[Qemu-devel] [PATCH v8 00/13] More fully implement ARM PMUv3

[Qemu-devel] [PATCH v8 00/13] More fully implement ARM PMUv3

[Aaron Lindsay]

The ARM PMU implementation currently contains a basic cycle counter, but
it is often useful to gather counts of other events, filter them based
on execution mode, and/or be notified on counter overflow. These patches
flesh out the implementations of various PMU registers including
PM[X]EVCNTR and PM[X]EVTYPER, add a struct definition to represent
arbitrary counter types, implement mode filtering, send interrupts on
counter overflow, and add instruction, cycle, and software increment
events.

Since v7 [1] I have made the following changes:
* Updated pmu_op_start/finish to not be called upon migration under KVM
* Added a patch updating PMCEID* to be 64-bit registers for AArch64 and
  added PMCEID2/3 for AArch32
* Changed get_pmceid() return two full 64-bit register values (since the
  underlying registers are now 64-bit post-ARMv8.1)
* Updated the comment for pmu_op_start/finish to match the
  implementation
* Added a check so the pmu_timer is not freed if it was not originally
  allocated

[1] - https://lists.gnu.org/archive/html/qemu-devel/2018-11/msg00837.html

Aaron Lindsay (13):
  migration: Add post_save function to VMStateDescription
  target/arm: Reorganize PMCCNTR accesses
  target/arm: Swap PMU values before/after migrations
  target/arm: Filter cycle counter based on PMCCFILTR_EL0
  target/arm: Allow AArch32 access for PMCCFILTR
  target/arm: Implement PMOVSSET
  target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]
  target/arm: Add array for supported PMU events, generate
    PMCEID[01]_EL0
  target/arm: Finish implementation of PM[X]EVCNTR and PM[X]EVTYPER
  target/arm: PMU: Add instruction and cycle events
  target/arm: PMU: Set PMCR.N to 4
  target/arm: Implement PMSWINC
  target/arm: Send interrupts on PMU counter overflow

 docs/devel/migration.rst    |   9 +-
 include/migration/vmstate.h |   1 +
 migration/vmstate.c         |  13 +-
 target/arm/cpu.c            |  28 +-
 target/arm/cpu.h            |  71 +++-
 target/arm/cpu64.c          |   4 -
 target/arm/helper.c         | 801 ++++++++++++++++++++++++++++++++----
 target/arm/machine.c        |  24 ++
 8 files changed, 846 insertions(+), 105 deletions(-)

-- 
2.19.1

[Qemu-devel] [PATCH v8 01/13] migration: Add post_save function to VMStateDescription

[Aaron Lindsay]

In some cases it may be helpful to modify state before saving it for
migration, and then modify the state back after it has been saved. The
existing pre_save function provides half of this functionality. This
patch adds a post_save function to provide the second half.

Signed-off-by: Aaron Lindsay <aclindsa@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 docs/devel/migration.rst    |  9 +++++++--
 include/migration/vmstate.h |  1 +
 migration/vmstate.c         | 13 ++++++++++++-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
index e7658ab050..220059679a 100644
--- a/docs/devel/migration.rst
+++ b/docs/devel/migration.rst
@@ -419,8 +419,13 @@ The functions to do that are inside a vmstate definition, and are called:
 
   This function is called before we save the state of one device.
 
-Example: You can look at hpet.c, that uses the three function to
-massage the state that is transferred.
+- ``int (*post_save)(void *opaque);``
+
+  This function is called after we save the state of one device
+  (even upon failure, unless the call to pre_save returned an error).
+
+Example: You can look at hpet.c, that uses the first three functions
+to massage the state that is transferred.
 
 The ``VMSTATE_WITH_TMP`` macro may be useful when the migration
 data doesn't match the stored device data well; it allows an
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 2b501d0466..9355d83056 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -185,6 +185,7 @@ struct VMStateDescription {
     int (*pre_load)(void *opaque);
     int (*post_load)(void *opaque, int version_id);
     int (*pre_save)(void *opaque);
+    int (*post_save)(void *opaque);
     bool (*needed)(void *opaque);
     VMStateField *fields;
     const VMStateDescription **subsections;
diff --git a/migration/vmstate.c b/migration/vmstate.c
index 0bc240a317..c15d75260a 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -387,6 +387,9 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
                 if (ret) {
                     error_report("Save of field %s/%s failed",
                                  vmsd->name, field->name);
+                    if (vmsd->post_save) {
+                        vmsd->post_save(opaque);
+                    }
                     return ret;
                 }
 
@@ -412,7 +415,15 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
         json_end_array(vmdesc);
     }
 
-    return vmstate_subsection_save(f, vmsd, opaque, vmdesc);
+    ret = vmstate_subsection_save(f, vmsd, opaque, vmdesc);
+
+    if (vmsd->post_save) {
+        int ps_ret = vmsd->post_save(opaque);
+        if (!ret) {
+            ret = ps_ret;
+        }
+    }
+    return ret;
 }
 
 static const VMStateDescription *
-- 
2.19.1

[Qemu-devel] [PATCH v8 02/13] target/arm: Reorganize PMCCNTR accesses

[Aaron Lindsay]

pmccntr_read and pmccntr_write contained duplicate code that was already
being handled by pmccntr_sync. Consolidate the duplicated code into two
functions: pmccntr_op_start and pmccntr_op_finish. Add a companion to
c15_ccnt in CPUARMState so that we can simultaneously save both the
architectural register value and the last underlying cycle count - this
ensures time isn't lost and will also allow us to access the 'old'
architectural register value in order to detect overflows in later
patches.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <aclindsa@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu.h    |  37 ++++++++++----
 target/arm/helper.c | 114 +++++++++++++++++++++++++++-----------------
 2 files changed, 98 insertions(+), 53 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 2a73fed9a0..61ac458627 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -468,10 +468,20 @@ typedef struct CPUARMState {
         uint64_t oslsr_el1; /* OS Lock Status */
         uint64_t mdcr_el2;
         uint64_t mdcr_el3;
-        /* If the counter is enabled, this stores the last time the counter
-         * was reset. Otherwise it stores the counter value
+        /* Stores the architectural value of the counter *the last time it was
+         * updated* by pmccntr_op_start. Accesses should always be surrounded
+         * by pmccntr_op_start/pmccntr_op_finish to guarantee the latest
+         * architecturally-correct value is being read/set.
          */
         uint64_t c15_ccnt;
+        /* Stores the delta between the architectural value and the underlying
+         * cycle count during normal operation. It is used to update c15_ccnt
+         * to be the correct architectural value before accesses. During
+         * accesses, c15_ccnt_delta contains the underlying count being used
+         * for the access, after which it reverts to the delta value in
+         * pmccntr_op_finish.
+         */
+        uint64_t c15_ccnt_delta;
         uint64_t pmccfiltr_el0; /* Performance Monitor Filter Register */
         uint64_t vpidr_el2; /* Virtualization Processor ID Register */
         uint64_t vmpidr_el2; /* Virtualization Multiprocessor ID Register */
@@ -956,15 +966,26 @@ int cpu_arm_signal_handler(int host_signum, void *pinfo,
                            void *puc);
 
 /**
- * pmccntr_sync
+ * pmccntr_op_start/finish
+ * @env: CPUARMState
+ *
+ * Convert the counter in the PMCCNTR between its delta form (the typical mode
+ * when it's enabled) and the guest-visible value. These two calls must always
+ * surround any action which might affect the counter.
+ */
+void pmccntr_op_start(CPUARMState *env);
+void pmccntr_op_finish(CPUARMState *env);
+
+/**
+ * pmu_op_start/finish
  * @env: CPUARMState
  *
- * Synchronises the counter in the PMCCNTR. This must always be called twice,
- * once before any action that might affect the timer and again afterwards.
- * The function is used to swap the state of the register if required.
- * This only happens when not in user mode (!CONFIG_USER_ONLY)
+ * Convert all PMU counters between their delta form (the typical mode when
+ * they are enabled) and the guest-visible values. These two calls must
+ * surround any action which might affect the counters.
  */
-void pmccntr_sync(CPUARMState *env);
+void pmu_op_start(CPUARMState *env);
+void pmu_op_finish(CPUARMState *env);
 
 /* SCTLR bit meanings. Several bits have been reused in newer
  * versions of the architecture; in that case we define constants
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 0da1424f72..497907fc79 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1085,28 +1085,63 @@ static inline bool arm_ccnt_enabled(CPUARMState *env)
 
     return true;
 }
-
-void pmccntr_sync(CPUARMState *env)
+/*
+ * Ensure c15_ccnt is the guest-visible count so that operations such as
+ * enabling/disabling the counter or filtering, modifying the count itself,
+ * etc. can be done logically. This is essentially a no-op if the counter is
+ * not enabled at the time of the call.
+ */
+void pmccntr_op_start(CPUARMState *env)
 {
-    uint64_t temp_ticks;
-
-    temp_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
+    uint64_t cycles = 0;
+    cycles = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
                           ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
 
-    if (env->cp15.c9_pmcr & PMCRD) {
-        /* Increment once every 64 processor clock cycles */
-        temp_ticks /= 64;
+    if (arm_ccnt_enabled(env)) {
+        uint64_t eff_cycles = cycles;
+        if (env->cp15.c9_pmcr & PMCRD) {
+            /* Increment once every 64 processor clock cycles */
+            eff_cycles /= 64;
+        }
+
+        env->cp15.c15_ccnt = eff_cycles - env->cp15.c15_ccnt_delta;
     }
+    env->cp15.c15_ccnt_delta = cycles;
+}
 
+/*
+ * If PMCCNTR is enabled, recalculate the delta between the clock and the
+ * guest-visible count. A call to pmccntr_op_finish should follow every call to
+ * pmccntr_op_start.
+ */
+void pmccntr_op_finish(CPUARMState *env)
+{
     if (arm_ccnt_enabled(env)) {
-        env->cp15.c15_ccnt = temp_ticks - env->cp15.c15_ccnt;
+        uint64_t prev_cycles = env->cp15.c15_ccnt_delta;
+
+        if (env->cp15.c9_pmcr & PMCRD) {
+            /* Increment once every 64 processor clock cycles */
+            prev_cycles /= 64;
+        }
+
+        env->cp15.c15_ccnt_delta = prev_cycles - env->cp15.c15_ccnt;
     }
 }
 
+void pmu_op_start(CPUARMState *env)
+{
+    pmccntr_op_start(env);
+}
+
+void pmu_op_finish(CPUARMState *env)
+{
+    pmccntr_op_finish(env);
+}
+
 static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                        uint64_t value)
 {
-    pmccntr_sync(env);
+    pmu_op_start(env);
 
     if (value & PMCRC) {
         /* The counter has been reset */
@@ -1117,26 +1152,16 @@ static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
     env->cp15.c9_pmcr &= ~0x39;
     env->cp15.c9_pmcr |= (value & 0x39);
 
-    pmccntr_sync(env);
+    pmu_op_finish(env);
 }
 
 static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri)
 {
-    uint64_t total_ticks;
-
-    if (!arm_ccnt_enabled(env)) {
-        /* Counter is disabled, do not change value */
-        return env->cp15.c15_ccnt;
-    }
-
-    total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
-                           ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
-
-    if (env->cp15.c9_pmcr & PMCRD) {
-        /* Increment once every 64 processor clock cycles */
-        total_ticks /= 64;
-    }
-    return total_ticks - env->cp15.c15_ccnt;
+    uint64_t ret;
+    pmccntr_op_start(env);
+    ret = env->cp15.c15_ccnt;
+    pmccntr_op_finish(env);
+    return ret;
 }
 
 static void pmselr_write(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -1153,22 +1178,9 @@ static void pmselr_write(CPUARMState *env, const ARMCPRegInfo *ri,
 static void pmccntr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                         uint64_t value)
 {
-    uint64_t total_ticks;
-
-    if (!arm_ccnt_enabled(env)) {
-        /* Counter is disabled, set the absolute value */
-        env->cp15.c15_ccnt = value;
-        return;
-    }
-
-    total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
-                           ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
-
-    if (env->cp15.c9_pmcr & PMCRD) {
-        /* Increment once every 64 processor clock cycles */
-        total_ticks /= 64;
-    }
-    env->cp15.c15_ccnt = total_ticks - value;
+    pmccntr_op_start(env);
+    env->cp15.c15_ccnt = value;
+    pmccntr_op_finish(env);
 }
 
 static void pmccntr_write32(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -1181,7 +1193,19 @@ static void pmccntr_write32(CPUARMState *env, const ARMCPRegInfo *ri,
 
 #else /* CONFIG_USER_ONLY */
 
-void pmccntr_sync(CPUARMState *env)
+void pmccntr_op_start(CPUARMState *env)
+{
+}
+
+void pmccntr_op_finish(CPUARMState *env)
+{
+}
+
+void pmu_op_start(CPUARMState *env)
+{
+}
+
+void pmu_op_finish(CPUARMState *env)
 {
 }
 
@@ -1190,9 +1214,9 @@ void pmccntr_sync(CPUARMState *env)
 static void pmccfiltr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                             uint64_t value)
 {
-    pmccntr_sync(env);
+    pmccntr_op_start(env);
     env->cp15.pmccfiltr_el0 = value & 0xfc000000;
-    pmccntr_sync(env);
+    pmccntr_op_finish(env);
 }
 
 static void pmcntenset_write(CPUARMState *env, const ARMCPRegInfo *ri,
-- 
2.19.1

[Qemu-devel] [PATCH v8 03/13] target/arm: Swap PMU values before/after migrations

[Aaron Lindsay]

Because of the PMU's design, many register accesses have side effects
which are inter-related, meaning that the normal method of saving CP
registers can result in inconsistent state. These side-effects are
largely handled in pmu_op_start/finish functions which can be called
before and after the state is saved/restored. By doing this and adding
raw read/write functions for the affected registers, we avoid
migration-related inconsistencies.

Signed-off-by: Aaron Lindsay <aclindsa@gmail.com>
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
---
 target/arm/helper.c  |  6 ++++--
 target/arm/machine.c | 24 ++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 497907fc79..71a5c71e0a 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1450,11 +1450,13 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 13, .opc2 = 0,
       .access = PL0_RW, .accessfn = pmreg_access_ccntr,
       .type = ARM_CP_IO,
-      .readfn = pmccntr_read, .writefn = pmccntr_write, },
+      .fieldoffset = offsetof(CPUARMState, cp15.c15_ccnt),
+      .readfn = pmccntr_read, .writefn = pmccntr_write,
+      .raw_readfn = raw_read, .raw_writefn = raw_write, },
 #endif
     { .name = "PMCCFILTR_EL0", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 15, .opc2 = 7,
-      .writefn = pmccfiltr_write,
+      .writefn = pmccfiltr_write, .raw_writefn = raw_write,
       .access = PL0_RW, .accessfn = pmreg_access,
       .type = ARM_CP_IO,
       .fieldoffset = offsetof(CPUARMState, cp15.pmccfiltr_el0),
diff --git a/target/arm/machine.c b/target/arm/machine.c
index 2033816a64..2f9cd993aa 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -620,6 +620,10 @@ static int cpu_pre_save(void *opaque)
 {
     ARMCPU *cpu = opaque;
 
+    if (!kvm_enabled()) {
+        pmu_op_start(&cpu->env);
+    }
+
     if (kvm_enabled()) {
         if (!write_kvmstate_to_list(cpu)) {
             /* This should never fail */
@@ -641,6 +645,17 @@ static int cpu_pre_save(void *opaque)
     return 0;
 }
 
+static int cpu_post_save(void *opaque)
+{
+    ARMCPU *cpu = opaque;
+
+    if (!kvm_enabled()) {
+        pmu_op_finish(&cpu->env);
+    }
+
+    return 0;
+}
+
 static int cpu_pre_load(void *opaque)
 {
     ARMCPU *cpu = opaque;
@@ -653,6 +668,10 @@ static int cpu_pre_load(void *opaque)
      */
     env->irq_line_state = UINT32_MAX;
 
+    if (!kvm_enabled()) {
+        pmu_op_start(&cpu->env);
+    }
+
     return 0;
 }
 
@@ -721,6 +740,10 @@ static int cpu_post_load(void *opaque, int version_id)
     hw_breakpoint_update_all(cpu);
     hw_watchpoint_update_all(cpu);
 
+    if (!kvm_enabled()) {
+        pmu_op_finish(&cpu->env);
+    }
+
     return 0;
 }
 
@@ -729,6 +752,7 @@ const VMStateDescription vmstate_arm_cpu = {
     .version_id = 22,
     .minimum_version_id = 22,
     .pre_save = cpu_pre_save,
+    .post_save = cpu_post_save,
     .pre_load = cpu_pre_load,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
-- 
2.19.1

[Qemu-devel] [PATCH v8 04/13] target/arm: Filter cycle counter based on PMCCFILTR_EL0

[Aaron Lindsay]

Rename arm_ccnt_enabled to pmu_counter_enabled, and add logic to only
return 'true' if the specified counter is enabled and neither prohibited
or filtered.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <aclindsa@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu.c    |  3 ++
 target/arm/cpu.h    | 10 ++++-
 target/arm/helper.c | 96 +++++++++++++++++++++++++++++++++++++++++----
 3 files changed, 101 insertions(+), 8 deletions(-)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 60411f6bfe..f7bad04f60 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1020,6 +1020,9 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
     if (!cpu->has_pmu) {
         unset_feature(env, ARM_FEATURE_PMU);
         cpu->id_aa64dfr0 &= ~0xf00;
+    } else if (!kvm_enabled()) {
+        arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
+        arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
     }
 
     if (!arm_feature(env, ARM_FEATURE_EL2)) {
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 61ac458627..627e5c1995 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -987,6 +987,12 @@ void pmccntr_op_finish(CPUARMState *env);
 void pmu_op_start(CPUARMState *env);
 void pmu_op_finish(CPUARMState *env);
 
+/**
+ * Functions to register as EL change hooks for PMU mode filtering
+ */
+void pmu_pre_el_change(ARMCPU *cpu, void *ignored);
+void pmu_post_el_change(ARMCPU *cpu, void *ignored);
+
 /* SCTLR bit meanings. Several bits have been reused in newer
  * versions of the architecture; in that case we define constants
  * for both old and new bit meanings. Code which tests against those
@@ -1048,7 +1054,8 @@ void pmu_op_finish(CPUARMState *env);
 
 #define MDCR_EPMAD    (1U << 21)
 #define MDCR_EDAD     (1U << 20)
-#define MDCR_SPME     (1U << 17)
+#define MDCR_SPME     (1U << 17)  /* MDCR_EL3 */
+#define MDCR_HPMD     (1U << 17)  /* MDCR_EL2 */
 #define MDCR_SDD      (1U << 16)
 #define MDCR_SPD      (3U << 14)
 #define MDCR_TDRA     (1U << 11)
@@ -1058,6 +1065,7 @@ void pmu_op_finish(CPUARMState *env);
 #define MDCR_HPME     (1U << 7)
 #define MDCR_TPM      (1U << 6)
 #define MDCR_TPMCR    (1U << 5)
+#define MDCR_HPMN     (0x1fU)
 
 /* Not all of the MDCR_EL3 bits are present in the 32-bit SDCR */
 #define SDCR_VALID_MASK (MDCR_EPMAD | MDCR_EDAD | MDCR_SPME | MDCR_SPD)
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 71a5c71e0a..ddb47813d2 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -976,10 +976,24 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
 /* Definitions for the PMU registers */
 #define PMCRN_MASK  0xf800
 #define PMCRN_SHIFT 11
+#define PMCRDP  0x10
 #define PMCRD   0x8
 #define PMCRC   0x4
 #define PMCRE   0x1
 
+#define PMXEVTYPER_P          0x80000000
+#define PMXEVTYPER_U          0x40000000
+#define PMXEVTYPER_NSK        0x20000000
+#define PMXEVTYPER_NSU        0x10000000
+#define PMXEVTYPER_NSH        0x08000000
+#define PMXEVTYPER_M          0x04000000
+#define PMXEVTYPER_MT         0x02000000
+#define PMXEVTYPER_EVTCOUNT   0x0000ffff
+#define PMXEVTYPER_MASK       (PMXEVTYPER_P | PMXEVTYPER_U | PMXEVTYPER_NSK | \
+                               PMXEVTYPER_NSU | PMXEVTYPER_NSH | \
+                               PMXEVTYPER_M | PMXEVTYPER_MT | \
+                               PMXEVTYPER_EVTCOUNT)
+
 static inline uint32_t pmu_num_counters(CPUARMState *env)
 {
   return (env->cp15.c9_pmcr & PMCRN_MASK) >> PMCRN_SHIFT;
@@ -1075,16 +1089,66 @@ static CPAccessResult pmreg_access_ccntr(CPUARMState *env,
     return pmreg_access(env, ri, isread);
 }
 
-static inline bool arm_ccnt_enabled(CPUARMState *env)
+/* Returns true if the counter (pass 31 for PMCCNTR) should count events using
+ * the current EL, security state, and register configuration.
+ */
+static bool pmu_counter_enabled(CPUARMState *env, uint8_t counter)
 {
-    /* This does not support checking PMCCFILTR_EL0 register */
+    uint64_t filter;
+    bool e, p, u, nsk, nsu, nsh, m;
+    bool enabled, prohibited, filtered;
+    bool secure = arm_is_secure(env);
+    int el = arm_current_el(env);
+    uint8_t hpmn = env->cp15.mdcr_el2 & MDCR_HPMN;
 
-    if (!(env->cp15.c9_pmcr & PMCRE) || !(env->cp15.c9_pmcnten & (1 << 31))) {
-        return false;
+    if (!arm_feature(env, ARM_FEATURE_EL2) ||
+            (counter < hpmn || counter == 31)) {
+        e = env->cp15.c9_pmcr & PMCRE;
+    } else {
+        e = env->cp15.mdcr_el2 & MDCR_HPME;
     }
+    enabled = e && (env->cp15.c9_pmcnten & (1 << counter));
 
-    return true;
+    if (!secure) {
+        if (el == 2 && (counter < hpmn || counter == 31)) {
+            prohibited = env->cp15.mdcr_el2 & MDCR_HPMD;
+        } else {
+            prohibited = false;
+        }
+    } else {
+        prohibited = arm_feature(env, ARM_FEATURE_EL3) &&
+           (env->cp15.mdcr_el3 & MDCR_SPME);
+    }
+
+    if (prohibited && counter == 31) {
+        prohibited = env->cp15.c9_pmcr & PMCRDP;
+    }
+
+    /* TODO Remove assert, set filter to correct PMEVTYPER */
+    assert(counter == 31);
+    filter = env->cp15.pmccfiltr_el0;
+
+    p   = filter & PMXEVTYPER_P;
+    u   = filter & PMXEVTYPER_U;
+    nsk = arm_feature(env, ARM_FEATURE_EL3) && (filter & PMXEVTYPER_NSK);
+    nsu = arm_feature(env, ARM_FEATURE_EL3) && (filter & PMXEVTYPER_NSU);
+    nsh = arm_feature(env, ARM_FEATURE_EL2) && (filter & PMXEVTYPER_NSH);
+    m   = arm_el_is_aa64(env, 1) &&
+              arm_feature(env, ARM_FEATURE_EL3) && (filter & PMXEVTYPER_M);
+
+    if (el == 0) {
+        filtered = secure ? u : u != nsu;
+    } else if (el == 1) {
+        filtered = secure ? p : p != nsk;
+    } else if (el == 2) {
+        filtered = !nsh;
+    } else { /* EL3 */
+        filtered = m != p;
+    }
+
+    return enabled && !prohibited && !filtered;
 }
+
 /*
  * Ensure c15_ccnt is the guest-visible count so that operations such as
  * enabling/disabling the counter or filtering, modifying the count itself,
@@ -1097,7 +1161,7 @@ void pmccntr_op_start(CPUARMState *env)
     cycles = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
                           ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
 
-    if (arm_ccnt_enabled(env)) {
+    if (pmu_counter_enabled(env, 31)) {
         uint64_t eff_cycles = cycles;
         if (env->cp15.c9_pmcr & PMCRD) {
             /* Increment once every 64 processor clock cycles */
@@ -1116,7 +1180,7 @@ void pmccntr_op_start(CPUARMState *env)
  */
 void pmccntr_op_finish(CPUARMState *env)
 {
-    if (arm_ccnt_enabled(env)) {
+    if (pmu_counter_enabled(env, 31)) {
         uint64_t prev_cycles = env->cp15.c15_ccnt_delta;
 
         if (env->cp15.c9_pmcr & PMCRD) {
@@ -1138,6 +1202,16 @@ void pmu_op_finish(CPUARMState *env)
     pmccntr_op_finish(env);
 }
 
+void pmu_pre_el_change(ARMCPU *cpu, void *ignored)
+{
+    pmu_op_start(&cpu->env);
+}
+
+void pmu_post_el_change(ARMCPU *cpu, void *ignored)
+{
+    pmu_op_finish(&cpu->env);
+}
+
 static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                        uint64_t value)
 {
@@ -1209,6 +1283,14 @@ void pmu_op_finish(CPUARMState *env)
 {
 }
 
+void pmu_pre_el_change(ARMCPU *cpu, void *ignored)
+{
+}
+
+void pmu_post_el_change(ARMCPU *cpu, void *ignored)
+{
+}
+
 #endif
 
 static void pmccfiltr_write(CPUARMState *env, const ARMCPRegInfo *ri,
-- 
2.19.1

[Qemu-devel] [PATCH v8 05/13] target/arm: Allow AArch32 access for PMCCFILTR

[Aaron Lindsay]

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index ddb47813d2..0aff261528 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -994,6 +994,10 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
                                PMXEVTYPER_M | PMXEVTYPER_MT | \
                                PMXEVTYPER_EVTCOUNT)
 
+#define PMCCFILTR             0xf8000000
+#define PMCCFILTR_M           PMXEVTYPER_M
+#define PMCCFILTR_EL0         (PMCCFILTR | PMCCFILTR_M)
+
 static inline uint32_t pmu_num_counters(CPUARMState *env)
 {
   return (env->cp15.c9_pmcr & PMCRN_MASK) >> PMCRN_SHIFT;
@@ -1297,10 +1301,26 @@ static void pmccfiltr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                             uint64_t value)
 {
     pmccntr_op_start(env);
-    env->cp15.pmccfiltr_el0 = value & 0xfc000000;
+    env->cp15.pmccfiltr_el0 = value & PMCCFILTR_EL0;
+    pmccntr_op_finish(env);
+}
+
+static void pmccfiltr_write_a32(CPUARMState *env, const ARMCPRegInfo *ri,
+                            uint64_t value)
+{
+    pmccntr_op_start(env);
+    /* M is not accessible from AArch32 */
+    env->cp15.pmccfiltr_el0 = (env->cp15.pmccfiltr_el0 & PMCCFILTR_M) |
+        (value & PMCCFILTR);
     pmccntr_op_finish(env);
 }
 
+static uint64_t pmccfiltr_read_a32(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    /* M is not visible in AArch32 */
+    return env->cp15.pmccfiltr_el0 & PMCCFILTR;
+}
+
 static void pmcntenset_write(CPUARMState *env, const ARMCPRegInfo *ri,
                             uint64_t value)
 {
@@ -1536,6 +1556,11 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .readfn = pmccntr_read, .writefn = pmccntr_write,
       .raw_readfn = raw_read, .raw_writefn = raw_write, },
 #endif
+    { .name = "PMCCFILTR", .cp = 15, .opc1 = 0, .crn = 14, .crm = 15, .opc2 = 7,
+      .writefn = pmccfiltr_write_a32, .readfn = pmccfiltr_read_a32,
+      .access = PL0_RW, .accessfn = pmreg_access,
+      .type = ARM_CP_ALIAS | ARM_CP_IO,
+      .resetvalue = 0, },
     { .name = "PMCCFILTR_EL0", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 15, .opc2 = 7,
       .writefn = pmccfiltr_write, .raw_writefn = raw_write,
-- 
2.19.1

[Qemu-devel] [PATCH v8 06/13] target/arm: Implement PMOVSSET

[Aaron Lindsay]

Add an array for PMOVSSET so we only define it for v7ve+ platforms

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 0aff261528..71be6fb578 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1342,6 +1342,13 @@ static void pmovsr_write(CPUARMState *env, const ARMCPRegInfo *ri,
     env->cp15.c9_pmovsr &= ~value;
 }
 
+static void pmovsset_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                         uint64_t value)
+{
+    value &= pmu_counter_mask(env);
+    env->cp15.c9_pmovsr |= value;
+}
+
 static void pmxevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
                              uint64_t value)
 {
@@ -1709,6 +1716,24 @@ static const ARMCPRegInfo v7mp_cp_reginfo[] = {
     REGINFO_SENTINEL
 };
 
+static const ARMCPRegInfo pmovsset_cp_reginfo[] = {
+    /* PMOVSSET is not implemented in v7 before v7ve */
+    { .name = "PMOVSSET", .cp = 15, .opc1 = 0, .crn = 9, .crm = 14, .opc2 = 3,
+      .access = PL0_RW, .accessfn = pmreg_access,
+      .type = ARM_CP_ALIAS,
+      .fieldoffset = offsetoflow32(CPUARMState, cp15.c9_pmovsr),
+      .writefn = pmovsset_write,
+      .raw_writefn = raw_write },
+    { .name = "PMOVSSET_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 14, .opc2 = 3,
+      .access = PL0_RW, .accessfn = pmreg_access,
+      .type = ARM_CP_ALIAS,
+      .fieldoffset = offsetof(CPUARMState, cp15.c9_pmovsr),
+      .writefn = pmovsset_write,
+      .raw_writefn = raw_write },
+    REGINFO_SENTINEL
+};
+
 static void teecr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                         uint64_t value)
 {
@@ -5191,6 +5216,9 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         !arm_feature(env, ARM_FEATURE_PMSA)) {
         define_arm_cp_regs(cpu, v7mp_cp_reginfo);
     }
+    if (arm_feature(env, ARM_FEATURE_V7VE)) {
+        define_arm_cp_regs(cpu, pmovsset_cp_reginfo);
+    }
     if (arm_feature(env, ARM_FEATURE_V7)) {
         /* v7 performance monitor control register: same implementor
          * field as main ID register, and we implement only the cycle
-- 
2.19.1

[Qemu-devel] [PATCH v8 07/13] target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]

[Aaron Lindsay]

Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
---
 target/arm/cpu.h    |  4 ++--
 target/arm/helper.c | 12 ++++++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 627e5c1995..50de58e4a2 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -837,8 +837,8 @@ struct ARMCPU {
     uint32_t id_pfr0;
     uint32_t id_pfr1;
     uint32_t id_dfr0;
-    uint32_t pmceid0;
-    uint32_t pmceid1;
+    uint64_t pmceid0;
+    uint64_t pmceid1;
     uint32_t id_afr0;
     uint32_t id_mmfr0;
     uint32_t id_mmfr1;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 71be6fb578..75f054fe79 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -5432,7 +5432,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             { .name = "PMCEID0", .state = ARM_CP_STATE_AA32,
               .cp = 15, .opc1 = 0, .crn = 9, .crm = 12, .opc2 = 6,
               .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
-              .resetvalue = cpu->pmceid0 },
+              .resetvalue = extract64(cpu->pmceid0, 0, 32) },
+            { .name = "PMCEID2", .state = ARM_CP_STATE_AA32,
+              .cp = 15, .opc1 = 0, .crn = 9, .crm = 14, .opc2 = 4,
+              .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
+              .resetvalue = extract64(cpu->pmceid0, 32, 32) },
             { .name = "PMCEID0_EL0", .state = ARM_CP_STATE_AA64,
               .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 6,
               .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
@@ -5440,7 +5444,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             { .name = "PMCEID1", .state = ARM_CP_STATE_AA32,
               .cp = 15, .opc1 = 0, .crn = 9, .crm = 12, .opc2 = 7,
               .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
-              .resetvalue = cpu->pmceid1 },
+              .resetvalue = extract64(cpu->pmceid1, 0, 32) },
+            { .name = "PMCEID3", .state = ARM_CP_STATE_AA32,
+              .cp = 15, .opc1 = 0, .crn = 9, .crm = 14, .opc2 = 5,
+              .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
+              .resetvalue = extract64(cpu->pmceid1, 32, 32) },
             { .name = "PMCEID1_EL0", .state = ARM_CP_STATE_AA64,
               .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 7,
               .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
-- 
2.19.1

[Qemu-devel] [PATCH v8 08/13] target/arm: Add array for supported PMU events, generate PMCEID[01]_EL0

[Aaron Lindsay]

This commit doesn't add any supported events, but provides the framework
for adding them. We store the pm_event structs in a simple array, and
provide the mapping from the event numbers to array indexes in the
supported_event_map array. Because the value of PMCEID[01] depends upon
which events are supported at runtime, generate it dynamically.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
---
 target/arm/cpu.c    | 19 +++++++++------
 target/arm/cpu.h    | 10 ++++++++
 target/arm/cpu64.c  |  4 ----
 target/arm/helper.c | 57 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 79 insertions(+), 11 deletions(-)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index f7bad04f60..208a08e867 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1019,10 +1019,19 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
 
     if (!cpu->has_pmu) {
         unset_feature(env, ARM_FEATURE_PMU);
+    }
+    if (arm_feature(env, ARM_FEATURE_PMU)) {
+        cpu->pmceid0 = get_pmceid(&cpu->env, 0);
+        cpu->pmceid1 = get_pmceid(&cpu->env, 1);
+
+        if (!kvm_enabled()) {
+            arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
+            arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
+        }
+    } else {
         cpu->id_aa64dfr0 &= ~0xf00;
-    } else if (!kvm_enabled()) {
-        arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
-        arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
+        cpu->pmceid0 = 0;
+        cpu->pmceid1 = 0;
     }
 
     if (!arm_feature(env, ARM_FEATURE_EL2)) {
@@ -1665,8 +1674,6 @@ static void cortex_a7_initfn(Object *obj)
     cpu->id_pfr0 = 0x00001131;
     cpu->id_pfr1 = 0x00011011;
     cpu->id_dfr0 = 0x02010555;
-    cpu->pmceid0 = 0x00000000;
-    cpu->pmceid1 = 0x00000000;
     cpu->id_afr0 = 0x00000000;
     cpu->id_mmfr0 = 0x10101105;
     cpu->id_mmfr1 = 0x40000000;
@@ -1712,8 +1719,6 @@ static void cortex_a15_initfn(Object *obj)
     cpu->id_pfr0 = 0x00001131;
     cpu->id_pfr1 = 0x00011011;
     cpu->id_dfr0 = 0x02010555;
-    cpu->pmceid0 = 0x0000000;
-    cpu->pmceid1 = 0x00000000;
     cpu->id_afr0 = 0x00000000;
     cpu->id_mmfr0 = 0x10201105;
     cpu->id_mmfr1 = 0x20000000;
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 50de58e4a2..32c3397948 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -993,6 +993,16 @@ void pmu_op_finish(CPUARMState *env);
 void pmu_pre_el_change(ARMCPU *cpu, void *ignored);
 void pmu_post_el_change(ARMCPU *cpu, void *ignored);
 
+/*
+ * get_pmceid
+ * @env: CPUARMState
+ *
+ * Return the PMCEID[01]_EL0 register values corresponding to the counters
+ * which are supported given the current configuration (`which` is 0 or 1 to
+ * indicate which PMCEID should be returned)
+ */
+uint64_t get_pmceid(CPUARMState *env, unsigned which);
+
 /* SCTLR bit meanings. Several bits have been reused in newer
  * versions of the architecture; in that case we define constants
  * for both old and new bit meanings. Code which tests against those
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 873f059bf2..a1aad772fa 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -138,8 +138,6 @@ static void aarch64_a57_initfn(Object *obj)
     cpu->isar.id_isar6 = 0;
     cpu->isar.id_aa64pfr0 = 0x00002222;
     cpu->id_aa64dfr0 = 0x10305106;
-    cpu->pmceid0 = 0x00000000;
-    cpu->pmceid1 = 0x00000000;
     cpu->isar.id_aa64isar0 = 0x00011120;
     cpu->id_aa64mmfr0 = 0x00001124;
     cpu->dbgdidr = 0x3516d000;
@@ -246,8 +244,6 @@ static void aarch64_a72_initfn(Object *obj)
     cpu->isar.id_isar5 = 0x00011121;
     cpu->isar.id_aa64pfr0 = 0x00002222;
     cpu->id_aa64dfr0 = 0x10305106;
-    cpu->pmceid0 = 0x00000000;
-    cpu->pmceid1 = 0x00000000;
     cpu->isar.id_aa64isar0 = 0x00011120;
     cpu->id_aa64mmfr0 = 0x00001124;
     cpu->dbgdidr = 0x3516d000;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 75f054fe79..68e9743606 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1009,6 +1009,63 @@ static inline uint64_t pmu_counter_mask(CPUARMState *env)
   return (1 << 31) | ((1 << pmu_num_counters(env)) - 1);
 }
 
+typedef struct pm_event {
+    uint16_t number; /* PMEVTYPER.evtCount is 16 bits wide */
+    /* If the event is supported on this CPU (used to generate PMCEID[01]) */
+    bool (*supported)(CPUARMState *);
+    /*
+     * Retrieve the current count of the underlying event. The programmed
+     * counters hold a difference from the return value from this function
+     */
+    uint64_t (*get_count)(CPUARMState *);
+} pm_event;
+
+static const pm_event pm_events[] = {
+};
+
+/*
+ * Note: Before increasing MAX_EVENT_ID beyond 0x3f into the 0x40xx range of
+ * events (i.e. the statistical profiling extension), this implementation
+ * should first be updated to something sparse instead of the current
+ * supported_event_map[] array.
+ */
+#define MAX_EVENT_ID 0x0
+#define UNSUPPORTED_EVENT UINT16_MAX
+static uint16_t supported_event_map[MAX_EVENT_ID + 1];
+
+/*
+ * Called upon initialization to build PMCEID0_EL0 or PMCEID1_EL0 (indicated by
+ * 'which'). We also use it to build a map of ARM event numbers to indices in
+ * our pm_events array.
+ *
+ * Note: Events in the 0x40XX range are not currently supported.
+ */
+uint64_t get_pmceid(CPUARMState *env, unsigned which)
+{
+    uint64_t pmceid = 0;
+    unsigned int i;
+
+    assert(which <= 1);
+
+    for (i = 0; i < ARRAY_SIZE(supported_event_map); i++) {
+        supported_event_map[i] = UNSUPPORTED_EVENT;
+    }
+
+    for (i = 0; i < ARRAY_SIZE(pm_events); i++) {
+        const pm_event *cnt = &pm_events[i];
+        assert(cnt->number <= MAX_EVENT_ID);
+        /* We do not currently support events in the 0x40xx range */
+        assert(cnt->number <= 0x3f);
+
+        if ((cnt->number & 0x20) == (which << 6) &&
+                cnt->supported(env)) {
+            pmceid |= (1 << (cnt->number & 0x1f));
+            supported_event_map[cnt->number] = i;
+        }
+    }
+    return pmceid;
+}
+
 static CPAccessResult pmreg_access(CPUARMState *env, const ARMCPRegInfo *ri,
                                    bool isread)
 {
-- 
2.19.1

[Qemu-devel] [PATCH v8 09/13] target/arm: Finish implementation of PM[X]EVCNTR and PM[X]EVTYPER

[Aaron Lindsay]

Add arrays to hold the registers, the definitions themselves, access
functions, and logic to reset counters when PMCR.P is set. Update
filtering code to support counters other than PMCCNTR. Support migration
with raw read/write functions.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu.h    |   3 +
 target/arm/helper.c | 296 +++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 282 insertions(+), 17 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 32c3397948..1539aa5a2f 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -482,6 +482,9 @@ typedef struct CPUARMState {
          * pmccntr_op_finish.
          */
         uint64_t c15_ccnt_delta;
+        uint64_t c14_pmevcntr[31];
+        uint64_t c14_pmevcntr_delta[31];
+        uint64_t c14_pmevtyper[31];
         uint64_t pmccfiltr_el0; /* Performance Monitor Filter Register */
         uint64_t vpidr_el2; /* Virtualization Processor ID Register */
         uint64_t vmpidr_el2; /* Virtualization Multiprocessor ID Register */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 68e9743606..02d12c078e 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -979,6 +979,7 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
 #define PMCRDP  0x10
 #define PMCRD   0x8
 #define PMCRC   0x4
+#define PMCRP   0x2
 #define PMCRE   0x1
 
 #define PMXEVTYPER_P          0x80000000
@@ -1066,6 +1067,17 @@ uint64_t get_pmceid(CPUARMState *env, unsigned which)
     return pmceid;
 }
 
+/*
+ * Check at runtime whether a PMU event is supported for the current machine
+ */
+static bool event_supported(uint16_t number)
+{
+    if (number > MAX_EVENT_ID) {
+        return false;
+    }
+    return supported_event_map[number] != UNSUPPORTED_EVENT;
+}
+
 static CPAccessResult pmreg_access(CPUARMState *env, const ARMCPRegInfo *ri,
                                    bool isread)
 {
@@ -1185,9 +1197,11 @@ static bool pmu_counter_enabled(CPUARMState *env, uint8_t counter)
         prohibited = env->cp15.c9_pmcr & PMCRDP;
     }
 
-    /* TODO Remove assert, set filter to correct PMEVTYPER */
-    assert(counter == 31);
-    filter = env->cp15.pmccfiltr_el0;
+    if (counter == 31) {
+        filter = env->cp15.pmccfiltr_el0;
+    } else {
+        filter = env->cp15.c14_pmevtyper[counter];
+    }
 
     p   = filter & PMXEVTYPER_P;
     u   = filter & PMXEVTYPER_U;
@@ -1207,6 +1221,17 @@ static bool pmu_counter_enabled(CPUARMState *env, uint8_t counter)
         filtered = m != p;
     }
 
+    if (counter != 31) {
+        /*
+         * If not checking PMCCNTR, ensure the counter is setup to an event we
+         * support
+         */
+        uint16_t event = filter & PMXEVTYPER_EVTCOUNT;
+        if (!event_supported(event)) {
+            return false;
+        }
+    }
+
     return enabled && !prohibited && !filtered;
 }
 
@@ -1253,14 +1278,47 @@ void pmccntr_op_finish(CPUARMState *env)
     }
 }
 
+static void pmevcntr_op_start(CPUARMState *env, uint8_t counter)
+{
+
+    uint16_t event = env->cp15.c14_pmevtyper[counter] & PMXEVTYPER_EVTCOUNT;
+    uint64_t count = 0;
+    if (event_supported(event)) {
+        uint16_t event_idx = supported_event_map[event];
+        count = pm_events[event_idx].get_count(env);
+    }
+
+    if (pmu_counter_enabled(env, counter)) {
+        env->cp15.c14_pmevcntr[counter] =
+            count - env->cp15.c14_pmevcntr_delta[counter];
+    }
+    env->cp15.c14_pmevcntr_delta[counter] = count;
+}
+
+static void pmevcntr_op_finish(CPUARMState *env, uint8_t counter)
+{
+    if (pmu_counter_enabled(env, counter)) {
+        env->cp15.c14_pmevcntr_delta[counter] -=
+            env->cp15.c14_pmevcntr[counter];
+    }
+}
+
 void pmu_op_start(CPUARMState *env)
 {
+    unsigned int i;
     pmccntr_op_start(env);
+    for (i = 0; i < pmu_num_counters(env); i++) {
+        pmevcntr_op_start(env, i);
+    }
 }
 
 void pmu_op_finish(CPUARMState *env)
 {
+    unsigned int i;
     pmccntr_op_finish(env);
+    for (i = 0; i < pmu_num_counters(env); i++) {
+        pmevcntr_op_finish(env, i);
+    }
 }
 
 void pmu_pre_el_change(ARMCPU *cpu, void *ignored)
@@ -1283,6 +1341,13 @@ static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
         env->cp15.c15_ccnt = 0;
     }
 
+    if (value & PMCRP) {
+        unsigned int i;
+        for (i = 0; i < pmu_num_counters(env); i++) {
+            env->cp15.c14_pmevcntr[i] = 0;
+        }
+    }
+
     /* only the DP, X, D and E bits are writable */
     env->cp15.c9_pmcr &= ~0x39;
     env->cp15.c9_pmcr |= (value & 0x39);
@@ -1336,6 +1401,14 @@ void pmccntr_op_finish(CPUARMState *env)
 {
 }
 
+void pmevcntr_op_start(CPUARMState *env, uint8_t i)
+{
+}
+
+void pmevcntr_op_finish(CPUARMState *env, uint8_t i)
+{
+}
+
 void pmu_op_start(CPUARMState *env)
 {
 }
@@ -1406,30 +1479,174 @@ static void pmovsset_write(CPUARMState *env, const ARMCPRegInfo *ri,
     env->cp15.c9_pmovsr |= value;
 }
 
-static void pmxevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
-                             uint64_t value)
+static void pmevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value, const uint8_t counter)
 {
+    if (counter == 31) {
+        pmccfiltr_write(env, ri, value);
+    } else if (counter < pmu_num_counters(env)) {
+        pmevcntr_op_start(env, counter);
+
+        /*
+         * If this counter's event type is changing, store the current
+         * underlying count for the new type in c14_pmevcntr_delta[counter] so
+         * pmevcntr_op_finish has the correct baseline when it converts back to
+         * a delta.
+         */
+        uint16_t old_event = env->cp15.c14_pmevtyper[counter] &
+            PMXEVTYPER_EVTCOUNT;
+        uint16_t new_event = value & PMXEVTYPER_EVTCOUNT;
+        if (old_event != new_event) {
+            uint64_t count = 0;
+            if (event_supported(new_event)) {
+                uint16_t event_idx = supported_event_map[new_event];
+                count = pm_events[event_idx].get_count(env);
+            }
+            env->cp15.c14_pmevcntr_delta[counter] = count;
+        }
+
+        env->cp15.c14_pmevtyper[counter] = value & PMXEVTYPER_MASK;
+        pmevcntr_op_finish(env, counter);
+    }
     /* Attempts to access PMXEVTYPER are CONSTRAINED UNPREDICTABLE when
      * PMSELR value is equal to or greater than the number of implemented
      * counters, but not equal to 0x1f. We opt to behave as a RAZ/WI.
      */
-    if (env->cp15.c9_pmselr == 0x1f) {
-        pmccfiltr_write(env, ri, value);
+}
+
+static uint64_t pmevtyper_read(CPUARMState *env, const ARMCPRegInfo *ri,
+                               const uint8_t counter)
+{
+    if (counter == 31) {
+        return env->cp15.pmccfiltr_el0;
+    } else if (counter < pmu_num_counters(env)) {
+        return env->cp15.c14_pmevtyper[counter];
+    } else {
+      /*
+       * We opt to behave as a RAZ/WI when attempts to access PMXEVTYPER
+       * are CONSTRAINED UNPREDICTABLE. See comments in pmevtyper_write().
+       */
+        return 0;
     }
 }
 
+static void pmevtyper_writefn(CPUARMState *env, const ARMCPRegInfo *ri,
+                              uint64_t value)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    pmevtyper_write(env, ri, value, counter);
+}
+
+static void pmevtyper_rawwrite(CPUARMState *env, const ARMCPRegInfo *ri,
+                               uint64_t value)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    env->cp15.c14_pmevtyper[counter] = value;
+
+    /*
+     * pmevtyper_rawwrite is called between a pair of pmu_op_start and
+     * pmu_op_finish calls when loading saved state for a migration. Because
+     * we're potentially updating the type of event here, the value written to
+     * c14_pmevcntr_delta by the preceeding pmu_op_start call may be for a
+     * different counter type. Therefore, we need to set this value to the
+     * current count for the counter type we're writing so that pmu_op_finish
+     * has the correct count for its calculation.
+     */
+    uint16_t event = value & PMXEVTYPER_EVTCOUNT;
+    if (event_supported(event)) {
+        uint16_t event_idx = supported_event_map[event];
+        env->cp15.c14_pmevcntr_delta[counter] =
+            pm_events[event_idx].get_count(env);
+    }
+}
+
+static uint64_t pmevtyper_readfn(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    return pmevtyper_read(env, ri, counter);
+}
+
+static void pmxevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value)
+{
+    pmevtyper_write(env, ri, value, env->cp15.c9_pmselr & 31);
+}
+
 static uint64_t pmxevtyper_read(CPUARMState *env, const ARMCPRegInfo *ri)
 {
-    /* We opt to behave as a RAZ/WI when attempts to access PMXEVTYPER
-     * are CONSTRAINED UNPREDICTABLE. See comments in pmxevtyper_write().
+    return pmevtyper_read(env, ri, env->cp15.c9_pmselr & 31);
+}
+
+static void pmevcntr_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value, uint8_t counter)
+{
+    if (counter < pmu_num_counters(env)) {
+        pmevcntr_op_start(env, counter);
+        env->cp15.c14_pmevcntr[counter] = value;
+        pmevcntr_op_finish(env, counter);
+    }
+    /*
+     * We opt to behave as a RAZ/WI when attempts to access PM[X]EVCNTR
+     * are CONSTRAINED UNPREDICTABLE.
      */
-    if (env->cp15.c9_pmselr == 0x1f) {
-        return env->cp15.pmccfiltr_el0;
+}
+
+static uint64_t pmevcntr_read(CPUARMState *env, const ARMCPRegInfo *ri,
+                              uint8_t counter)
+{
+    if (counter < pmu_num_counters(env)) {
+        uint64_t ret;
+        pmevcntr_op_start(env, counter);
+        ret = env->cp15.c14_pmevcntr[counter];
+        pmevcntr_op_finish(env, counter);
+        return ret;
     } else {
+      /* We opt to behave as a RAZ/WI when attempts to access PM[X]EVCNTR
+       * are CONSTRAINED UNPREDICTABLE. */
         return 0;
     }
 }
 
+static void pmevcntr_writefn(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    pmevcntr_write(env, ri, value, counter);
+}
+
+static uint64_t pmevcntr_readfn(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    return pmevcntr_read(env, ri, counter);
+}
+
+static void pmevcntr_rawwrite(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    assert(counter < pmu_num_counters(env));
+    env->cp15.c14_pmevcntr[counter] = value;
+    pmevcntr_write(env, ri, value, counter);
+}
+
+static uint64_t pmevcntr_rawread(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    assert(counter < pmu_num_counters(env));
+    return env->cp15.c14_pmevcntr[counter];
+}
+
+static void pmxevcntr_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value)
+{
+    pmevcntr_write(env, ri, value, env->cp15.c9_pmselr & 31);
+}
+
+static uint64_t pmxevcntr_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    return pmevcntr_read(env, ri, env->cp15.c9_pmselr & 31);
+}
+
 static void pmuserenr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                             uint64_t value)
 {
@@ -1633,16 +1850,23 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .fieldoffset = offsetof(CPUARMState, cp15.pmccfiltr_el0),
       .resetvalue = 0, },
     { .name = "PMXEVTYPER", .cp = 15, .crn = 9, .crm = 13, .opc1 = 0, .opc2 = 1,
-      .access = PL0_RW, .type = ARM_CP_NO_RAW, .accessfn = pmreg_access,
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access,
       .writefn = pmxevtyper_write, .readfn = pmxevtyper_read },
     { .name = "PMXEVTYPER_EL0", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 13, .opc2 = 1,
-      .access = PL0_RW, .type = ARM_CP_NO_RAW, .accessfn = pmreg_access,
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access,
       .writefn = pmxevtyper_write, .readfn = pmxevtyper_read },
-    /* Unimplemented, RAZ/WI. */
     { .name = "PMXEVCNTR", .cp = 15, .crn = 9, .crm = 13, .opc1 = 0, .opc2 = 2,
-      .access = PL0_RW, .type = ARM_CP_CONST, .resetvalue = 0,
-      .accessfn = pmreg_access_xevcntr },
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access_xevcntr,
+      .writefn = pmxevcntr_write, .readfn = pmxevcntr_read },
+    { .name = "PMXEVCNTR_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 13, .opc2 = 2,
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access_xevcntr,
+      .writefn = pmxevcntr_write, .readfn = pmxevcntr_read },
     { .name = "PMUSERENR", .cp = 15, .crn = 9, .crm = 14, .opc1 = 0, .opc2 = 0,
       .access = PL0_R | PL1_RW, .accessfn = access_tpm,
       .fieldoffset = offsetoflow32(CPUARMState, cp15.c9_pmuserenr),
@@ -4429,7 +4653,7 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
 #endif
     /* The only field of MDCR_EL2 that has a defined architectural reset value
      * is MDCR_EL2.HPMN which should reset to the value of PMCR_EL0.N; but we
-     * don't impelment any PMU event counters, so using zero as a reset
+     * don't implement any PMU event counters, so using zero as a reset
      * value for MDCR_EL2 is okay
      */
     { .name = "MDCR_EL2", .state = ARM_CP_STATE_BOTH,
@@ -5281,6 +5505,7 @@ void register_cp_regs_for_features(ARMCPU *cpu)
          * field as main ID register, and we implement only the cycle
          * count register.
          */
+        unsigned int i, pmcrn = 0;
 #ifndef CONFIG_USER_ONLY
         ARMCPRegInfo pmcr = {
             .name = "PMCR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 0,
@@ -5301,6 +5526,43 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         };
         define_one_arm_cp_reg(cpu, &pmcr);
         define_one_arm_cp_reg(cpu, &pmcr64);
+        for (i = 0; i < pmcrn; i++) {
+            char *pmevcntr_name = g_strdup_printf("PMEVCNTR%d", i);
+            char *pmevcntr_el0_name = g_strdup_printf("PMEVCNTR%d_EL0", i);
+            char *pmevtyper_name = g_strdup_printf("PMEVTYPER%d", i);
+            char *pmevtyper_el0_name = g_strdup_printf("PMEVTYPER%d_EL0", i);
+            ARMCPRegInfo pmev_regs[] = {
+                { .name = pmevcntr_name, .cp = 15, .crn = 15,
+                  .crm = 8 | (3 & (i >> 3)), .opc1 = 0, .opc2 = i & 7,
+                  .access = PL0_RW, .type = ARM_CP_IO | ARM_CP_ALIAS,
+                  .readfn = pmevcntr_readfn, .writefn = pmevcntr_writefn,
+                  .accessfn = pmreg_access },
+                { .name = pmevcntr_el0_name, .state = ARM_CP_STATE_AA64,
+                  .opc0 = 3, .opc1 = 3, .crn = 15, .crm = 8 | (3 & (i >> 3)),
+                  .opc2 = i & 7, .access = PL0_RW, .accessfn = pmreg_access,
+                  .type = ARM_CP_IO,
+                  .readfn = pmevcntr_readfn, .writefn = pmevcntr_writefn,
+                  .raw_readfn = pmevcntr_rawread,
+                  .raw_writefn = pmevcntr_rawwrite },
+                { .name = pmevtyper_name, .cp = 15, .crn = 15,
+                  .crm = 12 | (3 & (i >> 3)), .opc1 = 0, .opc2 = i & 7,
+                  .access = PL0_RW, .type = ARM_CP_IO | ARM_CP_ALIAS,
+                  .readfn = pmevtyper_readfn, .writefn = pmevtyper_writefn,
+                  .accessfn = pmreg_access },
+                { .name = pmevtyper_el0_name, .state = ARM_CP_STATE_AA64,
+                  .opc0 = 3, .opc1 = 3, .crn = 15, .crm = 12 | (3 & (i >> 3)),
+                  .opc2 = i & 7, .access = PL0_RW, .accessfn = pmreg_access,
+                  .type = ARM_CP_IO,
+                  .readfn = pmevtyper_readfn, .writefn = pmevtyper_writefn,
+                  .raw_writefn = pmevtyper_rawwrite },
+                REGINFO_SENTINEL
+            };
+            define_arm_cp_regs(cpu, pmev_regs);
+            g_free(pmevcntr_name);
+            g_free(pmevcntr_el0_name);
+            g_free(pmevtyper_name);
+            g_free(pmevtyper_el0_name);
+        }
 #endif
         ARMCPRegInfo clidr = {
             .name = "CLIDR", .state = ARM_CP_STATE_BOTH,
-- 
2.19.1

[Qemu-devel] [PATCH v8 10/13] target/arm: PMU: Add instruction and cycle events

[Aaron Lindsay]

The instruction event is only enabled when icount is used, cycles are
always supported. Always defining get_cycle_count (but altering its
behavior depending on CONFIG_USER_ONLY) allows us to remove some
CONFIG_USER_ONLY #defines throughout the rest of the code.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 90 ++++++++++++++++++++++-----------------------
 1 file changed, 44 insertions(+), 46 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 02d12c078e..6e5f00c0d5 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -15,6 +15,7 @@
 #include "arm_ldst.h"
 #include <zlib.h> /* For crc32 */
 #include "exec/semihost.h"
+#include "sysemu/cpus.h"
 #include "sysemu/kvm.h"
 #include "fpu/softfloat.h"
 #include "qemu/range.h"
@@ -1021,7 +1022,48 @@ typedef struct pm_event {
     uint64_t (*get_count)(CPUARMState *);
 } pm_event;
 
+static bool event_always_supported(CPUARMState *env)
+{
+    return true;
+}
+
+/*
+ * Return the underlying cycle count for the PMU cycle counters. If we're in
+ * usermode, simply return 0.
+ */
+static uint64_t cycles_get_count(CPUARMState *env)
+{
+#ifndef CONFIG_USER_ONLY
+    return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
+                   ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
+#else
+    return cpu_get_host_ticks();
+#endif
+}
+
+#ifndef CONFIG_USER_ONLY
+static bool instructions_supported(CPUARMState *env)
+{
+    return use_icount == 1 /* Precise instruction counting */;
+}
+
+static uint64_t instructions_get_count(CPUARMState *env)
+{
+    return (uint64_t)cpu_get_icount_raw();
+}
+#endif
+
 static const pm_event pm_events[] = {
+#ifndef CONFIG_USER_ONLY
+    { .number = 0x008, /* INST_RETIRED, Instruction architecturally executed */
+      .supported = instructions_supported,
+      .get_count = instructions_get_count,
+    },
+    { .number = 0x011, /* CPU_CYCLES, Cycle */
+      .supported = event_always_supported,
+      .get_count = cycles_get_count,
+    }
+#endif
 };
 
 /*
@@ -1030,7 +1072,7 @@ static const pm_event pm_events[] = {
  * should first be updated to something sparse instead of the current
  * supported_event_map[] array.
  */
-#define MAX_EVENT_ID 0x0
+#define MAX_EVENT_ID 0x11
 #define UNSUPPORTED_EVENT UINT16_MAX
 static uint16_t supported_event_map[MAX_EVENT_ID + 1];
 
@@ -1131,8 +1173,6 @@ static CPAccessResult pmreg_access_swinc(CPUARMState *env,
     return pmreg_access(env, ri, isread);
 }
 
-#ifndef CONFIG_USER_ONLY
-
 static CPAccessResult pmreg_access_selr(CPUARMState *env,
                                         const ARMCPRegInfo *ri,
                                         bool isread)
@@ -1243,9 +1283,7 @@ static bool pmu_counter_enabled(CPUARMState *env, uint8_t counter)
  */
 void pmccntr_op_start(CPUARMState *env)
 {
-    uint64_t cycles = 0;
-    cycles = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
-                          ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
+    uint64_t cycles = cycles_get_count(env);
 
     if (pmu_counter_enabled(env, 31)) {
         uint64_t eff_cycles = cycles;
@@ -1391,42 +1429,6 @@ static void pmccntr_write32(CPUARMState *env, const ARMCPRegInfo *ri,
     pmccntr_write(env, ri, deposit64(cur_val, 0, 32, value));
 }
 
-#else /* CONFIG_USER_ONLY */
-
-void pmccntr_op_start(CPUARMState *env)
-{
-}
-
-void pmccntr_op_finish(CPUARMState *env)
-{
-}
-
-void pmevcntr_op_start(CPUARMState *env, uint8_t i)
-{
-}
-
-void pmevcntr_op_finish(CPUARMState *env, uint8_t i)
-{
-}
-
-void pmu_op_start(CPUARMState *env)
-{
-}
-
-void pmu_op_finish(CPUARMState *env)
-{
-}
-
-void pmu_pre_el_change(ARMCPU *cpu, void *ignored)
-{
-}
-
-void pmu_post_el_change(ARMCPU *cpu, void *ignored)
-{
-}
-
-#endif
-
 static void pmccfiltr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                             uint64_t value)
 {
@@ -1814,7 +1816,6 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
     /* Unimplemented so WI. */
     { .name = "PMSWINC", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 4,
       .access = PL0_W, .accessfn = pmreg_access_swinc, .type = ARM_CP_NOP },
-#ifndef CONFIG_USER_ONLY
     { .name = "PMSELR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 5,
       .access = PL0_RW, .type = ARM_CP_ALIAS,
       .fieldoffset = offsetoflow32(CPUARMState, cp15.c9_pmselr),
@@ -1836,7 +1837,6 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .fieldoffset = offsetof(CPUARMState, cp15.c15_ccnt),
       .readfn = pmccntr_read, .writefn = pmccntr_write,
       .raw_readfn = raw_read, .raw_writefn = raw_write, },
-#endif
     { .name = "PMCCFILTR", .cp = 15, .opc1 = 0, .crn = 14, .crm = 15, .opc2 = 7,
       .writefn = pmccfiltr_write_a32, .readfn = pmccfiltr_read_a32,
       .access = PL0_RW, .accessfn = pmreg_access,
@@ -5506,7 +5506,6 @@ void register_cp_regs_for_features(ARMCPU *cpu)
          * count register.
          */
         unsigned int i, pmcrn = 0;
-#ifndef CONFIG_USER_ONLY
         ARMCPRegInfo pmcr = {
             .name = "PMCR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 0,
             .access = PL0_RW,
@@ -5563,7 +5562,6 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             g_free(pmevtyper_name);
             g_free(pmevtyper_el0_name);
         }
-#endif
         ARMCPRegInfo clidr = {
             .name = "CLIDR", .state = ARM_CP_STATE_BOTH,
             .opc0 = 3, .crn = 0, .crm = 0, .opc1 = 1, .opc2 = 1,
-- 
2.19.1

[Qemu-devel] [PATCH v8 11/13] target/arm: PMU: Set PMCR.N to 4

[Aaron Lindsay]

This both advertises that we support four counters and enables them
because the pmu_num_counters() reads this value from PMCR.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 6e5f00c0d5..b8462d429a 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1768,7 +1768,7 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .access = PL1_W, .type = ARM_CP_NOP },
     /* Performance monitors are implementation defined in v7,
      * but with an ARM recommended set of registers, which we
-     * follow (although we don't actually implement any counters)
+     * follow.
      *
      * Performance registers fall into three categories:
      *  (a) always UNDEF in PL0, RW in PL1 (PMINTENSET, PMINTENCLR)
@@ -5502,10 +5502,10 @@ void register_cp_regs_for_features(ARMCPU *cpu)
     }
     if (arm_feature(env, ARM_FEATURE_V7)) {
         /* v7 performance monitor control register: same implementor
-         * field as main ID register, and we implement only the cycle
-         * count register.
+         * field as main ID register, and we implement four counters in
+         * addition to the cycle count register.
          */
-        unsigned int i, pmcrn = 0;
+        unsigned int i, pmcrn = 4;
         ARMCPRegInfo pmcr = {
             .name = "PMCR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 0,
             .access = PL0_RW,
@@ -5520,7 +5520,7 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             .access = PL0_RW, .accessfn = pmreg_access,
             .type = ARM_CP_IO,
             .fieldoffset = offsetof(CPUARMState, cp15.c9_pmcr),
-            .resetvalue = cpu->midr & 0xff000000,
+            .resetvalue = (cpu->midr & 0xff000000) | (pmcrn << PMCRN_SHIFT),
             .writefn = pmcr_write, .raw_writefn = raw_write,
         };
         define_one_arm_cp_reg(cpu, &pmcr);
-- 
2.19.1

[Qemu-devel] [PATCH v8 12/13] target/arm: Implement PMSWINC

[Aaron Lindsay]

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper.c | 39 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index b8462d429a..99bce8a526 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1027,6 +1027,15 @@ static bool event_always_supported(CPUARMState *env)
     return true;
 }
 
+static uint64_t swinc_get_count(CPUARMState *env)
+{
+    /*
+     * SW_INCR events are written directly to the pmevcntr's by writes to
+     * PMSWINC, so there is no underlying count maintained by the PMU itself
+     */
+    return 0;
+}
+
 /*
  * Return the underlying cycle count for the PMU cycle counters. If we're in
  * usermode, simply return 0.
@@ -1054,6 +1063,10 @@ static uint64_t instructions_get_count(CPUARMState *env)
 #endif
 
 static const pm_event pm_events[] = {
+    { .number = 0x000, /* SW_INCR */
+      .supported = event_always_supported,
+      .get_count = swinc_get_count,
+    },
 #ifndef CONFIG_USER_ONLY
     { .number = 0x008, /* INST_RETIRED, Instruction architecturally executed */
       .supported = instructions_supported,
@@ -1393,6 +1406,24 @@ static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
     pmu_op_finish(env);
 }
 
+static void pmswinc_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                          uint64_t value)
+{
+    unsigned int i;
+    for (i = 0; i < pmu_num_counters(env); i++) {
+        /* Increment a counter's count iff: */
+        if ((value & (1 << i)) && /* counter's bit is set */
+                /* counter is enabled and not filtered */
+                pmu_counter_enabled(env, i) &&
+                /* counter is SW_INCR */
+                (env->cp15.c14_pmevtyper[i] & PMXEVTYPER_EVTCOUNT) == 0x0) {
+            pmevcntr_op_start(env, i);
+            env->cp15.c14_pmevcntr[i]++;
+            pmevcntr_op_finish(env, i);
+        }
+    }
+}
+
 static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri)
 {
     uint64_t ret;
@@ -1813,9 +1844,13 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .fieldoffset = offsetof(CPUARMState, cp15.c9_pmovsr),
       .writefn = pmovsr_write,
       .raw_writefn = raw_write },
-    /* Unimplemented so WI. */
     { .name = "PMSWINC", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 4,
-      .access = PL0_W, .accessfn = pmreg_access_swinc, .type = ARM_CP_NOP },
+      .access = PL0_W, .accessfn = pmreg_access_swinc, .type = ARM_CP_NO_RAW,
+      .writefn = pmswinc_write },
+    { .name = "PMSWINC_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 4,
+      .access = PL0_W, .accessfn = pmreg_access_swinc, .type = ARM_CP_NO_RAW,
+      .writefn = pmswinc_write },
     { .name = "PMSELR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 5,
       .access = PL0_RW, .type = ARM_CP_ALIAS,
       .fieldoffset = offsetoflow32(CPUARMState, cp15.c9_pmselr),
-- 
2.19.1

[Qemu-devel] [PATCH v8 13/13] target/arm: Send interrupts on PMU counter overflow

[Aaron Lindsay]

Setup a QEMUTimer to get a callback when we expect counters to next
overflow and trigger an interrupt at that time.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <alindsay@os.amperecomputing.com>
---
 target/arm/cpu.c    |  12 +++++
 target/arm/cpu.h    |   7 +++
 target/arm/helper.c | 126 +++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 139 insertions(+), 6 deletions(-)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 208a08e867..7311a48e3c 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -827,6 +827,13 @@ static void arm_cpu_finalizefn(Object *obj)
         QLIST_REMOVE(hook, node);
         g_free(hook);
     }
+#ifndef CONFIG_USER_ONLY
+    if (arm_feature(&cpu->env, ARM_FEATURE_PMU) && cpu->pmu_timer) {
+        timer_del(cpu->pmu_timer);
+        timer_deinit(cpu->pmu_timer);
+        timer_free(cpu->pmu_timer);
+    }
+#endif
 }
 
 static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
@@ -1028,6 +1035,11 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
             arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
             arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
         }
+
+#ifndef CONFIG_USER_ONLY
+        cpu->pmu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, arm_pmu_timer_cb,
+                cpu);
+#endif
     } else {
         cpu->id_aa64dfr0 &= ~0xf00;
         cpu->pmceid0 = 0;
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 1539aa5a2f..24354dba3b 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -733,6 +733,8 @@ struct ARMCPU {
 
     /* Timers used by the generic (architected) timer */
     QEMUTimer *gt_timer[NUM_GTIMERS];
+    /* Timer used by the PMU */
+    QEMUTimer *pmu_timer;
     /* GPIO outputs for generic timer */
     qemu_irq gt_timer_outputs[NUM_GTIMERS];
     /* GPIO output for GICv3 maintenance interrupt signal */
@@ -990,6 +992,11 @@ void pmccntr_op_finish(CPUARMState *env);
 void pmu_op_start(CPUARMState *env);
 void pmu_op_finish(CPUARMState *env);
 
+/**
+ * Called when a PMU counter is due to overflow
+ */
+void arm_pmu_timer_cb(void *opaque);
+
 /**
  * Functions to register as EL change hooks for PMU mode filtering
  */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 99bce8a526..d44c5852b5 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -977,6 +977,7 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
 /* Definitions for the PMU registers */
 #define PMCRN_MASK  0xf800
 #define PMCRN_SHIFT 11
+#define PMCRLC  0x40
 #define PMCRDP  0x10
 #define PMCRD   0x8
 #define PMCRC   0x4
@@ -996,6 +997,8 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
                                PMXEVTYPER_M | PMXEVTYPER_MT | \
                                PMXEVTYPER_EVTCOUNT)
 
+#define PMEVCNTR_OVERFLOW_MASK ((uint64_t)1 << 31)
+
 #define PMCCFILTR             0xf8000000
 #define PMCCFILTR_M           PMXEVTYPER_M
 #define PMCCFILTR_EL0         (PMCCFILTR | PMCCFILTR_M)
@@ -1020,6 +1023,11 @@ typedef struct pm_event {
      * counters hold a difference from the return value from this function
      */
     uint64_t (*get_count)(CPUARMState *);
+    /* Return how many nanoseconds it will take (at a minimum) for count events
+     * to occur. A negative value indicates the counter will never overflow, or
+     * that the counter has otherwise arranged for the overflow bit to be set
+     * and the PMU interrupt to be raised on overflow. */
+    int64_t (*ns_per_count)(uint64_t);
 } pm_event;
 
 static bool event_always_supported(CPUARMState *env)
@@ -1036,6 +1044,11 @@ static uint64_t swinc_get_count(CPUARMState *env)
     return 0;
 }
 
+static int64_t swinc_ns_per(uint64_t ignored)
+{
+    return -1;
+}
+
 /*
  * Return the underlying cycle count for the PMU cycle counters. If we're in
  * usermode, simply return 0.
@@ -1051,6 +1064,11 @@ static uint64_t cycles_get_count(CPUARMState *env)
 }
 
 #ifndef CONFIG_USER_ONLY
+static int64_t cycles_ns_per(uint64_t cycles)
+{
+    return (ARM_CPU_FREQ / NANOSECONDS_PER_SECOND) * cycles;
+}
+
 static bool instructions_supported(CPUARMState *env)
 {
     return use_icount == 1 /* Precise instruction counting */;
@@ -1060,21 +1078,29 @@ static uint64_t instructions_get_count(CPUARMState *env)
 {
     return (uint64_t)cpu_get_icount_raw();
 }
+
+static int64_t instructions_ns_per(uint64_t icount)
+{
+    return cpu_icount_to_ns((int64_t)icount);
+}
 #endif
 
 static const pm_event pm_events[] = {
     { .number = 0x000, /* SW_INCR */
       .supported = event_always_supported,
       .get_count = swinc_get_count,
+      .ns_per_count = swinc_ns_per,
     },
 #ifndef CONFIG_USER_ONLY
     { .number = 0x008, /* INST_RETIRED, Instruction architecturally executed */
       .supported = instructions_supported,
       .get_count = instructions_get_count,
+      .ns_per_count = instructions_ns_per,
     },
     { .number = 0x011, /* CPU_CYCLES, Cycle */
       .supported = event_always_supported,
       .get_count = cycles_get_count,
+      .ns_per_count = cycles_ns_per,
     }
 #endif
 };
@@ -1288,6 +1314,13 @@ static bool pmu_counter_enabled(CPUARMState *env, uint8_t counter)
     return enabled && !prohibited && !filtered;
 }
 
+static void pmu_update_irq(CPUARMState *env)
+{
+    ARMCPU *cpu = arm_env_get_cpu(env);
+    qemu_set_irq(cpu->pmu_interrupt, (env->cp15.c9_pmcr & PMCRE) &&
+            (env->cp15.c9_pminten & env->cp15.c9_pmovsr));
+}
+
 /*
  * Ensure c15_ccnt is the guest-visible count so that operations such as
  * enabling/disabling the counter or filtering, modifying the count itself,
@@ -1305,7 +1338,18 @@ void pmccntr_op_start(CPUARMState *env)
             eff_cycles /= 64;
         }
 
-        env->cp15.c15_ccnt = eff_cycles - env->cp15.c15_ccnt_delta;
+        uint64_t new_pmccntr = eff_cycles - env->cp15.c15_ccnt_delta;
+
+        unsigned int overflow_bit = (env->cp15.c9_pmcr & PMCRLC) ? 63 : 31;
+        uint64_t overflow_mask = (uint64_t)1 << overflow_bit;
+        if (!(new_pmccntr & overflow_mask) &&
+                (env->cp15.c15_ccnt & overflow_mask)) {
+            env->cp15.c9_pmovsr |= (1 << 31);
+            new_pmccntr &= ~overflow_mask;
+            pmu_update_irq(env);
+        }
+
+        env->cp15.c15_ccnt = new_pmccntr;
     }
     env->cp15.c15_ccnt_delta = cycles;
 }
@@ -1318,13 +1362,28 @@ void pmccntr_op_start(CPUARMState *env)
 void pmccntr_op_finish(CPUARMState *env)
 {
     if (pmu_counter_enabled(env, 31)) {
-        uint64_t prev_cycles = env->cp15.c15_ccnt_delta;
+#ifndef CONFIG_USER_ONLY
+        uint64_t delta;
+        if (env->cp15.c9_pmcr & PMCRLC) {
+            delta = UINT64_MAX - env->cp15.c15_ccnt + 1;
+        } else {
+            delta = UINT32_MAX - (uint32_t)env->cp15.c15_ccnt + 1;
+        }
+        int64_t overflow_in = cycles_ns_per(delta);
+
+        if (overflow_in > 0) {
+            int64_t overflow_at = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
+                overflow_in;
+            ARMCPU *cpu = arm_env_get_cpu(env);
+            timer_mod_anticipate_ns(cpu->pmu_timer, overflow_at);
+        }
+#endif
 
+        uint64_t prev_cycles = env->cp15.c15_ccnt_delta;
         if (env->cp15.c9_pmcr & PMCRD) {
             /* Increment once every 64 processor clock cycles */
             prev_cycles /= 64;
         }
-
         env->cp15.c15_ccnt_delta = prev_cycles - env->cp15.c15_ccnt;
     }
 }
@@ -1340,8 +1399,15 @@ static void pmevcntr_op_start(CPUARMState *env, uint8_t counter)
     }
 
     if (pmu_counter_enabled(env, counter)) {
-        env->cp15.c14_pmevcntr[counter] =
-            count - env->cp15.c14_pmevcntr_delta[counter];
+        uint64_t new_pmevcntr = count - env->cp15.c14_pmevcntr_delta[counter];
+
+        if (!(new_pmevcntr & PMEVCNTR_OVERFLOW_MASK) &&
+                (env->cp15.c14_pmevcntr[counter] & PMEVCNTR_OVERFLOW_MASK)) {
+            env->cp15.c9_pmovsr |= (1 << counter);
+            new_pmevcntr &= ~PMEVCNTR_OVERFLOW_MASK;
+            pmu_update_irq(env);
+        }
+        env->cp15.c14_pmevcntr[counter] = new_pmevcntr;
     }
     env->cp15.c14_pmevcntr_delta[counter] = count;
 }
@@ -1349,6 +1415,21 @@ static void pmevcntr_op_start(CPUARMState *env, uint8_t counter)
 static void pmevcntr_op_finish(CPUARMState *env, uint8_t counter)
 {
     if (pmu_counter_enabled(env, counter)) {
+#ifndef CONFIG_USER_ONLY
+        uint16_t event = env->cp15.c14_pmevtyper[counter] & PMXEVTYPER_EVTCOUNT;
+        uint16_t event_idx = supported_event_map[event];
+        uint64_t delta = UINT32_MAX -
+            (uint32_t)env->cp15.c14_pmevcntr[counter] + 1;
+        int64_t overflow_in = pm_events[event_idx].ns_per_count(delta);
+
+        if (overflow_in > 0) {
+            int64_t overflow_at = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
+                overflow_in;
+            ARMCPU *cpu = arm_env_get_cpu(env);
+            timer_mod_anticipate_ns(cpu->pmu_timer, overflow_at);
+        }
+#endif
+
         env->cp15.c14_pmevcntr_delta[counter] -=
             env->cp15.c14_pmevcntr[counter];
     }
@@ -1382,6 +1463,19 @@ void pmu_post_el_change(ARMCPU *cpu, void *ignored)
     pmu_op_finish(&cpu->env);
 }
 
+void arm_pmu_timer_cb(void *opaque)
+{
+    ARMCPU *cpu = opaque;
+
+    /* Update all the counter values based on the current underlying counts,
+     * triggering interrupts to be raised, if necessary. pmu_op_finish() also
+     * has the effect of setting the cpu->pmu_timer to the next earliest time a
+     * counter may expire.
+     */
+    pmu_op_start(&cpu->env);
+    pmu_op_finish(&cpu->env);
+}
+
 static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                        uint64_t value)
 {
@@ -1418,7 +1512,21 @@ static void pmswinc_write(CPUARMState *env, const ARMCPRegInfo *ri,
                 /* counter is SW_INCR */
                 (env->cp15.c14_pmevtyper[i] & PMXEVTYPER_EVTCOUNT) == 0x0) {
             pmevcntr_op_start(env, i);
-            env->cp15.c14_pmevcntr[i]++;
+
+            /* Detect if this write causes an overflow since we can't predict
+             * PMSWINC overflows like we can for other events
+             */
+            uint64_t new_pmswinc = env->cp15.c14_pmevcntr[i] + 1;
+
+            if (!(new_pmswinc & PMEVCNTR_OVERFLOW_MASK) &&
+                    (env->cp15.c14_pmevcntr[i] & PMEVCNTR_OVERFLOW_MASK)) {
+                env->cp15.c9_pmovsr |= (1 << i);
+                new_pmswinc &= ~PMEVCNTR_OVERFLOW_MASK;
+                pmu_update_irq(env);
+            }
+
+            env->cp15.c14_pmevcntr[i] = new_pmswinc;
+
             pmevcntr_op_finish(env, i);
         }
     }
@@ -1489,6 +1597,7 @@ static void pmcntenset_write(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     value &= pmu_counter_mask(env);
     env->cp15.c9_pmcnten |= value;
+    pmu_update_irq(env);
 }
 
 static void pmcntenclr_write(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -1496,6 +1605,7 @@ static void pmcntenclr_write(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     value &= pmu_counter_mask(env);
     env->cp15.c9_pmcnten &= ~value;
+    pmu_update_irq(env);
 }
 
 static void pmovsr_write(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -1503,6 +1613,7 @@ static void pmovsr_write(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     value &= pmu_counter_mask(env);
     env->cp15.c9_pmovsr &= ~value;
+    pmu_update_irq(env);
 }
 
 static void pmovsset_write(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -1510,6 +1621,7 @@ static void pmovsset_write(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     value &= pmu_counter_mask(env);
     env->cp15.c9_pmovsr |= value;
+    pmu_update_irq(env);
 }
 
 static void pmevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -1696,6 +1808,7 @@ static void pmintenset_write(CPUARMState *env, const ARMCPRegInfo *ri,
     /* We have no event counters so only the C bit can be changed */
     value &= pmu_counter_mask(env);
     env->cp15.c9_pminten |= value;
+    pmu_update_irq(env);
 }
 
 static void pmintenclr_write(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -1703,6 +1816,7 @@ static void pmintenclr_write(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     value &= pmu_counter_mask(env);
     env->cp15.c9_pminten &= ~value;
+    pmu_update_irq(env);
 }
 
 static void vbar_write(CPUARMState *env, const ARMCPRegInfo *ri,
-- 
2.19.1

Re: [Qemu-devel] [PATCH v8 03/13] target/arm: Swap PMU values before/after migrations

[Peter Maydell]

On Tue, 20 Nov 2018 at 21:26, Aaron Lindsay
<aaron@os.amperecomputing.com> wrote:
>
> Because of the PMU's design, many register accesses have side effects
> which are inter-related, meaning that the normal method of saving CP
> registers can result in inconsistent state. These side-effects are
> largely handled in pmu_op_start/finish functions which can be called
> before and after the state is saved/restored. By doing this and adding
> raw read/write functions for the affected registers, we avoid
> migration-related inconsistencies.
>
> Signed-off-by: Aaron Lindsay <aclindsa@gmail.com>
> Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH v8 07/13] target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]

[Peter Maydell]

On Tue, 20 Nov 2018 at 21:26, Aaron Lindsay
<aaron@os.amperecomputing.com> wrote:
>
> Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
> ---
>  target/arm/cpu.h    |  4 ++--
>  target/arm/helper.c | 12 ++++++++++--
>  2 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index 627e5c1995..50de58e4a2 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -837,8 +837,8 @@ struct ARMCPU {
>      uint32_t id_pfr0;
>      uint32_t id_pfr1;
>      uint32_t id_dfr0;
> -    uint32_t pmceid0;
> -    uint32_t pmceid1;
> +    uint64_t pmceid0;
> +    uint64_t pmceid1;
>      uint32_t id_afr0;
>      uint32_t id_mmfr0;
>      uint32_t id_mmfr1;
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 71be6fb578..75f054fe79 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -5432,7 +5432,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
>              { .name = "PMCEID0", .state = ARM_CP_STATE_AA32,
>                .cp = 15, .opc1 = 0, .crn = 9, .crm = 12, .opc2 = 6,
>                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> -              .resetvalue = cpu->pmceid0 },
> +              .resetvalue = extract64(cpu->pmceid0, 0, 32) },
> +            { .name = "PMCEID2", .state = ARM_CP_STATE_AA32,
> +              .cp = 15, .opc1 = 0, .crn = 9, .crm = 14, .opc2 = 4,
> +              .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> +              .resetvalue = extract64(cpu->pmceid0, 32, 32) },
>              { .name = "PMCEID0_EL0", .state = ARM_CP_STATE_AA64,
>                .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 6,
>                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> @@ -5440,7 +5444,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
>              { .name = "PMCEID1", .state = ARM_CP_STATE_AA32,
>                .cp = 15, .opc1 = 0, .crn = 9, .crm = 12, .opc2 = 7,
>                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> -              .resetvalue = cpu->pmceid1 },
> +              .resetvalue = extract64(cpu->pmceid1, 0, 32) },
> +            { .name = "PMCEID3", .state = ARM_CP_STATE_AA32,
> +              .cp = 15, .opc1 = 0, .crn = 9, .crm = 14, .opc2 = 5,
> +              .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> +              .resetvalue = extract64(cpu->pmceid1, 32, 32) },
>              { .name = "PMCEID1_EL0", .state = ARM_CP_STATE_AA64,
>                .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 7,
>                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> --

PMCEID2 and PMCEID3 are only defined from ARMv8.1; before that they
are UNDEFINED. So these registers need to be only defined if a
suitable feature bit or ID register field check passes.

thanks
-- PMM

Re: [Qemu-devel] [PATCH v8 08/13] target/arm: Add array for supported PMU events, generate PMCEID[01]_EL0

[Peter Maydell]

On Tue, 20 Nov 2018 at 21:26, Aaron Lindsay
<aaron@os.amperecomputing.com> wrote:
>
> This commit doesn't add any supported events, but provides the framework
> for adding them. We store the pm_event structs in a simple array, and
> provide the mapping from the event numbers to array indexes in the
> supported_event_map array. Because the value of PMCEID[01] depends upon
> which events are supported at runtime, generate it dynamically.
>
> Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
> ---
>  target/arm/cpu.c    | 19 +++++++++------
>  target/arm/cpu.h    | 10 ++++++++
>  target/arm/cpu64.c  |  4 ----
>  target/arm/helper.c | 57 +++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 79 insertions(+), 11 deletions(-)
>
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index f7bad04f60..208a08e867 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -1019,10 +1019,19 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>
>      if (!cpu->has_pmu) {
>          unset_feature(env, ARM_FEATURE_PMU);
> +    }
> +    if (arm_feature(env, ARM_FEATURE_PMU)) {
> +        cpu->pmceid0 = get_pmceid(&cpu->env, 0);
> +        cpu->pmceid1 = get_pmceid(&cpu->env, 1);
> +
> +        if (!kvm_enabled()) {
> +            arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
> +            arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
> +        }
> +    } else {
>          cpu->id_aa64dfr0 &= ~0xf00;
> -    } else if (!kvm_enabled()) {
> -        arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
> -        arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
> +        cpu->pmceid0 = 0;
> +        cpu->pmceid1 = 0;
>      }
>
>      if (!arm_feature(env, ARM_FEATURE_EL2)) {
> @@ -1665,8 +1674,6 @@ static void cortex_a7_initfn(Object *obj)
>      cpu->id_pfr0 = 0x00001131;
>      cpu->id_pfr1 = 0x00011011;
>      cpu->id_dfr0 = 0x02010555;
> -    cpu->pmceid0 = 0x00000000;
> -    cpu->pmceid1 = 0x00000000;
>      cpu->id_afr0 = 0x00000000;
>      cpu->id_mmfr0 = 0x10101105;
>      cpu->id_mmfr1 = 0x40000000;
> @@ -1712,8 +1719,6 @@ static void cortex_a15_initfn(Object *obj)
>      cpu->id_pfr0 = 0x00001131;
>      cpu->id_pfr1 = 0x00011011;
>      cpu->id_dfr0 = 0x02010555;
> -    cpu->pmceid0 = 0x0000000;
> -    cpu->pmceid1 = 0x00000000;
>      cpu->id_afr0 = 0x00000000;
>      cpu->id_mmfr0 = 0x10201105;
>      cpu->id_mmfr1 = 0x20000000;
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index 50de58e4a2..32c3397948 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -993,6 +993,16 @@ void pmu_op_finish(CPUARMState *env);
>  void pmu_pre_el_change(ARMCPU *cpu, void *ignored);
>  void pmu_post_el_change(ARMCPU *cpu, void *ignored);
>
> +/*
> + * get_pmceid
> + * @env: CPUARMState
> + *
> + * Return the PMCEID[01]_EL0 register values corresponding to the counters
> + * which are supported given the current configuration (`which` is 0 or 1 to
> + * indicate which PMCEID should be returned)
> + */

Nit: you should have a line here below the one for "@env"
for the "@which" parameter, and the reference to it in
the text should just be "@which", not "`which`" (or just
put that description in the line saying what @which is
rather than having it in a parenthetical).

> +uint64_t get_pmceid(CPUARMState *env, unsigned which);
> +
>  /* SCTLR bit meanings. Several bits have been reused in newer
>   * versions of the architecture; in that case we define constants
>   * for both old and new bit meanings. Code which tests against those
> diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
> index 873f059bf2..a1aad772fa 100644
> --- a/target/arm/cpu64.c
> +++ b/target/arm/cpu64.c
> @@ -138,8 +138,6 @@ static void aarch64_a57_initfn(Object *obj)
>      cpu->isar.id_isar6 = 0;
>      cpu->isar.id_aa64pfr0 = 0x00002222;
>      cpu->id_aa64dfr0 = 0x10305106;
> -    cpu->pmceid0 = 0x00000000;
> -    cpu->pmceid1 = 0x00000000;
>      cpu->isar.id_aa64isar0 = 0x00011120;
>      cpu->id_aa64mmfr0 = 0x00001124;
>      cpu->dbgdidr = 0x3516d000;
> @@ -246,8 +244,6 @@ static void aarch64_a72_initfn(Object *obj)
>      cpu->isar.id_isar5 = 0x00011121;
>      cpu->isar.id_aa64pfr0 = 0x00002222;
>      cpu->id_aa64dfr0 = 0x10305106;
> -    cpu->pmceid0 = 0x00000000;
> -    cpu->pmceid1 = 0x00000000;
>      cpu->isar.id_aa64isar0 = 0x00011120;
>      cpu->id_aa64mmfr0 = 0x00001124;
>      cpu->dbgdidr = 0x3516d000;
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 75f054fe79..68e9743606 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -1009,6 +1009,63 @@ static inline uint64_t pmu_counter_mask(CPUARMState *env)
>    return (1 << 31) | ((1 << pmu_num_counters(env)) - 1);
>  }
>
> +typedef struct pm_event {
> +    uint16_t number; /* PMEVTYPER.evtCount is 16 bits wide */
> +    /* If the event is supported on this CPU (used to generate PMCEID[01]) */
> +    bool (*supported)(CPUARMState *);
> +    /*
> +     * Retrieve the current count of the underlying event. The programmed
> +     * counters hold a difference from the return value from this function
> +     */
> +    uint64_t (*get_count)(CPUARMState *);
> +} pm_event;
> +
> +static const pm_event pm_events[] = {
> +};
> +
> +/*
> + * Note: Before increasing MAX_EVENT_ID beyond 0x3f into the 0x40xx range of
> + * events (i.e. the statistical profiling extension), this implementation
> + * should first be updated to something sparse instead of the current
> + * supported_event_map[] array.
> + */
> +#define MAX_EVENT_ID 0x0
> +#define UNSUPPORTED_EVENT UINT16_MAX
> +static uint16_t supported_event_map[MAX_EVENT_ID + 1];
> +
> +/*
> + * Called upon initialization to build PMCEID0_EL0 or PMCEID1_EL0 (indicated by
> + * 'which'). We also use it to build a map of ARM event numbers to indices in
> + * our pm_events array.
> + *
> + * Note: Events in the 0x40XX range are not currently supported.
> + */
> +uint64_t get_pmceid(CPUARMState *env, unsigned which)
> +{
> +    uint64_t pmceid = 0;
> +    unsigned int i;
> +
> +    assert(which <= 1);
> +
> +    for (i = 0; i < ARRAY_SIZE(supported_event_map); i++) {
> +        supported_event_map[i] = UNSUPPORTED_EVENT;
> +    }
> +
> +    for (i = 0; i < ARRAY_SIZE(pm_events); i++) {
> +        const pm_event *cnt = &pm_events[i];
> +        assert(cnt->number <= MAX_EVENT_ID);
> +        /* We do not currently support events in the 0x40xx range */
> +        assert(cnt->number <= 0x3f);
> +
> +        if ((cnt->number & 0x20) == (which << 6) &&
> +                cnt->supported(env)) {
> +            pmceid |= (1 << (cnt->number & 0x1f));
> +            supported_event_map[cnt->number] = i;
> +        }
> +    }
> +    return pmceid;
> +}
> +

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH v8 13/13] target/arm: Send interrupts on PMU counter overflow

[Richard Henderson]

On 11/20/18 1:26 PM, Aaron Lindsay wrote:
> Setup a QEMUTimer to get a callback when we expect counters to next
> overflow and trigger an interrupt at that time.
> 
> Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
> Signed-off-by: Aaron Lindsay <alindsay@os.amperecomputing.com>
> ---
>  target/arm/cpu.c    |  12 +++++
>  target/arm/cpu.h    |   7 +++
>  target/arm/helper.c | 126 +++++++++++++++++++++++++++++++++++++++++---
>  3 files changed, 139 insertions(+), 6 deletions(-)
> 
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 208a08e867..7311a48e3c 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -827,6 +827,13 @@ static void arm_cpu_finalizefn(Object *obj)
>          QLIST_REMOVE(hook, node);
>          g_free(hook);
>      }
> +#ifndef CONFIG_USER_ONLY
> +    if (arm_feature(&cpu->env, ARM_FEATURE_PMU) && cpu->pmu_timer) {

No need for two tests here.  Just check cpu->pmu_timer.
(If it's set for any reason it should be freed, surely.)

> @@ -1305,7 +1338,18 @@ void pmccntr_op_start(CPUARMState *env)
>              eff_cycles /= 64;
>          }
>  
> -        env->cp15.c15_ccnt = eff_cycles - env->cp15.c15_ccnt_delta;
> +        uint64_t new_pmccntr = eff_cycles - env->cp15.c15_ccnt_delta;
> +
> +        unsigned int overflow_bit = (env->cp15.c9_pmcr & PMCRLC) ? 63 : 31;
> +        uint64_t overflow_mask = (uint64_t)1 << overflow_bit;
> +        if (!(new_pmccntr & overflow_mask) &&
> +                (env->cp15.c15_ccnt & overflow_mask)) {

Fyi, this expression is

    env->cp15.c15_ccnt & ~new_pmccntr & overflow_mask

> +            env->cp15.c9_pmovsr |= (1 << 31);
> +            new_pmccntr &= ~overflow_mask;

Why this line?  You just checked that overflow_mask was unset in new_pmccntr above.

> @@ -1318,13 +1362,28 @@ void pmccntr_op_start(CPUARMState *env)
>  void pmccntr_op_finish(CPUARMState *env)
>  {
>      if (pmu_counter_enabled(env, 31)) {
> -        uint64_t prev_cycles = env->cp15.c15_ccnt_delta;
> +#ifndef CONFIG_USER_ONLY
> +        uint64_t delta;
> +        if (env->cp15.c9_pmcr & PMCRLC) {
> +            delta = UINT64_MAX - env->cp15.c15_ccnt + 1;
> +        } else {
> +            delta = UINT32_MAX - (uint32_t)env->cp15.c15_ccnt + 1;
> +        }

FWIW, this is the same as

    delta = -env->cp15.c15_ccnt;
    if (!(env->cp15.c9_pmcr & PMCRLC)) {
        delta = (uint32_t)delta;
    }


r~

Re: [Qemu-devel] [PATCH v8 13/13] target/arm: Send interrupts on PMU counter overflow

[Aaron Lindsay]

On Nov 30 09:13, Richard Henderson wrote:
> On 11/20/18 1:26 PM, Aaron Lindsay wrote:
> > Setup a QEMUTimer to get a callback when we expect counters to next
> > overflow and trigger an interrupt at that time.
> > 
> > Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
> > Signed-off-by: Aaron Lindsay <alindsay@os.amperecomputing.com>
> > ---
> >  target/arm/cpu.c    |  12 +++++
> >  target/arm/cpu.h    |   7 +++
> >  target/arm/helper.c | 126 +++++++++++++++++++++++++++++++++++++++++---
> >  3 files changed, 139 insertions(+), 6 deletions(-)
> > 
> > diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> > index 208a08e867..7311a48e3c 100644
> > --- a/target/arm/cpu.c
> > +++ b/target/arm/cpu.c
> > @@ -827,6 +827,13 @@ static void arm_cpu_finalizefn(Object *obj)
> >          QLIST_REMOVE(hook, node);
> >          g_free(hook);
> >      }
> > +#ifndef CONFIG_USER_ONLY
> > +    if (arm_feature(&cpu->env, ARM_FEATURE_PMU) && cpu->pmu_timer) {
> 
> No need for two tests here.  Just check cpu->pmu_timer.
> (If it's set for any reason it should be freed, surely.)
> 
> > @@ -1305,7 +1338,18 @@ void pmccntr_op_start(CPUARMState *env)
> >              eff_cycles /= 64;
> >          }
> >  
> > -        env->cp15.c15_ccnt = eff_cycles - env->cp15.c15_ccnt_delta;
> > +        uint64_t new_pmccntr = eff_cycles - env->cp15.c15_ccnt_delta;
> > +
> > +        unsigned int overflow_bit = (env->cp15.c9_pmcr & PMCRLC) ? 63 : 31;
> > +        uint64_t overflow_mask = (uint64_t)1 << overflow_bit;
> > +        if (!(new_pmccntr & overflow_mask) &&
> > +                (env->cp15.c15_ccnt & overflow_mask)) {
> 
> Fyi, this expression is
> 
>     env->cp15.c15_ccnt & ~new_pmccntr & overflow_mask
> 
> > +            env->cp15.c9_pmovsr |= (1 << 31);
> > +            new_pmccntr &= ~overflow_mask;
> 
> Why this line?  You just checked that overflow_mask was unset in new_pmccntr above.

This ensures that when overflow_bit == 31 (because PMCR.LC is not set)
the high 32 bits remain 0 even after an overflow has occurred. As you
point out, it's silly when overflow_bit == 64, but I didn't think it was
worth the extra conditional to avoid it.

> > @@ -1318,13 +1362,28 @@ void pmccntr_op_start(CPUARMState *env)
> >  void pmccntr_op_finish(CPUARMState *env)
> >  {
> >      if (pmu_counter_enabled(env, 31)) {
> > -        uint64_t prev_cycles = env->cp15.c15_ccnt_delta;
> > +#ifndef CONFIG_USER_ONLY
> > +        uint64_t delta;
> > +        if (env->cp15.c9_pmcr & PMCRLC) {
> > +            delta = UINT64_MAX - env->cp15.c15_ccnt + 1;
> > +        } else {
> > +            delta = UINT32_MAX - (uint32_t)env->cp15.c15_ccnt + 1;
> > +        }
> 
> FWIW, this is the same as
> 
>     delta = -env->cp15.c15_ccnt;
>     if (!(env->cp15.c9_pmcr & PMCRLC)) {
>         delta = (uint32_t)delta;
>     }

Thanks for your review. I'll take a look at your suggested logic
simplifications for v9, do you think that this patch looks OK at the
big-picture level?

-Aaron

Re: [Qemu-devel] [PATCH v8 13/13] target/arm: Send interrupts on PMU counter overflow

[Richard Henderson]

On 11/30/18 9:56 AM, Aaron Lindsay wrote:
> On Nov 30 09:13, Richard Henderson wrote:
>> On 11/20/18 1:26 PM, Aaron Lindsay wrote:
>>> Setup a QEMUTimer to get a callback when we expect counters to next
>>> overflow and trigger an interrupt at that time.
>>>
>>> Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
>>> Signed-off-by: Aaron Lindsay <alindsay@os.amperecomputing.com>
>>> ---
>>>  target/arm/cpu.c    |  12 +++++
>>>  target/arm/cpu.h    |   7 +++
>>>  target/arm/helper.c | 126 +++++++++++++++++++++++++++++++++++++++++---
>>>  3 files changed, 139 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
>>> index 208a08e867..7311a48e3c 100644
>>> --- a/target/arm/cpu.c
>>> +++ b/target/arm/cpu.c
>>> @@ -827,6 +827,13 @@ static void arm_cpu_finalizefn(Object *obj)
>>>          QLIST_REMOVE(hook, node);
>>>          g_free(hook);
>>>      }
>>> +#ifndef CONFIG_USER_ONLY
>>> +    if (arm_feature(&cpu->env, ARM_FEATURE_PMU) && cpu->pmu_timer) {
>>
>> No need for two tests here.  Just check cpu->pmu_timer.
>> (If it's set for any reason it should be freed, surely.)
>>
>>> @@ -1305,7 +1338,18 @@ void pmccntr_op_start(CPUARMState *env)
>>>              eff_cycles /= 64;
>>>          }
>>>  
>>> -        env->cp15.c15_ccnt = eff_cycles - env->cp15.c15_ccnt_delta;
>>> +        uint64_t new_pmccntr = eff_cycles - env->cp15.c15_ccnt_delta;
>>> +
>>> +        unsigned int overflow_bit = (env->cp15.c9_pmcr & PMCRLC) ? 63 : 31;
>>> +        uint64_t overflow_mask = (uint64_t)1 << overflow_bit;
>>> +        if (!(new_pmccntr & overflow_mask) &&
>>> +                (env->cp15.c15_ccnt & overflow_mask)) {
>>
>> Fyi, this expression is
>>
>>     env->cp15.c15_ccnt & ~new_pmccntr & overflow_mask
>>
>>> +            env->cp15.c9_pmovsr |= (1 << 31);
>>> +            new_pmccntr &= ~overflow_mask;
>>
>> Why this line?  You just checked that overflow_mask was unset in new_pmccntr above.
> 
> This ensures that when overflow_bit == 31 (because PMCR.LC is not set)
> the high 32 bits remain 0 even after an overflow has occurred. As you
> point out, it's silly when overflow_bit == 64, but I didn't think it was
> worth the extra conditional to avoid it.

Eh?  But we've set overflow_mask based on PMCR.LC, so what you say here doesn't
make sense.

> Thanks for your review. I'll take a look at your suggested logic
> simplifications for v9, do you think that this patch looks OK at the
> big-picture level?

Yes, big picture looks good.


r~

Re: [Qemu-devel] [PATCH v8 13/13] target/arm: Send interrupts on PMU counter overflow

[Aaron Lindsay]

On Nov 30 10:19, Richard Henderson wrote:
> On 11/30/18 9:56 AM, Aaron Lindsay wrote:
> > On Nov 30 09:13, Richard Henderson wrote:
> >> On 11/20/18 1:26 PM, Aaron Lindsay wrote:
> >>> Setup a QEMUTimer to get a callback when we expect counters to next
> >>> overflow and trigger an interrupt at that time.
> >>>
> >>> Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
> >>> Signed-off-by: Aaron Lindsay <alindsay@os.amperecomputing.com>
> >>> ---
> >>>  target/arm/cpu.c    |  12 +++++
> >>>  target/arm/cpu.h    |   7 +++
> >>>  target/arm/helper.c | 126 +++++++++++++++++++++++++++++++++++++++++---
> >>>  3 files changed, 139 insertions(+), 6 deletions(-)
> >>>
> >>> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> >>> index 208a08e867..7311a48e3c 100644
> >>> --- a/target/arm/cpu.c
> >>> +++ b/target/arm/cpu.c
> >>> @@ -827,6 +827,13 @@ static void arm_cpu_finalizefn(Object *obj)
> >>>          QLIST_REMOVE(hook, node);
> >>>          g_free(hook);
> >>>      }
> >>> +#ifndef CONFIG_USER_ONLY
> >>> +    if (arm_feature(&cpu->env, ARM_FEATURE_PMU) && cpu->pmu_timer) {
> >>
> >> No need for two tests here.  Just check cpu->pmu_timer.
> >> (If it's set for any reason it should be freed, surely.)
> >>
> >>> @@ -1305,7 +1338,18 @@ void pmccntr_op_start(CPUARMState *env)
> >>>              eff_cycles /= 64;
> >>>          }
> >>>  
> >>> -        env->cp15.c15_ccnt = eff_cycles - env->cp15.c15_ccnt_delta;
> >>> +        uint64_t new_pmccntr = eff_cycles - env->cp15.c15_ccnt_delta;
> >>> +
> >>> +        unsigned int overflow_bit = (env->cp15.c9_pmcr & PMCRLC) ? 63 : 31;
> >>> +        uint64_t overflow_mask = (uint64_t)1 << overflow_bit;
> >>> +        if (!(new_pmccntr & overflow_mask) &&
> >>> +                (env->cp15.c15_ccnt & overflow_mask)) {
> >>
> >> Fyi, this expression is
> >>
> >>     env->cp15.c15_ccnt & ~new_pmccntr & overflow_mask
> >>
> >>> +            env->cp15.c9_pmovsr |= (1 << 31);
> >>> +            new_pmccntr &= ~overflow_mask;
> >>
> >> Why this line?  You just checked that overflow_mask was unset in new_pmccntr above.
> > 
> > This ensures that when overflow_bit == 31 (because PMCR.LC is not set)
> > the high 32 bits remain 0 even after an overflow has occurred. As you
> > point out, it's silly when overflow_bit == 64, but I didn't think it was
> > worth the extra conditional to avoid it.
> 
> Eh?  But we've set overflow_mask based on PMCR.LC, so what you say here doesn't
> make sense.

Sorry, I had an off-by-one-bit think-o I couldn't get past until I
started typing a concrete example to explain myself. I'll change this
line to be:

if (!(env->cp15.c9_pmcr & PMCRLC))
	new_pmccntr &= 0xffffffff;

-Aaron

Re: [Qemu-devel] [PATCH v8 13/13] target/arm: Send interrupts on PMU counter overflow

[Richard Henderson]

On 11/30/18 11:57 AM, Aaron Lindsay wrote:
>> Eh?  But we've set overflow_mask based on PMCR.LC, so what you say here doesn't
>> make sense.
> 
> Sorry, I had an off-by-one-bit think-o I couldn't get past until I
> started typing a concrete example to explain myself. I'll change this
> line to be:
> 
> if (!(env->cp15.c9_pmcr & PMCRLC))
> 	new_pmccntr &= 0xffffffff;

Ah, much better.  Thanks.


r~

Re: [Qemu-devel] [PATCH v8 08/13] target/arm: Add array for supported PMU events, generate PMCEID[01]_EL0

[Aaron Lindsay]

On Nov 30 16:14, Peter Maydell wrote:
> On Tue, 20 Nov 2018 at 21:26, Aaron Lindsay
> <aaron@os.amperecomputing.com> wrote:
> > diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> > index 50de58e4a2..32c3397948 100644
> > --- a/target/arm/cpu.h
> > +++ b/target/arm/cpu.h
> > @@ -993,6 +993,16 @@ void pmu_op_finish(CPUARMState *env);
> >  void pmu_pre_el_change(ARMCPU *cpu, void *ignored);
> >  void pmu_post_el_change(ARMCPU *cpu, void *ignored);
> >
> > +/*
> > + * get_pmceid
> > + * @env: CPUARMState
> > + *
> > + * Return the PMCEID[01]_EL0 register values corresponding to the counters
> > + * which are supported given the current configuration (`which` is 0 or 1 to
> > + * indicate which PMCEID should be returned)
> > + */
> 
> Nit: you should have a line here below the one for "@env"
> for the "@which" parameter, and the reference to it in
> the text should just be "@which", not "`which`" (or just
> put that description in the line saying what @which is
> rather than having it in a parenthetical).

Thanks, I've fixed this for v9.

-Aaron

Re: [Qemu-devel] [PATCH v8 07/13] target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]

[Aaron Lindsay]

On Nov 30 16:10, Peter Maydell wrote:
> On Tue, 20 Nov 2018 at 21:26, Aaron Lindsay
> <aaron@os.amperecomputing.com> wrote:
> >
> > Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
> > ---
> >  target/arm/cpu.h    |  4 ++--
> >  target/arm/helper.c | 12 ++++++++++--
> >  2 files changed, 12 insertions(+), 4 deletions(-)
> >
> > diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> > index 627e5c1995..50de58e4a2 100644
> > --- a/target/arm/cpu.h
> > +++ b/target/arm/cpu.h
> > @@ -837,8 +837,8 @@ struct ARMCPU {
> >      uint32_t id_pfr0;
> >      uint32_t id_pfr1;
> >      uint32_t id_dfr0;
> > -    uint32_t pmceid0;
> > -    uint32_t pmceid1;
> > +    uint64_t pmceid0;
> > +    uint64_t pmceid1;
> >      uint32_t id_afr0;
> >      uint32_t id_mmfr0;
> >      uint32_t id_mmfr1;
> > diff --git a/target/arm/helper.c b/target/arm/helper.c
> > index 71be6fb578..75f054fe79 100644
> > --- a/target/arm/helper.c
> > +++ b/target/arm/helper.c
> > @@ -5432,7 +5432,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
> >              { .name = "PMCEID0", .state = ARM_CP_STATE_AA32,
> >                .cp = 15, .opc1 = 0, .crn = 9, .crm = 12, .opc2 = 6,
> >                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> > -              .resetvalue = cpu->pmceid0 },
> > +              .resetvalue = extract64(cpu->pmceid0, 0, 32) },
> > +            { .name = "PMCEID2", .state = ARM_CP_STATE_AA32,
> > +              .cp = 15, .opc1 = 0, .crn = 9, .crm = 14, .opc2 = 4,
> > +              .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> > +              .resetvalue = extract64(cpu->pmceid0, 32, 32) },
> >              { .name = "PMCEID0_EL0", .state = ARM_CP_STATE_AA64,
> >                .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 6,
> >                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> > @@ -5440,7 +5444,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
> >              { .name = "PMCEID1", .state = ARM_CP_STATE_AA32,
> >                .cp = 15, .opc1 = 0, .crn = 9, .crm = 12, .opc2 = 7,
> >                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> > -              .resetvalue = cpu->pmceid1 },
> > +              .resetvalue = extract64(cpu->pmceid1, 0, 32) },
> > +            { .name = "PMCEID3", .state = ARM_CP_STATE_AA32,
> > +              .cp = 15, .opc1 = 0, .crn = 9, .crm = 14, .opc2 = 5,
> > +              .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> > +              .resetvalue = extract64(cpu->pmceid1, 32, 32) },
> >              { .name = "PMCEID1_EL0", .state = ARM_CP_STATE_AA64,
> >                .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 7,
> >                .access = PL0_R, .accessfn = pmreg_access, .type = ARM_CP_CONST,
> > --
> 
> PMCEID2 and PMCEID3 are only defined from ARMv8.1; before that they
> are UNDEFINED. So these registers need to be only defined if a
> suitable feature bit or ID register field check passes.

It looks like we don't currently support any ARMv8.1+ CPUs and don't
have an entry in the `arm_features` enum for it. I'll plan to add
ARM_FEATURE_V81 and make defining these registers depend on it, assuming
any future CPUs supporting it will use that, unless you feel I should do
something different.

-Aaron

Re: [Qemu-devel] [PATCH v8 07/13] target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]

[Peter Maydell]

On Mon, 3 Dec 2018 at 20:45, Aaron Lindsay <aaron@os.amperecomputing.com> wrote:
>
> On Nov 30 16:10, Peter Maydell wrote:
> > PMCEID2 and PMCEID3 are only defined from ARMv8.1; before that they
> > are UNDEFINED. So these registers need to be only defined if a
> > suitable feature bit or ID register field check passes.
>
> It looks like we don't currently support any ARMv8.1+ CPUs and don't
> have an entry in the `arm_features` enum for it. I'll plan to add
> ARM_FEATURE_V81 and make defining these registers depend on it, assuming
> any future CPUs supporting it will use that, unless you feel I should do
> something different.

I think that the idea going forward is to prefer an ID
register check of some kind -- Richard ?

thanks
-- PMM

Re: [Qemu-devel] [PATCH v8 07/13] target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]

[Richard Henderson]

On 12/3/18 4:19 PM, Peter Maydell wrote:
> On Mon, 3 Dec 2018 at 20:45, Aaron Lindsay <aaron@os.amperecomputing.com> wrote:
>>
>> On Nov 30 16:10, Peter Maydell wrote:
>>> PMCEID2 and PMCEID3 are only defined from ARMv8.1; before that they
>>> are UNDEFINED. So these registers need to be only defined if a
>>> suitable feature bit or ID register field check passes.
>>
>> It looks like we don't currently support any ARMv8.1+ CPUs and don't
>> have an entry in the `arm_features` enum for it. I'll plan to add
>> ARM_FEATURE_V81 and make defining these registers depend on it, assuming
>> any future CPUs supporting it will use that, unless you feel I should do
>> something different.
> 
> I think that the idea going forward is to prefer an ID
> register check of some kind -- Richard ?

Yes.  It would appear that this feature should be controlled by
ID_DFR0.PerfMon.  So,

  if (FIELD_EX32(cpu->id_dfr0, ID_DFR0, PERFMON) >= 4)

once the appropriate FIELDs are added to cpu.h.

Since this test is not used within translate*.c, there is no need to move
id_dfr* into ARMISARegisters.  Since these are only aliases, they do not affect
migration, and so do not (yet) need to be filled in by kvm.


r~

Re: [Qemu-devel] [PATCH v8 07/13] target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]

[Aaron Lindsay]

On Dec 03 16:57, Richard Henderson wrote:
> On 12/3/18 4:19 PM, Peter Maydell wrote:
> > On Mon, 3 Dec 2018 at 20:45, Aaron Lindsay <aaron@os.amperecomputing.com> wrote:
> >>
> >> On Nov 30 16:10, Peter Maydell wrote:
> >>> PMCEID2 and PMCEID3 are only defined from ARMv8.1; before that they
> >>> are UNDEFINED. So these registers need to be only defined if a
> >>> suitable feature bit or ID register field check passes.
> >>
> >> It looks like we don't currently support any ARMv8.1+ CPUs and don't
> >> have an entry in the `arm_features` enum for it. I'll plan to add
> >> ARM_FEATURE_V81 and make defining these registers depend on it, assuming
> >> any future CPUs supporting it will use that, unless you feel I should do
> >> something different.
> > 
> > I think that the idea going forward is to prefer an ID
> > register check of some kind -- Richard ?
> 
> Yes.  It would appear that this feature should be controlled by
> ID_DFR0.PerfMon.  So,
> 
>   if (FIELD_EX32(cpu->id_dfr0, ID_DFR0, PERFMON) >= 4)
> 
> once the appropriate FIELDs are added to cpu.h.
> 
> Since this test is not used within translate*.c, there is no need to move
> id_dfr* into ARMISARegisters.  Since these are only aliases, they do not affect
> migration, and so do not (yet) need to be filled in by kvm.

Sounds reasonable to me. One clarification - do we also need to guard
against the 0b1111 value for ID_DFR0.PerfMon, which implies an
implementation-defined, non-PMUv3 PMU, or is it safe to assume no one
will attempt that flavor in QEMU?

-Aaron

Re: [Qemu-devel] [PATCH v8 07/13] target-arm: Make PMCEID[01]_EL0 64 bit registers, add PMCEID[23]

[Peter Maydell]

On Wed, 5 Dec 2018 at 13:00, Aaron Lindsay <aaron@os.amperecomputing.com> wrote:
>
> On Dec 03 16:57, Richard Henderson wrote:
> > Yes.  It would appear that this feature should be controlled by
> > ID_DFR0.PerfMon.  So,
> >
> >   if (FIELD_EX32(cpu->id_dfr0, ID_DFR0, PERFMON) >= 4)
> >
> > once the appropriate FIELDs are added to cpu.h.
> >
> > Since this test is not used within translate*.c, there is no need to move
> > id_dfr* into ARMISARegisters.  Since these are only aliases, they do not affect
> > migration, and so do not (yet) need to be filled in by kvm.
>
> Sounds reasonable to me. One clarification - do we also need to guard
> against the 0b1111 value for ID_DFR0.PerfMon, which implies an
> implementation-defined, non-PMUv3 PMU, or is it safe to assume no one
> will attempt that flavor in QEMU?

We should check for 0xf, yes, following the recommended check
logic described in the Arm ARM section "Alternative ID scheme used
for the Performance Monitors Extension version". It doesn't
seem likely that we'll end up with the 0xf case but we might
as well avoid the question in advance...

thanks
-- PMM