linux-kernel - [PATCH v5] x86/mm: Don't disable INVLPG if "incomplete Global INVLPG flushes" is fixed by microcode

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Message-ID: <20240327155920.7026-1-xry111@xry111.site>
Date: Wed, 27 Mar 2024 23:59:20 +0800
From: Xi Ruoyao <xry111@...111.site>
To: Dave Hansen <dave.hansen@...ux.intel.com>,
	Michael Kelley <mhklinux@...look.com>,
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
Cc: Andy Lutomirski <luto@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	x86@...nel.org,
	linux-kernel@...r.kernel.org,
	Xi Ruoyao <xry111@...111.site>
Subject: [PATCH v5] x86/mm: Don't disable INVLPG if "incomplete Global INVLPG flushes" is fixed by microcode

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 INVLPG if the microcode is new enough.  The precise
minimum microcode revision fixing the issue is provided by engineer from
Intel.

Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Link: https://lore.kernel.org/all/168436059559.404.13934972543631851306.tip-bot2@tip-bot2/
Link: https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/releases/tag/microcode-20240312
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/
Reviewed-by: Michael Kelley <mhklinux@...look.com>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
Signed-off-by: Xi Ruoyao <xry111@...111.site>
---
 arch/x86/mm/init.c | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 679893ea5e68..476eb39db09a 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -261,33 +261,48 @@ static void __init probe_page_size_mask(void)
 	}
 }
 
-#define INTEL_MATCH(_model) { .vendor  = X86_VENDOR_INTEL,	\
-			      .family  = 6,			\
-			      .model = _model,			\
-			    }
+#define INTEL_MATCH(_model, _fixed_microcode)	\
+	{					\
+	  .vendor	= X86_VENDOR_INTEL,	\
+	  .family	= 6,			\
+	  .model	= _model,		\
+	  .driver_data	= _fixed_microcode,	\
+	}
+
 /*
  * INVLPG may not properly flush Global entries
- * on these CPUs when PCIDs are enabled.
+ * on these CPUs when PCIDs are enabled and the
+ * microcode is not updated to fix the issue.
  */
 static const struct x86_cpu_id invlpg_miss_ids[] = {
-	INTEL_MATCH(INTEL_FAM6_ALDERLAKE   ),
-	INTEL_MATCH(INTEL_FAM6_ALDERLAKE_L ),
-	INTEL_MATCH(INTEL_FAM6_ATOM_GRACEMONT ),
-	INTEL_MATCH(INTEL_FAM6_RAPTORLAKE  ),
-	INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_P),
-	INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_S),
+	INTEL_MATCH(INTEL_FAM6_ALDERLAKE,	0x2e),
+	INTEL_MATCH(INTEL_FAM6_ALDERLAKE_L,	0x42c),
+	INTEL_MATCH(INTEL_FAM6_ATOM_GRACEMONT,	0x11),
+	INTEL_MATCH(INTEL_FAM6_RAPTORLAKE,	0x118),
+	INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_P,	0x4117),
+	INTEL_MATCH(INTEL_FAM6_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);
+
+	/*
+	 * The hypervisor may lie about the microcode revision, conservatively
+	 * consider the microcode not updated.
+	 */
+	if (invlpg_miss_match &&
+	    (boot_cpu_has(X86_FEATURE_HYPERVISOR) ||
+	     boot_cpu_data.microcode < invlpg_miss_match->driver_data)) {
 		pr_info("Incomplete global flushes, disabling PCID");
 		setup_clear_cpu_cap(X86_FEATURE_PCID);
 		return;
-- 
2.44.0