[PATCH v3] x86/mm: Don't disable INVLPG if "incomplete Global INVLPG flushes" is fixed by microcode

From: Xi Ruoyao
Date: Mon Mar 25 2024 - 17:28:54 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 INVLPG if the microcode is new enough.

Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
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
Signed-off-by: Xi Ruoyao <xry111@xxxxxxxxxxx>
---
arch/x86/mm/init.c | 37 +++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 679893ea5e68..1a7d6a61a4cb 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -261,33 +261,46 @@ 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, 0x34),
+ INTEL_MATCH(INTEL_FAM6_ALDERLAKE_L, 0x432),
+ INTEL_MATCH(INTEL_FAM6_ATOM_GRACEMONT, 0x15),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE, 0x122),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_P, 0x4121),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_S, 0x34),
{}
};

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) ||
+ invlpg_miss_match->driver_data > boot_cpu_data.microcode)) {
pr_info("Incomplete global flushes, disabling PCID");
setup_clear_cpu_cap(X86_FEATURE_PCID);
return;
--
2.44.0