[pve-devel] [PATCH pve-kernel] cherry-pick fix for new amd64 ucode

[Stoiko Ivanov]

The latest amd64-microcode package in sid [0] (which probably will
eventually make it to bookworm-security) has a change that requires
the added patch to work properly.

The changelog-entry refers to stable k.o branches only - but a quick
look through the linux-firmware.git log identifies:
`f2eb058afc57348cde66852272d6bf11da1eef8f` as relevant commit, which
refers (as NOTE in the patch) to:
a32b0f0db3f3 ("x86/microcode/AMD: Load late on both threads too")
which applies cleanly (although I cherry-picked the patch from the
6.1.y stable branch to have the original commit in the commit message).

quickly tested compiling and booting the result in a VM (however w/o
a fitting CPU (Epyc Genoa or Bergamo) it should cause a change)

reported in our Enterprise Support as potential culprit for one
thread from 128 being reported as offline in `lscpu`

[0] https://metadata.ftp-master.debian.org/changelogs//non-free-firmware/a/amd64-microcode/amd64-microcode_3.20230808.1.1_changelog

Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
---
 ...de-AMD-Load-late-on-both-threads-too.patch | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 patches/kernel/0018-x86-microcode-AMD-Load-late-on-both-threads-too.patch

diff --git a/patches/kernel/0018-x86-microcode-AMD-Load-late-on-both-threads-too.patch b/patches/kernel/0018-x86-microcode-AMD-Load-late-on-both-threads-too.patch
new file mode 100644
index 000000000000..7f62eac2efd1
--- /dev/null
+++ b/patches/kernel/0018-x86-microcode-AMD-Load-late-on-both-threads-too.patch
@@ -0,0 +1,32 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Borislav Petkov (AMD)" <bp at alien8.de>
+Date: Tue, 2 May 2023 19:53:50 +0200
+Subject: [PATCH] x86/microcode/AMD: Load late on both threads too
+
+commit a32b0f0db3f396f1c9be2fe621e77c09ec3d8e7d upstream.
+
+Do the same as early loading - load on both threads.
+
+Signed-off-by: Borislav Petkov (AMD) <bp at alien8.de>
+Cc: <stable at kernel.org>
+Link: https://lore.kernel.org/r/20230605141332.25948-1-bp@alien8.de
+Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
+(cherry picked from commit 94a69d6999419cd21365111b4493070182712299)
+Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
+---
+ arch/x86/kernel/cpu/microcode/amd.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
+index ac59783e6e9f..53f21fb431c0 100644
+--- a/arch/x86/kernel/cpu/microcode/amd.c
++++ b/arch/x86/kernel/cpu/microcode/amd.c
+@@ -705,7 +705,7 @@ static enum ucode_state apply_microcode_amd(int cpu)
+ 	rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
+ 
+ 	/* need to apply patch? */
+-	if (rev >= mc_amd->hdr.patch_id) {
++	if (rev > mc_amd->hdr.patch_id) {
+ 		ret = UCODE_OK;
+ 		goto out;
+ 	}
-- 
2.39.2