[PATCH v9 1/2] x86/mm: Don't disable PCID if "incomplete Global INVLPG flushes" is fixed by microcode

From: Xi Ruoyao
Date: Thu Apr 18 2024 - 16:54:38 EST


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 is provided by engineer from
Intel.

Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Michael Kelley <mhklinux@xxxxxxxxxxx>
Cc: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
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/
Signed-off-by: Xi Ruoyao <xry111@xxxxxxxxxxx>
---
arch/x86/mm/init.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 679893ea5e68..c318cdc35467 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -261,33 +261,43 @@ 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);
+
+ 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;
--
2.44.0