This patch refactors the handling of vhost-user memory regions by
introducing a new `struct vdev_memory` to encapsulate the regions
array and their count (`nregions`) within the main `vu_dev` structure.
This new `vdev_memory` structure is then passed to the packet pool by
re-using the existing `p->buf` field. A `p->buf_size` of 0 indicates
that `p->buf` holds a pointer to `struct vdev_memory` instead of a
regular packet buffer. A new helper, `get_vdev_memory()`, is added to
abstract this access pattern.
Previous implementation was using a marker at the end of the memory
regions array. We can now uses all the slots.
Signed-off-by: Laurent Vivier
Reviewed-by: David Gibson
---
packet.c | 21 +++++++++++++++++++--
packet.h | 6 ++++--
tap.c | 4 ++--
tap.h | 1 -
vhost_user.c | 28 +++++++++++-----------------
virtio.c | 4 ++--
virtio.h | 18 ++++++++++++++----
vu_common.c | 22 ++++++++++++----------
8 files changed, 64 insertions(+), 40 deletions(-)
diff --git a/packet.c b/packet.c
index cbc43c2fc22d..27693c55a138 100644
--- a/packet.c
+++ b/packet.c
@@ -22,6 +22,20 @@
#include "util.h"
#include "log.h"
+/**
+ * get_vdev_memory() - Return a pointer to the memory regions of the pool
+ * @p: Packet pool
+ *
+ * Return: Null if none, otherwise a pointer to vdev_memory structure
+ */
+static struct vdev_memory *get_vdev_memory(const struct pool *p)
+{
+ if (p->buf_size)
+ return NULL;
+
+ return (struct vdev_memory *)p->buf;
+}
+
/**
* packet_check_range() - Check if a memory range is valid for a pool
* @p: Packet pool
@@ -35,16 +49,19 @@
static int packet_check_range(const struct pool *p, const char *ptr, size_t len,
const char *func, int line)
{
+ struct vdev_memory *memory;
+
if (len > PACKET_MAX_LEN) {
debug("packet range length %zu (max %zu), %s:%i",
len, PACKET_MAX_LEN, func, line);
return -1;
}
- if (p->buf_size == 0) {
+ memory = get_vdev_memory(p);
+ if (memory) {
int ret;
- ret = vu_packet_check_range((void *)p->buf, ptr, len);
+ ret = vu_packet_check_range(memory, ptr, len);
if (ret == -1)
debug("cannot find region, %s:%i", func, line);
diff --git a/packet.h b/packet.h
index 43b9022075d1..e51cbd19fdc4 100644
--- a/packet.h
+++ b/packet.h
@@ -8,6 +8,7 @@
#include
#include "iov.h"
+#include "virtio.h"
/* Maximum size of a single packet stored in pool, including headers */
#define PACKET_MAX_LEN ((size_t)UINT16_MAX)
@@ -15,7 +16,7 @@
/**
* struct pool - Generic pool of packets stored in a buffer
* @buf: Buffer storing packet descriptors,
- * a struct vu_dev_region array for passt vhost-user mode
+ * a struct vdev_region for passt vhost-user mode
* @buf_size: Total size of buffer,
* 0 for passt vhost-user mode
* @size: Number of usable descriptors for the pool
@@ -30,7 +31,8 @@ struct pool {
struct iovec pkt[];
};
-int vu_packet_check_range(void *buf, const char *ptr, size_t len);
+int vu_packet_check_range(struct vdev_memory *memory,
+ const char *ptr, size_t len);
void packet_add_do(struct pool *p, struct iov_tail *data,
const char *func, int line);
bool packet_get_do(const struct pool *p, const size_t idx,
diff --git a/tap.c b/tap.c
index 4e09beac364b..12877e65f96f 100644
--- a/tap.c
+++ b/tap.c
@@ -1458,7 +1458,7 @@ static void tap_sock_tun_init(struct ctx *c)
* @base: Buffer base
* @size Buffer size
*/
-void tap_sock_update_pool(void *base, size_t size)
+static void tap_sock_update_pool(void *base, size_t size)
{
int i;
@@ -1479,8 +1479,8 @@ void tap_sock_update_pool(void *base, size_t size)
void tap_backend_init(struct ctx *c)
{
if (c->mode == MODE_VU) {
- tap_sock_update_pool(NULL, 0);
vu_init(c);
+ tap_sock_update_pool(&c->vdev->memory, 0);
} else {
tap_sock_update_pool(pkt_buf, sizeof(pkt_buf));
}
diff --git a/tap.h b/tap.h
index ce5510882d5d..21db4d219ecb 100644
--- a/tap.h
+++ b/tap.h
@@ -115,7 +115,6 @@ void tap_handler_passt(struct ctx *c, uint32_t events,
const struct timespec *now);
int tap_sock_unix_open(char *sock_path);
void tap_sock_reset(struct ctx *c);
-void tap_sock_update_pool(void *base, size_t size);
void tap_backend_init(struct ctx *c);
void tap_flush_pools(void);
void tap_handler(struct ctx *c, const struct timespec *now);
diff --git a/vhost_user.c b/vhost_user.c
index c1522d549f00..f97ec6064cac 100644
--- a/vhost_user.c
+++ b/vhost_user.c
@@ -137,8 +137,8 @@ static void *qva_to_va(struct vu_dev *dev, uint64_t qemu_addr)
unsigned int i;
/* Find matching memory region. */
- for (i = 0; i < dev->nregions; i++) {
- const struct vu_dev_region *r = &dev->regions[i];
+ for (i = 0; i < dev->memory.nregions; i++) {
+ const struct vu_dev_region *r = &dev->memory.regions[i];
if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) {
/* NOLINTNEXTLINE(performance-no-int-to-ptr) */
@@ -428,8 +428,8 @@ static bool vu_set_mem_table_exec(struct vu_dev *vdev,
struct vhost_user_memory m = vmsg->payload.memory, *memory = &m;
unsigned int i;
- for (i = 0; i < vdev->nregions; i++) {
- const struct vu_dev_region *r = &vdev->regions[i];
+ for (i = 0; i < vdev->memory.nregions; i++) {
+ const struct vu_dev_region *r = &vdev->memory.regions[i];
if (r->mmap_addr) {
/* NOLINTNEXTLINE(performance-no-int-to-ptr) */
@@ -437,12 +437,12 @@ static bool vu_set_mem_table_exec(struct vu_dev *vdev,
r->size + r->mmap_offset);
}
}
- vdev->nregions = memory->nregions;
+ vdev->memory.nregions = memory->nregions;
debug("vhost-user nregions: %u", memory->nregions);
- for (i = 0; i < vdev->nregions; i++) {
+ for (i = 0; i < vdev->memory.nregions; i++) {
struct vhost_user_memory_region *msg_region = &memory->regions[i];
- struct vu_dev_region *dev_region = &vdev->regions[i];
+ struct vu_dev_region *dev_region = &vdev->memory.regions[i];
void *mmap_addr;
debug("vhost-user region %d", i);
@@ -484,13 +484,7 @@ static bool vu_set_mem_table_exec(struct vu_dev *vdev,
}
}
- /* As vu_packet_check_range() has no access to the number of
- * memory regions, mark the end of the array with mmap_addr = 0
- */
- ASSERT(vdev->nregions < VHOST_USER_MAX_RAM_SLOTS - 1);
- vdev->regions[vdev->nregions].mmap_addr = 0;
-
- tap_sock_update_pool(vdev->regions, 0);
+ ASSERT(vdev->memory.nregions < VHOST_USER_MAX_RAM_SLOTS);
return false;
}
@@ -1106,8 +1100,8 @@ void vu_cleanup(struct vu_dev *vdev)
vq->vring.avail = 0;
}
- for (i = 0; i < vdev->nregions; i++) {
- const struct vu_dev_region *r = &vdev->regions[i];
+ for (i = 0; i < vdev->memory.nregions; i++) {
+ const struct vu_dev_region *r = &vdev->memory.regions[i];
if (r->mmap_addr) {
/* NOLINTNEXTLINE(performance-no-int-to-ptr) */
@@ -1115,7 +1109,7 @@ void vu_cleanup(struct vu_dev *vdev)
r->size + r->mmap_offset);
}
}
- vdev->nregions = 0;
+ vdev->memory.nregions = 0;
vu_close_log(vdev);
diff --git a/virtio.c b/virtio.c
index ed7842b4c78a..bd388c2dfc7f 100644
--- a/virtio.c
+++ b/virtio.c
@@ -102,8 +102,8 @@ static void *vu_gpa_to_va(const struct vu_dev *dev, uint64_t *plen,
return NULL;
/* Find matching memory region. */
- for (i = 0; i < dev->nregions; i++) {
- const struct vu_dev_region *r = &dev->regions[i];
+ for (i = 0; i < dev->memory.nregions; i++) {
+ const struct vu_dev_region *r = &dev->memory.regions[i];
if ((guest_addr >= r->gpa) &&
(guest_addr < (r->gpa + r->size))) {
diff --git a/virtio.h b/virtio.h
index 32757458ea95..b55cc4042521 100644
--- a/virtio.h
+++ b/virtio.h
@@ -96,11 +96,22 @@ struct vu_dev_region {
*/
#define VHOST_USER_MAX_RAM_SLOTS 32
+/**
+ * struct vdev_memory - Describes the shared memory regions for a vhost-user
+ * device
+ * @nregions: Number of shared memory regions
+ * @regions: Guest shared memory regions
+ */
+struct vdev_memory {
+ uint32_t nregions;
+ struct vu_dev_region regions[VHOST_USER_MAX_RAM_SLOTS];
+};
+
/**
* struct vu_dev - vhost-user device information
* @context: Execution context
- * @nregions: Number of shared memory regions
- * @regions: Guest shared memory regions
+ * @memory: Shared memory regions
+ * @vq: Virtqueues of the device
* @features: Vhost-user features
* @protocol_features: Vhost-user protocol features
* @log_call_fd: Eventfd to report logging update
@@ -109,8 +120,7 @@ struct vu_dev_region {
*/
struct vu_dev {
struct ctx *context;
- uint32_t nregions;
- struct vu_dev_region regions[VHOST_USER_MAX_RAM_SLOTS];
+ struct vdev_memory memory;
struct vu_virtq vq[VHOST_USER_MAX_QUEUES];
uint64_t features;
uint64_t protocol_features;
diff --git a/vu_common.c b/vu_common.c
index b77b21420c57..b716070ea3c3 100644
--- a/vu_common.c
+++ b/vu_common.c
@@ -25,26 +25,28 @@
/**
* vu_packet_check_range() - Check if a given memory zone is contained in
* a mapped guest memory region
- * @buf: Array of the available memory regions
+ * @memory: Array of the available memory regions
* @ptr: Start of desired data range
- * @size: Length of desired data range
+ * @len: Length of desired data range
*
* Return: 0 if the zone is in a mapped memory region, -1 otherwise
*/
-int vu_packet_check_range(void *buf, const char *ptr, size_t len)
+int vu_packet_check_range(struct vdev_memory *memory,
+ const char *ptr, size_t len)
{
- struct vu_dev_region *dev_region;
+ struct vu_dev_region *dev_region = memory->regions;
+ unsigned int i;
- for (dev_region = buf; dev_region->mmap_addr; dev_region++) {
- uintptr_t base_addr = dev_region->mmap_addr +
- dev_region->mmap_offset;
+ for (i = 0; i < memory->nregions; i++) {
+ uintptr_t base_addr = dev_region[i].mmap_addr +
+ dev_region[i].mmap_offset;
/* NOLINTNEXTLINE(performance-no-int-to-ptr) */
const char *base = (const char *)base_addr;
- ASSERT(base_addr >= dev_region->mmap_addr);
+ ASSERT(base_addr >= dev_region[i].mmap_addr);
- if (len <= dev_region->size && base <= ptr &&
- (size_t)(ptr - base) <= dev_region->size - len)
+ if (len <= dev_region[i].size && base <= ptr &&
+ (size_t)(ptr - base) <= dev_region[i].size - len)
return 0;
}
--
2.49.0