The ARM architecture only saves the exit class to the HSR (ESR_EL2 for
arm64) on synchronous exceptions, not on asynchronous exceptions like an
IRQ. However, we only report the exception class on kvm_exit, which is
confusing because an IRQ looks like it exited at some PC with the same
reason as the previous exit. Add a lookup table for the exception index
and prepend the kvm_exit tracepoint text with the exception type to
clarify this situation.
Also resolve the exception class (EC) to a human-friendly text version
so the trace output becomes immediately usable for debugging this code.
Cc: Wei Huang <wei@xxxxxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
---
arch/arm/include/asm/kvm_arm.h | 20 ++++++++++++++++++++
arch/arm/kvm/arm.c | 2 +-
arch/arm/kvm/trace.h | 10 +++++++---
arch/arm64/include/asm/kvm_arm.h | 16 ++++++++++++++++
4 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index d995821..dc641dd 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -218,4 +218,24 @@
#define HSR_DABT_CM (1U << 8)
#define HSR_DABT_EA (1U << 9)
+#define kvm_arm_exception_type \
+ {0, "RESET" }, \
+ {1, "UNDEFINED" }, \
+ {2, "SOFTWARE" }, \
+ {3, "PREF_ABORT" }, \
+ {4, "DATA_ABORT" }, \
+ {5, "IRQ" }, \
+ {6, "FIQ" }, \
+ {7, "HVC" }
+
+#define HSRECN(x) { HSR_EC_##x, #x }
+
+#define kvm_arm_exception_class \
+ HSRECN(UNKNOWN), HSRECN(WFI), HSRECN(CP15_32), HSRECN(CP15_64), \
+ HSRECN(CP14_MR), HSRECN(CP14_LS), HSRECN(CP_0_13), HSRECN(CP10_ID), \
+ HSRECN(JAZELLE), HSRECN(BXJ), HSRECN(CP14_64), HSRECN(SVC_HYP), \
+ HSRECN(HVC), HSRECN(SMC), HSRECN(IABT), HSRECN(IABT_HYP), \
+ HSRECN(DABT), HSRECN(DABT_HYP)
+
+
#endif /* __ARM_KVM_ARM_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index ed15747..eab83b2 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -635,7 +635,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
* guest time.
*/
kvm_guest_exit();
- trace_kvm_exit(kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
+ trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
/*
* We must sync the timer state before the vgic state so that
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
index 0ec3539..c25a885 100644
--- a/arch/arm/kvm/trace.h
+++ b/arch/arm/kvm/trace.h
@@ -25,21 +25,25 @@ TRACE_EVENT(kvm_entry,
);
TRACE_EVENT(kvm_exit,
- TP_PROTO(unsigned int exit_reason, unsigned long vcpu_pc),
- TP_ARGS(exit_reason, vcpu_pc),
+ TP_PROTO(int idx, unsigned int exit_reason, unsigned long vcpu_pc),
+ TP_ARGS(idx, exit_reason, vcpu_pc),
TP_STRUCT__entry(
+ __field( int, idx )
__field( unsigned int, exit_reason )
__field( unsigned long, vcpu_pc )
),
TP_fast_assign(
+ __entry->idx = idx;
__entry->exit_reason = exit_reason;
__entry->vcpu_pc = vcpu_pc;
),
- TP_printk("HSR_EC: 0x%04x, PC: 0x%08lx",
+ TP_printk("%s: HSR_EC: 0x%04x (%s), PC: 0x%08lx",
+ __print_symbolic(__entry->idx, kvm_arm_exception_type),
__entry->exit_reason,
+ __print_symbolic(__entry->exit_reason, kvm_arm_exception_class),
__entry->vcpu_pc)
);
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 9694f26..5e6857b 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -200,4 +200,20 @@
/* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
#define HPFAR_MASK (~UL(0xf))
+#define kvm_arm_exception_type \
+ {0, "IRQ" }, \
+ {1, "TRAP" }
+
+#define ECN(x) { ESR_ELx_EC_##x, #x }
+
+#define kvm_arm_exception_class \
+ ECN(UNKNOWN), ECN(WFx), ECN(CP15_32), ECN(CP15_64), ECN(CP14_MR), \
+ ECN(CP14_LS), ECN(FP_ASIMD), ECN(CP10_ID), ECN(CP14_64), ECN(SVC64), \
+ ECN(HVC64), ECN(SMC64), ECN(SYS64), ECN(IMP_DEF), ECN(IABT_LOW), \
+ ECN(IABT_CUR), ECN(PC_ALIGN), ECN(DABT_LOW), ECN(DABT_CUR), \
+ ECN(SP_ALIGN), ECN(FP_EXC32), ECN(FP_EXC64), ECN(SERROR), \
+ ECN(BREAKPT_LOW), ECN(BREAKPT_CUR), ECN(SOFTSTP_LOW), \
+ ECN(SOFTSTP_CUR), ECN(WATCHPT_LOW), ECN(WATCHPT_CUR), \
+ ECN(BKPT32), ECN(VECTOR32), ECN(BRK64)
+
#endif /* __ARM64_KVM_ARM_H__ */
--
2.1.2.330.g565301e.dirty
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