From 6a5c236b95ce475c556ccd92c2135ad48474e8fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>
Date: Tue, 23 Aug 2022 20:30:35 +0200
Subject: [PATCH 20/23] vhost_net: add NetClientState->load() callback
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RH-Author: Eugenio Pérez <eperezma@redhat.com>
RH-MergeRequest: 116: vdpa: Restore device state on destination
RH-Bugzilla: 2114060
RH-Acked-by: Cindy Lu <lulu@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [19/21] 439b4133a757b2f1c5f4a1441eca25329896491a (eperezmartin/qemu-kvm)
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2114060
Upstream status: git@github.com:jasowang/qemu.git net-next

It allows per-net client operations right after device's successful
start. In particular, to load the device status.

Vhost-vdpa net will use it to add the CVQ buffers to restore the device
status.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit 302f3d20e68a8a120d431f7ff7cb02a75917f54c)
---
 hw/net/vhost_net.c | 7 +++++++
 include/net/net.h  | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 275ece5324..ea3a8be1c9 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -281,6 +281,13 @@ static int vhost_net_start_one(struct vhost_net *net,
             }
         }
     }
+
+    if (net->nc->info->load) {
+        r = net->nc->info->load(net->nc);
+        if (r < 0) {
+            goto fail;
+        }
+    }
     return 0;
 fail:
     file.fd = -1;
diff --git a/include/net/net.h b/include/net/net.h
index 476ad45b9a..81d0b21def 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -45,6 +45,7 @@ typedef struct NICConf {
 typedef void (NetPoll)(NetClientState *, bool enable);
 typedef bool (NetCanReceive)(NetClientState *);
 typedef int (NetStart)(NetClientState *);
+typedef int (NetLoad)(NetClientState *);
 typedef void (NetStop)(NetClientState *);
 typedef ssize_t (NetReceive)(NetClientState *, const uint8_t *, size_t);
 typedef ssize_t (NetReceiveIOV)(NetClientState *, const struct iovec *, int);
@@ -74,6 +75,7 @@ typedef struct NetClientInfo {
     NetReceiveIOV *receive_iov;
     NetCanReceive *can_receive;
     NetStart *start;
+    NetLoad *load;
     NetStop *stop;
     NetCleanup *cleanup;
     LinkStatusChanged *link_status_changed;
-- 
2.31.1