Re: [PULL 0/7] Migration.next patches

[Juan Quintela]

"Li, Zhijian" <lizhijian@cn.fujitsu.com> wrote:
> on 2021/9/9 21:42, Peter Maydell wrote:
>> On Thu, 9 Sept 2021 at 11:36, Juan Quintela <quintela@redhat.com> wrote:
>> Fails to build, FreeBSD:
>>
>> ../src/migration/rdma.c:1146:23: error: use of undeclared identifier
>> 'IBV_ADVISE_MR_ADVICE_PREFETCH_WRITE'
>>      int advice = wr ? IBV_ADVISE_MR_ADVICE_PREFETCH_WRITE :
>>                        ^
>> ../src/migration/rdma.c:1147:18: error: use of undeclared identifier
>> 'IBV_ADVISE_MR_ADVICE_PREFETCH'
>>                   IBV_ADVISE_MR_ADVICE_PREFETCH;
>>                   ^
>> ../src/migration/rdma.c:1150:11: warning: implicit declaration of
>> function 'ibv_advise_mr' is invalid in C99
>> [-Wimplicit-function-declaration]
>>      ret = ibv_advise_mr(pd, advice,
>>            ^
>> ../src/migration/rdma.c:1151:25: error: use of undeclared identifier
>> 'IBV_ADVISE_MR_FLAG_FLUSH'
>>                          IBV_ADVISE_MR_FLAG_FLUSH, &sg_list, 1);
>>                          ^
>>
> it's introduced by [PULL 4/7] migration/rdma: advise prefetch write for ODP 
> region
> where it calls a ibv_advise_mr(). i have checked the latest FreeBSD, it 
> didn't ship with this API
> May i know if just FressBSD reports this failure? if so, i just need 
> filtering out FreeBSD only

The other way around I think.
What about:

It compiled on my Linux machine, but it *should* work on any (famous
last words).  Finishing compilation 

Later, Juan.

>From 964e436bdb8aef7dbebc28415e4ac3c5822b552e Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Thu, 9 Sep 2021 17:07:17 +0200
Subject: [PATCH] rdma: test for ibv_advise_mr API

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 configure        | 28 ++++++++++++++++++++++++++++
 migration/rdma.c |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/configure b/configure
index 8adf2127c3..70054fd702 100755
--- a/configure
+++ b/configure
@@ -339,6 +339,7 @@ whpx="auto"
 nvmm="auto"
 rdma="$default_feature"
 pvrdma="$default_feature"
+rdma_ibv_advise_mr="no"
 gprof="no"
 debug_tcg="no"
 debug="no"
@@ -2918,6 +2919,29 @@ EOF
     fi
 fi
 
+# Let's see if enhanced reg_mr is supported
+if test "$rdma" = "yes" ; then
+
+cat > $TMPC <<EOF &&
+#include <infiniband/verbs.h>
+
+int
+main(void)
+{
+    int advice = wr ? IBV_ADVISE_MR_ADVICE_PREFETCH_WRITE :
+                 IBV_ADVISE_MR_ADVICE_PREFETCH;
+    struct ibv_sge sg_list = {.lkey = lkey, .addr = addr, .length = len};
+
+    ibv_advise_mr(pd, advice, IBV_ADVISE_MR_FLAG_FLUSH, &sg_list, 1);
+    return 0;
+}
+EOF
+    if ! compile_prog "" "-libverbs"; then
+       rdma_ibv_advise_mr="yes"
+    fi
+fi
+
+
 ##########################################
 # xfsctl() probe, used for file-posix.c
 if test "$xfs" != "no" ; then
@@ -4802,6 +4826,10 @@ if test "$rdma" = "yes" ; then
   echo "RDMA_LIBS=$rdma_libs" >> $config_host_mak
 fi
 
+if test "$rdma_ibv_advise_mr" = "yes"; then
+  echo "CONFIG_IBV_ADVISE_MR=y" >> $config_host_mak
+fi
+
 if test "$pvrdma" = "yes" ; then
   echo "CONFIG_PVRDMA=y" >> $config_host_mak
 fi
diff --git a/migration/rdma.c b/migration/rdma.c
index 6c2cc3f617..aac343253f 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -1142,6 +1142,7 @@ static void qemu_rdma_advise_prefetch_mr(struct ibv_pd 
*pd, uint64_t addr,
                                          uint32_t len,  uint32_t lkey,
                                          const char *name, bool wr)
 {
+#if CONFIG_IBV_ADVISE_MR
     int ret;
     int advice = wr ? IBV_ADVISE_MR_ADVICE_PREFETCH_WRITE :
                  IBV_ADVISE_MR_ADVICE_PREFETCH;
@@ -1155,6 +1156,7 @@ static void qemu_rdma_advise_prefetch_mr(struct ibv_pd 
*pd, uint64_t addr,
     } else {
         trace_qemu_rdma_advise_mr(name, len, addr, "successed");
     }
+#endif
 }
 
 static int qemu_rdma_reg_whole_ram_blocks(RDMAContext *rdma)
-- 
2.31.1