[libvirt] [PATCH 2/3 RFC] Add functions to get sriov PF/VF relationship of a network interface
Stefan Berger
stefanb at linux.vnet.ibm.com
Tue Aug 2 13:46:26 UTC 2011
On 08/02/2011 08:46 AM, Roopa Prabhu wrote:
>
>
> On 8/1/11 6:10 PM, "Stefan Berger"<stefanb at linux.vnet.ibm.com> wrote:
>
>> On 08/01/2011 07:57 PM, Roopa Prabhu wrote:
>>> From: Roopa Prabhu<roprabhu at cisco.com>
>>>
>>> This patch adds helper functions to derive the PF/VF relationship of an sriov
>>> network device
>>>
>>> Signed-off-by: Roopa Prabhu<roprabhu at cisco.com>
>>> Signed-off-by: Christian Benvenuti<benve at cisco.com>
>>> Signed-off-by: David Wang<dwang2 at cisco.com>
>>> ---
>>> src/util/interface.c | 122
>>> ++++++++++++++++++++++++++++++++++++++++++++++++++
>>> src/util/interface.h | 8 +++
>>> 2 files changed, 130 insertions(+), 0 deletions(-)
>>>
>>>
>>> diff --git a/src/util/interface.c b/src/util/interface.c
>>> index f5eecfb..5ee5703 100644
>>> --- a/src/util/interface.c
>>> +++ b/src/util/interface.c
>>> @@ -30,6 +30,7 @@
>>> #include<sys/ioctl.h>
>>> #include<fcntl.h>
>>> #include<netinet/in.h>
>>> +#include<dirent.h>
>>>
>>> #ifdef __linux__
>>> # include<linux/if.h>
>>> @@ -45,6 +46,8 @@
>>> #include "virfile.h"
>>> #include "memory.h"
>>> #include "netlink.h"
>>> +#include "pci.h"
>>> +#include "logging.h"
>>>
>>> #define VIR_FROM_THIS VIR_FROM_NET
>>>
>>> @@ -1197,3 +1200,122 @@ ifaceRestoreMacAddress(const char *linkdev,
>>>
>>> return rc;
>>> }
>>> +
>>> +int ifaceIsVF(const char *ifname)
>>> +{
>>> + char *if_sysfs_device_link = NULL;
>>> + int ret;
>>> +
>>> + if (virAsprintf(&if_sysfs_device_link, NET_SYSFS "%s/device/physfn",
>>> + ifname)< 0) {
>>> + virReportOOMError();
>>> + return -1;
>>> + }
>>> +
>>> + ret = virFileExists(if_sysfs_device_link);
>>> +
>>> + VIR_FREE(if_sysfs_device_link);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +int ifaceGetVFIndex(const char *pfname, const char *vfname,
>>> + int *vf_index)
>>> +{
>>> + int ret = -1;
>>> + DIR *dir = NULL;
>>> + struct dirent *entry = NULL;
>>> + char *pf_sysfs_device_link = NULL, *vf_sysfs_device_link = NULL;
>>> + char *vf_sysfs_device = NULL;
>>> + char errbuf[64];
>>> +
>>> + if (virAsprintf(&pf_sysfs_device_link, NET_SYSFS "%s/device",
>>> + pfname)< 0) {
>>> + virReportOOMError();
>>> + return -1;
>>> + }
>>> +
>>> + if (virAsprintf(&vf_sysfs_device_link, NET_SYSFS "%s/device",
>>> + vfname)< 0) {
>>> + VIR_FREE(pf_sysfs_device_link);
>>> + virReportOOMError();
>>> + return -1;
>>> + }
>>> +
>>> + vf_sysfs_device = canonicalize_file_name(vf_sysfs_device_link);
>>> + if (vf_sysfs_device == NULL) {
>>> + memset(errbuf, '\0', sizeof(errbuf));
>>> + VIR_ERROR(_("Failed to resolve device link '%s': '%s'"),
>>> + vf_sysfs_device_link,
>>> + virStrerror(errno, errbuf, sizeof(errbuf)));
>>> + VIR_FREE(pf_sysfs_device_link);
>>> + VIR_FREE(vf_sysfs_device_link);
>>> + return -1;
>>> + }
>>> +
>>> + dir = opendir(pf_sysfs_device_link);
>>> + if (dir == NULL)
>>> + goto out;
>>> +
>>> + while ((entry = readdir(dir))) {
>>> + if (STRPREFIX(entry->d_name, "virtfn")) {
>>> + char *device_link, *device_path;
>>> +
>>> + if (virBuildPath(&device_link, pf_sysfs_device_link,
>>> + entry->d_name) == -1) {
>>> + virReportOOMError();
>>> + goto out;
>>> + }
>>> +
>>> + device_path = canonicalize_file_name(device_link);
>>> + if (device_path == NULL) {
>>> + memset(errbuf, '\0', sizeof(errbuf));
>>> + VIR_ERROR(_("Failed to resolve device link '%s': '%s'"),
>>> + device_link, virStrerror(errno, errbuf,
>>> + sizeof(errbuf)));
>>> + VIR_FREE(device_link);
>>> + goto out;
>>> + }
>>> +
>>> + if (!strcmp(vf_sysfs_device, device_path)) {
>>> + *vf_index = atoi(entry->d_name + strlen("virtfn"));
>> This looks odd. Can you explain?
> The PF device sysfs directory has links with the name "virtfn<vf_index>"
> pointing to the VF's pci device.
>
> Example:
> # ls -l virtfn*
> lrwxrwxrwx. 1 root root 0 Jul 27 11:09 virtfn0 -> ../0000:1e:00.1
> lrwxrwxrwx. 1 root root 0 Jul 27 11:09 virtfn1 -> ../0000:1e:00.2
> lrwxrwxrwx. 1 root root 0 Jul 27 11:09 virtfn10 -> ../0000:1e:01.3
> lrwxrwxrwx. 1 root root 0 Jul 27 11:09 virtfn11 -> ../0000:1e:01.4
> lrwxrwxrwx. 1 root root 0 Jul 27 11:09 virtfn12 -> ../0000:1e:01.5
>
> I see if the virt function link is pointing to the pci device of the VF I
> am looking for. If it is, then I try to get the vf index from the virtual
> function link name (I just need the number in "virtfn<vf_index>".
> This is one way to get the vf index. The other way is to get it by reading
> the pci config space of the PF, which the node device driver uses.
>
In that case I'd suggest to use 'if (sscanf(entry->d_name, "virtfn%u",
&vf_index) != 1) { error }'
Stefan
>>> + ret = 0;
>>> + }
>>> +
>>> + VIR_FREE(device_link);
>>> + VIR_FREE(device_path);
>>> +
>>> + if ( ret == 0 )
>>> + break;
>>> + }
>>> + }
>>> +
>>> + if (dir)
>>> + closedir(dir);
>> In this case the above test should be after the 'out:' label not to
>> cause a memory leak with the goto's above.
>>
> Thanks for catching it. Exactly similar lines of code exists in the previous
> patch. There was a bug in the out label location in previous patch. When I
> fixed the previous patch I accidently made the change in this patch too
> introducing a leak here. :) Will fix it. Thanks stefan.
>
>>> +
>>> +out:
>>> +
>>> + VIR_FREE(pf_sysfs_device_link);
>>> + VIR_FREE(vf_sysfs_device_link);
>>> + VIR_FREE(vf_sysfs_device);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +int ifaceGetPFName(const char *ifname, char **pfname)
>>> +{
>>> + char *physfn_sysfs_path = NULL;
>>> + int ret = -1;
>>> +
>>> + if (virAsprintf(&physfn_sysfs_path, NET_SYSFS "%s/device/physfn",
>>> + ifname)< 0) {
>>> + virReportOOMError();
>>> + return -1;
>>> + }
>>> +
>>> + ret = pciDeviceGetNetName(physfn_sysfs_path, pfname);
>>> +
>>> + VIR_FREE(physfn_sysfs_path);
>>> +
>>> + return ret;
>>> +}
>>> diff --git a/src/util/interface.h b/src/util/interface.h
>>> index 9647653..f2c84f8 100644
>>> --- a/src/util/interface.h
>>> +++ b/src/util/interface.h
>>> @@ -26,6 +26,8 @@ struct nlattr;
>>> # include "datatypes.h"
>>> # include "network.h"
>>>
>>> +#define NET_SYSFS "/sys/class/net/"
>>> +
>>> int ifaceGetFlags(const char *name, short *flags);
>>> int ifaceIsUp(const char *name, bool *up);
>>>
>>> @@ -76,4 +78,10 @@ int ifaceReplaceMacAddress(const unsigned char
>>> *macaddress,
>>> int ifaceRestoreMacAddress(const char *linkdev,
>>> const char *stateDir);
>>>
>>> +int ifaceIsVF(const char *ifname);
>>> +
>>> +int ifaceGetVFIndex(const char *pfname, const char *vfname, int *vf_index);
>>> +
>>> +int ifaceGetPFName(const char *ifname, char **pfname);
>>> +
>>> #endif /* __VIR_INTERFACE_H__ */
>>>
>> Stefan
>>
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