> -----Original Message----- > From: Stephen Hemminger [mailto:stephen at networkplumber.org] > Sent: Wednesday, June 11, 2014 9:08 PM > To: Carew, Alan > Cc: Neil Horman; dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v2 09/10] igbuio: show irq mode in sysfs > > This is what I am testing, along with 10 other virtio patches. > > Subject: virtio: check for using msix interrupt > > Fix how the device driver detects MSI-X vs INTX mode. > Look in sysfs to find if MSI-X is enabled. > > Suggested-by: Neil Horman <nhorman at tuxdriver.com> > Signed-off-by: Stephen Hemminger <stephen at networkplumber.org> > > > --- a/lib/librte_pmd_virtio/virtio_ethdev.c > +++ b/lib/librte_pmd_virtio/virtio_ethdev.c > @@ -709,6 +709,28 @@ > return 0; > } > > +/* > + * Detect if using INTX or MSI-X by looking for: > + * /sys/bus/pci/devices/<D:B:D.F>/msi_irqs/ > + * if directory exists, must be using msi-x > + */ > +static int > +has_msix(const struct rte_pci_addr *loc) > +{ > + DIR *d; > + char dirname[PATH_MAX]; > + > + rte_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); > +} > + > static int get_uio_dev(struct rte_pci_addr *loc, char *buf, unsigned int > buflen) > { > unsigned int uio_num; > @@ -872,6 +894,8 @@ > PMD_INIT_LOG(DEBUG, > "PCI Port IO found start=0x%lx with size=0x%lx\n", > start, size); > + > + hw->use_msix = has_msix(&pci_dev->addr); > } > #endif > hw->io_base = (uint32_t)(uintptr_t)pci_dev->mem_resource[0].addr; > --- a/lib/librte_pmd_virtio/virtio_pci.h > +++ b/lib/librte_pmd_virtio/virtio_pci.h > @@ -177,6 +177,7 @@ > 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; > }; > @@ -194,13 +195,11 @@ > 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.
Hi Stephen, The mechanism is fine, however I would be against OS specific code in abstracted drivers. If "has_msix" was a helper function in eal (and suitably renamed) we could then add a FreeBSD equivalent implementation. A less favourable solution would be conditional compilation(RTE_EXEC_ENV_LINUXAPP/BSDPAPP) around the above function. Thanks, Alan
