Changed eBPF map updates through mmaped array.
Mmaped arrays provide direct access to map data.
It should omit using bpf_map_update_elem() call,
which may require capabilities that are not present.
Signed-off-by: Andrew Melnychenko <and...@daynix.com>
---
ebpf/ebpf_rss.c | 117 ++++++++++++++++++++++++++++++++++++++----------
ebpf/ebpf_rss.h | 5 +++
2 files changed, 99 insertions(+), 23 deletions(-)
diff --git a/ebpf/ebpf_rss.c b/ebpf/ebpf_rss.c
index cee658c158b..247f5eee1b6 100644
--- a/ebpf/ebpf_rss.c
+++ b/ebpf/ebpf_rss.c
@@ -27,19 +27,83 @@ void ebpf_rss_init(struct EBPFRSSContext *ctx)
{
if (ctx != NULL) {
ctx->obj = NULL;
+ ctx->program_fd = -1;
+ ctx->map_configuration = -1;
+ ctx->map_toeplitz_key = -1;
+ ctx->map_indirections_table = -1;
+
+ ctx->mmap_configuration = NULL;
+ ctx->mmap_toeplitz_key = NULL;
+ ctx->mmap_indirections_table = NULL;
}
}
bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx)
{
- return ctx != NULL && ctx->obj != NULL;
+ return ctx != NULL && (ctx->obj != NULL || ctx->program_fd != -1);
+}
+
+static bool ebpf_rss_mmap(struct EBPFRSSContext *ctx)
+{
+ if (!ebpf_rss_is_loaded(ctx)) {
+ return false;
+ }
+
+ ctx->mmap_configuration = mmap(NULL, qemu_real_host_page_size(),
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ ctx->map_configuration, 0);
+ if (ctx->mmap_configuration == MAP_FAILED) {
+ trace_ebpf_error("eBPF RSS", "can not mmap eBPF configuration array");
+ return false;
+ }
+ ctx->mmap_toeplitz_key = mmap(NULL, qemu_real_host_page_size(),
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ ctx->map_toeplitz_key, 0);
+ if (ctx->mmap_toeplitz_key == MAP_FAILED) {
+ trace_ebpf_error("eBPF RSS", "can not mmap eBPF toeplitz key");
+ goto toeplitz_fail;
+ }
+ ctx->mmap_indirections_table = mmap(NULL, qemu_real_host_page_size(),
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ ctx->map_indirections_table, 0);
+ if (ctx->mmap_indirections_table == MAP_FAILED) {
+ trace_ebpf_error("eBPF RSS", "can not mmap eBPF indirection table");
+ goto indirection_fail;
+ }
+
+ return true;
+
+indirection_fail:
+ munmap(ctx->mmap_toeplitz_key, qemu_real_host_page_size());
+toeplitz_fail:
+ munmap(ctx->mmap_configuration, qemu_real_host_page_size());
+
+ ctx->mmap_configuration = NULL;
+ ctx->mmap_toeplitz_key = NULL;
+ ctx->mmap_indirections_table = NULL;
+ return false;
+}
+
+static void ebpf_rss_munmap(struct EBPFRSSContext *ctx)
+{
+ if (!ebpf_rss_is_loaded(ctx)) {
+ return;
+ }
+
+ munmap(ctx->mmap_indirections_table, qemu_real_host_page_size());
+ munmap(ctx->mmap_toeplitz_key, qemu_real_host_page_size());
+ munmap(ctx->mmap_configuration, qemu_real_host_page_size());
+
+ ctx->mmap_configuration = NULL;
+ ctx->mmap_toeplitz_key = NULL;
+ ctx->mmap_indirections_table = NULL;
}
bool ebpf_rss_load(struct EBPFRSSContext *ctx)
{
struct rss_bpf *rss_bpf_ctx;
- if (ctx == NULL) {
+ if (ctx == NULL || ebpf_rss_is_loaded(ctx)) {
return false;
}
@@ -66,10 +130,18 @@ bool ebpf_rss_load(struct EBPFRSSContext *ctx)
ctx->map_toeplitz_key = bpf_map__fd(
rss_bpf_ctx->maps.tap_rss_map_toeplitz_key);
+ if (!ebpf_rss_mmap(ctx)) {
+ goto error;
+ }
+
return true;
error:
rss_bpf__destroy(rss_bpf_ctx);
ctx->obj = NULL;
+ ctx->program_fd = -1;
+ ctx->map_configuration = -1;
+ ctx->map_toeplitz_key = -1;
+ ctx->map_indirections_table = -1;
return false;
}
@@ -77,15 +149,11 @@ error:
static bool ebpf_rss_set_config(struct EBPFRSSContext *ctx,
struct EBPFRSSConfig *config)
{
- uint32_t map_key = 0;
-
if (!ebpf_rss_is_loaded(ctx)) {
return false;
}
- if (bpf_map_update_elem(ctx->map_configuration,
- &map_key, config, 0) < 0) {
- return false;
- }
+
+ memcpy(ctx->mmap_configuration, config, sizeof(*config));
return true;
}
@@ -93,27 +161,19 @@ static bool ebpf_rss_set_indirections_table(struct
EBPFRSSContext *ctx,
uint16_t *indirections_table,
size_t len)
{
- uint32_t i = 0;
-
if (!ebpf_rss_is_loaded(ctx) || indirections_table == NULL ||
len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
return false;
}
- for (; i < len; ++i) {
- if (bpf_map_update_elem(ctx->map_indirections_table, &i,
- indirections_table + i, 0) < 0) {
- return false;
- }
- }
+ memcpy(ctx->mmap_indirections_table, indirections_table,
+ sizeof(*indirections_table) * len);
return true;
}
static bool ebpf_rss_set_toepliz_key(struct EBPFRSSContext *ctx,
uint8_t *toeplitz_key)
{
- uint32_t map_key = 0;
-
/* prepare toeplitz key */
uint8_t toe[VIRTIO_NET_RSS_MAX_KEY_SIZE] = {};
@@ -123,10 +183,7 @@ static bool ebpf_rss_set_toepliz_key(struct EBPFRSSContext
*ctx,
memcpy(toe, toeplitz_key, VIRTIO_NET_RSS_MAX_KEY_SIZE);
*(uint32_t *)toe = ntohl(*(uint32_t *)toe);
- if (bpf_map_update_elem(ctx->map_toeplitz_key, &map_key, toe,
- 0) < 0) {
- return false;
- }
+ memcpy(ctx->mmap_toeplitz_key, toe, VIRTIO_NET_RSS_MAX_KEY_SIZE);
return true;
}
@@ -160,6 +217,20 @@ void ebpf_rss_unload(struct EBPFRSSContext *ctx)
return;
}
- rss_bpf__destroy(ctx->obj);
+ ebpf_rss_munmap(ctx);
+
+ if (ctx->obj) {
+ rss_bpf__destroy(ctx->obj);
+ } else {
+ close(ctx->program_fd);
+ close(ctx->map_configuration);
+ close(ctx->map_toeplitz_key);
+ close(ctx->map_indirections_table);
+ }
+
ctx->obj = NULL;
+ ctx->program_fd = -1;
+ ctx->map_configuration = -1;
+ ctx->map_toeplitz_key = -1;
+ ctx->map_indirections_table = -1;
}
diff --git a/ebpf/ebpf_rss.h b/ebpf/ebpf_rss.h
index bf3f2572c7c..ab08a7266d0 100644
--- a/ebpf/ebpf_rss.h
+++ b/ebpf/ebpf_rss.h
@@ -20,6 +20,11 @@ struct EBPFRSSContext {
int map_configuration;
int map_toeplitz_key;
int map_indirections_table;
+
+ /* mapped eBPF maps for direct access to omit bpf_map_update_elem() */
+ void *mmap_configuration;
+ void *mmap_toeplitz_key;
+ void *mmap_indirections_table;
};
struct EBPFRSSConfig {
--
2.41.0
