Re: [libvirt] [PATCH 7/9] nodedev: Fix the improper logic when enumerating SRIOV VF

pciGetVirtualFunctions returns 0 even if there is no "virtfn" entry under the device sysfs path. And pciGetVirtualFunctions returns -1 when it fails to get the PCI config space of one VF, however, with keeping the the VFs already detected. That's why udevProcessPCI and gather_pci_cap use logic like: if (!pciGetVirtualFunctions(syspath, &data->pci_dev.virtual_functions, &data->pci_dev.num_virtual_functions) || data->pci_dev.num_virtual_functions > 0) data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION; to tag the PCI device with "virtual_function" cap. However, this results in a VF will aslo get "virtual_function" cap. This patch fixes it by: * Ignoring the VF which has failure of getting PCI config space (given that the successfully detected VFs are kept , it makes sense to not give up on the failure of one VF too) with a warning, so pciGetVirtualFunctions will not return -1 except out of memory. * Free the allocated *virtual_functions when out of memory And thus the logic can be changed to: /* Out of memory */ int rc = pciGetVirtualFunctions(syspath, &data->pci_dev.virtual_functions, &data->pci_dev.num_virtual_functions);

if (ret < 0 ) goto out; else if (!ret && (data->pci_dev.num_virtual_functions > 0)) data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION;

--- src/node_device/node_device_hal.c | 11 ++++++++--- src/node_device/node_device_udev.c | 11 ++++++++--- src/util/virpci.c | 36 +++++++++++++++++++++++------------- 3 files changed, 39 insertions(+), 19 deletions(-) diff --git a/src/node_device/node_device_hal.c b/src/node_device/node_device_hal.c index 1afa21c..d0c419d 100644 --- a/src/node_device/node_device_hal.c +++ b/src/node_device/node_device_hal.c @@ -151,10 +151,15 @@ static int gather_pci_cap(LibHalContext *ctx, const char *udi, if (!pciGetPhysicalFunction(sysfs_path, &d->pci_dev.physical_function)) d->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION; - if (!pciGetVirtualFunctions(sysfs_path, &d->pci_dev.virtual_functions, - &d->pci_dev.num_virtual_functions) || - d->pci_dev.num_virtual_functions > 0) + int ret = pciGetVirtualFunctions(sysfs_path, + &d->pci_dev.virtual_functions, + &d->pci_dev.num_virtual_functions); + if (ret < 0) { + VIR_FREE(sysfs_path); + return -1; + } else if (!ret && (d->pci_dev.num_virtual_functions > 0)) { d->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION; + } VIR_FREE(sysfs_path); } diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c index 87f1000..47ac4f4 100644 --- a/src/node_device/node_device_udev.c +++ b/src/node_device/node_device_udev.c @@ -416,6 +416,7 @@ static int udevProcessPCI(struct udev_device *device, union _virNodeDevCapData *data = &def->caps->data; int ret = -1; char *p; + int rc; syspath = udev_device_get_syspath(device); @@ -484,9 +485,13 @@ static int udevProcessPCI(struct udev_device *device, if (!pciGetPhysicalFunction(syspath, &data->pci_dev.physical_function)) data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION; - if (!pciGetVirtualFunctions(syspath, &data->pci_dev.virtual_functions, - &data->pci_dev.num_virtual_functions) || - data->pci_dev.num_virtual_functions > 0) + rc = pciGetVirtualFunctions(syspath, + &data->pci_dev.virtual_functions, + &data->pci_dev.num_virtual_functions); + /* Out of memory */ + if (rc < 0) + goto out; + else if (!rc && (data->pci_dev.num_virtual_functions > 0)) data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION; ret = 0; diff --git a/src/util/virpci.c b/src/util/virpci.c index 0fb9923..9f4f3c7 100644 --- a/src/util/virpci.c +++ b/src/util/virpci.c @@ -1968,6 +1968,7 @@ pciGetVirtualFunctions(const char *sysfs_path, unsigned int *num_virtual_functions) { int ret = -1; + int i; DIR *dir = NULL; struct dirent *entry = NULL; char *device_link = NULL; @@ -1989,6 +1990,7 @@ pciGetVirtualFunctions(const char *sysfs_path, *num_virtual_functions = 0; while ((entry = readdir(dir))) { if (STRPREFIX(entry->d_name, "virtfn")) { + struct pci_config_address *config_addr = NULL; if (virBuildPath(&device_link, sysfs_path, entry->d_name) == -1) { virReportOOMError(); @@ -1997,24 +1999,23 @@ pciGetVirtualFunctions(const char *sysfs_path, VIR_DEBUG("Number of virtual functions: %d", *num_virtual_functions); - if (VIR_REALLOC_N(*virtual_functions, - (*num_virtual_functions) + 1) != 0) { - virReportOOMError(); - VIR_FREE(device_link); - goto out; - } if (pciGetPciConfigAddressFromSysfsDeviceLink(device_link, - &((*virtual_functions)[*num_virtual_functions])) != + &config_addr) != SRIOV_FOUND) { - /* We should not get back SRIOV_NOT_FOUND in this - * case, so if we do, it's an error. */ - virReportError(VIR_ERR_INTERNAL_ERROR, - _("Failed to get SR IOV function from device " - "link '%s'"), device_link); + VIR_WARN("Failed to get SRIOV function from device " + "link '%s'", device_link); VIR_FREE(device_link); - goto out; + continue;

} else { + if (VIR_ALLOC_N(*virtual_functions, + *num_virtual_functions + 1) < 0) { + virReportOOMError(); + VIR_FREE(config_addr); + goto out; + } + + (*virtual_functions)[*num_virtual_functions] = config_addr; (*num_virtual_functions)++; } VIR_FREE(device_link); @@ -2022,8 +2023,17 @@ pciGetVirtualFunctions(const char *sysfs_path, } ret = 0; + goto cleanup; out: + if (*virtual_functions) { + for (i = 0; i < *num_virtual_functions; i++) + VIR_FREE((*virtual_functions)[i]); + VIR_FREE(*virtual_functions); + } + +cleanup: + VIR_FREE(device_link); if (dir) closedir(dir);