[libvirt] [PATCH] Force FLR on for buggy SR-IOV devices.
Some buggy PCI devices actually support FLR, but
forget to advertise that fact in their PCI config space.
However, Virtual Functions on SR-IOV devices are
*required* to support FLR by the spec, so force has_flr
on if this is a virtual function.
Signed-off-by: Chris Lalancette <clalance(a)redhat.com>
---
src/util/pci.c | 22 ++++++++++++++++++++++
1 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/src/util/pci.c b/src/util/pci.c
index c45b179..4bfad2c 100644
--- a/src/util/pci.c
+++ b/src/util/pci.c
@@ -385,6 +385,7 @@ pciDetectFunctionLevelReset(pciDevice *dev)
{
uint32_t caps;
uint8_t pos;
+ char *path;
/* The PCIe Function Level Reset capability allows
* individual device functions to be reset without
@@ -413,6 +414,27 @@ pciDetectFunctionLevelReset(pciDevice *dev)
}
}
+ /* there are some buggy devices that do support FLR, but forget to
+ * advertise that fact in their capabilities. However, FLR is *required*
+ * to be present for virtual functions (VFs), so if we see that this
+ * device is a VF, we just assume FLR works
+ */
+
+ if (virAsprintf(&path, PCI_SYSFS "devices/%s/physfn", dev->name)
< 0) {
+ VIR_ERROR("Failed to allocate memory when checking FLR for device %s",
+ dev->id);
+ return 0;
+ }
+
+ if (virFileExists(path)) {
+ VIR_FREE(path);
+ VIR_DEBUG("%s %s: buggy device didn't advertise FLR, but is a VF;
forcing flr on",
+ dev->id, dev->name);
+ return 1;
+ }
+
+ VIR_FREE(path);
+
VIR_DEBUG("%s %s: no FLR capability found", dev->id, dev->name);
return 0;
--
1.7.1.1