Re: [Qemu-devel] [PATCH V3 01/10] net: Add vnet_hdr_len related callback in NetClientInfo

[Jason Wang]

On 2017年04月28日 17:47, Zhang Chen wrote:
Add get_vnet_hdr_len and get_using_vnet_hdr callback
that make we get vnet_hdr_len easily.

Signed-off-by: Zhang Chen <zhangchen.f...@cn.fujitsu.com>
---
  include/net/net.h |  6 ++++++
  net/net.c         | 18 ++++++++++++++++++
  2 files changed, 24 insertions(+)

diff --git a/include/net/net.h b/include/net/net.h
index 99b28d5..402d913 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -57,7 +57,9 @@ typedef RxFilterInfo *(QueryRxFilter)(NetClientState *);
  typedef bool (HasUfo)(NetClientState *);
  typedef bool (HasVnetHdr)(NetClientState *);
  typedef bool (HasVnetHdrLen)(NetClientState *, int);
+typedef int (GetVnetHdrLen)(NetClientState *);
  typedef void (UsingVnetHdr)(NetClientState *, bool);
+typedef bool (GetUsingVnetHdr)(NetClientState *);
  typedef void (SetOffload)(NetClientState *, int, int, int, int, int);
  typedef void (SetVnetHdrLen)(NetClientState *, int);
  typedef int (SetVnetLE)(NetClientState *, bool);
@@ -79,7 +81,9 @@ typedef struct NetClientInfo {
      HasUfo *has_ufo;
      HasVnetHdr *has_vnet_hdr;
      HasVnetHdrLen *has_vnet_hdr_len;
+    GetVnetHdrLen *get_vnet_hdr_len;
      UsingVnetHdr *using_vnet_hdr;
+    GetUsingVnetHdr *get_using_vnet_hdr;
      SetOffload *set_offload;
      SetVnetHdrLen *set_vnet_hdr_len;
      SetVnetLE *set_vnet_le;
@@ -155,7 +159,9 @@ void qemu_format_nic_info_str(NetClientState *nc, uint8_t 
macaddr[6]);
  bool qemu_has_ufo(NetClientState *nc);
  bool qemu_has_vnet_hdr(NetClientState *nc);
  bool qemu_has_vnet_hdr_len(NetClientState *nc, int len);
+int qemu_get_vnet_hdr_len(NetClientState *nc);
  void qemu_using_vnet_hdr(NetClientState *nc, bool enable);
+bool qemu_get_using_vnet_hdr(NetClientState *nc);
  void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
                        int ecn, int ufo);
  void qemu_set_vnet_hdr_len(NetClientState *nc, int len);
diff --git a/net/net.c b/net/net.c
index 0ac3b9e..f69260f 100644
--- a/net/net.c
+++ b/net/net.c
@@ -466,6 +466,15 @@ bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
      return nc->info->has_vnet_hdr_len(nc, len);
  }
  
+int qemu_get_vnet_hdr_len(NetClientState *nc)
+{
+    if (!nc || !nc->info->get_vnet_hdr_len) {
+        return false;
+    }
+
+    return nc->info->get_vnet_hdr_len(nc);
+}
+
  void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
  {
      if (!nc || !nc->info->using_vnet_hdr) {
@@ -475,6 +484,15 @@ void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
      nc->info->using_vnet_hdr(nc, enable);
  }
  
+bool qemu_get_using_vnet_hdr(NetClientState *nc)
+{
+    if (!nc || !nc->info->get_using_vnet_hdr) {
+        return false;
+    }
+
+    return nc->info->get_using_vnet_hdr(nc);
+}

Looks like we can do this simply by:

Introduce two common fields in NetClientState:

bool using_vnet_hdr;
int vnet_hdr_len;

And set them during qemu_using_vnet_hdr() and qemu_set_vnet_hdr_len(). 
Then we can query them directly without introducing any new callbacks.

Thanks

+
  void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
                            int ecn, int ufo)
  {