From: Alan Carew <alan.carew@intel.com>
Date: Mon, 16 Jun 2014 11:10:26 +0000 (+0100)
Subject: virtio: fix device specific header offset when MSI-X is disabled
X-Git-Tag: spdx-start~10509
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=4d6d8babac6f1e1349d934eb3e1b15950822adbb;p=dpdk.git

virtio: fix device specific header offset when MSI-X is disabled

Suggested-by: Neil Horman <nhorman@tuxdriver.com>
Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Alan Carew <alan.carew@intel.com>
---

diff --git a/config/common_bsdapp b/config/common_bsdapp
index 3fbba874d1..23d3dddab5 100644
--- a/config/common_bsdapp
+++ b/config/common_bsdapp
@@ -191,7 +191,7 @@ CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL=-1
 #
 # Compile burst-oriented VIRTIO PMD driver
 #
-CONFIG_RTE_LIBRTE_VIRTIO_PMD=n
+CONFIG_RTE_LIBRTE_VIRTIO_PMD=y
 CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_INIT=n
 CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_RX=n
 CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_TX=n
diff --git a/lib/librte_pmd_virtio/virtio_ethdev.c b/lib/librte_pmd_virtio/virtio_ethdev.c
index d4730f907a..afc903c6c4 100644
--- a/lib/librte_pmd_virtio/virtio_ethdev.c
+++ b/lib/librte_pmd_virtio/virtio_ethdev.c
@@ -647,6 +647,30 @@ static int get_uio_dev(struct rte_pci_addr *loc, char *buf, unsigned int buflen)
 
 	return 0;
 }
+
+static int
+virtio_has_msix(const struct rte_pci_addr *loc)
+{
+	DIR *d;
+	char dirname[PATH_MAX];
+
+	snprintf(dirname, sizeof(dirname),
+		     SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/msi_irqs",
+		     loc->domain, loc->bus, loc->devid, loc->function);
+
+	d = opendir(dirname);
+	if (d)
+		closedir(d);
+
+	return (d != NULL);
+}
+#else
+static int
+virtio_has_msix(const struct rte_pci_addr *loc __rte_unused)
+{
+	/* nic_uio does not enable interrupts, return 0 (false). */
+	return 0;
+}
 #endif
 
 /*
@@ -720,6 +744,7 @@ eth_virtio_dev_init(__rte_unused struct eth_driver *eth_drv,
 			     start, size);
 	}
 #endif
+	hw->use_msix = virtio_has_msix(&pci_dev->addr);
 	hw->io_base = (uint32_t)(uintptr_t)pci_dev->mem_resource[0].addr;
 
 	/* Reset the device although not necessary at startup */
diff --git a/lib/librte_pmd_virtio/virtio_pci.h b/lib/librte_pmd_virtio/virtio_pci.h
index 864b084207..d27b734b1b 100644
--- a/lib/librte_pmd_virtio/virtio_pci.h
+++ b/lib/librte_pmd_virtio/virtio_pci.h
@@ -177,6 +177,7 @@ struct virtio_hw {
 	uint16_t    subsystem_device_id;
 	uint16_t    subsystem_vendor_id;
 	uint8_t     revision_id;
+	uint8_t	    use_msix;
 	uint8_t     mac_addr[ETHER_ADDR_LEN];
 	int         adapter_stopped;
 	struct      rte_eth_stats eth_stats;
@@ -195,13 +196,11 @@ struct virtio_net_config {
 	uint16_t   max_virtqueue_pairs;
 } __attribute__((packed));
 
-/* Value indicated in device config */
-#define VIRTIO_PCI_FLAG_MSIX  0x0020
 /*
  * The remaining space is defined by each driver as the per-driver
  * configuration space.
  */
-#define VIRTIO_PCI_CONFIG(hw) (((hw)->guest_features & VIRTIO_PCI_FLAG_MSIX) ? 24 : 20)
+#define VIRTIO_PCI_CONFIG(hw) (((hw)->use_msix) ? 24 : 20)
 
 /*
  * How many bits to shift physical queue address written to QUEUE_PFN.