> -----Original Message----- > From: Neil Horman [mailto:nhorman at tuxdriver.com] > Sent: Tuesday, June 17, 2014 1:40 PM > To: Richardson, Bruce > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH] vfio: correct system call error checking > > On Tue, Jun 17, 2014 at 08:21:29PM +0000, Richardson, Bruce wrote: > > > -----Original Message----- > > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Neil Horman > > > Sent: Tuesday, June 17, 2014 12:04 PM > > > To: dev at dpdk.org > > > Subject: [dpdk-dev] [PATCH] vfio: correct system call error checking > > > > > > Noticed today that ioctl error code return checking was incorrect in some > > > of > the > > > vfio code. ioctl can return a negative value if the system detects an > > > error > > > before the target device/driver can produce a return code. The dpdk vfio > code > > > only checks specfically for the values that it expects, which leaves it > > > open to > > > accepting unexpected error codes as success. For instance, if the vfio > > > layer > > > noted that the iommu driver hadn't finished registering yet, it would > > > return > an > > > -EINVAL error code, but the dpdk would accept that as success, becuase it > > > wasn't > > > 0. > > > > > > Fix this to specifically check for < 0 error codes > > > > > > Signed-off-by: Neil Horman <nhorman at tuxdriver.com> > > > CC: Thomas Monjalon <thomas.monjalon at 6wind.com> > > > --- > > > lib/librte_eal/linuxapp/eal/eal_pci_vfio.c | 8 ++++---- > > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > > > diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > > > b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > > > index 4de6061..65aa8ad 100644 > > > --- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > > > +++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > > > @@ -319,16 +319,16 @@ pci_vfio_get_container_fd(void) > > > > > > /* check VFIO API version */ > > > ret = ioctl(vfio_container_fd, VFIO_GET_API_VERSION); > > > - if (ret != VFIO_API_VERSION) { > > > - RTE_LOG(ERR, EAL, " unknown VFIO API version!\n"); > > > + if ((ret < 0) || (ret != VFIO_API_VERSION)) { > > > + RTE_LOG(ERR, EAL, " unknown VFIO API version! errno > > > = %d\n", errno); > > > close(vfio_container_fd); > > > return -1; > > > } > > > > Not sure how this change improves things, since the existing check will > > already > trigger an error on all values <0. Can you please clarify why you think this > needs > to be changed? > Ah, my bad, the ret < 0 is superfulous, as the != already catches it, but the > log message change is valuable in that it differentiates bad API version > detection from other system errors. I can respin that if you like. > Neil
Perhaps a respin separating out ioctl errors vs version errors might be good, giving different error messages for each case. /Bruce
