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

[Zhang, Qi Z]

> -----Original Message-----
> From: Burakov, Anatoly
> Sent: Thursday, July 12, 2018 5:25 PM
> To: Zhang, Qi Z <qi.z.zhang at intel.com>; thomas at monjalon.net
> Cc: Ananyev, Konstantin <konstantin.ananyev at intel.com>; dev at dpdk.org;
> Richardson, Bruce <bruce.richardson at intel.com>; Yigit, Ferruh
> <ferruh.yigit at intel.com>; Shelton, Benjamin H
> <benjamin.h.shelton at intel.com>; Vangati, Narender
> <narender.vangati at intel.com>; stable at dpdk.org
> Subject: Re: [PATCH v13 02/19] bus/pci: fix PCI address compare
> 
> 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")
> > 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?

NO, and rte_pci_addr_cmp is what I want :), thanks!
> 
> > +
> >   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