[dpdk-stable] patch 'net/virtio: fix multiple process support' has been queued to stable release 16.11.1

[Yuanhan Liu]

Hi,

FYI, your patch has been queued to stable release 16.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable
yet. It will be pushed if I get no objections before 02/18/17.
So please shout if anyone has objections.

Thanks.

	--yliu

---
>From f936571d05c297167ee29cf2f34e14668cbced89 Mon Sep 17 00:00:00 2001
From: Yuanhan Liu <yuanhan.liu at linux.intel.com>
Date: Fri, 6 Jan 2017 18:16:19 +0800
Subject: [PATCH] net/virtio: fix multiple process support

[ backported from upstream commit 6d890f8ab51295045a53f41c4d2654bb1f01cf38 ]

The introduce of virtio 1.0 support brings yet another set of ops, badly,
it's not handled correctly, that it breaks the multiple process support.

The issue is the data/function pointer may vary from different processes,
and the old used to do one time set (for primary process only). That
said, the function pointer the secondary process saw is actually from the
primary process space. Accessing it could likely result to a crash.

Kudos to the last patches, we now be able to maintain those info that may
vary among different process locally, meaning every process could have its
own copy for each of them, with the correct value set. And this is what
this patch does:

- remap the PCI (IO port for legacy device and memory map for modern
  device)

- set vtpci_ops correctly

After that, multiple process would work like a charm. (At least, it
passed my fuzzy test)

Fixes: b8f04520ad71 ("virtio: use PCI ioport API")
Fixes: d5bbeefca826 ("virtio: introduce PCI implementation structure")
Fixes: 6ba1f63b5ab0 ("virtio: support specification 1.0")

Reported-by: Juho Snellman <jsnell at iki.fi>
Reported-by: Yaron Illouz <yaroni at radcom.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
 doc/guides/nics/features/virtio.ini     |  1 +
 drivers/net/virtio/virtio_ethdev.c      | 50 +++++++++++++++++++++++++++++++++
 drivers/net/virtio/virtio_pci.c         |  4 +--
 drivers/net/virtio/virtio_pci.h         |  4 +++
 drivers/net/virtio/virtio_user_ethdev.c |  2 +-
 5 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/doc/guides/nics/features/virtio.ini b/doc/guides/nics/features/virtio.ini
index 41830c1..1d996c6 100644
--- a/doc/guides/nics/features/virtio.ini
+++ b/doc/guides/nics/features/virtio.ini
@@ -14,6 +14,7 @@ Multicast MAC filter = Y
 VLAN filter          = Y
 Basic stats          = Y
 Stats per queue      = Y
+Multiprocess aware   = Y
 BSD nic_uio          = Y
 Linux UIO            = Y
 Linux VFIO           = Y
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index fd0ffc2..6e5c5d6 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1291,6 +1291,49 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
 }
 
 /*
+ * Remap the PCI device again (IO port map for legacy device and
+ * memory map for modern device), so that the secondary process
+ * could have the PCI initiated correctly.
+ */
+static int
+virtio_remap_pci(struct rte_pci_device *pci_dev, struct virtio_hw *hw)
+{
+	if (hw->modern) {
+		/*
+		 * We don't have to re-parse the PCI config space, since
+		 * rte_eal_pci_map_device() makes sure the mapped address
+		 * in secondary process would equal to the one mapped in
+		 * the primary process: error will be returned if that
+		 * requirement is not met.
+		 *
+		 * That said, we could simply reuse all cap pointers
+		 * (such as dev_cfg, common_cfg, etc.) parsed from the
+		 * primary process, which is stored in shared memory.
+		 */
+		if (rte_eal_pci_map_device(pci_dev)) {
+			PMD_INIT_LOG(DEBUG, "failed to map pci device!");
+			return -1;
+		}
+	} else {
+		if (rte_eal_pci_ioport_map(pci_dev, 0, VTPCI_IO(hw)) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static void
+virtio_set_vtpci_ops(struct virtio_hw *hw)
+{
+	if (hw->virtio_user_dev)
+		VTPCI_OPS(hw) = &virtio_user_ops;
+	else if (hw->modern)
+		VTPCI_OPS(hw) = &modern_ops;
+	else
+		VTPCI_OPS(hw) = &legacy_ops;
+}
+
+/*
  * This function is based on probe() function in virtio_pci.c
  * It returns 0 on success.
  */
@@ -1308,6 +1351,13 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 	eth_dev->tx_pkt_burst = &virtio_xmit_pkts;
 
 	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+		if (!hw->virtio_user_dev) {
+			ret = virtio_remap_pci(eth_dev->pci_dev, hw);
+			if (ret)
+				return ret;
+		}
+
+		virtio_set_vtpci_ops(hw);
 		if (hw->use_simple_rxtx) {
 			eth_dev->tx_pkt_burst = virtio_xmit_pkts_simple;
 			eth_dev->rx_pkt_burst = virtio_recv_pkts_vec;
diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
index 7903e29..8d5355c 100644
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -304,7 +304,7 @@ legacy_virtio_resource_init(struct rte_pci_device *pci_dev,
 	return 0;
 }
 
-static const struct virtio_pci_ops legacy_ops = {
+const struct virtio_pci_ops legacy_ops = {
 	.read_dev_cfg	= legacy_read_dev_config,
 	.write_dev_cfg	= legacy_write_dev_config,
 	.reset		= legacy_reset,
@@ -520,7 +520,7 @@ modern_notify_queue(struct virtio_hw *hw __rte_unused, struct virtqueue *vq)
 	io_write16(1, vq->notify_addr);
 }
 
-static const struct virtio_pci_ops modern_ops = {
+const struct virtio_pci_ops modern_ops = {
 	.read_dev_cfg	= modern_read_dev_config,
 	.write_dev_cfg	= modern_write_dev_config,
 	.reset		= modern_reset,
diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
index 6b9aecf..511a1c8 100644
--- a/drivers/net/virtio/virtio_pci.h
+++ b/drivers/net/virtio/virtio_pci.h
@@ -333,4 +333,8 @@ uint8_t vtpci_isr(struct virtio_hw *);
 
 uint16_t vtpci_irq_config(struct virtio_hw *, uint16_t);
 
+extern const struct virtio_pci_ops legacy_ops;
+extern const struct virtio_pci_ops modern_ops;
+extern const struct virtio_pci_ops virtio_user_ops;
+
 #endif /* _VIRTIO_PCI_H_ */
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index d69d8fa..013600e 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -216,7 +216,7 @@ virtio_user_notify_queue(struct virtio_hw *hw, struct virtqueue *vq)
 			    strerror(errno));
 }
 
-static const struct virtio_pci_ops virtio_user_ops = {
+const struct virtio_pci_ops virtio_user_ops = {
 	.read_dev_cfg	= virtio_user_read_dev_config,
 	.write_dev_cfg	= virtio_user_write_dev_config,
 	.reset		= virtio_user_reset,
-- 
1.9.0