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vdpa_sim: implement .reset_map support 

In order to reduce excessive memory mapping cost in live migration and
VM reboot, it is desirable to decouple the vhost-vdpa IOTLB abstraction
from the virtio device life cycle, i.e. mappings can be kept intact
across virtio device reset. Leverage the .reset_map callback, which is
meant to destroy the iotlb on the given ASID and recreate the 1:1
passthrough/identity mapping. To be consistent, the mapping on device
creation is initiailized to passthrough/identity with PA 1:1 mapped as
IOVA. With this the device .reset op doesn't have to maintain and clean
up memory mappings by itself.

Additionally, implement .compat_reset to cater for older userspace,
which may wish to see mapping to be cleared during reset.

Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
Tested-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <1697880319-4937-8-git-send-email-si-wei.liu@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
This commit is contained in:
Si-Wei Liu 2023-10-21 02:25:19 -07:00 committed by Michael S. Tsirkin
parent 2eacf4b5e3
commit 86f6c224c9
1 changed files with 43 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
drivers/vdpa/vdpa_sim/vdpa_sim.c
View File

@ -139,7 +139,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim,
vq->vring.notify = NULL;
}
static void vdpasim_do_reset(struct vdpasim *vdpasim)
static void vdpasim_do_reset(struct vdpasim *vdpasim, u32 flags)
{
int i;
@ -151,11 +151,13 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim)
&vdpasim->iommu_lock);
}
for (i = 0; i < vdpasim->dev_attr.nas; i++) {
vhost_iotlb_reset(&vdpasim->iommu[i]);
vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX,
0, VHOST_MAP_RW);
vdpasim->iommu_pt[i] = true;
if (flags & VDPA_RESET_F_CLEAN_MAP) {
for (i = 0; i < vdpasim->dev_attr.nas; i++) {
vhost_iotlb_reset(&vdpasim->iommu[i]);
vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX,
0, VHOST_MAP_RW);
vdpasim->iommu_pt[i] = true;
}
}
vdpasim->running = true;
@ -259,8 +261,12 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr,
if (!vdpasim->iommu_pt)
goto err_iommu;
for (i = 0; i < vdpasim->dev_attr.nas; i++)
for (i = 0; i < vdpasim->dev_attr.nas; i++) {
vhost_iotlb_init(&vdpasim->iommu[i], max_iotlb_entries, 0);
vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX, 0,
VHOST_MAP_RW);
vdpasim->iommu_pt[i] = true;
}
for (i = 0; i < dev_attr->nvqs; i++)
vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0],
@ -480,18 +486,23 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
mutex_unlock(&vdpasim->mutex);
}
static int vdpasim_reset(struct vdpa_device *vdpa)
static int vdpasim_compat_reset(struct vdpa_device *vdpa, u32 flags)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
mutex_lock(&vdpasim->mutex);
vdpasim->status = 0;
vdpasim_do_reset(vdpasim);
vdpasim_do_reset(vdpasim, flags);
mutex_unlock(&vdpasim->mutex);
return 0;
}
static int vdpasim_reset(struct vdpa_device *vdpa)
{
return vdpasim_compat_reset(vdpa, 0);
}
static int vdpasim_suspend(struct vdpa_device *vdpa)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
@ -637,6 +648,25 @@ err:
return ret;
}
static int vdpasim_reset_map(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);
if (vdpasim->iommu_pt[asid])
goto out;
vhost_iotlb_reset(&vdpasim->iommu[asid]);
vhost_iotlb_add_range(&vdpasim->iommu[asid], 0, ULONG_MAX,
0, VHOST_MAP_RW);
vdpasim->iommu_pt[asid] = true;
out:
spin_unlock(&vdpasim->iommu_lock);
return 0;
}
static int vdpasim_bind_mm(struct vdpa_device *vdpa, struct mm_struct *mm)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
@ -749,6 +779,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
.get_status = vdpasim_get_status,
.set_status = vdpasim_set_status,
.reset = vdpasim_reset,
.compat_reset = vdpasim_compat_reset,
.suspend = vdpasim_suspend,
.resume = vdpasim_resume,
.get_config_size = vdpasim_get_config_size,
@ -759,6 +790,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
.set_group_asid = vdpasim_set_group_asid,
.dma_map = vdpasim_dma_map,
.dma_unmap = vdpasim_dma_unmap,
.reset_map = vdpasim_reset_map,
.bind_mm = vdpasim_bind_mm,
.unbind_mm = vdpasim_unbind_mm,
.free = vdpasim_free,
@ -787,6 +819,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
.get_status = vdpasim_get_status,
.set_status = vdpasim_set_status,
.reset = vdpasim_reset,
.compat_reset = vdpasim_compat_reset,
.suspend = vdpasim_suspend,
.resume = vdpasim_resume,
.get_config_size = vdpasim_get_config_size,
@ -796,6 +829,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
.get_iova_range = vdpasim_get_iova_range,
.set_group_asid = vdpasim_set_group_asid,
.set_map = vdpasim_set_map,
.reset_map = vdpasim_reset_map,
.bind_mm = vdpasim_bind_mm,
.unbind_mm = vdpasim_unbind_mm,
.free = vdpasim_free,