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vdpasim: control virtqueue support

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This patch introduces the control virtqueue support for vDPA
simulator. This is a requirement for supporting advanced features like
multiqueue.

A requirement for control virtqueue is to isolate its memory access
from the rx/tx virtqueues. This is because when using vDPA device
for VM, the control virqueue is not directly assigned to VM. Userspace
(Qemu) will present a shadow control virtqueue to control for
recording the device states.

The isolation is done via the virtqueue groups and ASID support in
vDPA through vhost-vdpa. The simulator is extended to have:

1) three virtqueues: RXVQ, TXVQ and CVQ (control virtqueue)
2) two virtqueue groups: group 0 contains RXVQ and TXVQ; group 1
   contains CVQ
3) two address spaces and the simulator simply implements the address
   spaces by mapping it 1:1 to IOTLB.

For the VM use cases, userspace(Qemu) may set AS 0 to group 0 and AS 1
to group 1. So we have:

1) The IOTLB for virtqueue group 0 contains the mappings of guest, so
   RX and TX can be assigned to guest directly.
2) The IOTLB for virtqueue group 1 contains the mappings of CVQ which
   is the buffers that allocated and managed by VMM only. So CVQ of
   vhost-vdpa is visible to VMM only. And Guest can not access the CVQ
   of vhost-vdpa.

For the other use cases, since AS 0 is associated to all virtqueue
groups by default. All virtqueues share the same mapping by default.

To demonstrate the function, VIRITO_NET_F_CTRL_MACADDR is
implemented in the simulator for the driver to set mac address.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
Message-Id: <20220330180436.24644-20-gdawar@xilinx.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Gautam Dawar 2022-03-30 23:33:59 +05:30 committed by Michael S. Tsirkin
parent cfe2268929
commit bda324fd03
3 changed files with 162 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

93
drivers/vdpa/vdpa_sim/vdpa_sim.c
View file

@ -96,11 +96,17 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim)
{
int i;
for (i = 0; i < vdpasim->dev_attr.nvqs; i++)
vdpasim_vq_reset(vdpasim, &vdpasim->vqs[i]);
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_reset(vdpasim->iommu);
for (i = 0; i < vdpasim->dev_attr.nvqs; i++) {
vdpasim_vq_reset(vdpasim, &vdpasim->vqs[i]);
vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0],
&vdpasim->iommu_lock);
}
for (i = 0; i < vdpasim->dev_attr.nas; i++)
vhost_iotlb_reset(&vdpasim->iommu[i]);
spin_unlock(&vdpasim->iommu_lock);
vdpasim->features = 0;
@ -145,7 +151,7 @@ static dma_addr_t vdpasim_map_range(struct vdpasim *vdpasim, phys_addr_t paddr,
dma_addr = iova_dma_addr(&vdpasim->iova, iova);
spin_lock(&vdpasim->iommu_lock);
ret = vhost_iotlb_add_range(vdpasim->iommu, (u64)dma_addr,
ret = vhost_iotlb_add_range(&vdpasim->iommu[0], (u64)dma_addr,
(u64)dma_addr + size - 1, (u64)paddr, perm);
spin_unlock(&vdpasim->iommu_lock);
@ -161,7 +167,7 @@ static void vdpasim_unmap_range(struct vdpasim *vdpasim, dma_addr_t dma_addr,
size_t size)
{
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_del_range(vdpasim->iommu, (u64)dma_addr,
vhost_iotlb_del_range(&vdpasim->iommu[0], (u64)dma_addr,
(u64)dma_addr + size - 1);
spin_unlock(&vdpasim->iommu_lock);
@ -250,8 +256,9 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
else
ops = &vdpasim_config_ops;
vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops, 1,
1, dev_attr->name, false);
vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
dev_attr->ngroups, dev_attr->nas,
dev_attr->name, false);
if (IS_ERR(vdpasim)) {
ret = PTR_ERR(vdpasim);
goto err_alloc;
@ -278,16 +285,20 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
if (!vdpasim->vqs)
goto err_iommu;
vdpasim->iommu = vhost_iotlb_alloc(max_iotlb_entries, 0);
vdpasim->iommu = kmalloc_array(vdpasim->dev_attr.nas,
sizeof(*vdpasim->iommu), GFP_KERNEL);
if (!vdpasim->iommu)
goto err_iommu;
for (i = 0; i < vdpasim->dev_attr.nas; i++)
vhost_iotlb_init(&vdpasim->iommu[i], 0, 0);
vdpasim->buffer = kvmalloc(dev_attr->buffer_size, GFP_KERNEL);
if (!vdpasim->buffer)
goto err_iommu;
for (i = 0; i < dev_attr->nvqs; i++)
vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu,
vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0],
&vdpasim->iommu_lock);
ret = iova_cache_get();
@ -401,7 +412,11 @@ static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
static u32 vdpasim_get_vq_group(struct vdpa_device *vdpa, u16 idx)
{
return 0;
/* RX and TX belongs to group 0, CVQ belongs to group 1 */
if (idx == 2)
return 1;
else
return 0;
}
static u64 vdpasim_get_device_features(struct vdpa_device *vdpa)
@ -539,20 +554,53 @@ static struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
return range;
}
static int vdpasim_set_group_asid(struct vdpa_device *vdpa, unsigned int group,
unsigned int asid)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vhost_iotlb *iommu;
int i;
if (group > vdpasim->dev_attr.ngroups)
return -EINVAL;
if (asid > vdpasim->dev_attr.nas)
return -EINVAL;
iommu = &vdpasim->iommu[asid];
spin_lock(&vdpasim->lock);
for (i = 0; i < vdpasim->dev_attr.nvqs; i++)
if (vdpasim_get_vq_group(vdpa, i) == group)
vringh_set_iotlb(&vdpasim->vqs[i].vring, iommu,
&vdpasim->iommu_lock);
spin_unlock(&vdpasim->lock);
return 0;
}
static int vdpasim_set_map(struct vdpa_device *vdpa, unsigned int asid,
struct vhost_iotlb *iotlb)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vhost_iotlb_map *map;
struct vhost_iotlb *iommu;
u64 start = 0ULL, last = 0ULL - 1;
int ret;
if (asid >= vdpasim->dev_attr.nas)
return -EINVAL;
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_reset(vdpasim->iommu);
iommu = &vdpasim->iommu[asid];
vhost_iotlb_reset(iommu);
for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
map = vhost_iotlb_itree_next(map, start, last)) {
ret = vhost_iotlb_add_range(vdpasim->iommu, map->start,
ret = vhost_iotlb_add_range(iommu, map->start,
map->last, map->addr, map->perm);
if (ret)
goto err;
@ -561,7 +609,7 @@ static int vdpasim_set_map(struct vdpa_device *vdpa, unsigned int asid,
return 0;
err:
vhost_iotlb_reset(vdpasim->iommu);
vhost_iotlb_reset(iommu);
spin_unlock(&vdpasim->iommu_lock);
return ret;
}
@ -573,9 +621,12 @@ static int vdpasim_dma_map(struct vdpa_device *vdpa, unsigned int asid,
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
int ret;
if (asid >= vdpasim->dev_attr.nas)
return -EINVAL;
spin_lock(&vdpasim->iommu_lock);
ret = vhost_iotlb_add_range_ctx(vdpasim->iommu, iova, iova + size - 1,
pa, perm, opaque);
ret = vhost_iotlb_add_range_ctx(&vdpasim->iommu[asid], iova,
iova + size - 1, pa, perm, opaque);
spin_unlock(&vdpasim->iommu_lock);
return ret;
@ -586,8 +637,11 @@ static int vdpasim_dma_unmap(struct vdpa_device *vdpa, unsigned int asid,
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
if (asid >= vdpasim->dev_attr.nas)
return -EINVAL;
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_del_range(vdpasim->iommu, iova, iova + size - 1);
vhost_iotlb_del_range(&vdpasim->iommu[asid], iova, iova + size - 1);
spin_unlock(&vdpasim->iommu_lock);
return 0;
@ -611,8 +665,7 @@ static void vdpasim_free(struct vdpa_device *vdpa)
}
kvfree(vdpasim->buffer);
if (vdpasim->iommu)
vhost_iotlb_free(vdpasim->iommu);
vhost_iotlb_free(vdpasim->iommu);
kfree(vdpasim->vqs);
kfree(vdpasim->config);
}
@ -643,6 +696,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
.set_config = vdpasim_set_config,
.get_generation = vdpasim_get_generation,
.get_iova_range = vdpasim_get_iova_range,
.set_group_asid = vdpasim_set_group_asid,
.dma_map = vdpasim_dma_map,
.dma_unmap = vdpasim_dma_unmap,
.free = vdpasim_free,
@ -674,6 +728,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
.set_config = vdpasim_set_config,
.get_generation = vdpasim_get_generation,
.get_iova_range = vdpasim_get_iova_range,
.set_group_asid = vdpasim_set_group_asid,
.set_map = vdpasim_set_map,
.free = vdpasim_free,
};

2
drivers/vdpa/vdpa_sim/vdpa_sim.h
View file

@ -41,6 +41,8 @@ struct vdpasim_dev_attr {
size_t buffer_size;
int nvqs;
u32 id;
u32 ngroups;
u32 nas;
work_func_t work_fn;
void (*get_config)(struct vdpasim *vdpasim, void *config);

88
drivers/vdpa/vdpa_sim/vdpa_sim_net.c
View file

@ -27,9 +27,14 @@
#define VDPASIM_NET_FEATURES (VDPASIM_FEATURES | \
(1ULL << VIRTIO_NET_F_MAC) | \
(1ULL << VIRTIO_NET_F_MTU))
(1ULL << VIRTIO_NET_F_MTU) | \
(1ULL << VIRTIO_NET_F_CTRL_VQ) | \
(1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR))
#define VDPASIM_NET_VQ_NUM 2
/* 3 virtqueues, 2 address spaces, 2 virtqueue groups */
#define VDPASIM_NET_VQ_NUM 3
#define VDPASIM_NET_AS_NUM 2
#define VDPASIM_NET_GROUP_NUM 2
static void vdpasim_net_complete(struct vdpasim_virtqueue *vq, size_t len)
{
@ -63,6 +68,81 @@ static bool receive_filter(struct vdpasim *vdpasim, size_t len)
return false;
}
static virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim,
u8 cmd)
{
struct virtio_net_config *vio_config = vdpasim->config;
struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
size_t read;
switch (cmd) {
case VIRTIO_NET_CTRL_MAC_ADDR_SET:
read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov,
vio_config->mac, ETH_ALEN);
if (read == ETH_ALEN)
status = VIRTIO_NET_OK;
break;
default:
break;
}
return status;
}
static void vdpasim_handle_cvq(struct vdpasim *vdpasim)
{
struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
struct virtio_net_ctrl_hdr ctrl;
size_t read, write;
int err;
if (!(vdpasim->features & (1ULL << VIRTIO_NET_F_CTRL_VQ)))
return;
if (!cvq->ready)
return;
while (true) {
err = vringh_getdesc_iotlb(&cvq->vring, &cvq->in_iov,
&cvq->out_iov,
&cvq->head, GFP_ATOMIC);
if (err <= 0)
break;
read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl,
sizeof(ctrl));
if (read != sizeof(ctrl))
break;
switch (ctrl.class) {
case VIRTIO_NET_CTRL_MAC:
status = vdpasim_handle_ctrl_mac(vdpasim, ctrl.cmd);
break;
default:
break;
}
/* Make sure data is wrote before advancing index */
smp_wmb();
write = vringh_iov_push_iotlb(&cvq->vring, &cvq->out_iov,
&status, sizeof(status));
vringh_complete_iotlb(&cvq->vring, cvq->head, write);
vringh_kiov_cleanup(&cvq->in_iov);
vringh_kiov_cleanup(&cvq->out_iov);
/* Make sure used is visible before rasing the interrupt. */
smp_wmb();
local_bh_disable();
if (cvq->cb)
cvq->cb(cvq->private);
local_bh_enable();
}
}
static void vdpasim_net_work(struct work_struct *work)
{
struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
@ -77,6 +157,8 @@ static void vdpasim_net_work(struct work_struct *work)
if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
goto out;
vdpasim_handle_cvq(vdpasim);
if (!txq->ready || !rxq->ready)
goto out;
@ -162,6 +244,8 @@ static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
dev_attr.id = VIRTIO_ID_NET;
dev_attr.supported_features = VDPASIM_NET_FEATURES;
dev_attr.nvqs = VDPASIM_NET_VQ_NUM;
dev_attr.ngroups = VDPASIM_NET_GROUP_NUM;
dev_attr.nas = VDPASIM_NET_AS_NUM;
dev_attr.config_size = sizeof(struct virtio_net_config);
dev_attr.get_config = vdpasim_net_get_config;
dev_attr.work_fn = vdpasim_net_work;