On Mon, Sep 20, 2021 at 02:04:21PM +0200, Juergen Gross wrote:
> Commit a799c2bd29d19c565 ("x86/setup: Consolidate early memory
> reservations") introduced early_reserve_memory() to do all needed
> initial memblock_reserve() calls in one function. Unfortunately the
> call of early_reserve_memory() is done too late for Xen dom0, as in
> some cases a Xen hook called by e820__memory_setup() will need those
> memory reservations to have happened already.
>
> Move the call of early_reserve_memory() before the call of
> e820__memory_setup() in order to avoid such problems.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: a799c2bd29d19c565 ("x86/setup: Consolidate early memory reservations")
> Reported-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
I had issues on an AMD Ryzen 3 4300G based system with v1. v2 does not
trigger any boot issues on that same machine or an Intel i5-4210U based
system that I also test with.
Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> ---
> V2:
> - update comment (Jan Beulich, Boris Petkov)
> - move call down in setup_arch() (Mike Galbraith)
> ---
> arch/x86/kernel/setup.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 79f164141116..40ed44ead063 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -830,6 +830,20 @@ void __init setup_arch(char **cmdline_p)
>
> x86_init.oem.arch_setup();
>
> + /*
> + * Do some memory reservations *before* memory is added to memblock, so
> + * memblock allocations won't overwrite it.
> + *
> + * After this point, everything still needed from the boot loader or
> + * firmware or kernel text should be early reserved or marked not RAM in
> + * e820. All other memory is free game.
> + *
> + * This call needs to happen before e820__memory_setup() which calls the
> + * xen_memory_setup() on Xen dom0 which relies on the fact that those
> + * early reservations have happened already.
> + */
> + early_reserve_memory();
> +
> iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
> e820__memory_setup();
> parse_setup_data();
> @@ -876,18 +890,6 @@ void __init setup_arch(char **cmdline_p)
>
> parse_early_param();
>
> - /*
> - * Do some memory reservations *before* memory is added to
> - * memblock, so memblock allocations won't overwrite it.
> - * Do it after early param, so we could get (unlikely) panic from
> - * serial.
> - *
> - * After this point everything still needed from the boot loader or
> - * firmware or kernel text should be early reserved or marked not
> - * RAM in e820. All other memory is free game.
> - */
> - early_reserve_memory();
> -
> #ifdef CONFIG_MEMORY_HOTPLUG
> /*
> * Memory used by the kernel cannot be hot-removed because Linux
> --
> 2.26.2
>
>
