On Fri, Jan 10, 2025 at 6:09 PM Jonah Palmer <jonah.pal...@oracle.com> wrote:
>
> Implements the GPA->IOVA tree for handling mapping and unmapping for
> guest memory. This, alongside the SVQ IOVA->HVA tree & IOVA-only tree
> implemented in the previous patches, allows us to handle guest and
> host-only memory mapping operations separately via their own respective
> trees.
>
> The next patches will implement a method to determine if an incomming
s/incomming/incoming/ (credits to google syntax highlight actually :) )
> address for translation is backed by guest or host-only memory.
>
> Signed-off-by: Jonah Palmer <jonah.pal...@oracle.com>
> ---
> hw/virtio/vhost-iova-tree.c | 50 +++++++++++++++++++++++++++++++++++++
> hw/virtio/vhost-iova-tree.h | 4 +++
> hw/virtio/vhost-vdpa.c | 22 ++++++++++------
> include/qemu/iova-tree.h | 22 ++++++++++++++++
> util/iova-tree.c | 46 ++++++++++++++++++++++++++++++++++
> 5 files changed, 136 insertions(+), 8 deletions(-)
>
> diff --git a/hw/virtio/vhost-iova-tree.c b/hw/virtio/vhost-iova-tree.c
> index f6a5694857..540bc35660 100644
> --- a/hw/virtio/vhost-iova-tree.c
> +++ b/hw/virtio/vhost-iova-tree.c
> @@ -31,6 +31,9 @@ struct VhostIOVATree {
>
> /* Allocated IOVA addresses */
> IOVATree *iova_map;
> +
> + /* GPA to IOVA address memory maps */
> + IOVATree *gpa_iova_map;
> };
>
> /**
> @@ -48,6 +51,7 @@ VhostIOVATree *vhost_iova_tree_new(hwaddr iova_first,
> hwaddr iova_last)
>
> tree->iova_taddr_map = iova_tree_new();
> tree->iova_map = iova_tree_new();
> + tree->gpa_iova_map = gpa_tree_new();
> return tree;
> }
>
> @@ -58,6 +62,7 @@ void vhost_iova_tree_delete(VhostIOVATree *iova_tree)
> {
> iova_tree_destroy(iova_tree->iova_taddr_map);
> iova_tree_destroy(iova_tree->iova_map);
> + iova_tree_destroy(iova_tree->gpa_iova_map);
> g_free(iova_tree);
> }
>
> @@ -134,3 +139,48 @@ int vhost_iova_tree_insert(VhostIOVATree *iova_tree,
> DMAMap *map)
>
> return iova_tree_insert(iova_tree->iova_taddr_map, map);
> }
> +
> +/** Insert a new GPA->IOVA mapping to the GPA->IOVA tree
> + *
> + * @iova_tree: The VhostIOVATree
> + * @map: The GPA->IOVA mapping
> + *
> + * Returns:
> + * - IOVA_OK if the map fits in the container
> + * - IOVA_ERR_INVALID if the map does not make sense (e.g. size overflow)
> + * - IOVA_ERR_OVERLAP if the GPA range overlaps with an existing range
> + */
> +int vhost_iova_tree_insert_gpa(VhostIOVATree *iova_tree, DMAMap *map)
> +{
> + if (map->iova + map->size < map->iova || map->perm == IOMMU_NONE) {
> + return IOVA_ERR_INVALID;
> + }
> +
> + return gpa_tree_insert(iova_tree->gpa_iova_map, map);
> +}
> +
> +/**
> + * Find the IOVA address stored from a guest memory address (GPA)
> + *
> + * @tree: The VhostIOVATree
> + * @map: The map with the guest memory address
> + *
> + * Returns the stored GPA->IOVA mapping, or NULL if not found.
> + */
> +const DMAMap *vhost_iova_tree_find_gpa(const VhostIOVATree *tree,
> + const DMAMap *map)
> +{
> + return iova_tree_find_iova(tree->gpa_iova_map, map);
> +}
> +
> +/**
> + * Remove existing mappings from the GPA->IOVA & IOVA trees
> + *
> + * @iova_tree: The VhostIOVATree
> + * @map: The guest memory address map to remove
> + */
> +void vhost_iova_tree_remove_gpa(VhostIOVATree *iova_tree, DMAMap map)
> +{
> + iova_tree_remove(iova_tree->gpa_iova_map, map);
> + iova_tree_remove(iova_tree->iova_map, map);
> +}
> diff --git a/hw/virtio/vhost-iova-tree.h b/hw/virtio/vhost-iova-tree.h
> index 8bf7b64786..3e3dcd04fe 100644
> --- a/hw/virtio/vhost-iova-tree.h
> +++ b/hw/virtio/vhost-iova-tree.h
> @@ -24,5 +24,9 @@ const DMAMap *vhost_iova_tree_find_iova(const VhostIOVATree
> *iova_tree,
> int vhost_iova_tree_map_alloc(VhostIOVATree *iova_tree, DMAMap *map);
> void vhost_iova_tree_remove(VhostIOVATree *iova_tree, DMAMap map);
> int vhost_iova_tree_insert(VhostIOVATree *iova_tree, DMAMap *map);
> +int vhost_iova_tree_insert_gpa(VhostIOVATree *iova_tree, DMAMap *map);
> +const DMAMap *vhost_iova_tree_find_gpa(const VhostIOVATree *iova_tree,
> + const DMAMap *map);
> +void vhost_iova_tree_remove_gpa(VhostIOVATree *iova_tree, DMAMap map);
>
> #endif
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index f5803f35f4..8587f3f6c8 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -361,10 +361,10 @@ static void
> vhost_vdpa_listener_region_add(MemoryListener *listener,
> if (s->shadow_data) {
> int r;
>
> - mem_region.translated_addr = (hwaddr)(uintptr_t)vaddr,
> mem_region.size = int128_get64(llsize) - 1,
> mem_region.perm = IOMMU_ACCESS_FLAG(true, section->readonly),
>
> + /* Allocate an IOVA range in the IOVA tree */
> r = vhost_iova_tree_map_alloc(s->iova_tree, &mem_region);
> if (unlikely(r != IOVA_OK)) {
> error_report("Can't allocate a mapping (%d)", r);
> @@ -372,6 +372,14 @@ static void
> vhost_vdpa_listener_region_add(MemoryListener *listener,
> }
>
> iova = mem_region.iova;
> + mem_region.translated_addr = section->offset_within_address_space;
> +
> + /* Add GPA->IOVA mapping to the GPA->IOVA tree */
> + r = vhost_iova_tree_insert_gpa(s->iova_tree, &mem_region);
> + if (unlikely(r != IOVA_OK)) {
> + error_report("Can't add listener region mapping (%d)", r);
> + goto fail_map;
> + }
If we want to make the two disjoint trees, we need to make the
previous commits working. I mean, either insert hva and then switch to
gpa here, or merge patches, or something similar. Otherwise, bisection
breaks.
> }
>
> vhost_vdpa_iotlb_batch_begin_once(s);
> @@ -386,7 +394,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener
> *listener,
>
> fail_map:
> if (s->shadow_data) {
> - vhost_iova_tree_remove(s->iova_tree, mem_region);
> + vhost_iova_tree_remove_gpa(s->iova_tree, mem_region);
> }
>
> fail:
> @@ -440,21 +448,19 @@ static void
> vhost_vdpa_listener_region_del(MemoryListener *listener,
>
> if (s->shadow_data) {
> const DMAMap *result;
> - const void *vaddr = memory_region_get_ram_ptr(section->mr) +
> - section->offset_within_region +
> - (iova - section->offset_within_address_space);
> DMAMap mem_region = {
> - .translated_addr = (hwaddr)(uintptr_t)vaddr,
> + .translated_addr = section->offset_within_address_space,
> .size = int128_get64(llsize) - 1,
> };
>
> - result = vhost_iova_tree_find_iova(s->iova_tree, &mem_region);
> + /* Search the GPA->IOVA tree */
> + result = vhost_iova_tree_find_gpa(s->iova_tree, &mem_region);
> if (!result) {
> /* The memory listener map wasn't mapped */
> return;
> }
> iova = result->iova;
> - vhost_iova_tree_remove(s->iova_tree, *result);
> + vhost_iova_tree_remove_gpa(s->iova_tree, *result);
> }
> vhost_vdpa_iotlb_batch_begin_once(s);
> /*
> diff --git a/include/qemu/iova-tree.h b/include/qemu/iova-tree.h
> index 44a45931d5..8467912a0b 100644
> --- a/include/qemu/iova-tree.h
> +++ b/include/qemu/iova-tree.h
> @@ -40,6 +40,15 @@ typedef struct DMAMap {
> } QEMU_PACKED DMAMap;
> typedef gboolean (*iova_tree_iterator)(DMAMap *map);
>
> +/**
> + * gpa_tree_new:
> + *
> + * Create a new GPA->IOVA tree.
> + *
> + * Returns: the tree pointer on success, or NULL otherwise.
> + */
> +IOVATree *gpa_tree_new(void);
> +
> /**
> * iova_tree_new:
> *
> @@ -49,6 +58,19 @@ typedef gboolean (*iova_tree_iterator)(DMAMap *map);
> */
> IOVATree *iova_tree_new(void);
>
> +/**
> + * gpa_tree_insert:
> + *
> + * @tree: The GPA->IOVA tree we're inserting the mapping to
> + * @map: The GPA->IOVA mapping to insert
> + *
> + * Inserts a GPA range to the GPA->IOVA tree. If there are overlapped
> + * ranges, IOVA_ERR_OVERLAP will be returned.
> + *
> + * Return: 0 if successful, < 0 otherwise.
> + */
> +int gpa_tree_insert(IOVATree *tree, const DMAMap *map);
> +
> /**
> * iova_tree_insert:
> *
> diff --git a/util/iova-tree.c b/util/iova-tree.c
> index 06295e2755..f45e63c3de 100644
> --- a/util/iova-tree.c
> +++ b/util/iova-tree.c
> @@ -55,6 +55,22 @@ static void iova_tree_alloc_args_iterate(struct
> IOVATreeAllocArgs *args,
> args->this = next;
> }
>
> +static int gpa_tree_compare(gconstpointer a, gconstpointer b, gpointer data)
> +{
> + const DMAMap *m1 = a, *m2 = b;
> +
> + if (m1->translated_addr > m2->translated_addr + m2->size) {
> + return 1;
> + }
> +
> + if (m1->translated_addr + m1->size < m2->translated_addr) {
> + return -1;
> + }
> +
> + /* Overlapped */
> + return 0;
> +}
> +
> static int iova_tree_compare(gconstpointer a, gconstpointer b, gpointer data)
> {
> const DMAMap *m1 = a, *m2 = b;
> @@ -71,6 +87,15 @@ static int iova_tree_compare(gconstpointer a,
> gconstpointer b, gpointer data)
> return 0;
> }
>
> +IOVATree *gpa_tree_new(void)
> +{
> + IOVATree *gpa_tree = g_new0(IOVATree, 1);
> +
> + gpa_tree->tree = g_tree_new_full(gpa_tree_compare, NULL, g_free, NULL);
> +
> + return gpa_tree;
> +}
> +
> IOVATree *iova_tree_new(void)
> {
> IOVATree *iova_tree = g_new0(IOVATree, 1);
> @@ -121,6 +146,27 @@ static inline void iova_tree_insert_internal(GTree
> *gtree, DMAMap *range)
> g_tree_insert(gtree, range, range);
> }
>
> +int gpa_tree_insert(IOVATree *tree, const DMAMap *map)
> +{
> + DMAMap *new;
> +
> + if (map->translated_addr + map->size < map->translated_addr ||
> + map->perm == IOMMU_NONE) {
> + return IOVA_ERR_INVALID;
> + }
> +
> + /* We don't allow inserting ranges that overlap with existing ones */
> + if (iova_tree_find(tree,map)) {
> + return IOVA_ERR_OVERLAP;
> + }
> +
> + new = g_new0(DMAMap, 1);
> + memcpy(new, map, sizeof(*new));
> + iova_tree_insert_internal(tree->tree, new);
> +
> + return IOVA_OK;
> +}
> +
I'm missing the advantage of using all of these functions, why not use
another iova_tree_new and iova_tree_insert? gpa_tree_compare seems
like a 1:1 copy of iova_tree_compare to me. Same with _insert.
> int iova_tree_insert(IOVATree *tree, const DMAMap *map)
> {
> DMAMap *new;
> --
> 2.43.5
>
