On Mon, Aug 24, 2020 at 11:53:44PM +0300, Dmitry Kozlyuk wrote: > On Thu, 20 Aug 2020 15:23:55 -0700, Narcisa Ana Maria Vasile wrote: > > From: Narcisa Vasile <navas...@microsoft.com> > > > > The Windows NetUIO kernel driver allows the DPDK userspace > > application to directly access the hardware. > > > > Cc: Harini Ramakrishnan <harini.ramakrish...@microsoft.com> > > Cc: Omar Cardona <ocard...@microsoft.com> > > Signed-off-by: Narcisa Vasile <navas...@microsoft.com> > > --- > > Major questions: > > 1. Does NetUIO still need to allocate and map a contiguous memory segment > now, when DPDK has user-mode memory management? > > 2. IOCTLs require to specify PCI address on each call. This is very > inconvenient for DPDK consumers and also seems to serve no purpose. > > 3. There is a need to document driver's design, preferably in commit message, > specifically: > > 3.1) DMA remapping capability in INF (AFAIK, vendors are notified); > 3.2) manual BAR probing instead of using resource lists; > 3.3) reason to use EvtIoInCallerContext and IO queues; > 3.4) IOCTL format. > > Also, I agree with everything Ranjit has noted already. > > General suggestions to cleanup the code a bit. We can do it later if you > wish. This also brings up the question, which code style should Windows > kernel code for DPDK follow (off-topic for now). > > * Remove boilerplate code and comments generated by VS wizard. > * Place `_Use_decl_annotations` on definitions to make them simpler. > * Limit line length, try using shorted variable names (e.g. > "netuio_contextdata" may be "context" or "ctx" with no loss). >
Thank you for you thorough review! > More specific comments inline. > > [snip] > > +[Strings] > > +SPSVCINST_ASSOCSERVICE= 0x00000002 > > +Intel = "Intel" > > +Broadcom = "Broadcom Corporation" > > IHVs are supposed to add this gradually. > Thanks! I've modified the inf to remove all the vendor specific strings but left the sections to avoid errors when generating the binary. > > +ClassName = "Windows UIO" > > +DiskName = "DPDK netUIO Installation Disk" > > +netuio.DeviceDesc = "netuio Device" > > +netuio.SVCDESC = "netuio Service" > > + > > + // Build symbolic link name as <netuio_symbolic_link>_BDF > > (bus/device/func) > > + CHAR symbolic_link[64] = { 0 }; > > + sprintf_s(symbolic_link, sizeof(symbolic_link), "%s_%04d%02d%02d", > > + NETUIO_DEVICE_SYMBOLIC_LINK_ANSI, > > netuio_contextdata->addr.bus_num, > > + netuio_contextdata->addr.dev_num, > > netuio_contextdata->addr.func_num); > > + > > + ANSI_STRING ansi_symbolic_link; > > + RtlInitAnsiString(&ansi_symbolic_link, symbolic_link); > > + > > + status = RtlAnsiStringToUnicodeString(&netuio_symbolic_link, > > &ansi_symbolic_link, TRUE); > > + if (!NT_SUCCESS(status)) > > + return status; > > Why not use Unicode directly? > It looks like either way, a cast will be needed (for example, if I use wchar for symbolic_link and then RtlInitUnicodeString()). I've left it as is, but let me know if there's an elegant solution that I didn't see. > > + > > + status = WdfDeviceCreateSymbolicLink(device, &netuio_symbolic_link); > > + > > + RtlFreeUnicodeString(&netuio_symbolic_link); > > + > > + return status;