 +579,10 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v,
>> vhost_vdpa_iotlb_unmap(v, iotlb, iova, iova + size - 1);
>>
>> if (ops->dma_map) {
>> - ops->dma_unmap(vdpa, iova, size);
>> + ops->dma_unmap(vdpa, 0, iova, size);
>> } else if (ops->set_map) {
>> if (!v->in_batch)
>> - ops->set_map(vdpa, iotlb);
>> + ops->set_map(vdpa, 0, iotlb);
>> } else {
>> iommu_unmap(v->domain, iova, size);
>> }
>> @@ -700,7 +700,7 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
>> break;
>> case VHOST_IOTLB_BATCH_END:
>> if (v->in_batch && ops->set_map)
>> - ops->set_map(vdpa, iotlb);
>> + ops->set_map(vdpa, 0, iotlb);
>> v->in_batch = false;
>> break;
>> default:
>> @@ -949,6 +949,10 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>> int minor;
>> int r;
>>
>> + /* Only support 1 address space */
>> + if (vdpa->ngroups != 1)
>> + return -ENOTSUPP;
>> +
> Did you mean to check agains vdpa->nas?
I think we should check both.
Thanks
>
>> /* Currently, we only accept the network devices. */
>> if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
>> return -ENOTSUPP;
>> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
>> index d829512efd27..1e1163daa352 100644
>> --- a/include/linux/vdpa.h
>> +++ b/include/linux/vdpa.h
>> @@ -43,6 +43,8 @@ struct vdpa_vq_state {
>> * @index: device index
>> * @features_valid: were features initialized? for legacy guests
>> * @nvqs: the number of virtqueues
>> + * @ngroups: the number of virtqueue groups
>> + * @nas: the number of address spaces
>> */
>> struct vdpa_device {
>> struct device dev;
>> @@ -52,6 +54,7 @@ struct vdpa_device {
>> bool features_valid;
>> int nvqs;
>> unsigned int ngroups;
>> + unsigned int nas;
>> };
>>
>> /**
>> @@ -161,6 +164,7 @@ struct vdpa_device {
>> * Needed for device that using device
>> * specific DMA translation (on-chip IOMMU)
>> * @vdev: vdpa device
>> + * @asid: address space identifier
>> * @iotlb: vhost memory mapping to be
>> * used by the vDPA
>> * Returns integer: success (0) or error (< 0)
>> @@ -169,6 +173,7 @@ struct vdpa_device {
>> * specific DMA translation (on-chip IOMMU)
>> * and preferring incremental map.
>> * @vdev: vdpa device
>> + * @asid: address space identifier
>> * @iova: iova to be mapped
>> * @size: size of the area
>> * @pa: physical address for the map
>> @@ -180,6 +185,7 @@ struct vdpa_device {
>> * specific DMA translation (on-chip IOMMU)
>> * and preferring incremental unmap.
>> * @vdev: vdpa device
>> + * @asid: address space identifier
>> * @iova: iova to be unmapped
>> * @size: size of the area
>> * Returns integer: success (0) or error (< 0)
>> @@ -225,10 +231,12 @@ struct vdpa_config_ops {
>> u32 (*get_generation)(struct vdpa_device *vdev);
>>
>> /* DMA ops */
>> - int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
>> - int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
>> - u64 pa, u32 perm);
>> - int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
>> + int (*set_map)(struct vdpa_device *vdev, unsigned int asid,
>> + struct vhost_iotlb *iotlb);
>> + int (*dma_map)(struct vdpa_device *vdev, unsigned int asid,
>> + u64 iova, u64 size, u64 pa, u32 perm);
>> + int (*dma_unmap)(struct vdpa_device *vdev, unsigned int asid,
>> + u64 iova, u64 size);
>>
>> /* Free device resources */
>> void (*free)(struct vdpa_device *vdev);
>> @@ -237,11 +245,12 @@ struct vdpa_config_ops {
>> struct vdpa_device *__vdpa_alloc_device(struct device *parent,
>> const struct vdpa_config_ops *config,
>> int nvqs, unsigned int ngroups,
>> - size_t size);
>> + unsigned int nas, size_t size);
>>
>> -#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs, ngroups) \
>> +#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs, \
>> + ngroups, nas) \
>> container_of(__vdpa_alloc_device( \
>> - parent, config, nvqs, ngroups, \
>> + parent, config, nvqs, ngroups, nas, \
>> sizeof(dev_struct) + \
>> BUILD_BUG_ON_ZERO(offsetof( \
>> dev_struct, member))), \
>> --
>> 2.20.1
>>
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