[PATCH] efi_loader: Don't carve out memory reservations too early

[Mark Kettenis]

> Date: Fri, 16 Feb 2024 00:38:25 +0100
> From: Heinrich Schuchardt <xypron.glpk at gmx.de>
> 
> Am 16. Februar 2024 00:25:34 MEZ schrieb Mark Kettenis <kettenis at openbsd.org>:
> >Moving the efi_carve_out_dt_rsv() call in commit 1be415b21b2d
> >("efi_loader: create memory reservations in ACPI case")
> >broke boards that create additional memory reservations in
> >ft_board_setup() since it is now called before those additional
> >memory reservations are made.  This is the case for the rk3588
> >boards and breaks booting OpenBSD on those boards.
> >
> >Move the call back to its original location and add a call in
> >the code path used for ACPI.
> >
> >Fixes: 1be415b21b2d ("efi_loader: create memory reservations in ACPI case")
> >Signed-off-by: Mark Kettenis <kettenis at openbsd.org>
> >---
> > lib/efi_loader/efi_helper.c | 11 +++++++----
> > 1 file changed, 7 insertions(+), 4 deletions(-)
> >
> >diff --git a/lib/efi_loader/efi_helper.c b/lib/efi_loader/efi_helper.c
> >index 5dd9cc876e..58761fae78 100644
> >--- a/lib/efi_loader/efi_helper.c
> >+++ b/lib/efi_loader/efi_helper.c
> >@@ -456,11 +456,11 @@ efi_status_t efi_install_fdt(void *fdt)
> > 		return EFI_LOAD_ERROR;
> > 	}
> > 
> >-	/* Create memory reservations as indicated by the device tree */
> >-	efi_carve_out_dt_rsv(fdt);
> >-
> >-	if (CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE))
> >+	if (CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)) {
> >+		/* Create memory reservations as indicated by the device tree */
> 
> Imagine booting the rk3588 board with ACPI.

I'd rather not, thank you ;)

> Wouldn't we miss creating the ft_board_setup() reservations before
> efi_carve_out_dt_rsv(fdt)?

Yes.  And arguably the these memory reservations should be made way
earlier, at the the time that efi_memory_init() runs.  I think we're
just lucky that efi_allocate_pages() doesn't hand us memory from these
areas in copy_fdt().

Better ideas?


> >+		efi_carve_out_dt_rsv(fdt);
> > 		return EFI_SUCCESS;
> >+	}
> > 
> > 	/* Prepare device tree for payload */
> > 	ret = copy_fdt(&fdt);
> >@@ -474,6 +474,9 @@ efi_status_t efi_install_fdt(void *fdt)
> > 		return EFI_LOAD_ERROR;
> > 	}
> > 
> >+	/* Create memory reservations as indicated by the device tree */
> >+	efi_carve_out_dt_rsv(fdt);
> >+
> > 	efi_try_purge_kaslr_seed(fdt);
> > 
> > 	if (CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL_MEASURE_DTB)) {
>