[v2] bus/pci: fix unexpected resource mapping override
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Commit Message
When scanning an already plugged device, the virtual address
of mapped PCI resource in rte_pci_device will be overridden
with 0, that may cause driver does not work correctly.
The fix is not to update any rte_pci_device's field if the being
scanned device's driver is already probed.
Bugzilla ID: 85
Fixes: c752998b5e2e ("pci: introduce library and driver")
Cc: stable@dpdk.org
Reported-by: Lv Geoffrey <geoffrey.lv@gmail.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
v2:
- use rte_dev_is_probed.
- reword comment.
drivers/bus/pci/linux/pci.c | 35 ++++++++++++++++++++++++++++++-----
1 file changed, 30 insertions(+), 5 deletions(-)
Comments
27/10/2018 05:20, Qi Zhang:
> When scanning an already plugged device, the virtual address
> of mapped PCI resource in rte_pci_device will be overridden
> with 0, that may cause driver does not work correctly.
> The fix is not to update any rte_pci_device's field if the being
> scanned device's driver is already probed.
>
> Bugzilla ID: 85
> Fixes: c752998b5e2e ("pci: introduce library and driver")
> Cc: stable@dpdk.org
>
> Reported-by: Lv Geoffrey <geoffrey.lv@gmail.com>
> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
I still think something must be fixed in PCI scan.
Anyway, there is an error:
passing argument 1 of ‘rte_dev_is_probed’ from incompatible pointer type
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> Sent: Sunday, October 28, 2018 6:27 PM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>
> Cc: dev@dpdk.org; Burakov, Anatoly <anatoly.burakov@intel.com>; Yigit,
> Ferruh <ferruh.yigit@intel.com>; geoffrey.lv@gmail.com;
> ajit.khaparde@broadcom.com; stable@dpdk.org; gaetan.rivet@6wind.com;
> arybchenko@solarflare.com
> Subject: Re: [dpdk-dev] [PATCH v2] bus/pci: fix unexpected resource mapping
> override
>
> 27/10/2018 05:20, Qi Zhang:
> > When scanning an already plugged device, the virtual address of mapped
> > PCI resource in rte_pci_device will be overridden with 0, that may
> > cause driver does not work correctly.
> > The fix is not to update any rte_pci_device's field if the being
> > scanned device's driver is already probed.
> >
> > Bugzilla ID: 85
> > Fixes: c752998b5e2e ("pci: introduce library and driver")
> > Cc: stable@dpdk.org
> >
> > Reported-by: Lv Geoffrey <geoffrey.lv@gmail.com>
> > Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
>
> I still think something must be fixed in PCI scan.
We are fixing something in PCI scan, right?
>
> Anyway, there is an error:
> passing argument 1 of ‘rte_dev_is_probed’ from incompatible pointer type
So sorry, I should compile it first
.
>
>
30/10/2018 16:19, Zhang, Qi Z:
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > 27/10/2018 05:20, Qi Zhang:
> > > When scanning an already plugged device, the virtual address of mapped
> > > PCI resource in rte_pci_device will be overridden with 0, that may
> > > cause driver does not work correctly.
> > > The fix is not to update any rte_pci_device's field if the being
> > > scanned device's driver is already probed.
> > >
> > > Bugzilla ID: 85
> > > Fixes: c752998b5e2e ("pci: introduce library and driver")
> > > Cc: stable@dpdk.org
> > >
> > > Reported-by: Lv Geoffrey <geoffrey.lv@gmail.com>
> > > Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
> >
> > I still think something must be fixed in PCI scan.
>
> We are fixing something in PCI scan, right?
Yes :)
I was thinking about not scanning an already scanned device.
If the device has been unplugged, it should be removed,
and re-added when plugged, instead of trying to update it.
I understand this is another kind of change and deserves more time
to think about the right design. That's why I will accept the v3
of this patch.
Anyway the road to get hotplug handled right is long :)
@@ -349,11 +349,36 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
if (ret < 0) {
rte_pci_insert_device(dev2, dev);
} else { /* already registered */
- dev2->kdrv = dev->kdrv;
- dev2->max_vfs = dev->max_vfs;
- pci_name_set(dev2);
- memmove(dev2->mem_resource, dev->mem_resource,
- sizeof(dev->mem_resource));
+ if (!rte_dev_is_probed(dev2)) {
+ dev2->kdrv = dev->kdrv;
+ dev2->max_vfs = dev->max_vfs;
+ pci_name_set(dev2);
+ memmove(dev2->mem_resource,
+ dev->mem_resource,
+ sizeof(dev->mem_resource));
+ } else {
+ /**
+ * If device is plugged and driver is
+ * probed already, (This happens when we
+ * call rte_dev_probe which will scan all
+ * device on the bus) we don't need
+ * to do anything here unless...
+ **/
+ if (dev2->kdrv != dev->kdrv ||
+ dev2->max_vfs != dev->max_vfs)
+ /*
+ * This should not happens.
+ * But it is still possible if
+ * we unbind a device from
+ * vfio or uio before hotplug
+ * remove and rebind it with
+ * a different configure.
+ * So we just print out the
+ * error as an alarm.
+ */
+ RTE_LOG(ERR, EAL, "Unexpected device scan at %s!\n",
+ filename);
+ }
free(dev);
}
return 0;