> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Stephen > Hemminger > Sent: Wednesday, December 9, 2015 5:56 PM > To: dev at dpdk.org > Subject: [dpdk-dev] [PATCH] vfio: support iommu group zero > > The current implementation of VFIO will not with the new no-IOMMU mode > in 4.4 kernel. The original code assumed that IOMMU group zero would > never be used. Group numbers are assigned starting at zero, and up until > now the group numbers came from the hardware which is likely to use group > 0 for system devices that are not used with DPDK. > > The fix is to allow 0 as a valid group and rearrange code to split the return > value from the group value. > > Signed-off-by: Stephen Hemminger <stephen at networkplumber.org> > --- > Why was this ignored? It was originally sent on 26 Oct 15 back when IOMMU > discussion was lively. > > lib/librte_eal/linuxapp/eal/eal_pci_vfio.c | 22 +++++++++++----------- > 1 file changed, 11 insertions(+), 11 deletions(-) > > diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > index 0e6c48a..74f91ba 100644 > --- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > +++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c > @@ -499,14 +499,15 @@ pci_vfio_get_group_fd(int iommu_group_no) } > > /* parse IOMMU group number for a PCI device > - * returns -1 for errors, 0 for non-existent group */ > + * returns 1 on success, -1 for errors, 0 for non-existent group */ > static int > -pci_vfio_get_group_no(const char *pci_addr) > +pci_vfio_get_group_no(const char *pci_addr, int *iommu_group_no) > { > char linkname[PATH_MAX]; > char filename[PATH_MAX]; > char *tok[16], *group_tok, *end; > - int ret, iommu_group_no; > + int ret; > > memset(linkname, 0, sizeof(linkname)); > memset(filename, 0, sizeof(filename)); @@ -533,13 +534,13 @@ > pci_vfio_get_group_no(const char *pci_addr) > errno = 0; > group_tok = tok[ret - 1]; > end = group_tok; > - iommu_group_no = strtol(group_tok, &end, 10); > + *iommu_group_no = strtol(group_tok, &end, 10); > if ((end != group_tok && *end != '\0') || errno != 0) { > RTE_LOG(ERR, EAL, " %s error parsing IOMMU number!\n", > pci_addr); > return -1; > } > > - return iommu_group_no; > + return 1; > } > > static void > @@ -581,16 +582,15 @@ pci_vfio_map_resource(struct rte_pci_device > *dev) > loc->domain, loc->bus, loc->devid, loc->function); > > /* get group number */ > - iommu_group_no = pci_vfio_get_group_no(pci_addr); > - > - /* if 0, group doesn't exist */ > - if (iommu_group_no == 0) { > + ret = pci_vfio_get_group_no(pci_addr, &iommu_group_no); > + if (ret == 0) { > RTE_LOG(WARNING, EAL, " %s not managed by VFIO driver, > skipping\n", > - pci_addr); > + pci_addr); > return 1; > } > + > /* if negative, something failed */ > - else if (iommu_group_no < 0) > + if (ret < 0) > return -1; > > /* get the actual group fd */ > -- > 2.1.4
Sorry, slipped through the cracks somehow. I see no obvious issues with the patch, however I've never encountered a group 0 while testing VFIO. As per Alex, that would be more used in the no-iommu scenario, and this break doesn't appear to affect anything else even without no-iommu functionality, so... Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
