Commit 93ed83ad authored by Zenghui Yu's avatar Zenghui Yu Committed by Zheng Zengkai
Browse files

KVM: arm64: Adjust entry/exit and trap related tracepoints 

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4IZPY


CVE: NA

-------------------------------------------------

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
explicitly 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: default avatarZenghui Yu <yuzenghui@huawei.com>
Reviewed-by: default avatarHailiang Zhang <zhang.zhanghailiang@huawei.com>
Signed-off-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/1560330526-15468-3-git-send-email-yuzenghui@huawei.com
Link: https://gitee.com/openeuler/kernel/commit/14b85d8d7d2d


Reviewed-by: default avatarYanan Wang <wangyanan55@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent b67390e4

arch/arm64/kvm/arm.c

+2 −2
Original line number Diff line number Diff line
@@ -836,7 +836,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 
		/**************************************************************

		 * Enter the guest

		 */

		trace_kvm_entry(*vcpu_pc(vcpu));

		trace_kvm_entry(vcpu->vcpu_id, *vcpu_pc(vcpu));

		guest_enter_irqoff();



		ret = kvm_call_hyp_ret(__kvm_vcpu_run, vcpu);
@@ -894,7 +894,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 
		 * 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, ret);

arch/arm64/kvm/handle_exit.c

+3 −0
Original line number Diff line number Diff line
@@ -232,7 +232,10 @@ static int handle_trap_exceptions(struct kvm_vcpu *vcpu) 
		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);

		trace_kvm_trap_exit(vcpu->vcpu_id);

	}



	return handled;

arch/arm64/kvm/trace_arm.h

+11 −10
Original line number Diff line number Diff line
@@ -12,40 +12,41 @@ 
 * 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%016lx", __entry->vcpu_pc)

	TP_printk("VCPU %u: PC=0x%016lx", __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%016lx",

	TP_printk("VCPU %u: exit_type=%s, PC=0x%016lx",

		  __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)

);

arch/arm64/kvm/trace_handle_exit.h

+35 −0
Original line number Diff line number Diff line
@@ -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),