On 2/15/2024 4:05 AM, Alejandro Jimenez wrote:
Use the tracing infrastructure helper __print_flags() for printing flag
bitfields, to enhance the trace output by displaying a string describing
each of the inhibit reasons set.
The kvm_apicv_inhibit_changed tracepoint currently shows the raw bitmap
value, requiring the user to consult the source file where the inhbit
reasons are defined to decode the trace output.
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@xxxxxxxxxx>
I have reviewed and tested this patch on AMD Genoa system. It looks good
to me.
Reviewed-by: Vasant Hegde <vasant.hegde@xxxxxxx>
-Vasant
---
checkpatch reports an error:
ERROR: Macros with complex values should be enclosed in parentheses
but that seems common for other patches that also use a macro to define an array
of struct trace_print_flags used by __print_flags().
I did not include an example of the new traces in the commit message since they
are longer than 80 columns, but perhaps that is desirable. e.g.:
qemu-system-x86-6961 [055] ..... 1779.344065: kvm_apicv_inhibit_changed: set reason=2, inhibits=0x4 ABSENT
qemu-system-x86-6961 [055] ..... 1779.356710: kvm_apicv_inhibit_changed: cleared reason=2, inhibits=0x0
qemu-system-x86-9912 [137] ..... 57106.196107: kvm_apicv_inhibit_changed: set reason=8, inhibits=0x300 IRQWIN|PIT_REINJ
qemu-system-x86-9912 [137] ..... 57106.196115: kvm_apicv_inhibit_changed: cleared reason=8, inhibits=0x200 PIT_REINJ
---
arch/x86/kvm/trace.h | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index b82e6ed4f024..8469e59dfce2 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1372,6 +1372,27 @@ TRACE_EVENT(kvm_hv_stimer_cleanup,
__entry->vcpu_id, __entry->timer_index)
);
+/*
+ * The inhibit flags in this flag array must be kept in sync with the
+ * kvm_apicv_inhibit enum members in <asm/kvm_host.h>.
+ */
+#define APICV_INHIBIT_FLAGS \
+ { BIT(APICV_INHIBIT_REASON_DISABLE), "DISABLED" }, \
+ { BIT(APICV_INHIBIT_REASON_HYPERV), "HYPERV" }, \
+ { BIT(APICV_INHIBIT_REASON_ABSENT), "ABSENT" }, \
+ { BIT(APICV_INHIBIT_REASON_BLOCKIRQ), "BLOCKIRQ" }, \
+ { BIT(APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED), "PHYS_ID_ALIASED" }, \
+ { BIT(APICV_INHIBIT_REASON_APIC_ID_MODIFIED), "APIC_ID_MOD" }, \
+ { BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED), "APIC_BASE_MOD" }, \
+ { BIT(APICV_INHIBIT_REASON_NESTED), "NESTED" }, \
+ { BIT(APICV_INHIBIT_REASON_IRQWIN), "IRQWIN" }, \
+ { BIT(APICV_INHIBIT_REASON_PIT_REINJ), "PIT_REINJ" }, \
+ { BIT(APICV_INHIBIT_REASON_SEV), "SEV" }, \
+ { BIT(APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED), "LOG_ID_ALIASED" } \
+
+#define show_inhibit_reasons(inhibits) \
+ __print_flags(inhibits, "|", APICV_INHIBIT_FLAGS)
+
TRACE_EVENT(kvm_apicv_inhibit_changed,
TP_PROTO(int reason, bool set, unsigned long inhibits),
TP_ARGS(reason, set, inhibits),
@@ -1388,9 +1409,12 @@ TRACE_EVENT(kvm_apicv_inhibit_changed,
__entry->inhibits = inhibits;
),
- TP_printk("%s reason=%u, inhibits=0x%lx",
+ TP_printk("%s reason=%u, inhibits=0x%lx%s%s",
__entry->set ? "set" : "cleared",
- __entry->reason, __entry->inhibits)
+ __entry->reason, __entry->inhibits,
+ __entry->inhibits ? " " : "",
+ __entry->inhibits ?
+ show_inhibit_reasons(__entry->inhibits) : "")
);
TRACE_EVENT(kvm_apicv_accept_irq,
base-commit: 7455665a3521aa7b56245c0a2810f748adc5fdd4
