Arch-PEBS introduces a new MSR IA32_PEBS_BASE to store the arch-PEBS
buffer physical address. This patch allocates arch-PEBS buffer and then
initialize IA32_PEBS_BASE MSR with the buffer physical address.
Co-developed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
arch/x86/events/intel/core.c | 11 ++++-
arch/x86/events/intel/ds.c | 82 ++++++++++++++++++++++++++++-----
arch/x86/events/perf_event.h | 11 ++++-
arch/x86/include/asm/intel_ds.h | 3 +-
4 files changed, 92 insertions(+), 15 deletions(-)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index de4dbde28adc..6e04d73dfae5 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -5227,7 +5227,13 @@ int intel_cpuc_prepare(struct cpu_hw_events *cpuc, int cpu)
static int intel_pmu_cpu_prepare(int cpu)
{
- return intel_cpuc_prepare(&per_cpu(cpu_hw_events, cpu), cpu);
+ int ret;
+
+ ret = intel_cpuc_prepare(&per_cpu(cpu_hw_events, cpu), cpu);
+ if (ret)
+ return ret;
+
+ return alloc_arch_pebs_buf_on_cpu(cpu);
}
static void flip_smm_bit(void *data)
@@ -5458,6 +5464,7 @@ static void intel_pmu_cpu_starting(int cpu)
return;
init_debug_store_on_cpu(cpu);
+ init_arch_pebs_on_cpu(cpu);
/*
* Deal with CPUs that don't clear their LBRs on power-up, and that may
* even boot with LBRs enabled.
@@ -5555,6 +5562,7 @@ static void free_excl_cntrs(struct cpu_hw_events *cpuc)
static void intel_pmu_cpu_dying(int cpu)
{
fini_debug_store_on_cpu(cpu);
+ fini_arch_pebs_on_cpu(cpu);
}
void intel_cpuc_finish(struct cpu_hw_events *cpuc)
@@ -5575,6 +5583,7 @@ static void intel_pmu_cpu_dead(int cpu)
{
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
+ release_arch_pebs_buf_on_cpu(cpu);
intel_cpuc_finish(cpuc);
if (is_hybrid() && cpuc->pmu)
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index fe1bf373409e..5c26a5235f94 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -625,13 +625,18 @@ static int alloc_pebs_buffer(int cpu)
int max, node = cpu_to_node(cpu);
void *buffer, *insn_buff, *cea;
- if (!x86_pmu.ds_pebs)
+ if (!intel_pmu_has_pebs())
return 0;
buffer = dsalloc_pages(bsiz, GFP_KERNEL, cpu);
if (unlikely(!buffer))
return -ENOMEM;
+ if (x86_pmu.arch_pebs) {
+ hwev->pebs_vaddr = buffer;
+ return 0;
+ }
+
/*
* HSW+ already provides us the eventing ip; no need to allocate this
* buffer then.
@@ -644,7 +649,7 @@ static int alloc_pebs_buffer(int cpu)
}
per_cpu(insn_buffer, cpu) = insn_buff;
}
- hwev->ds_pebs_vaddr = buffer;
+ hwev->pebs_vaddr = buffer;
/* Update the cpu entry area mapping */
cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
ds->pebs_buffer_base = (unsigned long) cea;
@@ -660,17 +665,20 @@ static void release_pebs_buffer(int cpu)
struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
void *cea;
- if (!x86_pmu.ds_pebs)
+ if (!intel_pmu_has_pebs())
return;
- kfree(per_cpu(insn_buffer, cpu));
- per_cpu(insn_buffer, cpu) = NULL;
+ if (x86_pmu.ds_pebs) {
+ kfree(per_cpu(insn_buffer, cpu));
+ per_cpu(insn_buffer, cpu) = NULL;
- /* Clear the fixmap */
- cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
- ds_clear_cea(cea, x86_pmu.pebs_buffer_size);
- dsfree_pages(hwev->ds_pebs_vaddr, x86_pmu.pebs_buffer_size);
- hwev->ds_pebs_vaddr = NULL;
+ /* Clear the fixmap */
+ cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
+ ds_clear_cea(cea, x86_pmu.pebs_buffer_size);
+ }
+
+ dsfree_pages(hwev->pebs_vaddr, x86_pmu.pebs_buffer_size);
+ hwev->pebs_vaddr = NULL;
}
static int alloc_bts_buffer(int cpu)
@@ -823,6 +831,56 @@ void reserve_ds_buffers(void)
}
}
+inline int alloc_arch_pebs_buf_on_cpu(int cpu)
+{
+ if (!x86_pmu.arch_pebs)
+ return 0;
+
+ return alloc_pebs_buffer(cpu);
+}
+
+inline void release_arch_pebs_buf_on_cpu(int cpu)
+{
+ if (!x86_pmu.arch_pebs)
+ return;
+
+ release_pebs_buffer(cpu);
+}
+
+void init_arch_pebs_on_cpu(int cpu)
+{
+ struct cpu_hw_events *cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
+ u64 arch_pebs_base;
+
+ if (!x86_pmu.arch_pebs)
+ return;
+
+ if (!cpuc->pebs_vaddr) {
+ WARN(1, "Fail to allocate PEBS buffer on CPU %d\n", cpu);
+ x86_pmu.pebs_active = 0;
+ return;
+ }
+
+ /*
+ * 4KB-aligned pointer of the output buffer
+ * (__alloc_pages_node() return page aligned address)
+ * Buffer Size = 4KB * 2^SIZE
+ * contiguous physical buffer (__alloc_pages_node() with order)
+ */
+ arch_pebs_base = virt_to_phys(cpuc->pebs_vaddr) | PEBS_BUFFER_SHIFT;
+ wrmsr_on_cpu(cpu, MSR_IA32_PEBS_BASE, (u32)arch_pebs_base,
+ (u32)(arch_pebs_base >> 32));
+ x86_pmu.pebs_active = 1;
+}
+
+inline void fini_arch_pebs_on_cpu(int cpu)
+{
+ if (!x86_pmu.arch_pebs)
+ return;
+
+ wrmsr_on_cpu(cpu, MSR_IA32_PEBS_BASE, 0, 0);
+}
+
/*
* BTS
*/
@@ -2883,8 +2941,8 @@ static void intel_pmu_drain_arch_pebs(struct pt_regs *iregs,
return;
}
- base = cpuc->ds_pebs_vaddr;
- top = (void *)((u64)cpuc->ds_pebs_vaddr +
+ base = cpuc->pebs_vaddr;
+ top = (void *)((u64)cpuc->pebs_vaddr +
(index.wr << ARCH_PEBS_INDEX_WR_SHIFT));
index.wr = 0;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index ca5289980b52..13f411bca6bc 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -283,8 +283,9 @@ struct cpu_hw_events {
* Intel DebugStore bits
*/
struct debug_store *ds;
- void *ds_pebs_vaddr;
void *ds_bts_vaddr;
+ /* DS based PEBS or arch-PEBS buffer address */
+ void *pebs_vaddr;
u64 pebs_enabled;
int n_pebs;
int n_large_pebs;
@@ -1617,6 +1618,14 @@ extern void intel_cpuc_finish(struct cpu_hw_events *cpuc);
int intel_pmu_init(void);
+int alloc_arch_pebs_buf_on_cpu(int cpu);
+
+void release_arch_pebs_buf_on_cpu(int cpu);
+
+void init_arch_pebs_on_cpu(int cpu);
+
+void fini_arch_pebs_on_cpu(int cpu);
+
void init_debug_store_on_cpu(int cpu);
void fini_debug_store_on_cpu(int cpu);
diff --git a/arch/x86/include/asm/intel_ds.h b/arch/x86/include/asm/intel_ds.h
index 5dbeac48a5b9..023c2883f9f3 100644
--- a/arch/x86/include/asm/intel_ds.h
+++ b/arch/x86/include/asm/intel_ds.h
@@ -4,7 +4,8 @@
#include <linux/percpu-defs.h>
#define BTS_BUFFER_SIZE (PAGE_SIZE << 4)
-#define PEBS_BUFFER_SIZE (PAGE_SIZE << 4)
+#define PEBS_BUFFER_SHIFT 4
+#define PEBS_BUFFER_SIZE (PAGE_SIZE << PEBS_BUFFER_SHIFT)
/* The maximal number of PEBS events: */
#define MAX_PEBS_EVENTS_FMT4 8
--
2.34.1
The following commit has been merged into the perf/core branch of tip:
Commit-ID: 9929dffce5ed7e2988e0274f4db98035508b16d9
Gitweb: https://git.kernel.org/tip/9929dffce5ed7e2988e0274f4db98035508b16d9
Author: Ingo Molnar <mingo@kernel.org>
AuthorDate: Wed, 12 Nov 2025 10:40:26 +01:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 12 Nov 2025 12:12:28 +01:00
perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use
The following commit introduced a build failure on x86-32:
21954c8a0ff ("perf/x86/intel: Process arch-PEBS records or record fragments")
...
arch/x86/events/intel/ds.c:2983:24: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
The forced type conversion to 'u64' and 'void *' are not 32-bit clean,
but they are also entirely unnecessary: ->pebs_vaddr is 'void *' already,
and integer-compatible pointer arithmetics will work just fine on it.
Fix & simplify the code.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: d21954c8a0ff ("perf/x86/intel: Process arch-PEBS records or record fragments")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Link: https://patch.msgid.link/20251029102136.61364-10-dapeng1.mi@linux.intel.com
---
arch/x86/events/intel/ds.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index c93bf97..2e170f2 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2979,8 +2979,7 @@ static void intel_pmu_drain_arch_pebs(struct pt_regs *iregs,
}
base = cpuc->pebs_vaddr;
- top = (void *)((u64)cpuc->pebs_vaddr +
- (index.wr << ARCH_PEBS_INDEX_WR_SHIFT));
+ top = cpuc->pebs_vaddr + (index.wr << ARCH_PEBS_INDEX_WR_SHIFT);
index.wr = 0;
index.full = 0;
The following commit has been merged into the perf/core branch of tip:
Commit-ID: 60f9f1d437201f6c457fc8a56f9df6d8a6d0bea6
Gitweb: https://git.kernel.org/tip/60f9f1d437201f6c457fc8a56f9df6d8a6d0bea6
Author: Ingo Molnar <mingo@kernel.org>
AuthorDate: Wed, 12 Nov 2025 10:40:26 +01:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 12 Nov 2025 10:49:35 +01:00
perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use
The following commit introduced a build failure on x86-32:
2721e8da2de7 ("perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR")
...
arch/x86/events/intel/ds.c:2983:24: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
The forced type conversion to 'u64' and 'void *' are not 32-bit clean,
but they are also entirely unnecessary: ->pebs_vaddr is 'void *' already,
and integer-compatible pointer arithmetics will work just fine on it.
Fix & simplify the code.
Fixes: 2721e8da2de7 ("perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://patch.msgid.link/20251029102136.61364-10-dapeng1.mi@linux.intel.com
---
arch/x86/events/intel/ds.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index c93bf97..2e170f2 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2979,8 +2979,7 @@ static void intel_pmu_drain_arch_pebs(struct pt_regs *iregs,
}
base = cpuc->pebs_vaddr;
- top = (void *)((u64)cpuc->pebs_vaddr +
- (index.wr << ARCH_PEBS_INDEX_WR_SHIFT));
+ top = cpuc->pebs_vaddr + (index.wr << ARCH_PEBS_INDEX_WR_SHIFT);
index.wr = 0;
index.full = 0;
The following commit has been merged into the perf/core branch of tip:
Commit-ID: 2721e8da2de7271533ac36285332219f700d16ca
Gitweb: https://git.kernel.org/tip/2721e8da2de7271533ac36285332219f700d16ca
Author: Dapeng Mi <dapeng1.mi@linux.intel.com>
AuthorDate: Wed, 29 Oct 2025 18:21:33 +08:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 07 Nov 2025 15:08:22 +01:00
perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR
Arch-PEBS introduces a new MSR IA32_PEBS_BASE to store the arch-PEBS
buffer physical address. This patch allocates arch-PEBS buffer and then
initialize IA32_PEBS_BASE MSR with the buffer physical address.
Co-developed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251029102136.61364-10-dapeng1.mi@linux.intel.com
---
arch/x86/events/intel/core.c | 11 +++-
arch/x86/events/intel/ds.c | 82 +++++++++++++++++++++++++++-----
arch/x86/events/perf_event.h | 11 +++-
arch/x86/include/asm/intel_ds.h | 3 +-
4 files changed, 92 insertions(+), 15 deletions(-)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index de4dbde..6e04d73 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -5227,7 +5227,13 @@ err:
static int intel_pmu_cpu_prepare(int cpu)
{
- return intel_cpuc_prepare(&per_cpu(cpu_hw_events, cpu), cpu);
+ int ret;
+
+ ret = intel_cpuc_prepare(&per_cpu(cpu_hw_events, cpu), cpu);
+ if (ret)
+ return ret;
+
+ return alloc_arch_pebs_buf_on_cpu(cpu);
}
static void flip_smm_bit(void *data)
@@ -5458,6 +5464,7 @@ static void intel_pmu_cpu_starting(int cpu)
return;
init_debug_store_on_cpu(cpu);
+ init_arch_pebs_on_cpu(cpu);
/*
* Deal with CPUs that don't clear their LBRs on power-up, and that may
* even boot with LBRs enabled.
@@ -5555,6 +5562,7 @@ static void free_excl_cntrs(struct cpu_hw_events *cpuc)
static void intel_pmu_cpu_dying(int cpu)
{
fini_debug_store_on_cpu(cpu);
+ fini_arch_pebs_on_cpu(cpu);
}
void intel_cpuc_finish(struct cpu_hw_events *cpuc)
@@ -5575,6 +5583,7 @@ static void intel_pmu_cpu_dead(int cpu)
{
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
+ release_arch_pebs_buf_on_cpu(cpu);
intel_cpuc_finish(cpuc);
if (is_hybrid() && cpuc->pmu)
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index fe1bf37..5c26a52 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -625,13 +625,18 @@ static int alloc_pebs_buffer(int cpu)
int max, node = cpu_to_node(cpu);
void *buffer, *insn_buff, *cea;
- if (!x86_pmu.ds_pebs)
+ if (!intel_pmu_has_pebs())
return 0;
buffer = dsalloc_pages(bsiz, GFP_KERNEL, cpu);
if (unlikely(!buffer))
return -ENOMEM;
+ if (x86_pmu.arch_pebs) {
+ hwev->pebs_vaddr = buffer;
+ return 0;
+ }
+
/*
* HSW+ already provides us the eventing ip; no need to allocate this
* buffer then.
@@ -644,7 +649,7 @@ static int alloc_pebs_buffer(int cpu)
}
per_cpu(insn_buffer, cpu) = insn_buff;
}
- hwev->ds_pebs_vaddr = buffer;
+ hwev->pebs_vaddr = buffer;
/* Update the cpu entry area mapping */
cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
ds->pebs_buffer_base = (unsigned long) cea;
@@ -660,17 +665,20 @@ static void release_pebs_buffer(int cpu)
struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
void *cea;
- if (!x86_pmu.ds_pebs)
+ if (!intel_pmu_has_pebs())
return;
- kfree(per_cpu(insn_buffer, cpu));
- per_cpu(insn_buffer, cpu) = NULL;
+ if (x86_pmu.ds_pebs) {
+ kfree(per_cpu(insn_buffer, cpu));
+ per_cpu(insn_buffer, cpu) = NULL;
- /* Clear the fixmap */
- cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
- ds_clear_cea(cea, x86_pmu.pebs_buffer_size);
- dsfree_pages(hwev->ds_pebs_vaddr, x86_pmu.pebs_buffer_size);
- hwev->ds_pebs_vaddr = NULL;
+ /* Clear the fixmap */
+ cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
+ ds_clear_cea(cea, x86_pmu.pebs_buffer_size);
+ }
+
+ dsfree_pages(hwev->pebs_vaddr, x86_pmu.pebs_buffer_size);
+ hwev->pebs_vaddr = NULL;
}
static int alloc_bts_buffer(int cpu)
@@ -823,6 +831,56 @@ void reserve_ds_buffers(void)
}
}
+inline int alloc_arch_pebs_buf_on_cpu(int cpu)
+{
+ if (!x86_pmu.arch_pebs)
+ return 0;
+
+ return alloc_pebs_buffer(cpu);
+}
+
+inline void release_arch_pebs_buf_on_cpu(int cpu)
+{
+ if (!x86_pmu.arch_pebs)
+ return;
+
+ release_pebs_buffer(cpu);
+}
+
+void init_arch_pebs_on_cpu(int cpu)
+{
+ struct cpu_hw_events *cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
+ u64 arch_pebs_base;
+
+ if (!x86_pmu.arch_pebs)
+ return;
+
+ if (!cpuc->pebs_vaddr) {
+ WARN(1, "Fail to allocate PEBS buffer on CPU %d\n", cpu);
+ x86_pmu.pebs_active = 0;
+ return;
+ }
+
+ /*
+ * 4KB-aligned pointer of the output buffer
+ * (__alloc_pages_node() return page aligned address)
+ * Buffer Size = 4KB * 2^SIZE
+ * contiguous physical buffer (__alloc_pages_node() with order)
+ */
+ arch_pebs_base = virt_to_phys(cpuc->pebs_vaddr) | PEBS_BUFFER_SHIFT;
+ wrmsr_on_cpu(cpu, MSR_IA32_PEBS_BASE, (u32)arch_pebs_base,
+ (u32)(arch_pebs_base >> 32));
+ x86_pmu.pebs_active = 1;
+}
+
+inline void fini_arch_pebs_on_cpu(int cpu)
+{
+ if (!x86_pmu.arch_pebs)
+ return;
+
+ wrmsr_on_cpu(cpu, MSR_IA32_PEBS_BASE, 0, 0);
+}
+
/*
* BTS
*/
@@ -2883,8 +2941,8 @@ static void intel_pmu_drain_arch_pebs(struct pt_regs *iregs,
return;
}
- base = cpuc->ds_pebs_vaddr;
- top = (void *)((u64)cpuc->ds_pebs_vaddr +
+ base = cpuc->pebs_vaddr;
+ top = (void *)((u64)cpuc->pebs_vaddr +
(index.wr << ARCH_PEBS_INDEX_WR_SHIFT));
index.wr = 0;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index ca52899..13f411b 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -283,8 +283,9 @@ struct cpu_hw_events {
* Intel DebugStore bits
*/
struct debug_store *ds;
- void *ds_pebs_vaddr;
void *ds_bts_vaddr;
+ /* DS based PEBS or arch-PEBS buffer address */
+ void *pebs_vaddr;
u64 pebs_enabled;
int n_pebs;
int n_large_pebs;
@@ -1617,6 +1618,14 @@ extern void intel_cpuc_finish(struct cpu_hw_events *cpuc);
int intel_pmu_init(void);
+int alloc_arch_pebs_buf_on_cpu(int cpu);
+
+void release_arch_pebs_buf_on_cpu(int cpu);
+
+void init_arch_pebs_on_cpu(int cpu);
+
+void fini_arch_pebs_on_cpu(int cpu);
+
void init_debug_store_on_cpu(int cpu);
void fini_debug_store_on_cpu(int cpu);
diff --git a/arch/x86/include/asm/intel_ds.h b/arch/x86/include/asm/intel_ds.h
index 5dbeac4..023c288 100644
--- a/arch/x86/include/asm/intel_ds.h
+++ b/arch/x86/include/asm/intel_ds.h
@@ -4,7 +4,8 @@
#include <linux/percpu-defs.h>
#define BTS_BUFFER_SIZE (PAGE_SIZE << 4)
-#define PEBS_BUFFER_SIZE (PAGE_SIZE << 4)
+#define PEBS_BUFFER_SHIFT 4
+#define PEBS_BUFFER_SIZE (PAGE_SIZE << PEBS_BUFFER_SHIFT)
/* The maximal number of PEBS events: */
#define MAX_PEBS_EVENTS_FMT4 8
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