[dpdk-stable] patch 'vfio: share default container in multi-process' has been queued to stable release 18.08.1

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 18.08.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/29/18. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the patch applied
to the branch. If the code is different (ie: not only metadata diffs), due for example to
a change in context or macro names, please double check it.

Thanks.

Kevin Traynor

---
>From 239dadd17803875567072a6efda6c5a1783b9b61 Mon Sep 17 00:00:00 2001
From: Darek Stojaczyk <dariusz.stojaczyk at intel.com>
Date: Wed, 3 Oct 2018 14:39:25 +0200
Subject: [PATCH] vfio: share default container in multi-process

[ upstream commit 6bcb7c95fe14544bca9de1a698e4553533192197 ]

So far each process in MP used to have a separate container
and relied on the primary process to register all memsegs.

Mapping external memory via rte_vfio_container_dma_map()
in secondary processes was broken, because the default
(process-local) container had no groups bound. There was
even no way to bind any groups to it, because the container
fd was deeply encapsulated within EAL.

This patch introduces a new SOCKET_REQ_DEFAULT_CONTAINER
message type for MP synchronization, makes all processes
within a MP party use a single default container, and hence
fixes rte_vfio_container_dma_map() for secondary processes.

>From what I checked this behavior was always the same, but
started to be invalid/insufficient once mapping external
memory was allowed.

While here, fix up the comment on rte_vfio_get_container_fd().
This function always opens a new container, never reuses
an old one.

Fixes: 73a639085938 ("vfio: allow to map other memory regions")

Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk at intel.com>
Reviewed-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 lib/librte_eal/common/include/rte_vfio.h      |  2 +-
 lib/librte_eal/linuxapp/eal/eal_vfio.c        | 49 ++++++++++++++++++-
 lib/librte_eal/linuxapp/eal/eal_vfio.h        |  4 ++
 .../linuxapp/eal/eal_vfio_mp_sync.c           | 11 +++++
 4 files changed, 64 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/include/rte_vfio.h b/lib/librte_eal/common/include/rte_vfio.h
index 5ca13fcce..1064426eb 100644
--- a/lib/librte_eal/common/include/rte_vfio.h
+++ b/lib/librte_eal/common/include/rte_vfio.h
@@ -228,5 +228,5 @@ rte_vfio_get_group_num(const char *sysfs_base,
 
 /**
- * Open VFIO container fd or get an existing one
+ * Open a new VFIO container fd
  *
  * This function is only relevant to linux and will return
diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/librte_eal/linuxapp/eal/eal_vfio.c
index 3fd5be79f..c4d80a994 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
@@ -897,5 +897,13 @@ rte_vfio_enable(const char *modname)
 	}
 
-	default_vfio_cfg->vfio_container_fd = rte_vfio_get_container_fd();
+	if (internal_config.process_type == RTE_PROC_PRIMARY) {
+		/* open a new container */
+		default_vfio_cfg->vfio_container_fd =
+				rte_vfio_get_container_fd();
+	} else {
+		/* get the default container from the primary process */
+		default_vfio_cfg->vfio_container_fd =
+				vfio_get_default_container_fd();
+	}
 
 	/* check if we have VFIO driver enabled */
@@ -917,4 +925,43 @@ rte_vfio_is_enabled(const char *modname)
 }
 
+int
+vfio_get_default_container_fd(void)
+{
+	struct rte_mp_msg mp_req, *mp_rep;
+	struct rte_mp_reply mp_reply;
+	struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
+	struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
+
+	if (default_vfio_cfg->vfio_enabled)
+		return default_vfio_cfg->vfio_container_fd;
+
+	if (internal_config.process_type == RTE_PROC_PRIMARY) {
+		/* if we were secondary process we would try requesting
+		 * container fd from the primary, but we're the primary
+		 * process so just exit here
+		 */
+		return -1;
+	}
+
+	p->req = SOCKET_REQ_DEFAULT_CONTAINER;
+	strcpy(mp_req.name, EAL_VFIO_MP);
+	mp_req.len_param = sizeof(*p);
+	mp_req.num_fds = 0;
+
+	if (rte_mp_request_sync(&mp_req, &mp_reply, &ts) == 0 &&
+	    mp_reply.nb_received == 1) {
+		mp_rep = &mp_reply.msgs[0];
+		p = (struct vfio_mp_param *)mp_rep->param;
+		if (p->result == SOCKET_OK && mp_rep->num_fds == 1) {
+			free(mp_reply.msgs);
+			return mp_rep->fds[0];
+		}
+		free(mp_reply.msgs);
+	}
+
+	RTE_LOG(ERR, EAL, "  cannot request default container fd\n");
+	return -1;
+}
+
 const struct vfio_iommu_type *
 vfio_set_iommu_type(int vfio_container_fd)
diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.h b/lib/librte_eal/linuxapp/eal/eal_vfio.h
index 68d4750a5..63ae115c3 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.h
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.h
@@ -116,4 +116,7 @@ struct vfio_iommu_type {
 };
 
+/* get the vfio container that devices are bound to by default */
+int vfio_get_default_container_fd(void);
+
 /* pick IOMMU type. returns a pointer to vfio_iommu_type or NULL for error */
 const struct vfio_iommu_type *
@@ -130,4 +133,5 @@ int vfio_mp_sync_setup(void);
 #define SOCKET_REQ_CONTAINER 0x100
 #define SOCKET_REQ_GROUP 0x200
+#define SOCKET_REQ_DEFAULT_CONTAINER 0x400
 #define SOCKET_OK 0x0
 #define SOCKET_NO_FD 0x1
diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c b/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
index 680a24aae..a1e8c834f 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
@@ -67,4 +67,15 @@ vfio_mp_primary(const struct rte_mp_msg *msg, const void *peer)
 		}
 		break;
+	case SOCKET_REQ_DEFAULT_CONTAINER:
+		r->req = SOCKET_REQ_DEFAULT_CONTAINER;
+		fd = vfio_get_default_container_fd();
+		if (fd < 0)
+			r->result = SOCKET_ERR;
+		else {
+			r->result = SOCKET_OK;
+			reply.num_fds = 1;
+			reply.fds[0] = fd;
+		}
+		break;
 	default:
 		RTE_LOG(ERR, EAL, "vfio received invalid message!\n");
-- 
2.19.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2018-11-23 10:22:54.506035172 +0000
+++ 0010-vfio-share-default-container-in-multi-process.patch	2018-11-23 10:22:54.000000000 +0000
@@ -1,8 +1,10 @@
-From 6bcb7c95fe14544bca9de1a698e4553533192197 Mon Sep 17 00:00:00 2001
+From 239dadd17803875567072a6efda6c5a1783b9b61 Mon Sep 17 00:00:00 2001
 From: Darek Stojaczyk <dariusz.stojaczyk at intel.com>
 Date: Wed, 3 Oct 2018 14:39:25 +0200
 Subject: [PATCH] vfio: share default container in multi-process
 
+[ upstream commit 6bcb7c95fe14544bca9de1a698e4553533192197 ]
+
 So far each process in MP used to have a separate container
 and relied on the primary process to register all memsegs.
 
@@ -26,7 +28,6 @@
 an old one.
 
 Fixes: 73a639085938 ("vfio: allow to map other memory regions")
-Cc: stable at dpdk.org
 
 Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk at intel.com>
 Reviewed-by: Anatoly Burakov <anatoly.burakov at intel.com>
@@ -38,10 +39,10 @@
  4 files changed, 64 insertions(+), 2 deletions(-)
 
 diff --git a/lib/librte_eal/common/include/rte_vfio.h b/lib/librte_eal/common/include/rte_vfio.h
-index 7d66438b5..cae96fab9 100644
+index 5ca13fcce..1064426eb 100644
 --- a/lib/librte_eal/common/include/rte_vfio.h
 +++ b/lib/librte_eal/common/include/rte_vfio.h
-@@ -257,5 +257,5 @@ rte_vfio_get_group_num(const char *sysfs_base,
+@@ -228,5 +228,5 @@ rte_vfio_get_group_num(const char *sysfs_base,
  
  /**
 - * Open VFIO container fd or get an existing one
@@ -49,10 +50,10 @@
   *
   * This function is only relevant to linux and will return
 diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/librte_eal/linuxapp/eal/eal_vfio.c
-index 13a8b1811..0516b1597 100644
+index 3fd5be79f..c4d80a994 100644
 --- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
 +++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
-@@ -911,5 +911,13 @@ rte_vfio_enable(const char *modname)
+@@ -897,5 +897,13 @@ rte_vfio_enable(const char *modname)
  	}
  
 -	default_vfio_cfg->vfio_container_fd = rte_vfio_get_container_fd();
@@ -67,7 +68,7 @@
 +	}
  
  	/* check if we have VFIO driver enabled */
-@@ -931,4 +939,43 @@ rte_vfio_is_enabled(const char *modname)
+@@ -917,4 +925,43 @@ rte_vfio_is_enabled(const char *modname)
  }
  
 +int