RISC-V UEFI/ACPI on QEMU regression?

[Ilias Apalodimas]

On Wed, 2 Apr 2025 at 17:26, Ilias Apalodimas
<ilias.apalodimas at linaro.org> wrote:
>
> Hey Bjorn
>
> Long time, hope all is well!
>
> On Wed, 2 Apr 2025 at 16:22, Björn Töpel <bjorn at kernel.org> wrote:
> >
> > Hi,
> >
> > I think I got a regression from commit 53d5a221632e ("emulation: Use
> > bloblist to hold tables"), and v2024.10 for
> > qemu-riscv64_smode_defconfig + acpi.config booting Linux with UEFI.
> >
> > TL;DR: It seems like the RSDP is placed in the wrong EFI memory map
> > type (it should be "ACPI Reclaim").
> >
> > I might also be misunderstanding what config fragments should be
> > used -- I'm out in the weeds here! ;-)
> >
> > When I was using v2024.10, ACPI RSDP was in ACPI Reclaim memory. All
> > good, and e.g. a kexec would properly work. However, when using u-boot
> > with commit 53d5a221632e ("emulation: Use bloblist to hold tables") I
> > get the following when booting, and then kexec:
> >
> > First kernel:
> > [    0.000000] ACPI: Early table checksum verification disabled
> >                                                   [    0.000000] ACPI:
> > RSDP 0x000000047EED3000 000024 (v02 BOCHS )
> > Kexec kernel:
> > [    0.000000] ACPI: Early table checksum verification disabled
> > [    0.000000] ACPI:      0x000000047EED3000 000000 (v00
> >   00000000      00000000)
> > [    0.000000] Oops - load access fault [#1]
> >
> > RSDP reside in:
> > [    0.000000] efi:   0x00047ded1000-0x00047eee3fff [Boot Code   |   |
> >  |  |  |  |  |  |  |  |  |   |WB|  |  |  ]
> >
> > (Boot Code vs ACPI Reclaimed)
> >
> > Now to get qemu-riscv64_smode_defconfig + acpi.config to build
> > post-2024.10, I needed to add the following fragments:
> >
> >   CONFIG_BLOBLIST=y
> >   CONFIG_BLOBLIST_ALLOC=y
> >   CONFIG_BLOBLIST_SIZE_RELOC=0x20000
> >
> > which is really just a "make the build not complain", guessing game
> > from my side.
> >
> > My guess would be that it's related to the change in
> > evt_write_acpi_tables(), where:
> >
> > -    ptr = memalign(SZ_4K, SZ_64K);
> > +    ptr = bloblist_add(BLOBLISTT_ACPI_TABLES, SZ_64K, 12);
> >
> > is done.
> >
> > Is my config fragment broken, or is this a proper regression?
>
> I think it's a regression and I think what breaks it is commit cfb4aa2a754ed1
>
> Can you apply the diff below and see if it fixes it for you?
>
> diff --git a/lib/efi_loader/efi_acpi.c b/lib/efi_loader/efi_acpi.c
> index 4422b31ac6a7..afa5eee85484 100644
> --- a/lib/efi_loader/efi_acpi.c
> +++ b/lib/efi_loader/efi_acpi.c
> @@ -34,8 +34,8 @@ efi_status_t efi_acpi_register(void)
>          * add_u_boot_and_runtime(). At some point that function could create a
>          * more detailed map.
>          */
> -       if (IS_ENABLED(CONFIG_BLOBLIST_TABLES))
> -               return EFI_SUCCESS;
> +       //if (IS_ENABLED(CONFIG_BLOBLIST_TABLES))
> +               ////return EFI_SUCCESS;
>
>         /* Mark space used for tables */
>         start = ALIGN_DOWN(gd->arch.table_start, EFI_PAGE_MASK);
>
> Simon, why that PR got sent with no ACKs from any of the EFI maintainers?

And please fix whatever tooling you use to CC the proper maintainers
next time [0] as I don't see my name in the CC list

[0] https://lore.kernel.org/u-boot/20250111000029.245022-27-sjg@chromium.org/

>
> Thanks
> /Ilias
> >
> >
> > Thanks!
> > Björn