Commit 5bbbed42 authored by Vincent Donnefort's avatar Vincent Donnefort Committed by Marc Zyngier
Browse files

KVM: arm64: Add selftest event support to nVHE/pKVM hyp 



Add a selftest event that can be triggered from a `write_event` tracefs
file. This intends to be used by trace remote selftests.

Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260309162516.2623589-30-vdonnefort@google.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 696dfec2

arch/arm64/include/asm/kvm_asm.h

+1 −0
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ enum __kvm_host_smccc_func { 
	__KVM_HOST_SMCCC_FUNC___tracing_update_clock,

	__KVM_HOST_SMCCC_FUNC___tracing_reset,

	__KVM_HOST_SMCCC_FUNC___tracing_enable_event,

	__KVM_HOST_SMCCC_FUNC___tracing_write_event,

};



#define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]

arch/arm64/include/asm/kvm_hypevents.h

+11 −0
Original line number Diff line number Diff line
@@ -46,4 +46,15 @@ HYP_EVENT(hyp_exit, 
	),

	HE_PRINTK("reason=%s vcpu=%d", __hyp_enter_exit_reason_str(__entry->reason), __entry->vcpu)

);



HYP_EVENT(selftest,

	HE_PROTO(u64 id),

	HE_STRUCT(

		he_field(u64, id)

	),

	HE_ASSIGN(

		__entry->id = id;

	),

	RE_PRINTK("id=%llu", __entry->id)

);

#endif

arch/arm64/kvm/hyp/nvhe/hyp-main.c

+8 −0
Original line number Diff line number Diff line
@@ -643,6 +643,13 @@ static void handle___tracing_enable_event(struct kvm_cpu_context *host_ctxt) 
	cpu_reg(host_ctxt, 1) = __tracing_enable_event(id, enable);

}



static void handle___tracing_write_event(struct kvm_cpu_context *host_ctxt)

{

	DECLARE_REG(u64, id, host_ctxt, 1);



	trace_selftest(id);

}



typedef void (*hcall_t)(struct kvm_cpu_context *);



#define HANDLE_FUNC(x)	[__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
@@ -691,6 +698,7 @@ static const hcall_t host_hcall[] = { 
	HANDLE_FUNC(__tracing_update_clock),

	HANDLE_FUNC(__tracing_reset),

	HANDLE_FUNC(__tracing_enable_event),

	HANDLE_FUNC(__tracing_write_event),

};



static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)

arch/arm64/kvm/hyp_trace.c

+22 −0
Original line number Diff line number Diff line
@@ -348,8 +348,30 @@ static int hyp_trace_clock_show(struct seq_file *m, void *v) 
}

DEFINE_SHOW_ATTRIBUTE(hyp_trace_clock);



static ssize_t hyp_trace_write_event_write(struct file *f, const char __user *ubuf,

					   size_t cnt, loff_t *pos)

{

	unsigned long val;

	int ret;



	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);

	if (ret)

		return ret;



	kvm_call_hyp_nvhe(__tracing_write_event, val);



	return cnt;

}



static const struct file_operations hyp_trace_write_event_fops = {

	.write	= hyp_trace_write_event_write,

};



static int hyp_trace_init_tracefs(struct dentry *d, void *priv)

{

	if (!tracefs_create_file("write_event", 0200, d, NULL, &hyp_trace_write_event_fops))

		return -ENOMEM;



	return tracefs_create_file("trace_clock", 0440, d, NULL, &hyp_trace_clock_fops) ?

		0 : -ENOMEM;

}