Re: PCIe with Designware RC.

[Shlomo Pongratz]

Thank you, see comment inside.

On Sun, Dec 24, 2023 at 1:11 PM BALATON Zoltan <balaton@eik.bme.hu> wrote:
>
> On Sun, 24 Dec 2023, Shlomo Pongratz wrote:
> > Hi,
> > I'm working on a AARCH64 project that uses the designeware
> > (hw/pci-host/designware.c).
> > I've copied the designware initialization from hw/arm/fsl-imx7.c and I
> > hope I've updated the dtsi correctly.
> > After fixing an issue with the iATU windows (see patch
> > https://lists.gnu.org/archive/html/qemu-devel/2023-12/msg02643.html)
> > I've tried to add virtualized NVMe controller.
> > When I added the lines:
> >        -device nvme,serial=deadbeef,drive=nvme0,bus=pcie \  (Or without 
> > bus=)
> >        -drive file=/home/pliops/disk-1.img,if=none,id=nvme1 \
>
> You define drive with if=none,id=nvme1 but have drive=nvme0 in your
> device. You should refer to the drive you want the device to use so I
> think it should either be -device nvme,drive=nvme1 or the if of drive
> should be nvme0.

This was a typo, All are nvme0.

 I don't know how this works for nvme but for CD drives
> for example adding a device would add it without disk and drive defines
> the disk to use. Not sure this makes sense for hard disks or nvme device
> but maybe the command line options don't consider that.
>
> > I could see in QEMU monitor that the NVMe device was preset i.e.
> > (qemu) info pci
> >  Bus  0, device   0, function 0:
> >    PCI bridge: PCI device 16c3:abcd
> >      IRQ 0, pin A
> >      BUS 0.
> >      secondary bus 1.
> >      subordinate bus 255.
> >      IO range [0xf000, 0x0fff]
> >      memory range [0xfff00000, 0x000fffff]
> >      prefetchable memory range [0xfff00000, 0x000fffff]
> >      id ""
> >  Bus  0, device   1, function 0:
> >    Class 0264: PCI device 1b36:0010
> >      PCI subsystem 1af4:1100
> >      IRQ 0, pin A
> >      BAR0: 64 bit memory at 0xffffffffffffffff [0x00003ffe].
> >      id ""
> > However in lspci it was missing
> > # lspci
> > 00:00.0 Class 0604: 16c3:abcd
> >
> > If I used the following command
> >        -drive file=/home/pliops/disk.img,if=none,id=nvme0 \
> >        -device nvme,serial=deadbeef,drive=nvme0,bus=dw-pcie \
>
> Here you correctly define both media and drive so it works as expected.
> There are some shortcuts for -drive with media=disk or media=cdrom and
> if=ide or scsi that don't need a separate drive option as if=none does but
> not sure if that supports nvme. You probably have to check documentation
> or code to find out.
>
> > Then in the monitor I see:
> > (qemu) info pci
> >  Bus  0, device   0, function 0:
> >    PCI bridge: PCI device 16c3:abcd
> >      IRQ 0, pin A
> >      BUS 0.
> >      secondary bus 1.
> >      subordinate bus 255.
> >      IO range [0xf000, 0x0fff]
> >      memory range [0x40000000, 0x401fffff]
> >      prefetchable memory range [0xfff00000, 0x000fffff]
> >      id ""
> >  Bus  1, device   0, function 0:
> >    Class 0264: PCI device 1b36:0010
> >      PCI subsystem 1af4:1100
> >      IRQ 1, pin A
> >      BAR0: 64 bit memory at 0xffffffffffffffff [0x00003ffe].
> >      id ""
> > That is the NVMe is on BUS 1.
> > And in lspci I can now see the device but on bus 1.
> > # lspci
> > 01:00.0 Class 0108: 1b36:0010
> > 00:00.0 Class 0604: 16c3:abcd
> >
> > Is this expected?
> >
> > But the main problem is that during the initialization of the
> > controller registers in BAR0 all the read and writes are actually done
> > into the config space.
>
> I don't know what this is but don't think it's related to the above.
>
> Regards,
> BALATON Zoltan
>
> > Any ideas?
> >
> > Thank you
> > Shlomo Pongratz.
> >
> >