Re: [libvirt] [PATCH v4 3/6] util: Add helper APIs to get/verify VF Representor name

On 06/28/2018 09:22 AM, Jai Singh Rana wrote:

Introduce new APIs virNetdevHostdevGetVFRIfName and virNetdevHostdevCheckVFRIfName to fetch/verify VF Representor name according to switch model for network devices in linux.

Switchdev VF representor interface name on host is queried based on Bus:Device:Function information of pci SR-IOV device in Domain's hostdev def and subsequently verifying the required net sysfs directory and file entries of VF representor.

Signed-off-by: Jai Singh Rana <JaiSingh.Rana@cavium.com> --- po/POTFILES | 1 + src/libvirt_private.syms | 7 ++ src/util/Makefile.inc.am | 2 + src/util/virhostdev.c | 2 +- src/util/virhostdev.h | 8 ++ src/util/virnetdevhostdev.c | 300 ++++++++++++++++++++++++++++++++++++++++++++ src/util/virnetdevhostdev.h | 34 +++++ 7 files changed, 353 insertions(+), 1 deletion(-) create mode 100644 src/util/virnetdevhostdev.c create mode 100644 src/util/virnetdevhostdev.h

This will certainly be where things get a bit more "unknown" to me... Still I think this patch can be split in half - with one patch being just the promotion of virHostdevNetDevice to external and the second adding the new module.

diff --git a/po/POTFILES b/po/POTFILES index be2874487c..3f8731f342 100644 --- a/po/POTFILES +++ b/po/POTFILES @@ -235,6 +235,7 @@ src/util/virmdev.c src/util/virnetdev.c src/util/virnetdevbandwidth.c src/util/virnetdevbridge.c +src/util/virnetdevhostdev.c src/util/virnetdevip.c src/util/virnetdevmacvlan.c src/util/virnetdevmidonet.c diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 0ba8cd2a14..5aa8f7ed64 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1968,6 +1968,7 @@ virHostdevFindUSBDevice; virHostdevIsMdevDevice; virHostdevIsSCSIDevice; virHostdevManagerGetDefault; +virHostdevNetDevice; virHostdevPCINodeDeviceDetach; virHostdevPCINodeDeviceReAttach; virHostdevPCINodeDeviceReset; @@ -2356,6 +2357,12 @@ virNetDevBridgeSetSTPDelay; virNetDevBridgeSetVlanFiltering;

+# util/virnetdevhostdev.h +virNetdevHostdevCheckVFRIfName; +virNetdevHostdevGetVFRIfName; +virNetdevHostdevVFRIfStats; + + # util/virnetdevip.h virNetDevIPAddrAdd; virNetDevIPAddrDel; diff --git a/src/util/Makefile.inc.am b/src/util/Makefile.inc.am index a22265606c..0846a8e025 100644 --- a/src/util/Makefile.inc.am +++ b/src/util/Makefile.inc.am @@ -108,6 +108,8 @@ UTIL_SOURCES = \ util/virnetdevbandwidth.h \ util/virnetdevbridge.c \ util/virnetdevbridge.h \ + util/virnetdevhostdev.c \ + util/virnetdevhostdev.h \ util/virnetdevip.c \ util/virnetdevip.h \ util/virnetdevmacvlan.c \ diff --git a/src/util/virhostdev.c b/src/util/virhostdev.c index f4bd19df64..c6ee725860 100644 --- a/src/util/virhostdev.c +++ b/src/util/virhostdev.c @@ -303,7 +303,7 @@ virHostdevIsVirtualFunction(virDomainHostdevDefPtr hostdev) }

Could you add a brief header here describing the inputs and what it returns. Perhaps of most interest is the values that @pfNetDevIdx can be (I see -1, 0, 1 being used). It also looks like @linkdev and @vf are returned as well as 0, -1 for success/failure. The @vf can be -1 and ret == 0 if the else condition is followed. Useful things to know for external consumers.

-static int +int virHostdevNetDevice(virDomainHostdevDefPtr hostdev, int pfNetDevIdx, char **linkdev, diff --git a/src/util/virhostdev.h b/src/util/virhostdev.h index 8f77c00221..7412a20aa9 100644 --- a/src/util/virhostdev.h +++ b/src/util/virhostdev.h @@ -60,6 +60,14 @@ struct _virHostdevManager { };

virHostdevManagerPtr virHostdevManagerGetDefault(void); + +int +virHostdevNetDevice(virDomainHostdevDefPtr hostdev, + int pfNetDevIdx, + char **linkdev, + int *vf) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(4);

(3) had better be NONNULL too!

+ int virHostdevPreparePCIDevices(virHostdevManagerPtr hostdev_mgr, const char *drv_name, diff --git a/src/util/virnetdevhostdev.c b/src/util/virnetdevhostdev.c new file mode 100644 index 0000000000..2d3e46c81f --- /dev/null +++ b/src/util/virnetdevhostdev.c @@ -0,0 +1,300 @@ +/* + * virnetdevhostdev.c: utilities to get/verify Switchdev VF Representor

Far be it for me to be the license expert, but there's no copyright year here. I would have at least expected something, such as: * Copyright (C) 2018 XXX where for XXX I've seen people add a company name or their own name - there's lots of examples to choose from. Not my exact area of expertise over the "right value" though. I would put Red Hat Inc. there, but then again, that's where I work.

+ * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>. + */ + +#include <config.h> + +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <dirent.h> + +#include "virhostdev.h" +#include "virnetdev.h" +#include "virnetdevhostdev.h" +#include "viralloc.h" +#include "virstring.h" +#include "virfile.h" +#include "virerror.h" +#include "virlog.h" +#include "c-ctype.h" + +#define VIR_FROM_THIS VIR_FROM_NONE + +VIR_LOG_INIT("util.netdevhostdev"); + +#ifndef IFNAMSIZ +# define IFNAMSIZ 16 +#endif + +#define IFSWITCHIDSIZ 20 + +#ifdef __linux__ +/** + * virNetdevHostdevNetSysfsPath + * + * @pf_name: netdev name of the physical function (PF) + * @vf: virtual function (VF) number for the device of interest + * @vf_ifname: name of the VF representor interface + * + * Finds the VF representor name of VF# @vf of SRIOV PF @pfname, + * and puts it in @vf_ifname. The caller must free @vf_ifname + * when it's finished with it + * + * Returns 1 on success, 0 for no switchdev support for @pfname device

Typically we prefer -1 on failure, 0 on success Still you seem to be having a 3rd condition where 0 could be we failed and we don't care and 1 could be we succeeded. The -1 could be left as a fatal error since currently there'd be no way to determine the difference between OOM from virAsprintf or failure from virFileReadAllQuiet. In both cases the caller should ignore/reset the last error rather than this lower down API.

+ */ +static int +virNetdevHostdevNetSysfsPath(char *pf_name, + int vf, + char **vf_ifname) +{ + size_t i; + char *pf_switch_id = NULL; + char *pf_switch_id_file = NULL; + char *pf_subsystem_device_file = NULL; + char *pf_subsystem_device_switch_id = NULL; + char *pf_subsystem_device_port_name_file = NULL; + char *pf_subsystem_dir = NULL; + char *vf_rep_ifname = NULL; + int vf_rep_num; + const char *vf_num_str; + DIR *dirp = NULL; + struct dirent *dp; + int ret = 0; + + if (virAsprintf(&pf_switch_id_file, SYSFS_NET_DIR "%s/phys_switch_id", + pf_name) < 0) + goto cleanup;

should be a fatal failure

+ + if (!virFileExists(pf_switch_id_file)) + goto cleanup;

could be a graceful failure

+ + /* If file exists, failure to read or if it's an empty file just means + * that driver doesn't support phys_switch_id, therefore ignoring the error

"that the driver" s/ignoring/ignore

+ * from virFileReadAllQuiet(). + */ + if (virFileReadAllQuiet(pf_switch_id_file, IFSWITCHIDSIZ, + &pf_switch_id) <= 0) + goto cleanup; +

Seems like this could be a graceful failure

+ if (virAsprintf(&pf_subsystem_dir, SYSFS_NET_DIR "%s/subsystem", + pf_name) < 0) + goto cleanup;

Would be a fatal failure. I'll let you decide on the rest.

+ + if (virDirOpen(&dirp, pf_subsystem_dir) < 0) + goto cleanup; + + /* Iterate over the PFs subsystem devices to find entry with matching + * switch_id with that of PF. + */ + while (virDirRead(dirp, &dp, pf_subsystem_dir) > 0) { + if (STREQ(dp->d_name, pf_name)) + continue; + + VIR_FREE(pf_subsystem_device_file); + if (virAsprintf(&pf_subsystem_device_file, "%s/%s/phys_switch_id", + pf_subsystem_dir, dp->d_name) < 0) + goto cleanup; + + if (!virFileExists(pf_subsystem_device_file)) + goto cleanup; + + /* If file exists, failure to read or if it's an empty file just means + * the driver doesn't support the entry being probed for current + * device in subsystem dir, therefore ignoring the error in the + * following calls to virFileReadAllQuiet() and continue the loop + * to find device which supports this and is a match. + */ + VIR_FREE(pf_subsystem_device_switch_id); + if (virFileReadAllQuiet(pf_subsystem_device_file, IFSWITCHIDSIZ, + &pf_subsystem_device_switch_id) > 0) { + if (STRNEQ(pf_switch_id, pf_subsystem_device_switch_id)) + continue; + } + else + continue; + + VIR_FREE(pf_subsystem_device_port_name_file); + if (virAsprintf(&pf_subsystem_device_port_name_file, + "%s/%s/phys_port_name", pf_subsystem_dir, + dp->d_name) < 0) + goto cleanup; + + if (!virFileExists(pf_subsystem_device_port_name_file)) + goto cleanup; + + VIR_FREE(vf_rep_ifname); + if (virFileReadAllQuiet + (pf_subsystem_device_port_name_file, IFNAMSIZ, + &vf_rep_ifname) <= 0) + continue; + + /* phys_port_name may contain just VF number or string in format + * as pf'X'vf'Y' or vf'Y', where X and Y are PF and VF numbers. + * As at this point, we are already with correct PF, just need + * to verify VF number which is always at the end. + */ + + /* vf_rep_ifname read from file may contain new line,replace with '\0' + for string comparison below */ + i = strlen(vf_rep_ifname); + if (c_isspace(vf_rep_ifname[i-1])) { + vf_rep_ifname[i-1] = '\0'; + i -= 1; + } + + /* Locating the start of numeric portion of VF in the string */ + while (c_isdigit(vf_rep_ifname[i-1])) + i -= 1; + + vf_num_str = vf_rep_ifname + i; + vf_rep_num = virParseNumber(&vf_num_str); + + if (vf_rep_num == vf) { + if (VIR_STRDUP(*vf_ifname, dp->d_name) < 0) + goto cleanup; + ret = 1; + break;

Could be a goto cleanup too... because...

+ } + }

...if we complete the virDirRead loop without any match is that a bad thing?

+ + cleanup: + VIR_DIR_CLOSE(dirp); + VIR_FREE(pf_switch_id); + VIR_FREE(pf_switch_id_file); + VIR_FREE(pf_subsystem_dir); + VIR_FREE(pf_subsystem_device_file); + VIR_FREE(pf_subsystem_device_switch_id); + VIR_FREE(pf_subsystem_device_port_name_file); + VIR_FREE(vf_rep_ifname); + return ret; +} + + +/** + * virNetdevHostdevGetVFRepIFName

^^^ This ....

+ * + * @hostdev: host device to check + * + * Returns VF string with VF representor name upon success else NULL + */ +char * +virNetdevHostdevGetVFRIfName(virDomainHostdevDefPtr hostdev)

... doesn't match this ^^^^ Asking from the point of not sure, but is "VFRIfName" redundant? That is could it just be "VFRName" or is there a delineation between a VFR Name and a VFR IFName that needs to be made. You may want to just call this "GetVFRInfo" leaving for the possibility of future expansion to more than just @ifname. Thus you pass the @ifname as a parameter and use 0 and -1 return values to indicate success or failure.

+{ + char *linkdev = NULL; + char *ifname = NULL; + char *vf_ifname = NULL; + int vf = -1; + + if (virHostdevNetDevice(hostdev, -1, &linkdev, &vf) < 0) + goto cleanup; + + if (!virNetdevHostdevNetSysfsPath(linkdev, vf, &vf_ifname)) { + virResetLastError();

This is what I meant earlier - you have no way to determine if the failure is fatal or not and resetting an OOM may not acceptible from this caller. I think the caller of this API should make that determination (something I validate later on).

+ goto cleanup; + } + + ignore_value(VIR_STRDUP(ifname, vf_ifname));

Why not just return vf_ifname directly later? It's already a VIR_STRDUP'd value - especially since you VIR_FREE it below.

+ + cleanup: + VIR_FREE(linkdev); + VIR_FREE(vf_ifname); + return ifname; +} + + +/** + * virNetdevHostdevCheckVFRepIFName + * + * @hostdev: host device to check + * @ifname : VF representor name to verify + * + * Returns true on success, false on failure + */ +bool +virNetdevHostdevCheckVFRIfName(virDomainHostdevDefPtr hostdev, + const char *ifname)

Same notes about the method name

+{ + char *linkdev = NULL; + char *vf_ifname = NULL; + int vf = -1; + bool ret = false; + + if (virHostdevNetDevice(hostdev, -1, &linkdev, &vf) < 0) + goto cleanup; + + if (!virNetdevHostdevNetSysfsPath(linkdev, vf, &vf_ifname)) { + virResetLastError();

Again, you really don't know the reason for failure here. This is a Check method with a couple of ways to fail. Even the previous call could have some sort of failure that isn't reset. So prehaps the Reset should be in cleanup in this case.

+ goto cleanup; + } + + if (STREQ(ifname, vf_ifname)) + ret = true;

ret = STREQ(ifname, vf_ifname);

+ + cleanup: + VIR_FREE(linkdev); + VIR_FREE(vf_ifname); + return ret; +} + + +/** + * virNetdevHostdevVFRepInterfaceStats: + * @ifname: interface + * @stats: where to store statistics + * @swapped: whether to swap RX/TX fields + * + * Returns 0 on success, -1 otherwise (with error reported). + */ +int +virNetdevHostdevVFRIfStats(const char *ifname, + virDomainInterfaceStatsPtr stats, + bool swapped) +{ + return virNetDevGetProcNetdevStats(ifname, stats, swapped);

Not sure I ever see the need for this to be specific... You're not validating that ifname is a VFRIfName, so the GetProcNetdevStats could just be called directly instead when it's needed later on. If by chance there could be multiple ways to obtain stats for one of these I could see use for the wrapper, but that doesn't happen in this patch series, so the direct call is better since the assumption is that @ifname is a vf_ifname (from the eventual caller).

+} +#else +static const char *unsupported = N_("not supported on non-linux platforms"); + +

If any of the above in the #ifdef __linux__ do change, don't forget to modify these as well!

+char * +virNetdevHostdevGetVFRIfName(virDomainHostdevDefPtr hostdev ATTRIBUTE_UNUSED) +{ + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _(unsupported)); + return NULL; +} + + +bool +virNetdevHostdevCheckVFRIfName(virDomainHostdevDefPtr hostdev ATTRIBUTE_UNUSED, + const char *ifname ATTRIBUTE_UNUSED) +{ + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _(unsupported)); + return false; +} + + +int +virNetdevHostdevVFRIfStats(const char *ifname ATTRIBUTE_UNUSED, + virDomainInterfaceStatsPtr stats ATTRIBUTE_UNUSED, + bool swapped ATTRIBUTE_UNUSED) +{ + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("interface stats not implemented on this platform"));

Why the change here? IDC, but consisitently speaking it's different.

+ return -1; +} +#endif diff --git a/src/util/virnetdevhostdev.h b/src/util/virnetdevhostdev.h new file mode 100644 index 0000000000..5fb846fad5 --- /dev/null +++ b/src/util/virnetdevhostdev.h @@ -0,0 +1,34 @@ +/* + * virnetdevhostdev.h: utilities to get/verify Switchdev VF Representor + *

Same here w/ copyright year

+ * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>. + */ + +#ifndef __VIR_NETDEV_HOSTDEV_H__ +# define __VIR_NETDEV_HOSTDEV_H__ + +char * virNetdevHostdevGetVFRIfName(virDomainHostdevDefPtr hostdev) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;

You can follow/copy the .c header here and the other two: char * virNetdevHostdevGetVFRIfName(...) John

+ +bool virNetdevHostdevCheckVFRIfName(virDomainHostdevDefPtr hostdev, + const char *ifname) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK; + +int virNetdevHostdevVFRIfStats(const char *ifname, + virDomainInterfaceStatsPtr stats, + bool swapped) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK; +#endif /* __VIR_NETDEV_HOSTDEV_H__ */