[dpdk-dev] [PATCH] pci: properly parse 32-bit domain numbers
Gaëtan Rivet
grive at u256.net
Wed May 13 11:04:29 CEST 2020
On 12/05/20 11:16 -0700, Stephen Hemminger wrote:
>
>
> On Tue, May 12, 2020 at 3:30 pm, Darek Stojaczyk
> <dariusz.stojaczyk at intel.com> wrote:
> > The parsing code was bailing on domains greater than UINT16_MAX,
> > but domain numbers like that are still valid and present on some
> > systems.
> > One example is Intel VMD (Volume Management Device), which acts somewhat
> > as a software-managed PCI switch and its upstream linux driver assigns
> > all downstream devices a PCI domain of 0x10000.
> >
> > Parsing a BDF like 10000:01:00.0 was failing before. To fix it, increase
> > the upper limit of domain number to UINT32_MAX. This matches the size of
> > struct rte_pci_addr->domain (uint32).
> >
> > Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk at intel.com
> > <mailto:dariusz.stojaczyk at intel.com>>
The original code predates the change from macro in commit c742e8d3110b.
Fixes: af75078fece3 ("first public release")
Cc: stable at dpdk.org
Thanks for the fix,
Acked-by: Gaetan Rivet <grive at u256.net>
> > ---
> > lib/librte_pci/rte_pci.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/librte_pci/rte_pci.c b/lib/librte_pci/rte_pci.c
> > index d1ab6b414d..ad2cdfebb2 100644
> > --- a/lib/librte_pci/rte_pci.c
> > +++ b/lib/librte_pci/rte_pci.c
> > @@ -72,9 +72,9 @@ pci_dbdf_parse(const char *input, struct rte_pci_addr
> > *dev_addr)
> >
> > errno = 0;
> > val = strtoul(in, &end, 16);
> > - if (errno != 0 || end[0] != ':' || val > UINT16_MAX)
> > + if (errno != 0 || end[0] != ':' || val > UINT32_MAX)
> > return -EINVAL;
> > - dev_addr->domain = (uint16_t)val;
> > + dev_addr->domain = (uint32_t)val;
> > in = end + 1;
> > in = get_u8_pciaddr_field(in, &dev_addr->bus, ':');
> > if (in == NULL)
> > --
> > 2.17.1
>
>
> Agree this came up before on Hyper-V as well. It meant fixing libpci.
>
> Not sure the cast of val is necessary, other than an attempt to silence some
> static checker
> about implicit type conversion causing loss of precision.
>
>
> >
>
The cast is useless indeed. Remnants from the original macro.
For now best to leave it as-is, make another patch to remove those
casts.
There are other potential bugs in parsing, -FFFFFFFFFFFF0001 is
considered valid (-FFFFFFFF00000001 with this patch) as well as an empty domain.
I will send a fix for those.
--
Gaëtan
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