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
---
ebpf/ebpf_rss.c | 120 ++--
ebpf/ebpf_rss.h | 8 +++-
2 files changed, 101 insertions(+), 27 deletions(-)
diff --git a/ebpf/ebpf_rss.c b/ebpf/ebpf_rss.c
index cee658c158..c6e10265a7 100644
--- a/ebpf/ebpf_rss.c
+++ b/ebpf/ebpf_rss.c
@@ -7,8 +7,7 @@
* Andrew Melnychenko
* Yuri Benditovich
*
- * This work is licensed under the terms of the GNU GPL, version 2. See
- * the COPYING file in the top-level directory.
+ * SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
@@ -27,19 +26,83 @@ 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());
+ctx->mmap_toeplitz_key = NULL;
+toeplitz_fail:
+munmap(ctx->mmap_configuration, qemu_real_host_page_size());
+ctx->mmap_configuration = 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 (ebpf_rss_is_loaded(ctx)) {
return false;
}
@@ -66,10 +129,18 @@ 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 +148,11 @@ 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,
-_key, config, 0) < 0) {
-return false;
-}
+
+memcpy(ctx->mmap_configuration, config, sizeof(*config));
return true;
}
@@ -93,27 +160,19 @@ 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
