[PATCH V9 01/18] perf/core: Use static_call to optimize perf_guest_info_callbacks

From: Zhu Lingshan
Date: Thu Jul 22 2021 - 01:42:42 EST

From: Like Xu <like.xu@xxxxxxxxxxxxxxx>

For "struct perf_guest_info_callbacks", the two fields "is_in_guest"
and "is_user_mode" are replaced with a new multiplexed member named
"state", and the "get_guest_ip" field will be renamed to "get_ip".

For arm64, xen and kvm/x86, the application of DEFINE_STATIC_CALL_RET0
could make all that perf_guest_cbs stuff suck less. For arm, csky, nds32,
and riscv, just applied some renamed refactoring.

Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Guo Ren <guoren@xxxxxxxxxx>
Cc: Nick Hu <nickhu@xxxxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-csky@xxxxxxxxxxxxxxx
Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Suggested-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Original-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Like Xu <like.xu@xxxxxxxxxxxxxxx>
Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
Reviewed-by: Boris Ostrovsky <boris.ostrvsky@xxxxxxxxxx>
---
arch/arm/kernel/perf_callchain.c | 16 +++++++-----
arch/arm64/kernel/perf_callchain.c | 29 +++++++++++++++++-----
arch/arm64/kvm/perf.c | 22 ++++++++---------
arch/csky/kernel/perf_callchain.c | 4 +--
arch/nds32/kernel/perf_event_cpu.c | 16 +++++++-----
arch/riscv/kernel/perf_callchain.c | 4 +--
arch/x86/events/core.c | 39 ++++++++++++++++++++++++------
arch/x86/events/intel/core.c | 7 +++---
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/pmu.c | 2 +-
arch/x86/kvm/x86.c | 37 +++++++++++++++-------------
arch/x86/xen/pmu.c | 33 ++++++++++---------------
include/linux/perf_event.h | 12 ++++++---
kernel/events/core.c | 9 +++++++
14 files changed, 144 insertions(+), 88 deletions(-)

diff --git a/arch/arm/kernel/perf_callchain.c b/arch/arm/kernel/perf_callchain.c
index 3b69a76d341e..1ce30f86d6c7 100644
--- a/arch/arm/kernel/perf_callchain.c
+++ b/arch/arm/kernel/perf_callchain.c
@@ -64,7 +64,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs
{
struct frame_tail __user *tail;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (perf_guest_cbs && perf_guest_cbs->state()) {
/* We don't support guest os callchain now */
return;
}
@@ -100,7 +100,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
{
struct stackframe fr;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (perf_guest_cbs && perf_guest_cbs->state()) {
/* We don't support guest os callchain now */
return;
}
@@ -111,8 +111,8 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re

unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
- return perf_guest_cbs->get_guest_ip();
+ if (perf_guest_cbs && perf_guest_cbs->state())
+ return perf_guest_cbs->get_ip();

return instruction_pointer(regs);
}
@@ -120,9 +120,13 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
unsigned long perf_misc_flags(struct pt_regs *regs)
{
int misc = 0;
+ unsigned int state = 0;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
- if (perf_guest_cbs->is_user_mode())
+ if (perf_guest_cbs)
+ state = perf_guest_cbs->state();
+
+ if (perf_guest_cbs && state) {
+ if (state & PERF_GUEST_USER)
misc |= PERF_RECORD_MISC_GUEST_USER;
else
misc |= PERF_RECORD_MISC_GUEST_KERNEL;
diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 4a72c2727309..1b344e23fd2f 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -5,6 +5,7 @@
* Copyright (C) 2015 ARM Limited
*/
#include <linux/perf_event.h>
+#include <linux/static_call.h>
#include <linux/uaccess.h>

#include <asm/pointer_auth.h>
@@ -99,10 +100,25 @@ compat_user_backtrace(struct compat_frame_tail __user *tail,
}
#endif /* CONFIG_COMPAT */

+DEFINE_STATIC_CALL_RET0(arm64_guest_state, *(perf_guest_cbs->state));
+DEFINE_STATIC_CALL_RET0(arm64_guest_get_ip, *(perf_guest_cbs->get_ip));
+
+void arch_perf_update_guest_cbs(void)
+{
+ static_call_update(arm64_guest_state, (void *)&__static_call_return0);
+ static_call_update(arm64_guest_get_ip, (void *)&__static_call_return0);
+
+ if (perf_guest_cbs && perf_guest_cbs->state)
+ static_call_update(arm64_guest_state, perf_guest_cbs->state);
+
+ if (perf_guest_cbs && perf_guest_cbs->get_ip)
+ static_call_update(arm64_guest_get_ip, perf_guest_cbs->get_ip);
+}
+
void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (static_call(arm64_guest_state)()) {
/* We don't support guest os callchain now */
return;
}
@@ -149,7 +165,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
{
struct stackframe frame;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (static_call(arm64_guest_state)()) {
/* We don't support guest os callchain now */
return;
}
@@ -160,8 +176,8 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,

unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
- return perf_guest_cbs->get_guest_ip();
+ if (static_call(arm64_guest_state)())
+ return static_call(arm64_guest_get_ip)();

return instruction_pointer(regs);
}
@@ -169,9 +185,10 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
unsigned long perf_misc_flags(struct pt_regs *regs)
{
int misc = 0;
+ unsigned int guest = static_call(arm64_guest_state)();

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
- if (perf_guest_cbs->is_user_mode())
+ if (guest) {
+ if (guest & PERF_GUEST_USER)
misc |= PERF_RECORD_MISC_GUEST_USER;
else
misc |= PERF_RECORD_MISC_GUEST_KERNEL;
diff --git a/arch/arm64/kvm/perf.c b/arch/arm64/kvm/perf.c
index 151c31fb9860..8a3387e58f42 100644
--- a/arch/arm64/kvm/perf.c
+++ b/arch/arm64/kvm/perf.c
@@ -13,21 +13,20 @@

DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available);

-static int kvm_is_in_guest(void)
-{
- return kvm_get_running_vcpu() != NULL;
-}
-
-static int kvm_is_user_mode(void)
+static unsigned int kvm_guest_state(void)
{
struct kvm_vcpu *vcpu;
+ unsigned int state = 0;
+
+ if (kvm_get_running_vcpu())
+ state |= PERF_GUEST_ACTIVE;

vcpu = kvm_get_running_vcpu();

- if (vcpu)
- return !vcpu_mode_priv(vcpu);
+ if (vcpu && !vcpu_mode_priv(vcpu))
+ state |= PERF_GUEST_USER;

- return 0;
+ return state;
}

static unsigned long kvm_get_guest_ip(void)
@@ -43,9 +42,8 @@ static unsigned long kvm_get_guest_ip(void)
}

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,
};

int kvm_perf_init(void)
diff --git a/arch/csky/kernel/perf_callchain.c b/arch/csky/kernel/perf_callchain.c
index ab55e98ee8f6..3e42239dd1b2 100644
--- a/arch/csky/kernel/perf_callchain.c
+++ b/arch/csky/kernel/perf_callchain.c
@@ -89,7 +89,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
unsigned long fp = 0;

/* C-SKY does not support virtualization. */
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
+ if (perf_guest_cbs && perf_guest_cbs->state())
return;

fp = regs->regs[4];
@@ -113,7 +113,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct stackframe fr;

/* C-SKY does not support virtualization. */
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (perf_guest_cbs && perf_guest_cbs->state()) {
pr_warn("C-SKY does not support perf in guest mode!");
return;
}
diff --git a/arch/nds32/kernel/perf_event_cpu.c b/arch/nds32/kernel/perf_event_cpu.c
index 0ce6f9f307e6..1dc32ba842ce 100644
--- a/arch/nds32/kernel/perf_event_cpu.c
+++ b/arch/nds32/kernel/perf_event_cpu.c
@@ -1371,7 +1371,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry,

leaf_fp = 0;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (perf_guest_cbs && perf_guest_cbs->state()) {
/* We don't support guest os callchain now */
return;
}
@@ -1481,7 +1481,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
{
struct stackframe fr;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (perf_guest_cbs && perf_guest_cbs->state()) {
/* We don't support guest os callchain now */
return;
}
@@ -1494,8 +1494,8 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
/* However, NDS32 does not support virtualization */
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
- return perf_guest_cbs->get_guest_ip();
+ if (perf_guest_cbs && perf_guest_cbs->state())
+ return perf_guest_cbs->get_ip();

return instruction_pointer(regs);
}
@@ -1503,10 +1503,14 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
unsigned long perf_misc_flags(struct pt_regs *regs)
{
int misc = 0;
+ unsigned int state = 0;
+
+ if (perf_guest_cbs)
+ state = perf_guest_cbs->state();

/* However, NDS32 does not support virtualization */
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
- if (perf_guest_cbs->is_user_mode())
+ if (perf_guest_cbs && state) {
+ if (state & PERF_GUEST_USER)
misc |= PERF_RECORD_MISC_GUEST_USER;
else
misc |= PERF_RECORD_MISC_GUEST_KERNEL;
diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
index 0bb1854dce83..ea63f70cae5d 100644
--- a/arch/riscv/kernel/perf_callchain.c
+++ b/arch/riscv/kernel/perf_callchain.c
@@ -59,7 +59,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
unsigned long fp = 0;

/* RISC-V does not support perf in guest mode. */
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
+ if (perf_guest_cbs && perf_guest_cbs->state())
return;

fp = regs->s0;
@@ -79,7 +79,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
/* RISC-V does not support perf in guest mode. */
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (perf_guest_cbs && perf_guest_cbs->state()) {
pr_warn("RISC-V does not support perf in guest mode!");
return;
}
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 1eb45139fcc6..9a908631f6cc 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -90,6 +90,28 @@ DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases);
*/
DEFINE_STATIC_CALL_RET0(x86_pmu_guest_get_msrs, *x86_pmu.guest_get_msrs);

+DEFINE_STATIC_CALL_RET0(x86_guest_state, *(perf_guest_cbs->state));
+DEFINE_STATIC_CALL_RET0(x86_guest_get_ip, *(perf_guest_cbs->get_ip));
+DEFINE_STATIC_CALL_RET0(x86_guest_handle_intel_pt_intr, *(perf_guest_cbs->handle_intel_pt_intr));
+
+void arch_perf_update_guest_cbs(void)
+{
+ static_call_update(x86_guest_state, (void *)&__static_call_return0);
+ static_call_update(x86_guest_get_ip, (void *)&__static_call_return0);
+ static_call_update(x86_guest_handle_intel_pt_intr, (void *)&__static_call_return0);
+
+ if (perf_guest_cbs && perf_guest_cbs->state)
+ static_call_update(x86_guest_state, perf_guest_cbs->state);
+
+ if (perf_guest_cbs && perf_guest_cbs->get_ip)
+ static_call_update(x86_guest_get_ip, perf_guest_cbs->get_ip);
+
+ if (perf_guest_cbs && perf_guest_cbs->handle_intel_pt_intr) {
+ static_call_update(x86_guest_handle_intel_pt_intr,
+ perf_guest_cbs->handle_intel_pt_intr);
+ }
+}
+
u64 __read_mostly hw_cache_event_ids
[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
@@ -2764,7 +2786,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
struct unwind_state state;
unsigned long addr;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (static_call(x86_guest_state)()) {
/* TODO: We don't support guest os callchain now */
return;
}
@@ -2867,7 +2889,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs
struct stack_frame frame;
const struct stack_frame __user *fp;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (static_call(x86_guest_state)()) {
/* TODO: We don't support guest os callchain now */
return;
}
@@ -2944,18 +2966,21 @@ static unsigned long code_segment_base(struct pt_regs *regs)

unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
- if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
- return perf_guest_cbs->get_guest_ip();
+ unsigned long ip = static_call(x86_guest_get_ip)();
+
+ if (likely(!ip))
+ ip = regs->ip + code_segment_base(regs);

- return regs->ip + code_segment_base(regs);
+ return ip;
}

unsigned long perf_misc_flags(struct pt_regs *regs)
{
+ unsigned int guest = static_call(x86_guest_state)();
int misc = 0;

- if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
- if (perf_guest_cbs->is_user_mode())
+ if (guest) {
+ if (guest & PERF_GUEST_USER)
misc |= PERF_RECORD_MISC_GUEST_USER;
else
misc |= PERF_RECORD_MISC_GUEST_KERNEL;
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index fca7a6e2242f..fb1bd7a0e1a6 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2782,6 +2782,8 @@ static void intel_pmu_reset(void)
local_irq_restore(flags);
}

+DECLARE_STATIC_CALL(x86_guest_handle_intel_pt_intr, *(perf_guest_cbs->handle_intel_pt_intr));
+
static int handle_pmi_common(struct pt_regs *regs, u64 status)
{
struct perf_sample_data data;
@@ -2852,10 +2854,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
*/
if (__test_and_clear_bit(GLOBAL_STATUS_TRACE_TOPAPMI_BIT, (unsigned long *)&status)) {
handled++;
- if (unlikely(perf_guest_cbs && perf_guest_cbs->is_in_guest() &&
- perf_guest_cbs->handle_intel_pt_intr))
- perf_guest_cbs->handle_intel_pt_intr();
- else
+ if (!static_call(x86_guest_handle_intel_pt_intr)())
intel_pt_interrupt();
}

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 974cbfb1eefe..128e2dd9c944 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1884,7 +1884,7 @@ 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);
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 827886c12c16..2dcbd1b30004 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -87,7 +87,7 @@ static void kvm_perf_overflow_intr(struct perf_event *perf_event,
* woken up. So we should wake it, but this is impossible from
* NMI context. Do it from irq work instead.
*/
- if (!kvm_is_in_guest())
+ if (!kvm_guest_state())
irq_work_queue(&pmc_to_pmu(pmc)->irq_work);
else
kvm_make_request(KVM_REQ_PMI, pmc->vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c6dc1b445231..429cb4c22097 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8259,44 +8259,47 @@ static void kvm_timer_init(void)
DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu);
EXPORT_PER_CPU_SYMBOL_GPL(current_vcpu);

-int kvm_is_in_guest(void)
+unsigned int kvm_guest_state(void)
{
- return __this_cpu_read(current_vcpu) != NULL;
-}
-
-static int kvm_is_user_mode(void)
-{
- int user_mode = 3;
+ struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu);
+ unsigned int state = 0;

- if (__this_cpu_read(current_vcpu))
- user_mode = static_call(kvm_x86_get_cpl)(__this_cpu_read(current_vcpu));
+ if (vcpu) {
+ state |= PERF_GUEST_ACTIVE;
+ if (static_call(kvm_x86_get_cpl)(vcpu))
+ state |= PERF_GUEST_USER;
+ }

- return user_mode != 0;
+ return state;
}

-static unsigned long kvm_get_guest_ip(void)
+static unsigned long kvm_guest_get_ip(void)
{
+ struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu);
unsigned long ip = 0;

- if (__this_cpu_read(current_vcpu))
- ip = kvm_rip_read(__this_cpu_read(current_vcpu));
+ if (vcpu)
+ ip = kvm_rip_read(vcpu);

return ip;
}

-static void kvm_handle_intel_pt_intr(void)
+static unsigned int kvm_handle_intel_pt_intr(void)
{
struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu);

+ if (!vcpu)
+ return 0;
+
kvm_make_request(KVM_REQ_PMI, vcpu);
__set_bit(MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT,
(unsigned long *)&vcpu->arch.pmu.global_status);
+ return 1;
}

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_guest_get_ip,
.handle_intel_pt_intr = kvm_handle_intel_pt_intr,
};

diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
index e13b0b49fcdf..85c6e6f6f422 100644
--- a/arch/x86/xen/pmu.c
+++ b/arch/x86/xen/pmu.c
@@ -413,34 +413,28 @@ int pmu_apic_update(uint32_t val)
}

/* perf callbacks */
-static int xen_is_in_guest(void)
+static unsigned int xen_guest_state(void)
{
const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
+ unsigned int state = 0;

if (!xenpmu_data) {
pr_warn_once("%s: pmudata not initialized\n", __func__);
- return 0;
+ return state;
}

if (!xen_initial_domain() || (xenpmu_data->domain_id >= DOMID_SELF))
- return 0;
+ return state;

- return 1;
-}
+ state |= PERF_GUEST_ACTIVE;

-static int xen_is_user_mode(void)
-{
- const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
+ if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_PV) {
+ if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_USER)
+ state |= PERF_GUEST_USER;
+ } else if (xenpmu_data->pmu.r.regs.cpl & 3)
+ state |= PERF_GUEST_USER;

- if (!xenpmu_data) {
- pr_warn_once("%s: pmudata not initialized\n", __func__);
- return 0;
- }
-
- if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_PV)
- return (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_USER);
- else
- return !!(xenpmu_data->pmu.r.regs.cpl & 3);
+ return state;
}

static unsigned long xen_get_guest_ip(void)
@@ -456,9 +450,8 @@ static unsigned long xen_get_guest_ip(void)
}

static struct perf_guest_info_callbacks xen_guest_cbs = {
- .is_in_guest = xen_is_in_guest,
- .is_user_mode = xen_is_user_mode,
- .get_guest_ip = xen_get_guest_ip,
+ .state = xen_guest_state,
+ .get_ip = xen_get_guest_ip,
};

/* Convert registers from Xen's format to Linux' */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 2d510ad750ed..e823677a214c 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -26,11 +26,13 @@
# include <asm/local64.h>
#endif

+#define PERF_GUEST_ACTIVE 0x01
+#define PERF_GUEST_USER 0x02
+
struct perf_guest_info_callbacks {
- int (*is_in_guest)(void);
- int (*is_user_mode)(void);
- unsigned long (*get_guest_ip)(void);
- void (*handle_intel_pt_intr)(void);
+ unsigned int (*state)(void);
+ unsigned long (*get_ip)(void);
+ unsigned int (*handle_intel_pt_intr)(void);
};

#ifdef CONFIG_HAVE_HW_BREAKPOINT
@@ -1237,6 +1239,8 @@ extern void perf_event_bpf_event(struct bpf_prog *prog,
u16 flags);

extern struct perf_guest_info_callbacks *perf_guest_cbs;
+extern void __weak arch_perf_update_guest_cbs(void);
+
extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 464917096e73..e466fc8176e1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6489,9 +6489,18 @@ static void perf_pending_event(struct irq_work *entry)
*/
struct perf_guest_info_callbacks *perf_guest_cbs;

+/* explicitly use __weak to fix duplicate symbol error */
+void __weak arch_perf_update_guest_cbs(void)
+{
+}
+
int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
{
+ if (WARN_ON_ONCE(perf_guest_cbs))
+ return -EBUSY;
+
perf_guest_cbs = cbs;
+ arch_perf_update_guest_cbs();
return 0;
}
EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
--
2.27.0