[PATCH 6.6] x86/mm: Don't disable PCID when INVLPG has been fixed by microcode - Linux-stable-mirror

7 Mar 2025

From: Xi Ruoyao xry111@xry111.site
commit f24f669d03f884a6ef95cca84317d0f329e93961 upstream.
Per the "Processor Specification Update" documentations referred by
the intel-microcode-20240312 release note, this microcode release has
fixed the issue for all affected models.
So don't disable PCID if the microcode is new enough.  The precise
minimum microcode revision fixing the issue was provided by Pawan
Intel.
[ dhansen: comment and changelog tweaks ]
[ pawan: backported to 6.6 ]
Signed-off-by: Xi Ruoyao xry111@xry111.site
Signed-off-by: Dave Hansen dave.hansen@linux.intel.com
Acked-by: Pawan Gupta pawan.kumar.gupta@linux.intel.com
Signed-off-by: Pawan Gupta pawan.kumar.gupta@linux.intel.com
Link: https://lore.kernel.org/all/168436059559.404.13934972543631851306.tip-bot2@t...
Link: https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/releases...
Link: https://cdrdv2.intel.com/v1/dl/getContent/740518 # RPL042, rev. 13
Link: https://cdrdv2.intel.com/v1/dl/getContent/682436 # ADL063, rev. 24
Link: https://lore.kernel.org/all/20240325231300.qrltbzf6twm43ftb@desk/
Link: https://lore.kernel.org/all/20240522020625.69418-1-xry111%40xry111.site
---
 arch/x86/mm/init.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 6215dfa23578..71d29dd7ad76 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -262,28 +262,33 @@ static void __init probe_page_size_mask(void)
 }
/*
- * INVLPG may not properly flush Global entries
- * on these CPUs when PCIDs are enabled.
+ * INVLPG may not properly flush Global entries on
+ * these CPUs.  New microcode fixes the issue.
  */
 static const struct x86_cpu_id invlpg_miss_ids[] = {
-	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE,      0),
-	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L,    0),
-	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GRACEMONT, 0),
-	X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE,     0),
-	X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE_P,   0),
-	X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE_S,   0),
+	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE,      0x2e),
+	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L,    0x42c),
+	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GRACEMONT, 0x11),
+	X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE,     0x118),
+	X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE_P,   0x4117),
+	X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE_S,   0x2e),
    {}
 };
static void setup_pcid(void)
 {
+	const struct x86_cpu_id *invlpg_miss_match;
+
    if (!IS_ENABLED(CONFIG_X86_64))
    	return;
if (!boot_cpu_has(X86_FEATURE_PCID))
    	return;
-	if (x86_match_cpu(invlpg_miss_ids)) {
+	invlpg_miss_match = x86_match_cpu(invlpg_miss_ids);
+
+	if (invlpg_miss_match &&
+	    boot_cpu_data.microcode < invlpg_miss_match->driver_data) {
    	pr_info("Incomplete global flushes, disabling PCID");
    	setup_clear_cpu_cap(X86_FEATURE_PCID);
    	return;
---
base-commit: 568e253c3e3bdfecf5a4d65ccc8fc971c6c4b31f
change-id: 20250307-clear-pcid-6-6-ce51baab3b5b
Best regards,
-- 
Thanks,
Pawan




    