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Re: [PATCH 23/31] vdpa: Add custom IOTLB translations to SVQ
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From: |
Jason Wang |
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Subject: |
Re: [PATCH 23/31] vdpa: Add custom IOTLB translations to SVQ |
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Date: |
Sun, 30 Jan 2022 13:57:54 +0800 |
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User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 |
在 2022/1/22 上午4:27, Eugenio Pérez 写道:
Use translations added in VhostIOVATree in SVQ.
Only introduce usage here, not allocation and deallocation. As with
previous patches, we use the dead code paths of shadow_vqs_enabled to
avoid commiting too many changes at once. These are impossible to take
at the moment.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
hw/virtio/vhost-shadow-virtqueue.h | 3 +-
include/hw/virtio/vhost-vdpa.h | 3 +
hw/virtio/vhost-shadow-virtqueue.c | 111 ++++++++++++++++----
hw/virtio/vhost-vdpa.c | 161 +++++++++++++++++++++++++----
4 files changed, 238 insertions(+), 40 deletions(-)
diff --git a/hw/virtio/vhost-shadow-virtqueue.h
b/hw/virtio/vhost-shadow-virtqueue.h
index 19c934af49..c6f67d6f76 100644
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -12,6 +12,7 @@
#include "hw/virtio/vhost.h"
#include "qemu/event_notifier.h"
+#include "hw/virtio/vhost-iova-tree.h"
typedef struct VhostShadowVirtqueue VhostShadowVirtqueue;
@@ -37,7 +38,7 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
VirtQueue *vq);
void vhost_svq_stop(VhostShadowVirtqueue *svq);
-VhostShadowVirtqueue *vhost_svq_new(uint16_t qsize);
+VhostShadowVirtqueue *vhost_svq_new(uint16_t qsize, VhostIOVATree *iova_map);
void vhost_svq_free(VhostShadowVirtqueue *vq);
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 009a9f3b6b..cd2388b3be 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -14,6 +14,7 @@
#include <gmodule.h>
+#include "hw/virtio/vhost-iova-tree.h"
#include "hw/virtio/virtio.h"
#include "standard-headers/linux/vhost_types.h"
@@ -30,6 +31,8 @@ typedef struct vhost_vdpa {
MemoryListener listener;
struct vhost_vdpa_iova_range iova_range;
bool shadow_vqs_enabled;
+ /* IOVA mapping used by Shadow Virtqueue */
+ VhostIOVATree *iova_tree;
GPtrArray *shadow_vqs;
struct vhost_dev *dev;
VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
diff --git a/hw/virtio/vhost-shadow-virtqueue.c
b/hw/virtio/vhost-shadow-virtqueue.c
index a1a404f68f..c7888eb8cf 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -11,6 +11,7 @@
#include "hw/virtio/vhost-shadow-virtqueue.h"
#include "hw/virtio/vhost.h"
#include "hw/virtio/virtio-access.h"
+#include "hw/virtio/vhost-iova-tree.h"
#include "standard-headers/linux/vhost_types.h"
#include "qemu/error-report.h"
@@ -45,6 +46,9 @@ typedef struct VhostShadowVirtqueue {
/* Virtio device */
VirtIODevice *vdev;
+ /* IOVA mapping */
+ VhostIOVATree *iova_tree;
+
/* Map for returning guest's descriptors */
VirtQueueElement **ring_id_maps;
@@ -97,13 +101,7 @@ bool vhost_svq_valid_device_features(uint64_t *dev_features)
continue;
case VIRTIO_F_ACCESS_PLATFORM:
- /* SVQ does not know how to translate addresses */
- if (*dev_features & BIT_ULL(b)) {
- clear_bit(b, dev_features);
- r = false;
- }
- break;
-
+ /* SVQ trust in host's IOMMU to translate addresses */
case VIRTIO_F_VERSION_1:
/* SVQ trust that guest vring is little endian */
if (!(*dev_features & BIT_ULL(b))) {
@@ -205,7 +203,55 @@ static void
vhost_svq_set_notification(VhostShadowVirtqueue *svq, bool enable)
}
}
+/**
+ * Translate addresses between qemu's virtual address and SVQ IOVA
+ *
+ * @svq Shadow VirtQueue
+ * @vaddr Translated IOVA addresses
+ * @iovec Source qemu's VA addresses
+ * @num Length of iovec and minimum length of vaddr
+ */
+static bool vhost_svq_translate_addr(const VhostShadowVirtqueue *svq,
+ void **addrs, const struct iovec *iovec,
+ size_t num)
+{
+ size_t i;
+
+ if (num == 0) {
+ return true;
+ }
+
+ for (i = 0; i < num; ++i) {
+ DMAMap needle = {
+ .translated_addr = (hwaddr)iovec[i].iov_base,
+ .size = iovec[i].iov_len,
+ };
+ size_t off;
+
+ const DMAMap *map = vhost_iova_tree_find_iova(svq->iova_tree, &needle);
+ /*
+ * Map cannot be NULL since iova map contains all guest space and
+ * qemu already has a physical address mapped
+ */
+ if (unlikely(!map)) {
+ error_report("Invalid address 0x%"HWADDR_PRIx" given by guest",
+ needle.translated_addr);
This can be triggered by guest, we need use once or log_guest_error() etc.
+ return false;
+ }
+
+ /*
+ * Map->iova chunk size is ignored. What to do if descriptor
+ * (addr, size) does not fit is delegated to the device.
+ */
I think we need at least check the size and fail if the size doesn't
match here. Or is it possible that we have a buffer that may cross two
memory regions?
+ off = needle.translated_addr - map->translated_addr;
+ addrs[i] = (void *)(map->iova + off);
+ }
+
+ return true;
+}
+
static void vhost_vring_write_descs(VhostShadowVirtqueue *svq,
+ void * const *vaddr_sg,
const struct iovec *iovec,
size_t num, bool more_descs, bool write)
{
@@ -224,7 +270,7 @@ static void vhost_vring_write_descs(VhostShadowVirtqueue
*svq,
} else {
descs[i].flags = flags;
}
- descs[i].addr = cpu_to_le64((hwaddr)iovec[n].iov_base);
+ descs[i].addr = cpu_to_le64((hwaddr)vaddr_sg[n]);
descs[i].len = cpu_to_le32(iovec[n].iov_len);
last = i;
@@ -234,42 +280,60 @@ static void vhost_vring_write_descs(VhostShadowVirtqueue
*svq,
svq->free_head = le16_to_cpu(descs[last].next);
}
-static unsigned vhost_svq_add_split(VhostShadowVirtqueue *svq,
- VirtQueueElement *elem)
+static bool vhost_svq_add_split(VhostShadowVirtqueue *svq,
+ VirtQueueElement *elem,
+ unsigned *head)
I'd suggest to make it returns bool since the patch that introduces this
function.
{
- int head;
unsigned avail_idx;
vring_avail_t *avail = svq->vring.avail;
+ bool ok;
+ g_autofree void **sgs = g_new(void *, MAX(elem->out_num, elem->in_num));
- head = svq->free_head;
+ *head = svq->free_head;
/* We need some descriptors here */
assert(elem->out_num || elem->in_num);
- vhost_vring_write_descs(svq, elem->out_sg, elem->out_num,
+ ok = vhost_svq_translate_addr(svq, sgs, elem->out_sg, elem->out_num);
+ if (unlikely(!ok)) {
+ return false;
+ }
+ vhost_vring_write_descs(svq, sgs, elem->out_sg, elem->out_num,
elem->in_num > 0, false);
- vhost_vring_write_descs(svq, elem->in_sg, elem->in_num, false, true);
+
+
+ ok = vhost_svq_translate_addr(svq, sgs, elem->in_sg, elem->in_num);
+ if (unlikely(!ok)) {
+ return false;
+ }
+
+ vhost_vring_write_descs(svq, sgs, elem->in_sg, elem->in_num, false, true);
/*
* Put entry in available array (but don't update avail->idx until they
* do sync).
*/
avail_idx = svq->avail_idx_shadow & (svq->vring.num - 1);
- avail->ring[avail_idx] = cpu_to_le16(head);
+ avail->ring[avail_idx] = cpu_to_le16(*head);
svq->avail_idx_shadow++;
/* Update avail index after the descriptor is wrote */
smp_wmb();
avail->idx = cpu_to_le16(svq->avail_idx_shadow);
- return head;
+ return true;
}
-static void vhost_svq_add(VhostShadowVirtqueue *svq, VirtQueueElement *elem)
+static bool vhost_svq_add(VhostShadowVirtqueue *svq, VirtQueueElement *elem)
{
- unsigned qemu_head = vhost_svq_add_split(svq, elem);
+ unsigned qemu_head;
+ bool ok = vhost_svq_add_split(svq, elem, &qemu_head);
+ if (unlikely(!ok)) {
+ return false;
+ }
svq->ring_id_maps[qemu_head] = elem;
+ return true;
}
static void vhost_svq_kick(VhostShadowVirtqueue *svq)
@@ -309,6 +373,7 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue
*svq)
while (true) {
VirtQueueElement *elem;
+ bool ok;
if (svq->next_guest_avail_elem) {
elem = g_steal_pointer(&svq->next_guest_avail_elem);
@@ -337,7 +402,11 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue
*svq)
return;
}
- vhost_svq_add(svq, elem);
+ ok = vhost_svq_add(svq, elem);
+ if (unlikely(!ok)) {
+ /* VQ is broken, just return and ignore any other kicks */
+ return;
+ }
vhost_svq_kick(svq);
}
@@ -619,12 +688,13 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)
* methods and file descriptors.
*
* @qsize Shadow VirtQueue size
+ * @iova_tree Tree to perform descriptors translations
*
* Returns the new virtqueue or NULL.
*
* In case of error, reason is reported through error_report.
*/
-VhostShadowVirtqueue *vhost_svq_new(uint16_t qsize)
+VhostShadowVirtqueue *vhost_svq_new(uint16_t qsize, VhostIOVATree *iova_tree)
{
size_t desc_size = sizeof(vring_desc_t) * qsize;
size_t device_size, driver_size;
@@ -656,6 +726,7 @@ VhostShadowVirtqueue *vhost_svq_new(uint16_t qsize)
memset(svq->vring.desc, 0, driver_size);
svq->vring.used = qemu_memalign(qemu_real_host_page_size, device_size);
memset(svq->vring.used, 0, device_size);
+ svq->iova_tree = iova_tree;
svq->ring_id_maps = g_new0(VirtQueueElement *, qsize);
event_notifier_set_handler(&svq->hdev_call, vhost_svq_handle_call);
return g_steal_pointer(&svq);
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 0e5c00ed7e..276a559649 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -209,6 +209,18 @@ static void vhost_vdpa_listener_region_add(MemoryListener
*listener,
vaddr, section->readonly);
llsize = int128_sub(llend, int128_make64(iova));
+ if (v->shadow_vqs_enabled) {
+ DMAMap mem_region = {
+ .translated_addr = (hwaddr)vaddr,
+ .size = int128_get64(llsize) - 1,
+ .perm = IOMMU_ACCESS_FLAG(true, section->readonly),
+ };
+
+ int r = vhost_iova_tree_map_alloc(v->iova_tree, &mem_region);
+ assert(r == IOVA_OK);
It's better to fail or warn here.
+
+ iova = mem_region.iova;
+ }
vhost_vdpa_iotlb_batch_begin_once(v);
ret = vhost_vdpa_dma_map(v, iova, int128_get64(llsize),
@@ -261,6 +273,20 @@ static void vhost_vdpa_listener_region_del(MemoryListener
*listener,
llsize = int128_sub(llend, int128_make64(iova));
+ if (v->shadow_vqs_enabled) {
+ 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)vaddr,
+ .size = int128_get64(llsize) - 1,
+ };
+
+ result = vhost_iova_tree_find_iova(v->iova_tree, &mem_region);
+ iova = result->iova;
+ vhost_iova_tree_remove(v->iova_tree, &mem_region);
+ }
vhost_vdpa_iotlb_batch_begin_once(v);
ret = vhost_vdpa_dma_unmap(v, iova, int128_get64(llsize));
if (ret) {
@@ -783,33 +809,70 @@ static int vhost_vdpa_svq_set_fds(struct vhost_dev *dev,
/**
* Unmap SVQ area in the device
*/
-static bool vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr iova,
- hwaddr size)
+static bool vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v,
+ const DMAMap *needle)
{
+ const DMAMap *result = vhost_iova_tree_find_iova(v->iova_tree, needle);
+ hwaddr size;
int r;
- size = ROUND_UP(size, qemu_real_host_page_size);
- r = vhost_vdpa_dma_unmap(v, iova, size);
+ if (unlikely(!result)) {
+ error_report("Unable to find SVQ address to unmap");
+ return false;
+ }
+
+ size = ROUND_UP(result->size, qemu_real_host_page_size);
+ r = vhost_vdpa_dma_unmap(v, result->iova, size);
return r == 0;
}
static bool vhost_vdpa_svq_unmap_rings(struct vhost_dev *dev,
const VhostShadowVirtqueue *svq)
{
+ DMAMap needle;
struct vhost_vdpa *v = dev->opaque;
struct vhost_vring_addr svq_addr;
- size_t device_size = vhost_svq_device_area_size(svq);
- size_t driver_size = vhost_svq_driver_area_size(svq);
bool ok;
vhost_svq_get_vring_addr(svq, &svq_addr);
- ok = vhost_vdpa_svq_unmap_ring(v, svq_addr.desc_user_addr, driver_size);
+ needle = (DMAMap) {
+ .translated_addr = svq_addr.desc_user_addr,
+ };
+ ok = vhost_vdpa_svq_unmap_ring(v, &needle);
if (unlikely(!ok)) {
return false;
}
- return vhost_vdpa_svq_unmap_ring(v, svq_addr.used_user_addr, device_size);
+ needle = (DMAMap) {
+ .translated_addr = svq_addr.used_user_addr,
+ };
+ return vhost_vdpa_svq_unmap_ring(v, &needle);
+}
+
+/**
+ * Map SVQ area in the device
+ *
+ * @v Vhost-vdpa device
+ * @needle The area to search iova
+ * @readonly Permissions of the area
+ */
+static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, const DMAMap *needle,
+ bool readonly)
+{
+ hwaddr off;
+ const DMAMap *result = vhost_iova_tree_find_iova(v->iova_tree, needle);
+ int r;
+
+ if (unlikely(!result)) {
+ error_report("Can't locate SVQ ring");
+ return false;
+ }
+
+ off = needle->translated_addr - result->translated_addr;
+ r = vhost_vdpa_dma_map(v, result->iova + off, needle->size,
+ (void *)needle->translated_addr, readonly);
+ return r == 0;
}
/**
@@ -821,23 +884,29 @@ static bool vhost_vdpa_svq_unmap_rings(struct vhost_dev
*dev,
static bool vhost_vdpa_svq_map_rings(struct vhost_dev *dev,
const VhostShadowVirtqueue *svq)
{
+ DMAMap needle;
struct vhost_vdpa *v = dev->opaque;
struct vhost_vring_addr svq_addr;
size_t device_size = vhost_svq_device_area_size(svq);
size_t driver_size = vhost_svq_driver_area_size(svq);
- int r;
+ bool ok;
vhost_svq_get_vring_addr(svq, &svq_addr);
- r = vhost_vdpa_dma_map(v, svq_addr.desc_user_addr, driver_size,
- (void *)svq_addr.desc_user_addr, true);
- if (unlikely(r != 0)) {
+ needle = (DMAMap) {
+ .translated_addr = svq_addr.desc_user_addr,
+ .size = driver_size,
+ };
+ ok = vhost_vdpa_svq_map_ring(v, &needle, true);
+ if (unlikely(!ok)) {
return false;
}
- r = vhost_vdpa_dma_map(v, svq_addr.used_user_addr, device_size,
- (void *)svq_addr.used_user_addr, false);
- return r == 0;
+ needle = (DMAMap) {
+ .translated_addr = svq_addr.used_user_addr,
+ .size = device_size,
+ };
+ return vhost_vdpa_svq_map_ring(v, &needle, false);
}
static bool vhost_vdpa_svq_setup(struct vhost_dev *dev,
@@ -1006,6 +1075,23 @@ static int vhost_vdpa_set_owner(struct vhost_dev *dev)
return vhost_vdpa_call(dev, VHOST_SET_OWNER, NULL);
}
+static bool vhost_vdpa_svq_get_vq_region(struct vhost_vdpa *v,
+ unsigned long long addr,
+ uint64_t *iova_addr)
+{
+ const DMAMap needle = {
+ .translated_addr = addr,
+ };
+ const DMAMap *translation = vhost_iova_tree_find_iova(v->iova_tree,
+ &needle);
+ if (!translation) {
+ return false;
+ }
+
+ *iova_addr = translation->iova + (addr - translation->translated_addr);
+ return true;
+}
+
static void vhost_vdpa_vq_get_guest_addr(struct vhost_vring_addr *addr,
struct vhost_virtqueue *vq)
{
@@ -1023,10 +1109,23 @@ static int vhost_vdpa_vq_get_addr(struct vhost_dev *dev,
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
if (v->shadow_vqs_enabled) {
+ struct vhost_vring_addr svq_addr;
int idx = vhost_vdpa_get_vq_index(dev, addr->index);
VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, idx);
- vhost_svq_get_vring_addr(svq, addr);
+ vhost_svq_get_vring_addr(svq, &svq_addr);
+ if (!vhost_vdpa_svq_get_vq_region(v, svq_addr.desc_user_addr,
+ &addr->desc_user_addr)) {
+ return -1;
+ }
+ if (!vhost_vdpa_svq_get_vq_region(v, svq_addr.avail_user_addr,
+ &addr->avail_user_addr)) {
+ return -1;
+ }
+ if (!vhost_vdpa_svq_get_vq_region(v, svq_addr.used_user_addr,
+ &addr->used_user_addr)) {
+ return -1;
+ }
} else {
vhost_vdpa_vq_get_guest_addr(addr, vq);
}
@@ -1095,13 +1194,37 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev,
struct vhost_vdpa *v,
shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_psvq_free);
for (unsigned n = 0; n < hdev->nvqs; ++n) {
- VhostShadowVirtqueue *svq = vhost_svq_new(qsize);
-
+ DMAMap device_region, driver_region;
+ struct vhost_vring_addr addr;
+ VhostShadowVirtqueue *svq = vhost_svq_new(qsize, v->iova_tree);
if (unlikely(!svq)) {
error_setg(errp, "Cannot create svq %u", n);
return -1;
}
- g_ptr_array_add(v->shadow_vqs, svq);
+
+ vhost_svq_get_vring_addr(svq, &addr);
+ driver_region = (DMAMap) {
+ .translated_addr = (hwaddr)addr.desc_user_addr,
+
+ /*
+ * DMAMAp.size include the last byte included in the range, while
+ * sizeof marks one past it. Substract one byte to make them match.
+ */
+ .size = vhost_svq_driver_area_size(svq) - 1,
+ .perm = VHOST_ACCESS_RO,
+ };
+ device_region = (DMAMap) {
+ .translated_addr = (hwaddr)addr.used_user_addr,
+ .size = vhost_svq_device_area_size(svq) - 1,
+ .perm = VHOST_ACCESS_RW,
+ };
+
+ r = vhost_iova_tree_map_alloc(v->iova_tree, &driver_region);
+ assert(r == IOVA_OK);
Let's fail instead of assert here.
Thanks
+ r = vhost_iova_tree_map_alloc(v->iova_tree, &device_region);
+ assert(r == IOVA_OK);
+
+ g_ptr_array_add(shadow_vqs, svq);
}
out:
[PATCH 20/31] util: Store DMA entries in a list, Eugenio Pérez, 2022/01/21
[PATCH 22/31] vhost: Add VhostIOVATree, Eugenio Pérez, 2022/01/21
[PATCH 24/31] vhost: Add vhost_svq_get_last_used_idx, Eugenio Pérez, 2022/01/21
[PATCH 23/31] vdpa: Add custom IOTLB translations to SVQ, Eugenio Pérez, 2022/01/21
- Re: [PATCH 23/31] vdpa: Add custom IOTLB translations to SVQ,
Jason Wang <=
[PATCH 25/31] vdpa: Adapt vhost_vdpa_get_vring_base to SVQ, Eugenio Pérez, 2022/01/21
[PATCH 26/31] vdpa: Clear VHOST_VRING_F_LOG at vhost_vdpa_set_vring_addr in SVQ, Eugenio Pérez, 2022/01/21
[PATCH 27/31] vdpa: Never set log_base addr if SVQ is enabled, Eugenio Pérez, 2022/01/21
[PATCH 28/31] vdpa: Expose VHOST_F_LOG_ALL on SVQ, Eugenio Pérez, 2022/01/21
[PATCH 29/31] vdpa: Make ncs autofree, Eugenio Pérez, 2022/01/21
[PATCH 30/31] vdpa: Move vhost_vdpa_get_iova_range to net/vhost-vdpa.c, Eugenio Pérez, 2022/01/21