[PATCH v7 08/10] x86/nmi: Enable NMI-source for IPIs delivered as NMIs

[Sohil Mehta]

With the IPI handling APIs ready to support the new NMI encoding, encode
the NMI delivery mode directly with the NMI-source vectors to trigger
NMIs.

Move most of the existing NMI-based IPIs to use the new NMI-source
vectors, except for the microcode rendezvous NMI and the crash reboot
NMI. NMI handling for them is special-cased in exc_nmi() and does not
need NMI-source reporting.

However, in the future, it might be useful to assign a source vector to
all NMI sources to improve isolation and debuggability.

Originally-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Co-developed-by: Xin Li (Intel) <xin@xxxxxxxxx>
Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx>
Signed-off-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>
---
v7: No change.

v6: Include asm/nmi.h to avoid compile errors. (LKP)

v5: Encode APIC_DM_NMI directly with the NMI-source vector.
---
 arch/x86/include/asm/apic.h      | 8 ++++++++
 arch/x86/kernel/apic/hw_nmi.c    | 2 +-
 arch/x86/kernel/cpu/mce/inject.c | 2 +-
 arch/x86/kernel/kgdb.c           | 2 +-
 arch/x86/kernel/nmi_selftest.c   | 2 +-
 arch/x86/kernel/smp.c            | 2 +-
 6 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 32cdd81e5e45..5789df1708bd 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -14,6 +14,7 @@
 #include <asm/msr.h>
 #include <asm/hardirq.h>
 #include <asm/io.h>
+#include <asm/nmi.h>
 #include <asm/posted_intr.h>
 
 #define ARCH_APICTIMER_STOPS_ON_C3	1
@@ -23,6 +24,13 @@
 #define APIC_EXTNMI_ALL		1
 #define APIC_EXTNMI_NONE	2
 
+/* Trigger NMIs with source information */
+#define TEST_NMI		(APIC_DM_NMI | NMIS_VECTOR_TEST)
+#define SMP_STOP_NMI		(APIC_DM_NMI | NMIS_VECTOR_SMP_STOP)
+#define BT_NMI			(APIC_DM_NMI | NMIS_VECTOR_BT)
+#define KGDB_NMI		(APIC_DM_NMI | NMIS_VECTOR_KGDB)
+#define MCE_NMI			(APIC_DM_NMI | NMIS_VECTOR_MCE)
+
 /*
  * Debugging macros
  */
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index 4e04f13d2de9..586f4b25feae 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -33,7 +33,7 @@ u64 hw_nmi_get_sample_period(int watchdog_thresh)
 #ifdef arch_trigger_cpumask_backtrace
 static void nmi_raise_cpu_backtrace(cpumask_t *mask)
 {
-	__apic_send_IPI_mask(mask, NMI_VECTOR);
+	__apic_send_IPI_mask(mask, BT_NMI);
 }
 
 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)
diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c
index 320068e01c22..81a04836ac74 100644
--- a/arch/x86/kernel/cpu/mce/inject.c
+++ b/arch/x86/kernel/cpu/mce/inject.c
@@ -270,7 +270,7 @@ static void __maybe_unused raise_mce(struct mce *m)
 					mce_irq_ipi, NULL, 0);
 				preempt_enable();
 			} else if (m->inject_flags & MCJ_NMI_BROADCAST)
-				__apic_send_IPI_mask(mce_inject_cpumask, NMI_VECTOR);
+				__apic_send_IPI_mask(mce_inject_cpumask, MCE_NMI);
 		}
 		start = jiffies;
 		while (!cpumask_empty(mce_inject_cpumask)) {
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index dfde434d2992..013feeb6a9ef 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -416,7 +416,7 @@ static void kgdb_disable_hw_debug(struct pt_regs *regs)
  */
 void kgdb_roundup_cpus(void)
 {
-	apic_send_IPI_allbutself(NMI_VECTOR);
+	apic_send_IPI_allbutself(KGDB_NMI);
 }
 #endif
 
diff --git a/arch/x86/kernel/nmi_selftest.c b/arch/x86/kernel/nmi_selftest.c
index f3918888e494..d5578370b47f 100644
--- a/arch/x86/kernel/nmi_selftest.c
+++ b/arch/x86/kernel/nmi_selftest.c
@@ -72,7 +72,7 @@ static void __init test_nmi_ipi(struct cpumask *mask)
 	/* sync above data before sending NMI */
 	wmb();
 
-	__apic_send_IPI_mask(mask, NMI_VECTOR);
+	__apic_send_IPI_mask(mask, TEST_NMI);
 
 	/* Don't wait longer than a second */
 	timeout = USEC_PER_SEC;
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 1ed065b78467..239e9bf97abb 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -217,7 +217,7 @@ static void native_stop_other_cpus(int wait)
 			pr_emerg("Shutting down cpus with NMI\n");
 
 			for_each_cpu(cpu, &cpus_stop_mask)
-				__apic_send_IPI(cpu, NMI_VECTOR);
+				__apic_send_IPI(cpu, SMP_STOP_NMI);
 		}
 		/*
 		 * Don't wait longer than 10 ms if the caller didn't
-- 
2.43.0