[dpdk-dev] [PATCH v13 02/19] bus/pci: fix PCI address compare

Gaëtan Rivet gaetan.rivet at 6wind.com
Thu Jul 12 11:32:09 CEST 2018


Hi,

On Thu, Jul 12, 2018 at 10:24:44AM +0100, Burakov, Anatoly wrote:
> On 12-Jul-18 2:14 AM, Qi Zhang wrote:
> > When use memcmp to compare two PCI address, sizeof(struct rte_pci_addr)
> > is 4 bytes aligned, and it is 8. While only 7 byte of struct rte_pci_addr
> > is valid. So compare the 8th byte will cause the unexpected result, which
> > happens when repeatedly attach/detach a device.
> > 
> > Fixes: c752998b5e2e ("pci: introduce library and driver")

Shouldn't be the original commit be

Fixes: 94c0776b1bad ("vfio: support hotplug")

instead?

> > Cc: stable at dpdk.org
> > 
> > Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
> > ---
> >   drivers/bus/pci/linux/pci_vfio.c | 13 ++++++++++++-
> >   1 file changed, 12 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
> > index aeeaa9ed8..dd25c3542 100644
> > --- a/drivers/bus/pci/linux/pci_vfio.c
> > +++ b/drivers/bus/pci/linux/pci_vfio.c
> > @@ -43,6 +43,17 @@ static struct rte_tailq_elem rte_vfio_tailq = {
> >   };
> >   EAL_REGISTER_TAILQ(rte_vfio_tailq)
> > +/* Compair two pci address */
> > +static int pci_addr_cmp(struct rte_pci_addr *addr1, struct rte_pci_addr *addr2)
> > +{
> > +	if (addr1->domain == addr2->domain &&
> > +		addr1->bus == addr2->bus &&
> > +		addr1->devid == addr2->devid &&
> > +		addr1->function == addr2->function)
> > +		return 0;
> > +	return 1;
> > +}
> 
> Generally, change looks OK to me, but I think we already have this function
> in PCI library - rte_pci_addr_cmp(). Is there a specific reason to
> reimplement it here?
> 

+1

> > +
> >   int
> >   pci_vfio_read_config(const struct rte_intr_handle *intr_handle,
> >   		    void *buf, size_t len, off_t offs)
> > @@ -642,7 +653,7 @@ pci_vfio_unmap_resource(struct rte_pci_device *dev)
> >   	vfio_res_list = RTE_TAILQ_CAST(rte_vfio_tailq.head, mapped_pci_res_list);
> >   	/* Get vfio_res */
> >   	TAILQ_FOREACH(vfio_res, vfio_res_list, next) {
> > -		if (memcmp(&vfio_res->pci_addr, &dev->addr, sizeof(dev->addr)))
> > +		if (pci_addr_cmp(&vfio_res->pci_addr, &dev->addr))
> >   			continue;
> >   		break;
> >   	}
> > 
> 
> 
> -- 
> Thanks,
> Anatoly

-- 
Gaëtan Rivet
6WIND


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