From: Zenghui Yu yuzenghui@huawei.com
euleros inclusion category: feature feature: perf kvm stat on arm64
picked from https://patchwork.kernel.org/patch/10989099/.
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Currently, we use trace_kvm_exit() to report exception type (e.g., "IRQ", "TRAP") and exception class (ESR_ELx's bit[31:26]) together. But hardware only saves the exit class to ESR_ELx on synchronous exceptions, not on asynchronous exceptions. When the guest exits due to external interrupts, we will get tracing output like:
"kvm_exit: IRQ: HSR_EC: 0x0000 (UNKNOWN), PC: 0xffff87259e30"
Obviously, "HSR_EC" here is meaningless.
This patch splits "exit" and "trap" events by adding two tracepoints explictly in handle_trap_exceptions(). Let trace_kvm_exit() report VM exit events, and trace_kvm_trap_exit() report VM trap events.
These tracepoints are adjusted also in preparation for supporting 'perf kvm stat' on arm64.
Signed-off-by: Zenghui Yu yuzenghui@huawei.com Reviewed-by: Hailiang Zhang zhang.zhanghailiang@huawei.com Signed-off-by: Zenghui Yu yuzenghui@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/arm64/kvm/handle_exit.c | 3 +++ arch/arm64/kvm/trace.h | 35 +++++++++++++++++++++++++++++++++++ virt/kvm/arm/arm.c | 4 ++-- virt/kvm/arm/trace.h | 21 +++++++++++---------- 4 files changed, 51 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 35a81beb..2349c26 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -226,7 +226,10 @@ static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run) exit_handle_fn exit_handler;
exit_handler = kvm_get_exit_handler(vcpu); + trace_kvm_trap_enter(vcpu->vcpu_id, + kvm_vcpu_trap_get_class(vcpu)); handled = exit_handler(vcpu, run); + trace_kvm_trap_exit(vcpu->vcpu_id); }
/* diff --git a/arch/arm64/kvm/trace.h b/arch/arm64/kvm/trace.h index eab91ad..6014c73 100644 --- a/arch/arm64/kvm/trace.h +++ b/arch/arm64/kvm/trace.h @@ -8,6 +8,41 @@ #undef TRACE_SYSTEM #define TRACE_SYSTEM kvm
+TRACE_EVENT(kvm_trap_enter, + TP_PROTO(unsigned int vcpu_id, unsigned int esr_ec), + TP_ARGS(vcpu_id, esr_ec), + + TP_STRUCT__entry( + __field(unsigned int, vcpu_id) + __field(unsigned int, esr_ec) + ), + + TP_fast_assign( + __entry->vcpu_id = vcpu_id; + __entry->esr_ec = esr_ec; + ), + + TP_printk("VCPU %u: HSR_EC=0x%04x (%s)", + __entry->vcpu_id, + __entry->esr_ec, + __print_symbolic(__entry->esr_ec, kvm_arm_exception_class)) +); + +TRACE_EVENT(kvm_trap_exit, + TP_PROTO(unsigned int vcpu_id), + TP_ARGS(vcpu_id), + + TP_STRUCT__entry( + __field(unsigned int, vcpu_id) + ), + + TP_fast_assign( + __entry->vcpu_id = vcpu_id; + ), + + TP_printk("VCPU %u", __entry->vcpu_id) +); + TRACE_EVENT(kvm_wfx_arm64, TP_PROTO(unsigned long vcpu_pc, bool is_wfe), TP_ARGS(vcpu_pc, is_wfe), diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index cc21446..5611d6c 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -788,7 +788,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) /************************************************************** * Enter the guest */ - trace_kvm_entry(*vcpu_pc(vcpu)); + trace_kvm_entry(vcpu->vcpu_id, *vcpu_pc(vcpu)); guest_enter_irqoff();
if (has_vhe()) { @@ -852,7 +852,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) * guest time. */ guest_exit(); - trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu)); + trace_kvm_exit(vcpu->vcpu_id, ret, *vcpu_pc(vcpu));
/* Exit types that need handling before we can be preempted */ handle_exit_early(vcpu, run, ret); diff --git a/virt/kvm/arm/trace.h b/virt/kvm/arm/trace.h index 3828bea..e32fee7 100644 --- a/virt/kvm/arm/trace.h +++ b/virt/kvm/arm/trace.h @@ -11,40 +11,41 @@ * Tracepoints for entry/exit to guest */ TRACE_EVENT(kvm_entry, - TP_PROTO(unsigned long vcpu_pc), - TP_ARGS(vcpu_pc), + TP_PROTO(unsigned int vcpu_id, unsigned long vcpu_pc), + TP_ARGS(vcpu_id, vcpu_pc),
TP_STRUCT__entry( + __field( unsigned int, vcpu_id ) __field( unsigned long, vcpu_pc ) ),
TP_fast_assign( + __entry->vcpu_id = vcpu_id; __entry->vcpu_pc = vcpu_pc; ),
- TP_printk("PC: 0x%08lx", __entry->vcpu_pc) + TP_printk("VCPU %u: PC=0x%08lx",__entry->vcpu_id, __entry->vcpu_pc) );
TRACE_EVENT(kvm_exit, - TP_PROTO(int ret, unsigned int esr_ec, unsigned long vcpu_pc), - TP_ARGS(ret, esr_ec, vcpu_pc), + TP_PROTO(unsigned int vcpu_id, int ret, unsigned long vcpu_pc), + TP_ARGS(vcpu_id, ret, vcpu_pc),
TP_STRUCT__entry( + __field( unsigned int, vcpu_id ) __field( int, ret ) - __field( unsigned int, esr_ec ) __field( unsigned long, vcpu_pc ) ),
TP_fast_assign( + __entry->vcpu_id = vcpu_id; __entry->ret = ARM_EXCEPTION_CODE(ret); - __entry->esr_ec = ARM_EXCEPTION_IS_TRAP(ret) ? esr_ec : 0; __entry->vcpu_pc = vcpu_pc; ),
- TP_printk("%s: HSR_EC: 0x%04x (%s), PC: 0x%08lx", + TP_printk("VCPU %u: exit_type=%s, PC=0x%08lx", + __entry->vcpu_id, __print_symbolic(__entry->ret, kvm_arm_exception_type), - __entry->esr_ec, - __print_symbolic(__entry->esr_ec, kvm_arm_exception_class), __entry->vcpu_pc) );