From: Andrew Melnychenko <andrew@daynix.com>
Date: Mon, 5 Feb 2024 16:54:33 +0000 (+0200)
Subject: virtio-net: Added property to load eBPF RSS with fds.
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6b230b7dfcd8123a902e41cd313714b5a57dcac4;p=qemu.git

virtio-net: Added property to load eBPF RSS with fds.

eBPF RSS program and maps may now be passed during initialization.
Initially was implemented for libvirt to launch qemu without permissions,
and initialized eBPF program through the helper.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index a3c711b56d..403a693baf 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -42,6 +42,7 @@
 #include "sysemu/sysemu.h"
 #include "trace.h"
 #include "monitor/qdev.h"
+#include "monitor/monitor.h"
 #include "hw/pci/pci_device.h"
 #include "net_rx_pkt.h"
 #include "hw/virtio/vhost.h"
@@ -1328,14 +1329,53 @@ static void virtio_net_detach_epbf_rss(VirtIONet *n)
     virtio_net_attach_ebpf_to_backend(n->nic, -1);
 }
 
-static bool virtio_net_load_ebpf(VirtIONet *n)
+static bool virtio_net_load_ebpf_fds(VirtIONet *n, Error **errp)
 {
-    if (!virtio_net_attach_ebpf_to_backend(n->nic, -1)) {
-        /* backend doesn't support steering ebpf */
-        return false;
+    int fds[EBPF_RSS_MAX_FDS] = { [0 ... EBPF_RSS_MAX_FDS - 1] = -1};
+    int ret = true;
+    int i = 0;
+
+    ERRP_GUARD();
+
+    if (n->nr_ebpf_rss_fds != EBPF_RSS_MAX_FDS) {
+        error_setg(errp,
+                  "Expected %d file descriptors but got %d",
+                  EBPF_RSS_MAX_FDS, n->nr_ebpf_rss_fds);
+       return false;
+   }
+
+    for (i = 0; i < n->nr_ebpf_rss_fds; i++) {
+        fds[i] = monitor_fd_param(monitor_cur(), n->ebpf_rss_fds[i], errp);
+        if (*errp) {
+            ret = false;
+            goto exit;
+        }
+    }
+
+    ret = ebpf_rss_load_fds(&n->ebpf_rss, fds[0], fds[1], fds[2], fds[3]);
+
+exit:
+    if (!ret || *errp) {
+        for (i = 0; i < n->nr_ebpf_rss_fds && fds[i] != -1; i++) {
+            close(fds[i]);
+        }
     }
 
-    return ebpf_rss_load(&n->ebpf_rss);
+    return ret;
+}
+
+static bool virtio_net_load_ebpf(VirtIONet *n, Error **errp)
+{
+    bool ret = false;
+
+    if (virtio_net_attach_ebpf_to_backend(n->nic, -1)) {
+        if (!(n->ebpf_rss_fds
+                && virtio_net_load_ebpf_fds(n, errp))) {
+            ret = ebpf_rss_load(&n->ebpf_rss);
+        }
+    }
+
+    return ret;
 }
 
 static void virtio_net_unload_ebpf(VirtIONet *n)
@@ -3768,7 +3808,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     net_rx_pkt_init(&n->rx_pkt);
 
     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
-        virtio_net_load_ebpf(n);
+        virtio_net_load_ebpf(n, errp);
     }
 }
 
@@ -3930,6 +3970,8 @@ static Property virtio_net_properties[] = {
                     VIRTIO_NET_F_RSS, false),
     DEFINE_PROP_BIT64("hash", VirtIONet, host_features,
                     VIRTIO_NET_F_HASH_REPORT, false),
+    DEFINE_PROP_ARRAY("ebpf-rss-fds", VirtIONet, nr_ebpf_rss_fds,
+                      ebpf_rss_fds, qdev_prop_string, char*),
     DEFINE_PROP_BIT64("guest_rsc_ext", VirtIONet, host_features,
                     VIRTIO_NET_F_RSC_EXT, false),
     DEFINE_PROP_UINT32("rsc_interval", VirtIONet, rsc_timeout,
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index eaee8f4243..060c23c04d 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -225,6 +225,8 @@ struct VirtIONet {
     VirtioNetRssData rss_data;
     struct NetRxPkt *rx_pkt;
     struct EBPFRSSContext ebpf_rss;
+    uint32_t nr_ebpf_rss_fds;
+    char **ebpf_rss_fds;
 };
 
 size_t virtio_net_handle_ctrl_iov(VirtIODevice *vdev,