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Subject[PATCH 5.15 064/128] x86/boot: Move EFI range reservation after cmdline parsing
From: Mike Rapoport <>

commit 2f5b3514c33fecad4003ce0f22ca9691492d310b upstream.

The memory reservation in arch/x86/platform/efi/efi.c depends on at
least two command line parameters. Put it back later in the boot process
and move efi_memblock_x86_reserve_range() out of early_memory_reserve().

An attempt to fix this was done in

8d48bf8206f7 ("x86/boot: Pull up cmdline preparation and early param parsing")

but that caused other troubles so it got reverted.

The bug this is addressing is:

Dan reports that Anjaneya Chagam can no longer use the efi=nosoftreserve
kernel command line parameter to suppress "soft reservation" behavior.

This is due to the fact that the following call-chain happens at boot:

|-> efi_memblock_x86_reserve_range
|-> efi_fake_memmap_early

which does

if (!efi_soft_reserve_enabled())

and that would have set EFI_MEM_NO_SOFT_RESERVE after having parsed

However, parse_early_param() gets called *after* it, leading to the boot
cmdline not being taken into account.

See also

[ bp: Turn into a proper patch. ]

Signed-off-by: Mike Rapoport <>
Signed-off-by: Borislav Petkov <>
Signed-off-by: Greg Kroah-Hartman <>
arch/x86/kernel/setup.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -713,9 +713,6 @@ static void __init early_reserve_memory(


- if (efi_enabled(EFI_BOOT))
- efi_memblock_x86_reserve_range();

@@ -890,6 +887,9 @@ void __init setup_arch(char **cmdline_p)


+ if (efi_enabled(EFI_BOOT))
+ efi_memblock_x86_reserve_range();
* Memory used by the kernel cannot be hot-removed because Linux

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