On 2023/08/31 15:51, Andrew Melnychenko wrote:
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 cee658c158..247f5eee1b 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;
What about: > +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; It will be clearer when the pointer becomes invalid this way.
+ 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; }
You can omit ctx == NULL just as you do for ebpf_rss_munmap().
@@ -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);
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