Re: [Qemu-devel] [PATCH v4 4/5] acpi: arm: add fw_cfg device node to dsdt

[Gabriel L. Somlo]

On Tue, Sep 29, 2015 at 12:40:16PM +0200, Laszlo Ersek wrote:
> On 09/27/15 23:29, Gabriel L. Somlo wrote:
> > Add a fw_cfg device node to the ACPI DSDT. This is mostly
> > informational, as the authoritative fw_cfg MMIO region(s)
> > are listed in the Device Tree. However, since we are building
> > ACPI tables, we might as well be thorough while at it...
> > 
> > Signed-off-by: Gabriel Somlo <address@hidden>
> > ---
> >  hw/arm/virt-acpi-build.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> > 
> > diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> > index 1aaff1f..f314132 100644
> > --- a/hw/arm/virt-acpi-build.c
> > +++ b/hw/arm/virt-acpi-build.c
> > @@ -110,6 +110,20 @@ static void acpi_dsdt_add_rtc(Aml *scope, const 
> > MemMapEntry *rtc_memmap,
> >      aml_append(scope, dev);
> >  }
> >  
> > +static void acpi_dsdt_add_fw_cfg(Aml *scope, const MemMapEntry 
> > *fw_cfg_memmap)
> > +{
> > +    Aml *dev = aml_device("FWCF");
> > +    aml_append(dev, aml_name_decl("_HID", aml_string("QEMU0002")));
> > +    /* device present, functioning, decoding, not shown in UI */
> > +    aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
> > +
> > +    Aml *crs = aml_resource_template();
> > +    aml_append(crs, aml_memory32_fixed(fw_cfg_memmap->base,
> > +                                       fw_cfg_memmap->size, 
> > AML_READ_WRITE));
> > +    aml_append(dev, aml_name_decl("_CRS", crs));
> > +    aml_append(scope, dev);
> > +}
> > +
> >  static void acpi_dsdt_add_flash(Aml *scope, const MemMapEntry 
> > *flash_memmap)
> >  {
> >      Aml *dev, *crs;
> > @@ -529,6 +543,7 @@ build_dsdt(GArray *table_data, GArray *linker, 
> > VirtGuestInfo *guest_info)
> >                         (irqmap[VIRT_UART] + ARM_SPI_BASE));
> >      acpi_dsdt_add_rtc(scope, &memmap[VIRT_RTC],
> >                        (irqmap[VIRT_RTC] + ARM_SPI_BASE));
> > +    acpi_dsdt_add_fw_cfg(scope, &memmap[VIRT_FW_CFG]);
> >      acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]);
> >      acpi_dsdt_add_virtio(scope, &memmap[VIRT_MMIO],
> >                      (irqmap[VIRT_MMIO] + ARM_SPI_BASE), 
> > NUM_VIRTIO_TRANSPORTS);
> > 
> 
> Looks sane to me.
> 
> Did you test this with an aarch64 Linux guest (acpidump -b; iasl -d; cat
> /proc/iomem?) I can help with that, if you'd like.

I have a F22 arm setup generated by virt-builder, which I start using:

bin/qemu-system-arm -M virt,accel=tcg -cpu cortex-a15 \
  -kernel ./ArmVirtBuilder/vmlinuz-4.0.4-301.fc22.armv7hl+lpae \
  -initrd ./ArmVirtBuilder/initramfs-4.0.4-301.fc22.armv7hl+lpae.img \
  -append "console=ttyAMA0 root=/dev/vda3 ro" \
  -device virtio-blk-device,drive=hd0 \
  -drive id=hd0,if=none,snapshot=on,file=./ArmVirtBuilder/fedora-22.img \
  -device virtio-net-device,netdev=usernet \
  -netdev user,id=usernet \
  -monitor stdio

I used it to successfully test my (rude, mmio-poking) kernel sysfs
driver, but somehow it doesn't seem to pay any attention to ACPI.

/proc/iomem looks the same before and after my patch, so no entry for
fw_cfg once I add it to the ssdt host-side.

'acpidump -b' says "Could not get ACPI tables, AE_NOT_FOUND". There's
no /proc/acpi or /sys/firmware/acpi...

Although ACPI tables do get placed in fw_cfg (after loading my linux
kernel driver I can see the "/etc/acpi/tables" blob). And if I 'iasl -d'
that, I can see the FWCF node in the ssdt :)

In the short run, if you can test on your end that'd be great. Also,
if you have any idea why I'm not seeing ACPI at all (missing kernel
module, or wrong firmware, or ???) please let me know...

Thanks,
--Gabriel

> 
> Reviewed-by: Laszlo Ersek <address@hidden>
> 
> Thanks
> Laszlo