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Re: [PATCH v2] vhost-vdpa: add support for vIOMMU
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From: |
Jason Wang |
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Subject: |
Re: [PATCH v2] vhost-vdpa: add support for vIOMMU |
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Date: |
Thu, 20 Oct 2022 10:14:39 +0800 |
On Wed, Oct 19, 2022 at 2:39 PM Cindy Lu <lulu@redhat.com> wrote:
>
> Add support for vIOMMU. Register a memory listener to dma_as in
> dev_start
> - during region_add register a specific IOMMU notifier, and store all
> notifiers in a list.
> - during region_del, compare and delete the IOMMU notifier from the list
>
> Verified in vp_vdpa and vdpa_sim_net driver
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
> hw/virtio/vhost-vdpa.c | 218 ++++++++++++++++++++++++++++++++-
> include/hw/virtio/vhost-vdpa.h | 11 ++
> 2 files changed, 226 insertions(+), 3 deletions(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 3ff9ce3501..8f36423c28 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -26,6 +26,7 @@
> #include "cpu.h"
> #include "trace.h"
> #include "qapi/error.h"
> +#include "hw/virtio/virtio-access.h"
>
> /*
> * Return one past the end of the end of section. Be careful with uint64_t
> @@ -146,9 +147,8 @@ static void vhost_vdpa_iotlb_batch_begin_once(struct
> vhost_vdpa *v)
> v->iotlb_batch_begin_sent = true;
> }
>
> -static void vhost_vdpa_listener_commit(MemoryListener *listener)
> +static void vhost_vdpa_iotlb_batch_end(struct vhost_vdpa *v)
> {
> - struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa,
> listener);
> struct vhost_dev *dev = v->dev;
> struct vhost_msg_v2 msg = {};
> int fd = v->device_fd;
> @@ -172,6 +172,18 @@ static void vhost_vdpa_listener_commit(MemoryListener
> *listener)
>
> v->iotlb_batch_begin_sent = false;
> }
> +static void vhost_vdpa_listener_commit(MemoryListener *listener)
> +{
> + struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa,
> listener);
> + return vhost_vdpa_iotlb_batch_end(v);
> +}
> +
> +static void vhost_vdpa_listener_iommu_commit(MemoryListener *listener)
> +{
> + struct vhost_vdpa *v =
> + container_of(listener, struct vhost_vdpa, iommu_listener);
> + return vhost_vdpa_iotlb_batch_end(v);
> +}
>
> static void vhost_vdpa_listener_region_add(MemoryListener *listener,
> MemoryRegionSection *section)
> @@ -186,6 +198,9 @@ static void vhost_vdpa_listener_region_add(MemoryListener
> *listener,
> v->iova_range.last)) {
> return;
> }
> + if (memory_region_is_iommu(section->mr)) {
> + return;
> + }
>
> if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK)
> !=
> (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> @@ -260,6 +275,9 @@ static void vhost_vdpa_listener_region_del(MemoryListener
> *listener,
> v->iova_range.last)) {
> return;
> }
> + if (memory_region_is_iommu(section->mr)) {
> + return;
> + }
>
> if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK)
> !=
> (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> @@ -312,6 +330,180 @@ static const MemoryListener vhost_vdpa_memory_listener
> = {
> .region_del = vhost_vdpa_listener_region_del,
> };
>
> +/* Called with rcu_read_lock held. */
> +static bool vhost_vdpa_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
> + ram_addr_t *ram_addr, bool *read_only)
So this looks exact the same as what VFIO did, try to unify them?
> +{
> + MemoryRegion *mr;
> + hwaddr xlat;
> + hwaddr len = iotlb->addr_mask + 1;
> + bool writable = iotlb->perm & IOMMU_WO;
> +
> + /*
> + * The IOMMU TLB entry we have just covers translation through
> + * this IOMMU to its immediate target. We need to translate
> + * it the rest of the way through to memory.
> + */
> + mr = address_space_translate(&address_space_memory,
> iotlb->translated_addr,
> + &xlat, &len, writable,
> MEMTXATTRS_UNSPECIFIED);
> + if (!memory_region_is_ram(mr)) {
> + error_report("iommu map to non memory area %" HWADDR_PRIx "", xlat);
> + return false;
> + } else if (memory_region_has_ram_discard_manager(mr)) {
> + RamDiscardManager *rdm = memory_region_get_ram_discard_manager(mr);
> + MemoryRegionSection tmp = {
> + .mr = mr,
> + .offset_within_region = xlat,
> + .size = int128_make64(len),
> + };
> +
> + if (!ram_discard_manager_is_populated(rdm, &tmp)) {
> + error_report("iommu map to discarded memory (e.g., unplugged via"
> + " virtio-mem): %" HWADDR_PRIx "",
> + iotlb->translated_addr);
> + return false;
> + }
> + }
> + /*
> + * Translation truncates length to the IOMMU page size,
> + * check that it did not truncate too much.
> + */
> + if (len & iotlb->addr_mask) {
> + error_report("iommu has granularity incompatible with target AS");
> + return false;
> + }
> +
> + if (vaddr) {
> + *vaddr = memory_region_get_ram_ptr(mr) + xlat;
> + }
> +
> + if (ram_addr) {
> + *ram_addr = memory_region_get_ram_addr(mr) + xlat;
> + }
> +
> + if (read_only) {
> + *read_only = !writable || mr->readonly;
> + }
> +
> + return true;
> +}
> +
> +static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry
> *iotlb)
> +{
> + struct vdpa_iommu *iommu = container_of(n, struct vdpa_iommu, n);
> +
> + hwaddr iova = iotlb->iova + iommu->iommu_offset;
> + struct vhost_vdpa *v = iommu->dev;
> + void *vaddr;
> + int ret;
> +
> + if (iotlb->target_as != &address_space_memory) {
> + error_report("Wrong target AS \"%s\", only system memory is allowed",
> + iotlb->target_as->name ? iotlb->target_as->name :
> "none");
> + return;
> + }
> + RCU_READ_LOCK_GUARD();
> + vhost_vdpa_iotlb_batch_begin_once(v);
> +
> + if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
> + bool read_only;
> +
> + if (!vhost_vdpa_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) {
> + return;
> + }
> + ret =
> + vhost_vdpa_dma_map(v, iova, iotlb->addr_mask + 1, vaddr,
> read_only);
> + if (ret) {
> + error_report("vhost_vdpa_dma_map(%p, 0x%" HWADDR_PRIx ", "
> + "0x%" HWADDR_PRIx ", %p) = %d (%m)",
> + v, iova, iotlb->addr_mask + 1, vaddr, ret);
> + }
> + } else {
> + ret = vhost_vdpa_dma_unmap(v, iova, iotlb->addr_mask + 1);
> + if (ret) {
> + error_report("vhost_vdpa_dma_unmap(%p, 0x%" HWADDR_PRIx ", "
> + "0x%" HWADDR_PRIx ") = %d (%m)",
> + v, iova, iotlb->addr_mask + 1, ret);
> + }
> + }
> +}
> +
> +static void vhost_vdpa_iommu_region_add(MemoryListener *listener,
> + MemoryRegionSection *section)
> +{
> + struct vhost_vdpa *v =
> + container_of(listener, struct vhost_vdpa, iommu_listener);
> +
> + struct vdpa_iommu *iommu;
> + Int128 end;
> + int iommu_idx;
> + IOMMUMemoryRegion *iommu_mr;
> + int ret;
> +
> + if (!memory_region_is_iommu(section->mr)) {
> + return;
> + }
> +
> + iommu_mr = IOMMU_MEMORY_REGION(section->mr);
> +
> + iommu = g_malloc0(sizeof(*iommu));
> + end =
> + int128_add(int128_make64(section->offset_within_region),
> section->size);
I'd suggest to tweak the line breaking here and below, e.g you can
keep int128_add and other stuffs as long as it does not exceeds 70 or
80 characters at the line where "end =" sits.
> + end = int128_sub(end, int128_one());
> + iommu_idx =
> + memory_region_iommu_attrs_to_index(iommu_mr, MEMTXATTRS_UNSPECIFIED);
> + iommu->iommu_mr = iommu_mr;
> +
> + iommu_notifier_init(
> + &iommu->n, vhost_vdpa_iommu_map_notify, IOMMU_NOTIFIER_IOTLB_EVENTS,
> + section->offset_within_region, int128_get64(end), iommu_idx);
> + iommu->iommu_offset =
> + section->offset_within_address_space - section->offset_within_region;
> + iommu->dev = v;
> +
> + ret = memory_region_register_iommu_notifier(section->mr, &iommu->n,
> NULL);
> + if (ret) {
> + g_free(iommu);
> + return;
> + }
> +
> + QLIST_INSERT_HEAD(&v->iommu_list, iommu, iommu_next);
> + memory_region_iommu_replay(iommu->iommu_mr, &iommu->n);
> +
> + return;
> +}
> +
> +static void vhost_vdpa_iommu_region_del(MemoryListener *listener,
> + MemoryRegionSection *section)
> +{
> + struct vhost_vdpa *v =
> + container_of(listener, struct vhost_vdpa, iommu_listener);
> +
> + struct vdpa_iommu *iommu;
> +
> + if (!memory_region_is_iommu(section->mr)) {
> + return;
> + }
> +
> + QLIST_FOREACH(iommu, &v->iommu_list, iommu_next)
> + {
> + if (MEMORY_REGION(iommu->iommu_mr) == section->mr &&
> + iommu->n.start == section->offset_within_region) {
> + memory_region_unregister_iommu_notifier(section->mr, &iommu->n);
> + QLIST_REMOVE(iommu, iommu_next);
> + g_free(iommu);
> + break;
> + }
> + }
> +}
> +
> +static const MemoryListener vhost_vdpa_iommu_listener = {
> + .name = "vhost-vdpa-iommu",
> + .region_add = vhost_vdpa_iommu_region_add,
> + .region_del = vhost_vdpa_iommu_region_del,
> + .commit = vhost_vdpa_listener_iommu_commit,
Unless there's a special requirement. I'd suggest to reuse the
existing listener (since you've already had if (iommu_region()) check
there).
Thanks
> +};
> +
> static int vhost_vdpa_call(struct vhost_dev *dev, unsigned long int request,
> void *arg)
> {
> @@ -433,6 +625,18 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev,
> struct vhost_vdpa *v,
> return 0;
> }
>
> +static bool vdpa_dev_has_iommu(struct vhost_dev *dev)
> +{
> + VirtIODevice *vdev = dev->vdev;
> +
> + if (vdev) {
> + return virtio_bus_device_iommu_enabled(vdev) &&
> + virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
> + } else {
> + return false;
> + }
> +}
> +
> static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
> {
> struct vhost_vdpa *v;
> @@ -454,6 +658,7 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void
> *opaque, Error **errp)
> v->dev = dev;
> dev->opaque = opaque ;
> v->listener = vhost_vdpa_memory_listener;
> + v->iommu_listener = vhost_vdpa_iommu_listener;
> v->msg_type = VHOST_IOTLB_MSG_V2;
> ret = vhost_vdpa_init_svq(dev, v, errp);
> if (ret) {
> @@ -587,7 +792,6 @@ static int vhost_vdpa_cleanup(struct vhost_dev *dev)
> v = dev->opaque;
> trace_vhost_vdpa_cleanup(dev, v);
> vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
> - memory_listener_unregister(&v->listener);
> vhost_vdpa_svq_cleanup(dev);
>
> dev->opaque = NULL;
> @@ -1128,11 +1332,19 @@ static int vhost_vdpa_dev_start(struct vhost_dev
> *dev, bool started)
>
> if (started) {
> memory_listener_register(&v->listener, &address_space_memory);
> + if (vdpa_dev_has_iommu(dev)) {
> + memory_listener_register(&v->iommu_listener, dev->vdev->dma_as);
> + }
> +
> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> } else {
> vhost_vdpa_reset_device(dev);
> vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> VIRTIO_CONFIG_S_DRIVER);
> +
> + if (vdpa_dev_has_iommu(dev)) {
> + memory_listener_unregister(&v->iommu_listener);
> + }
> memory_listener_unregister(&v->listener);
>
> return 0;
> diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
> index d10a89303e..22cbce7934 100644
> --- a/include/hw/virtio/vhost-vdpa.h
> +++ b/include/hw/virtio/vhost-vdpa.h
> @@ -30,6 +30,7 @@ typedef struct vhost_vdpa {
> uint32_t msg_type;
> bool iotlb_batch_begin_sent;
> MemoryListener listener;
> + MemoryListener iommu_listener;
> struct vhost_vdpa_iova_range iova_range;
> uint64_t acked_features;
> bool shadow_vqs_enabled;
> @@ -41,8 +42,18 @@ typedef struct vhost_vdpa {
> void *shadow_vq_ops_opaque;
> struct vhost_dev *dev;
> VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
> + QLIST_HEAD(, vdpa_iommu) iommu_list;
> + IOMMUNotifier n;
> } VhostVDPA;
>
> +struct vdpa_iommu {
> + struct vhost_vdpa *dev;
> + IOMMUMemoryRegion *iommu_mr;
> + hwaddr iommu_offset;
> + IOMMUNotifier n;
> + QLIST_ENTRY(vdpa_iommu) iommu_next;
> +};
> +
> int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
> void *vaddr, bool readonly);
> int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova, hwaddr size);
> --
> 2.34.3
>