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

[Ard Biesheuvel]

On 29 September 2015 at 20:26, Gabriel L. Somlo <address@hidden> wrote:
> 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
>

Note that you are booting 32-bit ARM here, which does not support ACPI nor UEFI.
(UEFI is work in progress, so you can try my ARM 32-bit UEFI tree if
you need to: 
https://git.linaro.org/people/ard.biesheuvel/linux-arm.git/shortlog/refs/heads/arm-efi-combined-v2)

You will need to create an arm64 / AArch64 setup and boot the virt
model using 'qemu-system-aarch64 -M virt -cpu cortex-a57 ...' instead.
In either case, as Laszlo pointed out, you need UEFI firmware in QEMU
as well.

-- 
Ard.