Commit b9f5621c authored by Like Xu's avatar Like Xu Committed by Peter Zijlstra
Browse files

perf/core: Rework guest callbacks to prepare for static_call support 



To prepare for using static_calls to optimize perf's guest callbacks,
replace ->is_in_guest and ->is_user_mode with a new multiplexed hook
->state, tweak ->handle_intel_pt_intr to play nice with being called when
there is no active guest, and drop "guest" from ->get_guest_ip.

Return '0' from ->state and ->handle_intel_pt_intr to indicate "not in
guest" so that DEFINE_STATIC_CALL_RET0 can be used to define the static
calls, i.e. no callback == !guest.

[sean: extracted from static_call patch, fixed get_ip() bug, wrote changelog]
Suggested-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Originally-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarLike Xu <like.xu@linux.intel.com>
Signed-off-by: default avatarZhu Lingshan <lingshan.zhu@intel.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-7-seanjc@google.com
parent 84af21d8

arch/arm64/kernel/perf_callchain.c

+7 −6
Original line number Diff line number Diff line
@@ -104,7 +104,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, 
{

	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();



	if (guest_cbs && guest_cbs->is_in_guest()) {

	if (guest_cbs && guest_cbs->state()) {

		/* We don't support guest os callchain now */

		return;

	}
@@ -152,7 +152,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, 
	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();

	struct stackframe frame;



	if (guest_cbs && guest_cbs->is_in_guest()) {

	if (guest_cbs && guest_cbs->state()) {

		/* We don't support guest os callchain now */

		return;

	}
@@ -165,8 +165,8 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) 
{

	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();



	if (guest_cbs && guest_cbs->is_in_guest())

		return guest_cbs->get_guest_ip();

	if (guest_cbs && guest_cbs->state())

		return guest_cbs->get_ip();



	return instruction_pointer(regs);

}
@@ -174,10 +174,11 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) 
unsigned long perf_misc_flags(struct pt_regs *regs)

{

	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();

	unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0;

	int misc = 0;



	if (guest_cbs && guest_cbs->is_in_guest()) {

		if (guest_cbs->is_user_mode())

	if (guest_state) {

		if (guest_state & PERF_GUEST_USER)

			misc |= PERF_RECORD_MISC_GUEST_USER;

		else

			misc |= PERF_RECORD_MISC_GUEST_KERNEL;

arch/arm64/kvm/perf.c

+15 −20
Original line number Diff line number Diff line
@@ -13,39 +13,34 @@ 


DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available);



static int kvm_is_in_guest(void)

static unsigned int kvm_guest_state(void)

{

        return kvm_get_running_vcpu() != NULL;

}



static int kvm_is_user_mode(void)

{

	struct kvm_vcpu *vcpu;

	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();

	unsigned int state;



	vcpu = kvm_get_running_vcpu();

	if (!vcpu)

		return 0;



	if (vcpu)

		return !vcpu_mode_priv(vcpu);

	state = PERF_GUEST_ACTIVE;

	if (!vcpu_mode_priv(vcpu))

		state |= PERF_GUEST_USER;



	return 0;

	return state;

}



static unsigned long kvm_get_guest_ip(void)

{

	struct kvm_vcpu *vcpu;

	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();



	vcpu = kvm_get_running_vcpu();

	if (WARN_ON_ONCE(!vcpu))

		return 0;



	if (vcpu)

	return *vcpu_pc(vcpu);



	return 0;

}



static struct perf_guest_info_callbacks kvm_guest_cbs = {

	.is_in_guest	= kvm_is_in_guest,

	.is_user_mode	= kvm_is_user_mode,

	.get_guest_ip	= kvm_get_guest_ip,

	.state		= kvm_guest_state,

	.get_ip		= kvm_get_guest_ip,

};



void kvm_perf_init(void)

arch/x86/events/core.c

+7 −6
Original line number Diff line number Diff line
@@ -2772,7 +2772,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re 
	struct unwind_state state;

	unsigned long addr;



	if (guest_cbs && guest_cbs->is_in_guest()) {

	if (guest_cbs && guest_cbs->state()) {

		/* TODO: We don't support guest os callchain now */

		return;

	}
@@ -2876,7 +2876,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs 
	struct stack_frame frame;

	const struct stack_frame __user *fp;



	if (guest_cbs && guest_cbs->is_in_guest()) {

	if (guest_cbs && guest_cbs->state()) {

		/* TODO: We don't support guest os callchain now */

		return;

	}
@@ -2955,8 +2955,8 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) 
{

	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();



	if (guest_cbs && guest_cbs->is_in_guest())

		return guest_cbs->get_guest_ip();

	if (guest_cbs && guest_cbs->state())

		return guest_cbs->get_ip();



	return regs->ip + code_segment_base(regs);

}
@@ -2964,10 +2964,11 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs) 
unsigned long perf_misc_flags(struct pt_regs *regs)

{

	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();

	unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0;

	int misc = 0;



	if (guest_cbs && guest_cbs->is_in_guest()) {

		if (guest_cbs->is_user_mode())

	if (guest_state) {

		if (guest_state & PERF_GUEST_USER)

			misc |= PERF_RECORD_MISC_GUEST_USER;

		else

			misc |= PERF_RECORD_MISC_GUEST_KERNEL;

arch/x86/events/intel/core.c

+1 −4
Original line number Diff line number Diff line
@@ -2906,10 +2906,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) 
		handled++;



		guest_cbs = perf_get_guest_cbs();

		if (unlikely(guest_cbs && guest_cbs->is_in_guest() &&

			     guest_cbs->handle_intel_pt_intr))

			guest_cbs->handle_intel_pt_intr();

		else

		if (likely(!guest_cbs || !guest_cbs->handle_intel_pt_intr()))

			intel_pt_interrupt();

	}

arch/x86/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -1895,7 +1895,7 @@ int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu); 
int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err);

void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu);



int kvm_is_in_guest(void);

unsigned int kvm_guest_state(void);



void __user *__x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa,

				     u32 size);