2017-02-13 01:16, Zhang, Qi Z: > Hi Thomas: > > From: Thomas Monjalon [mailto:thomas.monja...@6wind.com] > > 2017-02-09 14:59, Qi Zhang: > > > The max number of interrupt request is possible be changed after > > > rte_intr_callback_register, so in get_max_intr, we need to check if > > > nessesary to update the max_intr. > > > > So you are using rte_intr_enable() to update the max_intr field in the case > > of > > VFIO_MSIX. > > What about MSI, INTX and UIO cases? > > My thought is, even without my fix, VFIO_MSIX is already the only case that > try to modify max_intr field > In get_max_intr, we have: > if (!src->intr_handle.max_intr) > src->intr_handle.max_intr = 1; > else if (src->intr_handle.max_intr > RTE_MAX_RXTX_INTR_VEC_ID) > src->intr_handle.max_intr > = RTE_MAX_RXTX_INTR_VEC_ID + 1; > So my patch just follow this and fix some problem. > > Another option is I can use a local variable that assigned by max_intr with > boundary check, so get_max_intr can be totally removed and max_intr in > intr_source will not be modified. > > To me both fix are not perfect, I think the problem is in > rte_intr_callback_register we just save a copy of the pci_dev->intr_handle > but not the address point, so we are missing some mechanism to sync them. > But since we have tight schedule on the 17.02 release and this issue does > cause some example code can't work, so we need to a fix it first, we may > consider improve the mechanism later. > > Thanks > Qi
Applied with this title: "vfio: fix maximum number of interrupt for MSI-X" Please check how to document this behaviour and make it consistent with other types of interrupts.
