[PATCH 0/2] perf kvm: Add kvm stat support on riscv

[PATCH 0/2] perf kvm: Add kvm stat support on riscv

[Shenlin Liang]

'perf kvm stat report/record' generates a statistical analysis of KVM
events and can be used to analyze guest exit reasons. This patch tries
to add stat support on riscv.

Map the return value of trace_kvm_exit() to the specific cause of the 
exception, and export it to userspace.

It records on two available KVM tracepoints for riscv: "kvm:kvm_entry"
and "kvm:kvm_exit", and reports statistical data which includes events
handles time, samples, and so on.

Simple tests go below:

# ./perf kvm record -e "kvm:kvm_entry" -e "kvm:kvm_exit"
Lowering default frequency rate from 4000 to 2500.
Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate.
[ perf record: Woken up 18 times to write data ]
[ perf record: Captured and wrote 5.433 MB perf.data.guest (62519 samples) 

# ./perf kvm report
31K kvm:kvm_entry
31K kvm:kvm_exit

# ./perf kvm stat record -a
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 8.502 MB perf.data.guest (99338 samples) ]

# ./perf kvm stat report --event=vmexit
Event name                Samples   Sample%    Time (ns)     Time%   Max Time (ns)   Min Time (ns)  Mean Time (ns)
STORE_GUEST_PAGE_FAULT     26968     54.00%    2003031800    40.00%     3361400         27600          74274
LOAD_GUEST_PAGE_FAULT      17645     35.00%    1153338100    23.00%     2513400         30800          65363
VIRTUAL_INST_FAULT         1247      2.00%     340820800     6.00%      1190800         43300          273312
INST_GUEST_PAGE_FAULT      1128      2.00%     340645800     6.00%      2123200         30200          301990
SUPERVISOR_SYSCALL         1019      2.00%     245989900     4.00%      1851500         29300          241403
LOAD_ACCESS                986       1.00%     671556200     13.00%     4180200         100700         681091
INST_ACCESS                655       1.00%     170054800     3.00%      1808300         54600          259625
HYPERVISOR_SYSCALL         21        0.00%     4276400       0.00%      716500          116000         203638 

Shenlin Liang (2):
  RISCV: KVM: add tracepoints for entry and exit events
  perf kvm/riscv: Port perf kvm stat to RISC-V

 arch/riscv/kvm/trace_riscv.h                  | 60 ++++++++++++++
 arch/riscv/kvm/vcpu.c                         |  7 ++
 tools/perf/arch/riscv/Makefile                |  1 +
 tools/perf/arch/riscv/util/Build              |  1 +
 tools/perf/arch/riscv/util/kvm-stat.c         | 78 +++++++++++++++++++
 .../arch/riscv/util/riscv_exception_types.h   | 41 ++++++++++
 6 files changed, 188 insertions(+)
 create mode 100644 arch/riscv/kvm/trace_riscv.h
 create mode 100644 tools/perf/arch/riscv/util/kvm-stat.c
 create mode 100644 tools/perf/arch/riscv/util/riscv_exception_types.h

-- 
2.37.2

[PATCH 1/2] RISCV: KVM: add tracepoints for entry and exit events

[Shenlin Liang]

Like other architectures, RISCV KVM also needs to add these event
tracepoints to count the number of times kvm guest entry/exit.

Signed-off-by: Shenlin Liang <liangshenlin@eswincomputing.com>
---
 arch/riscv/kvm/trace_riscv.h | 60 ++++++++++++++++++++++++++++++++++++
 arch/riscv/kvm/vcpu.c        |  7 +++++
 2 files changed, 67 insertions(+)
 create mode 100644 arch/riscv/kvm/trace_riscv.h

diff --git a/arch/riscv/kvm/trace_riscv.h b/arch/riscv/kvm/trace_riscv.h
new file mode 100644
index 000000000000..5848083c7a5e
--- /dev/null
+++ b/arch/riscv/kvm/trace_riscv.h
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tracepoints for RISC-V KVM
+ *
+ * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ */
+#if !defined(_TRACE_RSICV_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RSICV_KVM_H
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM kvm
+
+TRACE_EVENT(kvm_entry,
+	TP_PROTO(struct kvm_vcpu *vcpu),
+	TP_ARGS(vcpu),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, pc)
+	),
+
+	TP_fast_assign(
+		__entry->pc	= vcpu->arch.guest_context.sepc;
+	),
+
+	TP_printk("PC: 0x%016lx", __entry->pc)
+);
+
+TRACE_EVENT(kvm_exit,
+	TP_PROTO(struct kvm_vcpu *vcpu, unsigned long exit_reason,
+			unsigned long scause),
+	TP_ARGS(vcpu, exit_reason, scause),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, pc)
+		__field(unsigned long, exit_reason)
+		__field(unsigned long, scause)
+	),
+
+	TP_fast_assign(
+		__entry->pc		= vcpu->arch.guest_context.sepc;
+		__entry->exit_reason	= exit_reason;
+		__entry->scause		= scause;
+	),
+
+	TP_printk("EXIT_REASON:0x%lx,PC: 0x%016lx,SCAUSE:0x%lx",
+			__entry->exit_reason, __entry->pc, __entry->scause)
+);
+
+#endif /* _TRACE_RSICV_KVM_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace_riscv
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index b5ca9f2e98ac..ed0932f0d514 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -21,6 +21,9 @@
 #include <asm/cacheflush.h>
 #include <asm/kvm_vcpu_vector.h>
 
+#define CREATE_TRACE_POINTS
+#include "trace_riscv.h"
+
 const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
 	KVM_GENERIC_VCPU_STATS(),
 	STATS_DESC_COUNTER(VCPU, ecall_exit_stat),
@@ -782,6 +785,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		 */
 		kvm_riscv_local_tlb_sanitize(vcpu);
 
+		trace_kvm_entry(vcpu);
+
 		guest_timing_enter_irqoff();
 
 		kvm_riscv_vcpu_enter_exit(vcpu);
@@ -820,6 +825,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 
 		local_irq_enable();
 
+		trace_kvm_exit(vcpu, run->exit_reason, trap.scause);
+
 		preempt_enable();
 
 		kvm_vcpu_srcu_read_lock(vcpu);
-- 
2.37.2

[PATCH 2/2] perf kvm/riscv: Port perf kvm stat to RISC-V

[Shenlin Liang]

'perf kvm stat report/record' generates a statistical analysis of KVM
events and can be used to analyze guest exit reasons.

"report" reports statistical analysis of guest exit events.

To record kvm events on the host:
 # perf kvm stat record -a

To report kvm VM EXIT events:
 # perf kvm stat report --event=vmexit

Signed-off-by: Shenlin Liang <liangshenlin@eswincomputing.com>
---
 tools/perf/arch/riscv/Makefile                |  1 +
 tools/perf/arch/riscv/util/Build              |  1 +
 tools/perf/arch/riscv/util/kvm-stat.c         | 78 +++++++++++++++++++
 .../arch/riscv/util/riscv_exception_types.h   | 41 ++++++++++
 4 files changed, 121 insertions(+)
 create mode 100644 tools/perf/arch/riscv/util/kvm-stat.c
 create mode 100644 tools/perf/arch/riscv/util/riscv_exception_types.h

diff --git a/tools/perf/arch/riscv/Makefile b/tools/perf/arch/riscv/Makefile
index a8d25d005207..e1e445615536 100644
--- a/tools/perf/arch/riscv/Makefile
+++ b/tools/perf/arch/riscv/Makefile
@@ -3,3 +3,4 @@ PERF_HAVE_DWARF_REGS := 1
 endif
 PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
 PERF_HAVE_JITDUMP := 1
+HAVE_KVM_STAT_SUPPORT := 1
\ No newline at end of file
diff --git a/tools/perf/arch/riscv/util/Build b/tools/perf/arch/riscv/util/Build
index 603dbb5ae4dc..d72b04f8d32b 100644
--- a/tools/perf/arch/riscv/util/Build
+++ b/tools/perf/arch/riscv/util/Build
@@ -1,5 +1,6 @@
 perf-y += perf_regs.o
 perf-y += header.o
 
+perf-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o
 perf-$(CONFIG_DWARF) += dwarf-regs.o
 perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
diff --git a/tools/perf/arch/riscv/util/kvm-stat.c b/tools/perf/arch/riscv/util/kvm-stat.c
new file mode 100644
index 000000000000..db7183e0f09f
--- /dev/null
+++ b/tools/perf/arch/riscv/util/kvm-stat.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Arch specific functions for perf kvm stat.
+ *
+ * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ */
+#include <errno.h>
+#include <memory.h>
+#include "../../../util/evsel.h"
+#include "../../../util/kvm-stat.h"
+#include "riscv_exception_types.h"
+#include "debug.h"
+
+define_exit_reasons_table(riscv_exit_reasons, kvm_riscv_exception_class);
+
+const char *kvm_exit_reason = "scause";
+const char *kvm_entry_trace = "kvm:kvm_entry";
+const char *kvm_exit_trace = "kvm:kvm_exit";
+
+const char *kvm_events_tp[] = {
+	"kvm:kvm_entry",
+	"kvm:kvm_exit",
+	NULL,
+};
+
+static void event_get_key(struct evsel *evsel,
+			  struct perf_sample *sample,
+			  struct event_key *key)
+{
+	key->info = 0;
+	key->key = evsel__intval(evsel, sample, kvm_exit_reason);
+	key->key = (int)key->key;
+	key->exit_reasons = riscv_exit_reasons;
+}
+
+static bool event_begin(struct evsel *evsel,
+			struct perf_sample *sample __maybe_unused,
+			struct event_key *key __maybe_unused)
+{
+	return evsel__name_is(evsel, kvm_entry_trace);
+}
+
+static bool event_end(struct evsel *evsel,
+		      struct perf_sample *sample,
+		      struct event_key *key)
+{
+	if (evsel__name_is(evsel, kvm_exit_trace)) {
+		event_get_key(evsel, sample, key);
+		return true;
+	}
+	return false;
+}
+
+static struct kvm_events_ops exit_events = {
+	.is_begin_event = event_begin,
+	.is_end_event	= event_end,
+	.decode_key	= exit_event_decode_key,
+	.name		= "VM-EXIT"
+};
+
+struct kvm_reg_events_ops kvm_reg_events_ops[] = {
+	{
+		.name	= "vmexit",
+		.ops	= &exit_events,
+	},
+	{ NULL, NULL },
+};
+
+const char * const kvm_skip_events[] = {
+	NULL,
+};
+
+int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid __maybe_unused)
+{
+	kvm->exit_reasons_isa = "riscv64";
+	return 0;
+}
diff --git a/tools/perf/arch/riscv/util/riscv_exception_types.h b/tools/perf/arch/riscv/util/riscv_exception_types.h
new file mode 100644
index 000000000000..2e42150f72b2
--- /dev/null
+++ b/tools/perf/arch/riscv/util/riscv_exception_types.h
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISCV exception types
+ *
+ * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ */
+#ifndef ARCH_PERF_RISCV_EXCEPTION_TYPES_H
+#define ARCH_PERF_RISCV_EXCEPTION_TYPES_H
+
+#define EXC_INST_MISALIGNED 0
+#define EXC_INST_ACCESS 1
+#define EXC_INST_ILLEGAL 2
+#define EXC_BREAKPOINT 3
+#define EXC_LOAD_MISALIGNED 4
+#define EXC_LOAD_ACCESS 5
+#define EXC_STORE_MISALIGNED 6
+#define EXC_STORE_ACCESS 7
+#define EXC_SYSCALL 8
+#define EXC_HYPERVISOR_SYSCALL 9
+#define EXC_SUPERVISOR_SYSCALL 10
+#define EXC_INST_PAGE_FAULT 12
+#define EXC_LOAD_PAGE_FAULT 13
+#define EXC_STORE_PAGE_FAULT 15
+#define EXC_INST_GUEST_PAGE_FAULT 20
+#define EXC_LOAD_GUEST_PAGE_FAULT 21
+#define EXC_VIRTUAL_INST_FAULT 22
+#define EXC_STORE_GUEST_PAGE_FAULT 23
+
+#define EXC(x) {EXC_##x, #x }
+
+#define kvm_riscv_exception_class                                           \
+	(EXC(INST_MISALIGNED), EXC(INST_ACCESS), EXC(INST_ILLEGAL),         \
+	 EXC(BREAKPOINT), EXC(LOAD_MISALIGNED), EXC(LOAD_ACCESS),           \
+	 EXC(STORE_MISALIGNED), EXC(STORE_ACCESS), EXC(SYSCALL),            \
+	 EXC(HYPERVISOR_SYSCALL), EXC(SUPERVISOR_SYSCALL),                  \
+	 EXC(INST_PAGE_FAULT), EXC(LOAD_PAGE_FAULT), EXC(STORE_PAGE_FAULT), \
+	 EXC(INST_GUEST_PAGE_FAULT), EXC(LOAD_GUEST_PAGE_FAULT),            \
+	 EXC(VIRTUAL_INST_FAULT), EXC(STORE_GUEST_PAGE_FAULT))
+
+#endif /* ARCH_PERF_RISCV_EXCEPTION_TYPES_H */
-- 
2.37.2

Re: [PATCH 0/2] perf kvm: Add kvm stat support on riscv

[Shenlin Liang]

Gentle ping...

> 
> 'perf kvm stat report/record' generates a statistical analysis of KVM
> events and can be used to analyze guest exit reasons. This patch tries
> to add stat support on riscv.
> 
> Map the return value of trace_kvm_exit() to the specific cause of the 
> exception, and export it to userspace.
> 
> It records on two available KVM tracepoints for riscv: "kvm:kvm_entry"
> and "kvm:kvm_exit", and reports statistical data which includes events
> handles time, samples, and so on.
> 
> Simple tests go below:
> 
> # ./perf kvm record -e "kvm:kvm_entry" -e "kvm:kvm_exit"
> Lowering default frequency rate from 4000 to 2500.
> Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate.
> [ perf record: Woken up 18 times to write data ]
> [ perf record: Captured and wrote 5.433 MB perf.data.guest (62519 samples) 
> 
> # ./perf kvm report
> 31K kvm:kvm_entry
> 31K kvm:kvm_exit
> 
> # ./perf kvm stat record -a
> [ perf record: Woken up 3 times to write data ]
> [ perf record: Captured and wrote 8.502 MB perf.data.guest (99338 samples) ]
> 
> # ./perf kvm stat report --event=vmexit
> Event name                Samples   Sample%    Time (ns)     Time%   Max Time (ns)   Min Time (ns)  Mean Time (ns)
> STORE_GUEST_PAGE_FAULT     26968     54.00%    2003031800    40.00%     3361400         27600          74274
> LOAD_GUEST_PAGE_FAULT      17645     35.00%    1153338100    23.00%     2513400         30800          65363
> VIRTUAL_INST_FAULT         1247      2.00%     340820800     6.00%      1190800         43300          273312
> INST_GUEST_PAGE_FAULT      1128      2.00%     340645800     6.00%      2123200         30200          301990
> SUPERVISOR_SYSCALL         1019      2.00%     245989900     4.00%      1851500         29300          241403
> LOAD_ACCESS                986       1.00%     671556200     13.00%     4180200         100700         681091
> INST_ACCESS                655       1.00%     170054800     3.00%      1808300         54600          259625
> HYPERVISOR_SYSCALL         21        0.00%     4276400       0.00%      716500          116000         203638 
> 
> Shenlin Liang (2):
>   RISCV: KVM: add tracepoints for entry and exit events
>   perf kvm/riscv: Port perf kvm stat to RISC-V
> 
>  arch/riscv/kvm/trace_riscv.h                  | 60 ++++++++++++++
>  arch/riscv/kvm/vcpu.c                         |  7 ++
>  tools/perf/arch/riscv/Makefile                |  1 +
>  tools/perf/arch/riscv/util/Build              |  1 +
>  tools/perf/arch/riscv/util/kvm-stat.c         | 78 +++++++++++++++++++
>  .../arch/riscv/util/riscv_exception_types.h   | 41 ++++++++++
>  6 files changed, 188 insertions(+)
>  create mode 100644 arch/riscv/kvm/trace_riscv.h
>  create mode 100644 tools/perf/arch/riscv/util/kvm-stat.c
>  create mode 100644 tools/perf/arch/riscv/util/riscv_exception_types.h
> 
> -- 
> 2.37.2

Re: [PATCH 1/2] RISCV: KVM: add tracepoints for entry and exit events

[Anup Patel]

On Thu, Mar 28, 2024 at 8:49 AM Shenlin Liang
<liangshenlin@eswincomputing.com> wrote:
>
> Like other architectures, RISCV KVM also needs to add these event
> tracepoints to count the number of times kvm guest entry/exit.
>
> Signed-off-by: Shenlin Liang <liangshenlin@eswincomputing.com>
> ---
>  arch/riscv/kvm/trace_riscv.h | 60 ++++++++++++++++++++++++++++++++++++
>  arch/riscv/kvm/vcpu.c        |  7 +++++
>  2 files changed, 67 insertions(+)
>  create mode 100644 arch/riscv/kvm/trace_riscv.h
>
> diff --git a/arch/riscv/kvm/trace_riscv.h b/arch/riscv/kvm/trace_riscv.h
> new file mode 100644
> index 000000000000..5848083c7a5e
> --- /dev/null
> +++ b/arch/riscv/kvm/trace_riscv.h
> @@ -0,0 +1,60 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Tracepoints for RISC-V KVM
> + *
> + * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
> + *
> + */
> +#if !defined(_TRACE_RSICV_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_RSICV_KVM_H

s/_RSICV_/_RISCV_/

> +
> +#include <linux/tracepoint.h>
> +
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM kvm
> +
> +TRACE_EVENT(kvm_entry,
> +       TP_PROTO(struct kvm_vcpu *vcpu),
> +       TP_ARGS(vcpu),
> +
> +       TP_STRUCT__entry(
> +               __field(unsigned long, pc)
> +       ),
> +
> +       TP_fast_assign(
> +               __entry->pc     = vcpu->arch.guest_context.sepc;
> +       ),
> +
> +       TP_printk("PC: 0x%016lx", __entry->pc)
> +);
> +
> +TRACE_EVENT(kvm_exit,
> +       TP_PROTO(struct kvm_vcpu *vcpu, unsigned long exit_reason,
> +                       unsigned long scause),
> +       TP_ARGS(vcpu, exit_reason, scause),
> +
> +       TP_STRUCT__entry(
> +               __field(unsigned long, pc)
> +               __field(unsigned long, exit_reason)
> +               __field(unsigned long, scause)

This is not the right contents describing a KVM exit.

The fields over here should be aligned with "struct kvm_cpu_trap"
so we should have following fields:
    __field(unsigned long, sepc)
    __field(unsigned long, scause)
    __field(unsigned long, stval)
    __field(unsigned long, htval)
    __field(unsigned long, htinst)

> +       ),
> +
> +       TP_fast_assign(
> +               __entry->pc             = vcpu->arch.guest_context.sepc;
> +               __entry->exit_reason    = exit_reason;
> +               __entry->scause         = scause;
> +       ),
> +
> +       TP_printk("EXIT_REASON:0x%lx,PC: 0x%016lx,SCAUSE:0x%lx",
> +                       __entry->exit_reason, __entry->pc, __entry->scause)
> +);
> +
> +#endif /* _TRACE_RSICV_KVM_H */
> +
> +#undef TRACE_INCLUDE_PATH
> +#define TRACE_INCLUDE_PATH .
> +#undef TRACE_INCLUDE_FILE
> +#define TRACE_INCLUDE_FILE trace_riscv
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>
> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> index b5ca9f2e98ac..ed0932f0d514 100644
> --- a/arch/riscv/kvm/vcpu.c
> +++ b/arch/riscv/kvm/vcpu.c
> @@ -21,6 +21,9 @@
>  #include <asm/cacheflush.h>
>  #include <asm/kvm_vcpu_vector.h>
>
> +#define CREATE_TRACE_POINTS
> +#include "trace_riscv.h"
> +
>  const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
>         KVM_GENERIC_VCPU_STATS(),
>         STATS_DESC_COUNTER(VCPU, ecall_exit_stat),
> @@ -782,6 +785,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
>                  */
>                 kvm_riscv_local_tlb_sanitize(vcpu);
>
> +               trace_kvm_entry(vcpu);
> +
>                 guest_timing_enter_irqoff();
>
>                 kvm_riscv_vcpu_enter_exit(vcpu);
> @@ -820,6 +825,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
>
>                 local_irq_enable();
>
> +               trace_kvm_exit(vcpu, run->exit_reason, trap.scause);
> +
>                 preempt_enable();
>
>                 kvm_vcpu_srcu_read_lock(vcpu);
> --
> 2.37.2
>

Regards,
Anup

Re: [PATCH 1/2] RISCV: KVM: add tracepoints for entry and exit events

[Eric Cheng]

On 3/28/2024 11:12 AM, Shenlin Liang wrote:
> Like other architectures, RISCV KVM also needs to add these event
> tracepoints to count the number of times kvm guest entry/exit.
> 
> Signed-off-by: Shenlin Liang <liangshenlin@eswincomputing.com>
> ---
>   arch/riscv/kvm/trace_riscv.h | 60 ++++++++++++++++++++++++++++++++++++

Conventionally, it should be named to trace.h, especially if only one. Refer to 
other arch's.

Re: [PATCH 1/2] RISCV: KVM: add tracepoints for entry and exit events

[Shenlin Liang]

On 2024-04-08 20:37, Anup Patel <anup@brainfault.org> wrote:

> 
> On Thu, Mar 28, 2024 at 8:49 AM Shenlin Liang
> <liangshenlin@eswincomputing.com> wrote:
> >
> > Like other architectures, RISCV KVM also needs to add these event
> > tracepoints to count the number of times kvm guest entry/exit.
> >
> > Signed-off-by: Shenlin Liang <liangshenlin@eswincomputing.com>
> > ---
> >  arch/riscv/kvm/trace_riscv.h | 60 ++++++++++++++++++++++++++++++++++++
> >  arch/riscv/kvm/vcpu.c        |  7 +++++
> >  2 files changed, 67 insertions(+)
> >  create mode 100644 arch/riscv/kvm/trace_riscv.h
> >
> > diff --git a/arch/riscv/kvm/trace_riscv.h b/arch/riscv/kvm/trace_riscv.h
> > new file mode 100644
> > index 000000000000..5848083c7a5e
> > --- /dev/null
> > +++ b/arch/riscv/kvm/trace_riscv.h
> > @@ -0,0 +1,60 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Tracepoints for RISC-V KVM
> > + *
> > + * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
> > + *
> > + */
> > +#if !defined(_TRACE_RSICV_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
> > +#define _TRACE_RSICV_KVM_H
> 
> s/_RSICV_/_RISCV_/
> 
> > +
> > +#include <linux/tracepoint.h>
> > +
> > +#undef TRACE_SYSTEM
> > +#define TRACE_SYSTEM kvm
> > +
> > +TRACE_EVENT(kvm_entry,
> > +       TP_PROTO(struct kvm_vcpu *vcpu),
> > +       TP_ARGS(vcpu),
> > +
> > +       TP_STRUCT__entry(
> > +               __field(unsigned long, pc)
> > +       ),
> > +
> > +       TP_fast_assign(
> > +               __entry->pc     = vcpu->arch.guest_context.sepc;
> > +       ),
> > +
> > +       TP_printk("PC: 0x%016lx", __entry->pc)
> > +);
> > +
> > +TRACE_EVENT(kvm_exit,
> > +       TP_PROTO(struct kvm_vcpu *vcpu, unsigned long exit_reason,
> > +                       unsigned long scause),
> > +       TP_ARGS(vcpu, exit_reason, scause),
> > +
> > +       TP_STRUCT__entry(
> > +               __field(unsigned long, pc)
> > +               __field(unsigned long, exit_reason)
> > +               __field(unsigned long, scause)
> 
> This is not the right contents describing a KVM exit.
> 
> The fields over here should be aligned with "struct kvm_cpu_trap"
> so we should have following fields:
>     __field(unsigned long, sepc)
>     __field(unsigned long, scause)
>     __field(unsigned long, stval)
>     __field(unsigned long, htval)
>     __field(unsigned long, htinst)
> 
> > +       ),
> > +
> > +       TP_fast_assign(
> > +               __entry->pc             = vcpu->arch.guest_context.sepc;
> > +               __entry->exit_reason    = exit_reason;
> > +               __entry->scause         = scause;
> > +       ),
> > +
> > +       TP_printk("EXIT_REASON:0x%lx,PC: 0x%016lx,SCAUSE:0x%lx",
> > +                       __entry->exit_reason, __entry->pc, __entry->scause)
> > +);
> > +
> > +#endif /* _TRACE_RSICV_KVM_H */
> > +
> > +#undef TRACE_INCLUDE_PATH
> > +#define TRACE_INCLUDE_PATH .
> > +#undef TRACE_INCLUDE_FILE
> > +#define TRACE_INCLUDE_FILE trace_riscv
> > +
> > +/* This part must be outside protection */
> > +#include <trace/define_trace.h>
> > diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> > index b5ca9f2e98ac..ed0932f0d514 100644
> > --- a/arch/riscv/kvm/vcpu.c
> > +++ b/arch/riscv/kvm/vcpu.c
> > @@ -21,6 +21,9 @@
> >  #include <asm/cacheflush.h>
> >  #include <asm/kvm_vcpu_vector.h>
> >
> > +#define CREATE_TRACE_POINTS
> > +#include "trace_riscv.h"
> > +
> >  const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> >         KVM_GENERIC_VCPU_STATS(),
> >         STATS_DESC_COUNTER(VCPU, ecall_exit_stat),
> > @@ -782,6 +785,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
> >                  */
> >                 kvm_riscv_local_tlb_sanitize(vcpu);
> >
> > +               trace_kvm_entry(vcpu);
> > +
> >                 guest_timing_enter_irqoff();
> >
> >                 kvm_riscv_vcpu_enter_exit(vcpu);
> > @@ -820,6 +825,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
> >
> >                 local_irq_enable();
> >
> > +               trace_kvm_exit(vcpu, run->exit_reason, trap.scause);
> > +
> >                 preempt_enable();
> >
> >                 kvm_vcpu_srcu_read_lock(vcpu);
> > --
> > 2.37.2
> >
> 
> Regards,
> Anup

Thank you for the review. I will send the v2 version.

Re: [PATCH 1/2] RISCV: KVM: add tracepoints for entry and exit events

[Shenlin Liang]

On 2024-04-10 15:12, Eric Cheng <eric.cheng.linux@gmail.com> wrote:

> 
> On 3/28/2024 11:12 AM, Shenlin Liang wrote:
> > Like other architectures, RISCV KVM also needs to add these event
> > tracepoints to count the number of times kvm guest entry/exit.
> > 
> > Signed-off-by: Shenlin Liang <liangshenlin@eswincomputing.com>
> > ---
> >   arch/riscv/kvm/trace_riscv.h | 60 ++++++++++++++++++++++++++++++++++++
> 
> Conventionally, it should be named to trace.h, especially if only one. Refer to 
> other arch's.

Thank you for the review. I will send the v2 version.