On Thu, Nov 07, 2013 at 01:10:39PM +0200, Laine Stump wrote: > This resolves: > > https://bugzilla.redhat.com/show_bug.cgi?id=1025397 > > When libvirt creates the list of an SRIOV Physical Function's (PF) > Virtual Functions (VF), it assumes that the order of "virtfn*" links > returned by readdir() from the PF's sysfs directory is already in the > correct order. Experience has shown that this is not always the case. > > This results in 1) incorrect assumptions made by consumers of the > output of the virt_functions list of virsh nodedev-dumpxml, and 2) > setting MAC address and vlan tag on the wrong VF (since libvirt uses > netlink to set mac address and vlan tag, netlink requires the VF#, and > the function virPCIGetVirtualFunctionIndex() returns the wrong index > due to the improperly ordered VF list). See the bugzilla report for an > example of this improper behavior. > > The solution provided by this patch is for virPCIGetVirtualFunctions > to first gather all the "virtfn*" names from the PFs sysfs directory, > then allocate a virtual_functions array large enough to hold all > entries, and finally to create a device entry for each virtfn* name > and place it into the virtual_functions array at the proper index > (based on interpreting the value following "virtfn" in the name). > > Checks are introduced to ensure that 1) the virtfn list given in sysfs > is not sparse (ie, there are no indexes larger than the length of the > list), and that no two virtfn* entries decode to the same index. > --- > > Difference from V1: Based on jtomko's review, truncate trailing NULLs > in virtual_functions array, and actually check for NULLs in the middle > (a sparse array) and generate an error in that case, as we already > claimed to do in the commit message. > > (Sorry for the lack of inter-diff, but the only changes from V1 are > the addition of the lines starting with "truncate any trailing nulls" > and continuing until the next VIR_DEBUG.) > > src/util/virpci.c | 115 ++++++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 90 insertions(+), 25 deletions(-) > Disclaimer: I don't want this to sound rude (just that it does to me every time I read it), this is just a question that popped in my mind. Why don't we do it differently? If we have a while loop with a number starting from 1 and access(, F_OK)'ing '"virtfn%d", number' in that loop, we'll have all those VFs sorted. And if that's not nice enough, we should be able to read the number of VFs from the device's "/config" (in offset 0x10 [1]) and do a nice, clean for loop over already known filenames. Or am I missing something? I just Took that from "drivers/pci/iov.c", so this may be "Just Wrong". Martin [1] http://lxr.free-electrons.com/source/include/uapi/linux/pci_regs.h#L804 > diff --git a/src/util/virpci.c b/src/util/virpci.c > index 148631f..f744c8b 100644 > --- a/src/util/virpci.c > +++ b/src/util/virpci.c > @@ -2379,6 +2379,8 @@ virPCIGetPhysicalFunction(const char *vf_sysfs_path, > return ret; > } > > +static const char *virtfnPrefix = "virtfn"; > + > /* > * Returns virtual functions of a physical function > */ > @@ -2393,6 +2395,8 @@ virPCIGetVirtualFunctions(const char *sysfs_path, > struct dirent *entry = NULL; > char *device_link = NULL; > char errbuf[64]; > + char **virtfnNames = NULL; > + size_t nVirtfnNames = 0; > > VIR_DEBUG("Attempting to get SR IOV virtual functions for device" > "with sysfs path '%s'", sysfs_path); > @@ -2411,51 +2415,112 @@ virPCIGetVirtualFunctions(const char *sysfs_path, > > while ((entry = readdir(dir))) { > if (STRPREFIX(entry->d_name, "virtfn")) { > - virPCIDeviceAddress *config_addr = NULL; > + char *tempName; > > - if (virBuildPath(&device_link, sysfs_path, entry->d_name) == -1) { > - virReportOOMError(); > + /* save these to sort into virtual_functions array */ > + if (VIR_STRDUP(tempName, entry->d_name) < 0) > + goto error; > + if (VIR_APPEND_ELEMENT(virtfnNames, nVirtfnNames, tempName) < 0) { > + VIR_FREE(tempName); > goto error; > } > + } > + } > > - VIR_DEBUG("Number of virtual functions: %d", > - *num_virtual_functions); > + /* pre-allocate because we will be filling in out of order */ > + if (nVirtfnNames && VIR_ALLOC_N(*virtual_functions, nVirtfnNames) < 0) > + goto error; > + *num_virtual_functions = nVirtfnNames; > > - if (virPCIGetDeviceAddressFromSysfsLink(device_link, > - &config_addr) != > - SRIOV_FOUND) { > - VIR_WARN("Failed to get SRIOV function from device " > - "link '%s'", device_link); > - VIR_FREE(device_link); > - continue; > - } > + for (i = 0; i < nVirtfnNames; i++) { > + virPCIDeviceAddress *config_addr = NULL; > + unsigned int virtfnIndex; > > - if (VIR_REALLOC_N(*virtual_functions, > - *num_virtual_functions + 1) < 0) { > - VIR_FREE(config_addr); > - goto error; > - } > + if (virBuildPath(&device_link, sysfs_path, virtfnNames[i]) < 0) { > + virReportOOMError(); > + goto error; > + } > + > + if (virStrToLong_ui(virtfnNames[i] + strlen(virtfnPrefix), > + 0, 10, &virtfnIndex) < 0) { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + _("Invalid virtual function link name '%s' " > + "in physical function directory '%s'"), > + virtfnNames[i], sysfs_path); > + goto error; > + } > + > + if (virtfnIndex >= nVirtfnNames) { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + _("Virtual function link name '%s' larger than " > + "total count of virtual functions %zu " > + "in physical function directory '%s'"), > + virtfnNames[i], nVirtfnNames, sysfs_path); > + goto error; > + } > + > + if ((*virtual_functions)[virtfnIndex]) { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + _("Virtual function link name '%s' " > + "generates duplicate index %zu " > + "in physical function directory '%s'"), > + virtfnNames[i], nVirtfnNames, sysfs_path); > + goto error; > + } > > - (*virtual_functions)[*num_virtual_functions] = config_addr; > - (*num_virtual_functions)++; > + if (virPCIGetDeviceAddressFromSysfsLink(device_link, &config_addr) != > + SRIOV_FOUND) { > + VIR_WARN("Failed to get SRIOV function from device link '%s'", > + device_link); > VIR_FREE(device_link); > + continue; > } > + > + VIR_DEBUG("Found virtual function %d", virtfnIndex); > + (*virtual_functions)[virtfnIndex] = config_addr; > + VIR_FREE(device_link); > } > > + /* truncate any trailing nulls due to files having names starting > + * with "virtfn" which weren't actually a link to a virtual > + * function. > + */ > + while (*num_virtual_functions && > + !(*virtual_functions)[(*num_virtual_functions) - 1]) > + (*num_virtual_functions)--; > + > + /* failure of realloc when shrinking is safe */ > + ignore_value(VIR_REALLOC_N(*virtual_functions, *num_virtual_functions)); > + > + /* if there are any NULLs left in the array, fail and log an error > + * - the virtual function array cannot be sparse. > + */ > + for (i = 0; i < *num_virtual_functions; i++) { > + if (!(*virtual_functions)[*num_virtual_functions]) { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + _("Missing virtual function link for VF %zu " > + "in physical function directory '%s'"), > + i, sysfs_path); > + goto error; > + } > + } > + > + VIR_DEBUG("Number of virtual functions: %d", *num_virtual_functions); > ret = 0; > > cleanup: > + for (i = 0; i < nVirtfnNames; i++) > + VIR_FREE(virtfnNames[i]); > + VIR_FREE(virtfnNames); > VIR_FREE(device_link); > if (dir) > closedir(dir); > return ret; > > error: > - if (*virtual_functions) { > - for (i = 0; i < *num_virtual_functions; i++) > - VIR_FREE((*virtual_functions)[i]); > - VIR_FREE(*virtual_functions); > - } > + for (i = 0; i < *num_virtual_functions; i++) > + VIR_FREE((*virtual_functions)[i]); > + VIR_FREE(*virtual_functions); > goto cleanup; > } > > -- > 1.8.3.1 > > -- > libvir-list mailing list > libvir-list@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvir-list
Attachment:
signature.asc
Description: Digital signature
-- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list