This is a note to let you know that I've just added the patch titled
x86/CPU/AMD: Move the DIV0 bug detection to the Zen1 init function
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-cpu-amd-move-the-div0-bug-detection-to-the-zen1-.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c8f64e23c80be972a2487a650a389285357cf77e
Author: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Date: Wed Nov 1 12:52:01 2023 +0100
x86/CPU/AMD: Move the DIV0 bug detection to the Zen1 init function
[ Upstream commit bfff3c6692ce64fa9d86eb829d18229c307a0855 ]
No functional changes.
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Reviewed-by: Nikolay Borisov <nik.borisov@xxxxxxxx>
Link: http://lore.kernel.org/r/20231120104152.13740-9-bp@xxxxxxxxx
Stable-dep-of: c7b2edd8377b ("perf/x86/amd/core: Update and fix stalled-cycles-* events for Zen 2 and later")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index d8a0dc01a7db2..f4373530c7de0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -70,10 +70,6 @@ static const int amd_erratum_383[] =
static const int amd_erratum_1054[] =
AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0, 0, 0x2f, 0xf));
-static const int amd_div0[] =
- AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0x00, 0x0, 0x2f, 0xf),
- AMD_MODEL_RANGE(0x17, 0x50, 0x0, 0x5f, 0xf));
-
static const int amd_erratum_1485[] =
AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x19, 0x10, 0x0, 0x1f, 0xf),
AMD_MODEL_RANGE(0x19, 0x60, 0x0, 0xaf, 0xf));
@@ -1043,6 +1039,9 @@ static void init_amd_zen(struct cpuinfo_x86 *c)
if (c->x86 == 0x19 && !cpu_has(c, X86_FEATURE_BTC_NO))
set_cpu_cap(c, X86_FEATURE_BTC_NO);
}
+
+ pr_notice_once("AMD Zen1 DIV0 bug detected. Disable SMT for full protection.\n");
+ setup_force_cpu_bug(X86_BUG_DIV0);
}
static bool cpu_has_zenbleed_microcode(void)
@@ -1211,11 +1210,6 @@ static void init_amd(struct cpuinfo_x86 *c)
cpu_has(c, X86_FEATURE_AUTOIBRS))
WARN_ON_ONCE(msr_set_bit(MSR_EFER, _EFER_AUTOIBRS));
- if (cpu_has_amd_erratum(c, amd_div0)) {
- pr_notice_once("AMD Zen1 DIV0 bug detected. Disable SMT for full protection.\n");
- setup_force_cpu_bug(X86_BUG_DIV0);
- }
-
if (!cpu_has(c, X86_FEATURE_HYPERVISOR) &&
cpu_has_amd_erratum(c, amd_erratum_1485))
msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT);
