Re: [PULL 13/18] hw/core: implement a guest-loader to support static hypervisor guests

[Philippe Mathieu-Daudé]

On 3/15/21 5:16 PM, Christian Borntraeger wrote:
> 
> 
> On 08.03.21 14:50, Alex Bennée wrote:
>> Hypervisors, especially type-1 ones, need the firmware/bootcode to put
>> their initial guest somewhere in memory and pass the information to it
>> via platform data. The guest-loader is modelled after the generic
>> loader for exactly this sort of purpose:
>>
>>    $QEMU $ARGS  -kernel ~/xen.git/xen/xen \
>>      -append "dom0_mem=1G,max:1G loglvl=all guest_loglvl=all" \
>>      -device
>> guest-loader,addr=0x42000000,kernel=Image,bootargs="root=/dev/sda2 ro
>> console=hvc0 earlyprintk=xen" \
>>      -device guest-loader,addr=0x47000000,initrd=rootfs.cpio
>>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
>> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> Message-Id: <20210303173642.3805-5-alex.bennee@linaro.org>
>>
> 
> This now results in
> 
>     /usr/bin/ld: libcommon.fa.p/hw_core_guest-loader.c.o: in function
> `loader_insert_platform_data':
>     build/../hw/core/guest-loader.c:56: undefined reference to
> `qemu_fdt_add_subnode'
>     /usr/bin/ld: build/../hw/core/guest-loader.c:57: undefined reference
> to `qemu_fdt_setprop'
>     /usr/bin/ld: build/../hw/core/guest-loader.c:61: undefined reference
> to `qemu_fdt_setprop_string_array'
>     /usr/bin/ld: build/../hw/core/guest-loader.c:68: undefined reference
> to `qemu_fdt_setprop_string'
>     /usr/bin/ld: build/../hw/core/guest-loader.c:74: undefined reference
> to `qemu_fdt_setprop_string_array'
>     collect2: error: ld returned 1 exit status
>     ninja: build stopped: subcommand failed.
> 
> when building s390-softmmu on s390 with  --disable-fdt, which was in my
> build script.
>

Oops. Quick fix:

-- >8 --
diff --git a/hw/core/meson.build b/hw/core/meson.build
index 9cd72edf513..5827996206e 100644
--- a/hw/core/meson.build
+++ b/hw/core/meson.build
@@ -37,7 +37,7 @@
   'clock-vmstate.c',
 ))

-softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('guest-loader.c'))
+softmmu_ss.add(when: ['CONFIG_TCG', fdt], if_true: files('guest-loader.c'))

 specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: files(
   'machine-qmp-cmds.c',

---

But better is a Kconfig entry to be able to deselect this
device.