[PATCH v5] Restore support for virtio on FreeBSD

[Raz Amir <razamir22-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Fixes: 8a312224bcde ("eal/bsd: fix fd leak")

Closing /dev/io fd causes SIGBUS in inb/outb instructions
as the process loses the IOPL privileges once the fd is closed:
(gdb) bt
0  0x0000000000492f2c in outb (port=49170, data=0 '\000')
    at /usr/include/machine/cpufunc.h:244
1  0x0000000000492f7a in outb_p (data=0 '\000', port=49170)
    at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_pci.h:211
2  0x000000000049328d in vtpci_set_status (hw=0x80331f380, status=0 '\000')
    at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_pci.c:130
3  0x00000000004931fe in vtpci_reset (hw=0x80331f380)
    at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_pci.c:108
4  0x00000000004a175e in eth_virtio_dev_init (eth_dev=0x831b80 <rte_eth_devices>)
    at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_ethdev.c:1150
5  0x0000000000462c09 in rte_eth_dev_init (pci_drv=0x79d1a0 <rte_virtio_pmd>,
    pci_dev=0x802417560) at /dpdk/dpdk-2.0.0/lib/librte_ether/rte_ethdev.c:326
6  0x000000000046f03f in rte_eal_pci_probe_one_driver (dr=0x79d1a0 <rte_virtio_pmd>,
    dev=0x802417560) at /dpdk/dpdk-2.0.0/lib/librte_eal/bsdapp/eal/eal_pci.c:487
7  0x0000000000475b06 in pci_probe_all_drivers (dev=0x802417560)
    at /dpdk/dpdk-2.0.0/lib/librte_eal/common/eal_common_pci.c:116
8  0x0000000000475bb9 in rte_eal_pci_probe ()
    at /dpdk/dpdk-2.0.0/lib/librte_eal/common/eal_common_pci.c:246
9  0x000000000046cd63 in rte_eal_init (argc=5, argv=0x7fffffffeaf0)
    at /dpdk/dpdk-2.0.0/lib/librte_eal/bsdapp/eal/eal.c:554
10 0x0000000000404544 in main ()

Signed-off-by: Raz Amir <razamir22-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 lib/librte_eal/bsdapp/eal/eal.c         | 19 ++++++++++++++-----
 lib/librte_eal/common/include/rte_eal.h | 10 ++++++++++
 lib/librte_eal/linuxapp/eal/eal.c       |  5 +++++
 lib/librte_pmd_virtio/virtio_ethdev.c   |  9 +++++++++
 4 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c
index 871d5f4..687dd83 100644
--- a/lib/librte_eal/bsdapp/eal/eal.c
+++ b/lib/librte_eal/bsdapp/eal/eal.c
@@ -112,6 +112,9 @@ struct internal_config internal_config;
 /* used by rte_rdtsc() */
 int rte_cycles_vmware_tsc_map;
 
+/* fd to keep open for iopl */
+static int iopl_fd = -1;
+
 /* Return a pointer to the configuration structure */
 struct rte_config *
 rte_eal_get_configuration(void)
@@ -421,15 +424,21 @@ int rte_eal_has_hugepages(void)
 int
 rte_eal_iopl_init(void)
 {
-	int fd;
-
-	fd = open("/dev/io", O_RDWR);
-	if (fd < 0)
+	iopl_fd = open("/dev/io", O_RDWR);
+	if (iopl_fd < 0)
 		return -1;
-	close(fd);
+	/* keep fd open for iopl */
 	return 0;
 }
 
+void
+rte_eal_iopl_uninit(void)
+{
+	if (iopl_fd != -1)
+		close(iopl_fd);
+	iopl_fd = -1;
+}
+
 /* Launch threads, called at application init(). */
 int
 rte_eal_init(int argc, char **argv)
diff --git a/lib/librte_eal/common/include/rte_eal.h b/lib/librte_eal/common/include/rte_eal.h
index 1385a73..9151e08 100644
--- a/lib/librte_eal/common/include/rte_eal.h
+++ b/lib/librte_eal/common/include/rte_eal.h
@@ -127,6 +127,16 @@ enum rte_proc_type_t rte_eal_process_type(void);
 int rte_eal_iopl_init(void);
 
 /**
+ * Release iopl priviledge - currently relevant only for FreeBSD.
+ *
+ * This function should be called by pmds which need access to ioports.
+
+ * @return
+ *   void
+ */
+void rte_eal_iopl_uninit(void);
+
+/**
  * Initialize the Environment Abstraction Layer (EAL).
  *
  * This function is to be executed on the MASTER lcore only, as soon
diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index bd770cf..687cebf 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -695,6 +695,11 @@ rte_eal_iopl_init(void)
 #endif
 }
 
+void
+rte_eal_iopl_uninit(void)
+{
+}
+
 /* Launch threads, called at application init(). */
 int
 rte_eal_init(int argc, char **argv)
diff --git a/lib/librte_pmd_virtio/virtio_ethdev.c b/lib/librte_pmd_virtio/virtio_ethdev.c
index 7b83d9b..5be5c27 100644
--- a/lib/librte_pmd_virtio/virtio_ethdev.c
+++ b/lib/librte_pmd_virtio/virtio_ethdev.c
@@ -1265,6 +1265,14 @@ rte_virtio_pmd_init(const char *name __rte_unused,
 	return 0;
 }
 
+static int
+rte_virtio_pmd_uninit(const char *name)
+{
+	(void)name;
+	rte_eal_iopl_uninit();
+	return 0;
+}
+
 /*
  * Only 1 queue is supported, no queue release related operation
  */
@@ -1499,6 +1507,7 @@ __rte_unused uint8_t is_rx)
 static struct rte_driver rte_virtio_driver = {
 	.type = PMD_PDEV,
 	.init = rte_virtio_pmd_init,
+	.uninit = rte_virtio_pmd_uninit,
 };
 
 PMD_REGISTER_DRIVER(rte_virtio_driver);
-- 
2.1.2