linux-kernel - Re: [regression] microcode files missing in initramfs imgages from dracut (was Re: [PATCH] x86: Clean up remaining references to CONFIG_MICROCODE

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Date:   Thu, 23 Nov 2023 12:20:13 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Antonio Alvarez Feijoo <antonio.feijoo@...e.com>
Cc:     Linux regressions mailing list <regressions@...ts.linux.dev>,
        lukas.bulwahn@...il.com, dave.hansen@...ux.intel.com,
        hpa@...or.com, kernel-janitors@...r.kernel.org,
        linux-kernel@...r.kernel.org, mingo@...hat.com, tglx@...utronix.de,
        x86@...nel.org
Subject: Re: [regression] microcode files missing in initramfs imgages from
 dracut (was Re: [PATCH] x86: Clean up remaining references to
 CONFIG_MICROCODE_AMD)

Adding Antonio who did that last fix to dracut:

6c80408c8644 ("fix(dracut.sh): remove microcode check based on CONFIG_MICROCODE_[AMD|INTEL]")

On Wed, Nov 22, 2023 at 01:08:41PM -0800, Linus Torvalds wrote:
> There are dracut command lines, like "--early-microcode" and
> "--no-early-microcode", so people who really want to save space could
> just force it that way. Doing the CONFIG_xyz check seems broken.
> 
> But that's for the dracut people to worry about.

Yeah, I guess something like this below.

Antonio, how about something like the totally untested thing below?

dracut would simply always build in microcode - this is the majority of
the setups anyway - and people who want to save space, do:

--no-early-microcode

?

---
diff --git a/dracut.sh b/dracut.sh
index 3b292910f324..c0a88b083f8e 100755
--- a/dracut.sh
+++ b/dracut.sh
@@ -1561,20 +1561,16 @@ fi
 
 if [[ $early_microcode == yes ]]; then
     if [[ $hostonly ]]; then
-        if [[ $(get_cpu_vendor) == "AMD" || $(get_cpu_vendor) == "Intel" ]]; then
-            check_kernel_config CONFIG_MICROCODE || unset early_microcode
-        else
+        if [[ $(get_cpu_vendor) != "AMD" && $(get_cpu_vendor) != "Intel" ]]; then
             unset early_microcode
         fi
-    else
-        ! check_kernel_config CONFIG_MICROCODE \
-            && unset early_microcode
     fi
+
     # Do not complain on non-x86 architectures as it makes no sense
     case "${DRACUT_ARCH:-$(uname -m)}" in
         x86_64 | i?86)
             [[ $early_microcode != yes ]] \
-                && dwarn "Disabling early microcode, because kernel does not support it. CONFIG_MICROCODE!=y"
+                && dwarn "Disabling early microcode, unsupported configuration"
             ;;
         *) ;;
     esac

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette