linux-kernel - RE: [PATCH v2] arm64: efi: Force the use of SetVirtualAddressMap() on eMAG and Altra Max machines

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Date:   Thu, 9 Feb 2023 04:26:16 +0000
From:   Justin He <Justin.He@....com>
To:     Darren Hart <darren@...amperecomputing.com>,
        LKML <linux-kernel@...r.kernel.org>
CC:     "stable@...r.kernel.org" <stable@...r.kernel.org>,
        "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
        Alexandru Elisei <alexandru.elisei@...il.com>,
        Huacai Chen <chenhuacai@...nel.org>,
        "Jason A. Donenfeld" <Jason@...c4.com>,
        Ard Biesheuvel <ardb@...nel.org>, nd <nd@....com>
Subject: RE: [PATCH v2] arm64: efi: Force the use of SetVirtualAddressMap() on
 eMAG and Altra Max machines



> -----Original Message-----
> From: Darren Hart <darren@...amperecomputing.com>
> Sent: Thursday, February 9, 2023 8:28 AM
> To: LKML <linux-kernel@...r.kernel.org>
> Cc: stable@...r.kernel.org; linux-efi@...r.kernel.org; Alexandru Elisei
> <alexandru.elisei@...il.com>; Justin He <Justin.He@....com>; Huacai Chen
> <chenhuacai@...nel.org>; Jason A. Donenfeld <Jason@...c4.com>; Ard
> Biesheuvel <ardb@...nel.org>
> Subject: [PATCH v2] arm64: efi: Force the use of SetVirtualAddressMap() on
> eMAG and Altra Max machines
> 
> Commit 550b33cfd445 ("arm64: efi: Force the use of SetVirtualAddressMap()
> on Altra machines") identifies the Altra family via the family field in the type#1
> SMBIOS record. eMAG and Altra Max machines are similarly affected but not
> detected with the strict strcmp test.
> 
> The type1_family smbios string is not an entirely reliable means of identifying
> systems with this issue as OEMs can, and do, use their own strings for these
> fields. However, until we have a better solution, capture the bulk of these
> systems by adding strcmp matching for "eMAG"
> and "Altra Max".
> 
> Fixes: 550b33cfd445 ("arm64: efi: Force the use of SetVirtualAddressMap() on
> Altra machines")
> Cc: <stable@...r.kernel.org> # 6.1.x
> Cc: <linux-efi@...r.kernel.org>
> Cc: Alexandru Elisei <alexandru.elisei@...il.com>
> Cc: Justin He <Justin.He@....com>
> Cc: Huacai Chen <chenhuacai@...nel.org>
> Cc: "Jason A. Donenfeld" <Jason@...c4.com>
> Cc: Ard Biesheuvel <ardb@...nel.org>
> Signed-off-by: Darren Hart <darren@...amperecomputing.com>
Tested-by: justin.he@....com
> ---
> V1 -> V2: include eMAG
> 
>  drivers/firmware/efi/libstub/arm64.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/firmware/efi/libstub/arm64.c
> b/drivers/firmware/efi/libstub/arm64.c
> index ff2d18c42ee7..4501652e11ab 100644
> --- a/drivers/firmware/efi/libstub/arm64.c
> +++ b/drivers/firmware/efi/libstub/arm64.c
> @@ -19,10 +19,13 @@ static bool system_needs_vamap(void)
>  	const u8 *type1_family = efi_get_smbios_string(1, family);
> 
>  	/*
> -	 * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap()
> -	 * has not been called prior.
> +	 * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if
> +	 * SetVirtualAddressMap() has not been called prior.
>  	 */
> -	if (!type1_family || strcmp(type1_family, "Altra"))
> +	if (!type1_family || (
> +	    strcmp(type1_family, "eMAG") &&
> +	    strcmp(type1_family, "Altra") &&
> +	    strcmp(type1_family, "Altra Max")))
In terms of resolving the boot hang issue, it looks good to me. And I've verified the
"eMAG" part check.
So please feel free to add:
Tested-by: Justin He <justin.he@....com>

But I have some other concerns:
1. On an Altra server, the type1_family returns "Server". I don't know whether it
is a smbios or server firmware bug.
2. On an eMAG server, I once successfully run efibootmgr -t 10 to call the
Set_variable rts, but currently I always met the error, even with above patch:
# efibootmgr -t 9; efibootmgr -t 5;
Could not set Timeout: Input/output error
Could not set Timeout: Input/output error

Meanwhile, on the Altra server, it works:
# efibootmgr -t 9; efibootmgr -t 5;
BootCurrent: 0007
Timeout: 9 seconds
BootOrder: 0007,0005,0006,0001
Boot0001* UEFI: Built-in EFI Shell
Boot0005* UEFI: PXE IPv4 Intel(R) I350 Gigabit Network Connection
Boot0006* UEFI: PXE IPv4 Intel(R) I350 Gigabit Network Connection
Boot0007* ubuntu
BootCurrent: 0007
Timeout: 5 seconds
BootOrder: 0007,0005,0006,0001
Boot0001* UEFI: Built-in EFI Shell
Boot0005* UEFI: PXE IPv4 Intel(R) I350 Gigabit Network Connection
Boot0006* UEFI: PXE IPv4 Intel(R) I350 Gigabit Network Connection
Boot0007* ubuntu



--
Cheers,
Justin (Jia He)