Verify PMU snapshot functionality by setting up the shared memory
correctly and reading the counter values from the shared memory
instead of the CSR.
Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
.../selftests/kvm/include/riscv/processor.h | 25 ++++
.../selftests/kvm/lib/riscv/processor.c | 12 ++
tools/testing/selftests/kvm/riscv/sbi_pmu.c | 124 ++++++++++++++++++
3 files changed, 161 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
index a49a39c8e8d4..e114d039e87b 100644
--- a/tools/testing/selftests/kvm/include/riscv/processor.h
+++ b/tools/testing/selftests/kvm/include/riscv/processor.h
@@ -173,6 +173,7 @@ enum sbi_ext_id {
};
enum sbi_ext_base_fid {
+ SBI_EXT_BASE_GET_IMP_VERSION = 2,
SBI_EXT_BASE_PROBE_EXT = 3,
};
@@ -201,6 +202,12 @@ union sbi_pmu_ctr_info {
};
};
+struct riscv_pmu_snapshot_data {
+ u64 ctr_overflow_mask;
+ u64 ctr_values[64];
+ u64 reserved[447];
+};
+
struct sbiret {
long error;
long value;
@@ -247,6 +254,14 @@ enum sbi_pmu_ctr_type {
#define SBI_PMU_STOP_FLAG_RESET (1 << 0)
#define SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT BIT(1)
+#define SBI_STA_SHMEM_DISABLE -1
+
+/* SBI spec version fields */
+#define SBI_SPEC_VERSION_DEFAULT 0x1
+#define SBI_SPEC_VERSION_MAJOR_SHIFT 24
+#define SBI_SPEC_VERSION_MAJOR_MASK 0x7f
+#define SBI_SPEC_VERSION_MINOR_MASK 0xffffff
+
struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
unsigned long arg1, unsigned long arg2,
unsigned long arg3, unsigned long arg4,
@@ -254,6 +269,16 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
bool guest_sbi_probe_extension(int extid, long *out_val);
+/* Make SBI version */
+static inline unsigned long sbi_mk_version(unsigned long major,
+ unsigned long minor)
+{
+ return ((major & SBI_SPEC_VERSION_MAJOR_MASK) <<
+ SBI_SPEC_VERSION_MAJOR_SHIFT) | minor;
+}
+
+unsigned long get_host_sbi_impl_version(void);
+
static inline void local_irq_enable(void)
{
csr_set(CSR_SSTATUS, SR_SIE);
diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
index ec66d331a127..b0162d923e38 100644
--- a/tools/testing/selftests/kvm/lib/riscv/processor.c
+++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
@@ -499,3 +499,15 @@ bool guest_sbi_probe_extension(int extid, long *out_val)
return true;
}
+
+unsigned long get_host_sbi_impl_version(void)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_IMP_VERSION, 0,
+ 0, 0, 0, 0, 0);
+
+ GUEST_ASSERT(!ret.error);
+
+ return ret.value;
+}
diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu.c b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
index fc1fc5eea99e..8ea2a6db6610 100644
--- a/tools/testing/selftests/kvm/riscv/sbi_pmu.c
+++ b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
@@ -21,6 +21,11 @@
#define RISCV_MAX_PMU_COUNTERS 64
union sbi_pmu_ctr_info ctrinfo_arr[RISCV_MAX_PMU_COUNTERS];
+/* Snapshot shared memory data */
+#define PMU_SNAPSHOT_GPA_BASE (1 << 30)
+static void *snapshot_gva;
+static vm_paddr_t snapshot_gpa;
+
/* Cache the available counters in a bitmask */
static unsigned long counter_mask_available;
@@ -173,6 +178,20 @@ static void stop_counter(unsigned long counter, unsigned long stop_flags)
counter, ret.error);
}
+static void snapshot_set_shmem(vm_paddr_t gpa, unsigned long flags)
+{
+ unsigned long lo = (unsigned long)gpa;
+#if __riscv_xlen == 32
+ unsigned long hi = (unsigned long)(gpa >> 32);
+#else
+ unsigned long hi = gpa == -1 ? -1 : 0;
+#endif
+ struct sbiret ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
+ lo, hi, flags, 0, 0, 0);
+
+ GUEST_ASSERT(ret.value == 0 && ret.error == 0);
+}
+
static void test_pmu_event(unsigned long event)
{
unsigned long counter;
@@ -207,6 +226,43 @@ static void test_pmu_event(unsigned long event)
stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
}
+static void test_pmu_event_snapshot(unsigned long event)
+{
+ unsigned long counter;
+ unsigned long counter_value_pre, counter_value_post;
+ unsigned long counter_init_value = 100;
+ struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
+
+ counter = get_counter_index(0, counter_mask_available, 0, event);
+ counter_value_pre = read_counter(counter, ctrinfo_arr[counter]);
+
+ /* Do not set the initial value */
+ start_counter(counter, 0, 0);
+ dummy_func_loop(10000);
+
+ stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
+
+ /* The counter value is updated w.r.t relative index of cbase */
+ counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
+ __GUEST_ASSERT(counter_value_post > counter_value_pre,
+ "counter_value_post %lx counter_value_pre %lx\n",
+ counter_value_post, counter_value_pre);
+
+ /* Now set the initial value and compare */
+ WRITE_ONCE(snapshot_data->ctr_values[0], counter_init_value);
+ start_counter(counter, SBI_PMU_START_FLAG_INIT_FROM_SNAPSHOT, 0);
+ dummy_func_loop(10000);
+
+ stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
+
+ counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
+ __GUEST_ASSERT(counter_value_post > counter_init_value,
+ "counter_value_post %lx counter_init_value %lx for counter\n",
+ counter_value_post, counter_init_value);
+
+ stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
+}
+
static void test_invalid_event(void)
{
struct sbiret ret;
@@ -270,6 +326,41 @@ static void test_pmu_basic_sanity(int cpu)
GUEST_DONE();
}
+static void test_pmu_events_snaphost(int cpu)
+{
+ long out_val = 0;
+ bool probe;
+ int num_counters = 0;
+ unsigned long sbi_impl_version;
+ struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
+ int i;
+
+ probe = guest_sbi_probe_extension(SBI_EXT_PMU, &out_val);
+ GUEST_ASSERT(probe && out_val == 1);
+
+ sbi_impl_version = get_host_sbi_impl_version();
+ if (sbi_impl_version >= sbi_mk_version(2, 0))
+ __GUEST_ASSERT(0, "SBI implementation version doesn't support PMU Snapshot");
+
+ snapshot_set_shmem(snapshot_gpa, 0);
+
+ /* Get the counter details */
+ num_counters = get_num_counters();
+ update_counter_info(num_counters);
+
+ /* Validate shared memory access */
+ GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_overflow_mask), 0);
+ for (i = 0; i < num_counters; i++) {
+ if (counter_mask_available & (1UL << i))
+ GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_values[i]), 0);
+ }
+ /* Only these two events are guranteed to be present */
+ test_pmu_event_snapshot(SBI_PMU_HW_CPU_CYCLES);
+ test_pmu_event_snapshot(SBI_PMU_HW_INSTRUCTIONS);
+
+ GUEST_DONE();
+}
+
static void run_vcpu(struct kvm_vcpu *vcpu)
{
struct ucall uc;
@@ -328,6 +419,36 @@ static void test_vm_events_test(void *guest_code)
test_vm_destroy(vm);
}
+static void test_vm_setup_snapshot_mem(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
+{
+ vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, PMU_SNAPSHOT_GPA_BASE, 1, 1, 0);
+ /* PMU Snapshot requires single page only */
+ virt_map(vm, PMU_SNAPSHOT_GPA_BASE, PMU_SNAPSHOT_GPA_BASE, 1);
+
+ /* PMU_SNAPSHOT_GPA_BASE is identity mapped */
+ snapshot_gva = (void *)(PMU_SNAPSHOT_GPA_BASE);
+ snapshot_gpa = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)snapshot_gva);
+ sync_global_to_guest(vcpu->vm, snapshot_gva);
+ sync_global_to_guest(vcpu->vm, snapshot_gpa);
+}
+
+static void test_vm_events_snapshot_test(void *guest_code)
+{
+ struct kvm_vm *vm = NULL;
+ struct kvm_vcpu *vcpu = NULL;
+
+ vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+ __TEST_REQUIRE(__vcpu_has_ext(vcpu, RISCV_ISA_EXT_REG(KVM_RISCV_SBI_EXT_PMU)),
+ "SBI PMU not available, skipping test");
+
+ test_vm_setup_snapshot_mem(vm, vcpu);
+
+ vcpu_args_set(vcpu, 1, 0);
+ run_vcpu(vcpu);
+
+ test_vm_destroy(vm);
+}
+
int main(void)
{
test_vm_basic_test(test_pmu_basic_sanity);
@@ -336,5 +457,8 @@ int main(void)
test_vm_events_test(test_pmu_events);
pr_info("SBI PMU event verification test : PASS\n");
+ test_vm_events_snapshot_test(test_pmu_events_snaphost);
+ pr_info("SBI PMU event verification with snapshot test : PASS\n");
+
return 0;
}
--
2.34.1On Wed, Feb 28, 2024 at 05:01:29PM -0800, Atish Patra wrote:
> Verify PMU snapshot functionality by setting up the shared memory
> correctly and reading the counter values from the shared memory
> instead of the CSR.
>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
> .../selftests/kvm/include/riscv/processor.h | 25 ++++
> .../selftests/kvm/lib/riscv/processor.c | 12 ++
> tools/testing/selftests/kvm/riscv/sbi_pmu.c | 124 ++++++++++++++++++
> 3 files changed, 161 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
> index a49a39c8e8d4..e114d039e87b 100644
> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
> @@ -173,6 +173,7 @@ enum sbi_ext_id {
> };
>
> enum sbi_ext_base_fid {
> + SBI_EXT_BASE_GET_IMP_VERSION = 2,
> SBI_EXT_BASE_PROBE_EXT = 3,
> };
>
> @@ -201,6 +202,12 @@ union sbi_pmu_ctr_info {
> };
> };
>
> +struct riscv_pmu_snapshot_data {
> + u64 ctr_overflow_mask;
> + u64 ctr_values[64];
> + u64 reserved[447];
> +};
> +
> struct sbiret {
> long error;
> long value;
> @@ -247,6 +254,14 @@ enum sbi_pmu_ctr_type {
> #define SBI_PMU_STOP_FLAG_RESET (1 << 0)
> #define SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT BIT(1)
>
> +#define SBI_STA_SHMEM_DISABLE -1
unrelated change
> +
> +/* SBI spec version fields */
> +#define SBI_SPEC_VERSION_DEFAULT 0x1
> +#define SBI_SPEC_VERSION_MAJOR_SHIFT 24
> +#define SBI_SPEC_VERSION_MAJOR_MASK 0x7f
> +#define SBI_SPEC_VERSION_MINOR_MASK 0xffffff
> +
> struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
> unsigned long arg1, unsigned long arg2,
> unsigned long arg3, unsigned long arg4,
> @@ -254,6 +269,16 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>
> bool guest_sbi_probe_extension(int extid, long *out_val);
>
> +/* Make SBI version */
> +static inline unsigned long sbi_mk_version(unsigned long major,
> + unsigned long minor)
> +{
> + return ((major & SBI_SPEC_VERSION_MAJOR_MASK) <<
> + SBI_SPEC_VERSION_MAJOR_SHIFT) | minor;
> +}
We should probably just synch sbi.h into tools, since we need plenty
from it.
> +
> +unsigned long get_host_sbi_impl_version(void);
> +
> static inline void local_irq_enable(void)
> {
> csr_set(CSR_SSTATUS, SR_SIE);
> diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
> index ec66d331a127..b0162d923e38 100644
> --- a/tools/testing/selftests/kvm/lib/riscv/processor.c
> +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
> @@ -499,3 +499,15 @@ bool guest_sbi_probe_extension(int extid, long *out_val)
>
> return true;
> }
> +
> +unsigned long get_host_sbi_impl_version(void)
> +{
> + struct sbiret ret;
> +
> + ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_IMP_VERSION, 0,
> + 0, 0, 0, 0, 0);
> +
> + GUEST_ASSERT(!ret.error);
> +
> + return ret.value;
> +}
> diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu.c b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
> index fc1fc5eea99e..8ea2a6db6610 100644
> --- a/tools/testing/selftests/kvm/riscv/sbi_pmu.c
> +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
> @@ -21,6 +21,11 @@
> #define RISCV_MAX_PMU_COUNTERS 64
> union sbi_pmu_ctr_info ctrinfo_arr[RISCV_MAX_PMU_COUNTERS];
>
> +/* Snapshot shared memory data */
> +#define PMU_SNAPSHOT_GPA_BASE (1 << 30)
> +static void *snapshot_gva;
> +static vm_paddr_t snapshot_gpa;
> +
> /* Cache the available counters in a bitmask */
> static unsigned long counter_mask_available;
>
> @@ -173,6 +178,20 @@ static void stop_counter(unsigned long counter, unsigned long stop_flags)
> counter, ret.error);
> }
>
> +static void snapshot_set_shmem(vm_paddr_t gpa, unsigned long flags)
> +{
> + unsigned long lo = (unsigned long)gpa;
> +#if __riscv_xlen == 32
> + unsigned long hi = (unsigned long)(gpa >> 32);
> +#else
> + unsigned long hi = gpa == -1 ? -1 : 0;
> +#endif
> + struct sbiret ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
> + lo, hi, flags, 0, 0, 0);
> +
> + GUEST_ASSERT(ret.value == 0 && ret.error == 0);
> +}
> +
> static void test_pmu_event(unsigned long event)
> {
> unsigned long counter;
> @@ -207,6 +226,43 @@ static void test_pmu_event(unsigned long event)
> stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
> }
>
> +static void test_pmu_event_snapshot(unsigned long event)
> +{
> + unsigned long counter;
> + unsigned long counter_value_pre, counter_value_post;
> + unsigned long counter_init_value = 100;
> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
> +
> + counter = get_counter_index(0, counter_mask_available, 0, event);
> + counter_value_pre = read_counter(counter, ctrinfo_arr[counter]);
> +
> + /* Do not set the initial value */
> + start_counter(counter, 0, 0);
> + dummy_func_loop(10000);
> +
> + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
> +
> + /* The counter value is updated w.r.t relative index of cbase */
> + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
> + __GUEST_ASSERT(counter_value_post > counter_value_pre,
> + "counter_value_post %lx counter_value_pre %lx\n",
> + counter_value_post, counter_value_pre);
> +
> + /* Now set the initial value and compare */
> + WRITE_ONCE(snapshot_data->ctr_values[0], counter_init_value);
> + start_counter(counter, SBI_PMU_START_FLAG_INIT_FROM_SNAPSHOT, 0);
> + dummy_func_loop(10000);
> +
> + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
> +
> + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
> + __GUEST_ASSERT(counter_value_post > counter_init_value,
> + "counter_value_post %lx counter_init_value %lx for counter\n",
> + counter_value_post, counter_init_value);
> +
> + stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
This function is almost identical to test_pmu_event(). If we change one,
we'll likely have to change the other. We should have a single function
which can be used by both tests. We can do that by passing a function
pointer for the read which is different for non-snapshot and snapshot.
> +}
> +
> static void test_invalid_event(void)
> {
> struct sbiret ret;
> @@ -270,6 +326,41 @@ static void test_pmu_basic_sanity(int cpu)
> GUEST_DONE();
> }
>
> +static void test_pmu_events_snaphost(int cpu)
unnecessary cpu parameter
> +{
> + long out_val = 0;
> + bool probe;
> + int num_counters = 0;
> + unsigned long sbi_impl_version;
> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
> + int i;
> +
> + probe = guest_sbi_probe_extension(SBI_EXT_PMU, &out_val);
> + GUEST_ASSERT(probe && out_val == 1);
> +
> + sbi_impl_version = get_host_sbi_impl_version();
> + if (sbi_impl_version >= sbi_mk_version(2, 0))
> + __GUEST_ASSERT(0, "SBI implementation version doesn't support PMU Snapshot");
> +
> + snapshot_set_shmem(snapshot_gpa, 0);
> +
> + /* Get the counter details */
> + num_counters = get_num_counters();
> + update_counter_info(num_counters);
> +
> + /* Validate shared memory access */
> + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_overflow_mask), 0);
> + for (i = 0; i < num_counters; i++) {
> + if (counter_mask_available & (1UL << i))
BIT()
> + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_values[i]), 0);
> + }
> + /* Only these two events are guranteed to be present */
> + test_pmu_event_snapshot(SBI_PMU_HW_CPU_CYCLES);
> + test_pmu_event_snapshot(SBI_PMU_HW_INSTRUCTIONS);
> +
> + GUEST_DONE();
> +}
> +
> static void run_vcpu(struct kvm_vcpu *vcpu)
> {
> struct ucall uc;
> @@ -328,6 +419,36 @@ static void test_vm_events_test(void *guest_code)
> test_vm_destroy(vm);
> }
>
> +static void test_vm_setup_snapshot_mem(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
> +{
> + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, PMU_SNAPSHOT_GPA_BASE, 1, 1, 0);
> + /* PMU Snapshot requires single page only */
This comment should go above the memory region add
> + virt_map(vm, PMU_SNAPSHOT_GPA_BASE, PMU_SNAPSHOT_GPA_BASE, 1);
> +
> + /* PMU_SNAPSHOT_GPA_BASE is identity mapped */
This comment should go above the virt_map
> + snapshot_gva = (void *)(PMU_SNAPSHOT_GPA_BASE);
> + snapshot_gpa = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)snapshot_gva);
> + sync_global_to_guest(vcpu->vm, snapshot_gva);
> + sync_global_to_guest(vcpu->vm, snapshot_gpa);
> +}
> +
> +static void test_vm_events_snapshot_test(void *guest_code)
> +{
> + struct kvm_vm *vm = NULL;
> + struct kvm_vcpu *vcpu = NULL;
nit: no need to set to NULL
> +
> + vm = vm_create_with_one_vcpu(&vcpu, guest_code);
> + __TEST_REQUIRE(__vcpu_has_ext(vcpu, RISCV_ISA_EXT_REG(KVM_RISCV_SBI_EXT_PMU)),
RISCV_SBI_EXT_REG
> + "SBI PMU not available, skipping test");
> +
> + test_vm_setup_snapshot_mem(vm, vcpu);
> +
> + vcpu_args_set(vcpu, 1, 0);
no need to set args
> + run_vcpu(vcpu);
> +
> + test_vm_destroy(vm);
> +}
> +
> int main(void)
> {
> test_vm_basic_test(test_pmu_basic_sanity);
> @@ -336,5 +457,8 @@ int main(void)
> test_vm_events_test(test_pmu_events);
> pr_info("SBI PMU event verification test : PASS\n");
>
> + test_vm_events_snapshot_test(test_pmu_events_snaphost);
> + pr_info("SBI PMU event verification with snapshot test : PASS\n");
> +
> return 0;
> }
> --
> 2.34.1
>
Thanks,
drew
On 3/2/24 04:13, Andrew Jones wrote:
> On Wed, Feb 28, 2024 at 05:01:29PM -0800, Atish Patra wrote:
>> Verify PMU snapshot functionality by setting up the shared memory
>> correctly and reading the counter values from the shared memory
>> instead of the CSR.
>>
>> Signed-off-by: Atish Patra <atishp@rivosinc.com>
>> ---
>> .../selftests/kvm/include/riscv/processor.h | 25 ++++
>> .../selftests/kvm/lib/riscv/processor.c | 12 ++
>> tools/testing/selftests/kvm/riscv/sbi_pmu.c | 124 ++++++++++++++++++
>> 3 files changed, 161 insertions(+)
>>
>> diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
>> index a49a39c8e8d4..e114d039e87b 100644
>> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
>> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
>> @@ -173,6 +173,7 @@ enum sbi_ext_id {
>> };
>>
>> enum sbi_ext_base_fid {
>> + SBI_EXT_BASE_GET_IMP_VERSION = 2,
>> SBI_EXT_BASE_PROBE_EXT = 3,
>> };
>>
>> @@ -201,6 +202,12 @@ union sbi_pmu_ctr_info {
>> };
>> };
>>
>> +struct riscv_pmu_snapshot_data {
>> + u64 ctr_overflow_mask;
>> + u64 ctr_values[64];
>> + u64 reserved[447];
>> +};
>> +
>> struct sbiret {
>> long error;
>> long value;
>> @@ -247,6 +254,14 @@ enum sbi_pmu_ctr_type {
>> #define SBI_PMU_STOP_FLAG_RESET (1 << 0)
>> #define SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT BIT(1)
>>
>> +#define SBI_STA_SHMEM_DISABLE -1
>
> unrelated change
>
Dropped it.
>> +
>> +/* SBI spec version fields */
>> +#define SBI_SPEC_VERSION_DEFAULT 0x1
>> +#define SBI_SPEC_VERSION_MAJOR_SHIFT 24
>> +#define SBI_SPEC_VERSION_MAJOR_MASK 0x7f
>> +#define SBI_SPEC_VERSION_MINOR_MASK 0xffffff
>> +
>> struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>> unsigned long arg1, unsigned long arg2,
>> unsigned long arg3, unsigned long arg4,
>> @@ -254,6 +269,16 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>>
>> bool guest_sbi_probe_extension(int extid, long *out_val);
>>
>> +/* Make SBI version */
>> +static inline unsigned long sbi_mk_version(unsigned long major,
>> + unsigned long minor)
>> +{
>> + return ((major & SBI_SPEC_VERSION_MAJOR_MASK) <<
>> + SBI_SPEC_VERSION_MAJOR_SHIFT) | minor;
>> +}
>
> We should probably just synch sbi.h into tools, since we need plenty
> from it.
>
As of now I have created sbi.h and moved all the definitions there.
There is a still lot of difference between sbi.h. Do we really want to
bring everything in ? Should we adopt kvmtool like policy to sync sbi.h
or just do it as new test cases need sbi.h?
I can send another version with syncing sbi.h if you still think that's
better.
>> +
>> +unsigned long get_host_sbi_impl_version(void);
>> +
>> static inline void local_irq_enable(void)
>> {
>> csr_set(CSR_SSTATUS, SR_SIE);
>> diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
>> index ec66d331a127..b0162d923e38 100644
>> --- a/tools/testing/selftests/kvm/lib/riscv/processor.c
>> +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
>> @@ -499,3 +499,15 @@ bool guest_sbi_probe_extension(int extid, long *out_val)
>>
>> return true;
>> }
>> +
>> +unsigned long get_host_sbi_impl_version(void)
>> +{
>> + struct sbiret ret;
>> +
>> + ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_IMP_VERSION, 0,
>> + 0, 0, 0, 0, 0);
>> +
>> + GUEST_ASSERT(!ret.error);
>> +
>> + return ret.value;
>> +}
>> diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu.c b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
>> index fc1fc5eea99e..8ea2a6db6610 100644
>> --- a/tools/testing/selftests/kvm/riscv/sbi_pmu.c
>> +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
>> @@ -21,6 +21,11 @@
>> #define RISCV_MAX_PMU_COUNTERS 64
>> union sbi_pmu_ctr_info ctrinfo_arr[RISCV_MAX_PMU_COUNTERS];
>>
>> +/* Snapshot shared memory data */
>> +#define PMU_SNAPSHOT_GPA_BASE (1 << 30)
>> +static void *snapshot_gva;
>> +static vm_paddr_t snapshot_gpa;
>> +
>> /* Cache the available counters in a bitmask */
>> static unsigned long counter_mask_available;
>>
>> @@ -173,6 +178,20 @@ static void stop_counter(unsigned long counter, unsigned long stop_flags)
>> counter, ret.error);
>> }
>>
>> +static void snapshot_set_shmem(vm_paddr_t gpa, unsigned long flags)
>> +{
>> + unsigned long lo = (unsigned long)gpa;
>> +#if __riscv_xlen == 32
>> + unsigned long hi = (unsigned long)(gpa >> 32);
>> +#else
>> + unsigned long hi = gpa == -1 ? -1 : 0;
>> +#endif
>> + struct sbiret ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
>> + lo, hi, flags, 0, 0, 0);
>> +
>> + GUEST_ASSERT(ret.value == 0 && ret.error == 0);
>> +}
>> +
>> static void test_pmu_event(unsigned long event)
>> {
>> unsigned long counter;
>> @@ -207,6 +226,43 @@ static void test_pmu_event(unsigned long event)
>> stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
>> }
>>
>> +static void test_pmu_event_snapshot(unsigned long event)
>> +{
>> + unsigned long counter;
>> + unsigned long counter_value_pre, counter_value_post;
>> + unsigned long counter_init_value = 100;
>> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
>> +
>> + counter = get_counter_index(0, counter_mask_available, 0, event);
>> + counter_value_pre = read_counter(counter, ctrinfo_arr[counter]);
>> +
>> + /* Do not set the initial value */
>> + start_counter(counter, 0, 0);
>> + dummy_func_loop(10000);
>> +
>> + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
>> +
>> + /* The counter value is updated w.r.t relative index of cbase */
>> + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
>> + __GUEST_ASSERT(counter_value_post > counter_value_pre,
>> + "counter_value_post %lx counter_value_pre %lx\n",
>> + counter_value_post, counter_value_pre);
>> +
>> + /* Now set the initial value and compare */
>> + WRITE_ONCE(snapshot_data->ctr_values[0], counter_init_value);
>> + start_counter(counter, SBI_PMU_START_FLAG_INIT_FROM_SNAPSHOT, 0);
>> + dummy_func_loop(10000);
>> +
>> + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
>> +
>> + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
>> + __GUEST_ASSERT(counter_value_post > counter_init_value,
>> + "counter_value_post %lx counter_init_value %lx for counter\n",
>> + counter_value_post, counter_init_value);
>> +
>> + stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
>
> This function is almost identical to test_pmu_event(). If we change one,
> we'll likely have to change the other. We should have a single function
> which can be used by both tests. We can do that by passing a function
> pointer for the read which is different for non-snapshot and snapshot.
>
There are more difference than just read function. Stop/start takes
snapshot specific flag. We also have to update the counter in the shared
memory. If we combine the two functions to a single one, we will end up
with bunch of if else condition which I don't like.
I am okay modifying it if you feel strongly about it though.
>> +}
>> +
>> static void test_invalid_event(void)
>> {
>> struct sbiret ret;
>> @@ -270,6 +326,41 @@ static void test_pmu_basic_sanity(int cpu)
>> GUEST_DONE();
>> }
>>
>> +static void test_pmu_events_snaphost(int cpu)
>
> unnecessary cpu parameter
>
Removed.
>> +{
>> + long out_val = 0;
>> + bool probe;
>> + int num_counters = 0;
>> + unsigned long sbi_impl_version;
>> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
>> + int i;
>> +
>> + probe = guest_sbi_probe_extension(SBI_EXT_PMU, &out_val);
>> + GUEST_ASSERT(probe && out_val == 1);
>> +
>> + sbi_impl_version = get_host_sbi_impl_version();
>> + if (sbi_impl_version >= sbi_mk_version(2, 0))
>> + __GUEST_ASSERT(0, "SBI implementation version doesn't support PMU Snapshot");
>> +
>> + snapshot_set_shmem(snapshot_gpa, 0);
>> +
>> + /* Get the counter details */
>> + num_counters = get_num_counters();
>> + update_counter_info(num_counters);
>> +
>> + /* Validate shared memory access */
>> + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_overflow_mask), 0);
>> + for (i = 0; i < num_counters; i++) {
>> + if (counter_mask_available & (1UL << i))
>
> BIT()
>
Done.
>> + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_values[i]), 0);
>> + }
>> + /* Only these two events are guranteed to be present */
>> + test_pmu_event_snapshot(SBI_PMU_HW_CPU_CYCLES);
>> + test_pmu_event_snapshot(SBI_PMU_HW_INSTRUCTIONS);
>> +
>> + GUEST_DONE();
>> +}
>> +
>> static void run_vcpu(struct kvm_vcpu *vcpu)
>> {
>> struct ucall uc;
>> @@ -328,6 +419,36 @@ static void test_vm_events_test(void *guest_code)
>> test_vm_destroy(vm);
>> }
>>
>> +static void test_vm_setup_snapshot_mem(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
>> +{
>> + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, PMU_SNAPSHOT_GPA_BASE, 1, 1, 0);
>> + /* PMU Snapshot requires single page only */
>
> This comment should go above the memory region add
>
>> + virt_map(vm, PMU_SNAPSHOT_GPA_BASE, PMU_SNAPSHOT_GPA_BASE, 1);
>> +
>> + /* PMU_SNAPSHOT_GPA_BASE is identity mapped */
>
> This comment should go above the virt_map
>
Fixed.
>> + snapshot_gva = (void *)(PMU_SNAPSHOT_GPA_BASE);
>> + snapshot_gpa = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)snapshot_gva);
>> + sync_global_to_guest(vcpu->vm, snapshot_gva);
>> + sync_global_to_guest(vcpu->vm, snapshot_gpa);
>> +}
>> +
>> +static void test_vm_events_snapshot_test(void *guest_code)
>> +{
>> + struct kvm_vm *vm = NULL;
>> + struct kvm_vcpu *vcpu = NULL;
>
> nit: no need to set to NULL
>
>> +
>> + vm = vm_create_with_one_vcpu(&vcpu, guest_code);
>> + __TEST_REQUIRE(__vcpu_has_ext(vcpu, RISCV_ISA_EXT_REG(KVM_RISCV_SBI_EXT_PMU)),
>
> RISCV_SBI_EXT_REG
>
Updated to use the new helper functions as suggested in the earlier patch.
>> + "SBI PMU not available, skipping test");
>> +
>> + test_vm_setup_snapshot_mem(vm, vcpu);
>> +
>> + vcpu_args_set(vcpu, 1, 0);
>
> no need to set args
>
Fixed.
>> + run_vcpu(vcpu);
>> +
>> + test_vm_destroy(vm);
>> +}
>> +
>> int main(void)
>> {
>> test_vm_basic_test(test_pmu_basic_sanity);
>> @@ -336,5 +457,8 @@ int main(void)
>> test_vm_events_test(test_pmu_events);
>> pr_info("SBI PMU event verification test : PASS\n");
>>
>> + test_vm_events_snapshot_test(test_pmu_events_snaphost);
>> + pr_info("SBI PMU event verification with snapshot test : PASS\n");
>> +
>> return 0;
>> }
>> --
>> 2.34.1
>>
>
> Thanks,
> drew
On Thu, Feb 29, 2024 at 6:32 AM Atish Patra <atishp@rivosinc.com> wrote:
>
> Verify PMU snapshot functionality by setting up the shared memory
> correctly and reading the counter values from the shared memory
> instead of the CSR.
>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
LGTM.
Reviewed-by: Anup Patel <anup@brainfault.org>
Regards,
Anup
> ---
> .../selftests/kvm/include/riscv/processor.h | 25 ++++
> .../selftests/kvm/lib/riscv/processor.c | 12 ++
> tools/testing/selftests/kvm/riscv/sbi_pmu.c | 124 ++++++++++++++++++
> 3 files changed, 161 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
> index a49a39c8e8d4..e114d039e87b 100644
> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
> @@ -173,6 +173,7 @@ enum sbi_ext_id {
> };
>
> enum sbi_ext_base_fid {
> + SBI_EXT_BASE_GET_IMP_VERSION = 2,
> SBI_EXT_BASE_PROBE_EXT = 3,
> };
>
> @@ -201,6 +202,12 @@ union sbi_pmu_ctr_info {
> };
> };
>
> +struct riscv_pmu_snapshot_data {
> + u64 ctr_overflow_mask;
> + u64 ctr_values[64];
> + u64 reserved[447];
> +};
> +
> struct sbiret {
> long error;
> long value;
> @@ -247,6 +254,14 @@ enum sbi_pmu_ctr_type {
> #define SBI_PMU_STOP_FLAG_RESET (1 << 0)
> #define SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT BIT(1)
>
> +#define SBI_STA_SHMEM_DISABLE -1
> +
> +/* SBI spec version fields */
> +#define SBI_SPEC_VERSION_DEFAULT 0x1
> +#define SBI_SPEC_VERSION_MAJOR_SHIFT 24
> +#define SBI_SPEC_VERSION_MAJOR_MASK 0x7f
> +#define SBI_SPEC_VERSION_MINOR_MASK 0xffffff
> +
> struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
> unsigned long arg1, unsigned long arg2,
> unsigned long arg3, unsigned long arg4,
> @@ -254,6 +269,16 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>
> bool guest_sbi_probe_extension(int extid, long *out_val);
>
> +/* Make SBI version */
> +static inline unsigned long sbi_mk_version(unsigned long major,
> + unsigned long minor)
> +{
> + return ((major & SBI_SPEC_VERSION_MAJOR_MASK) <<
> + SBI_SPEC_VERSION_MAJOR_SHIFT) | minor;
> +}
> +
> +unsigned long get_host_sbi_impl_version(void);
> +
> static inline void local_irq_enable(void)
> {
> csr_set(CSR_SSTATUS, SR_SIE);
> diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
> index ec66d331a127..b0162d923e38 100644
> --- a/tools/testing/selftests/kvm/lib/riscv/processor.c
> +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
> @@ -499,3 +499,15 @@ bool guest_sbi_probe_extension(int extid, long *out_val)
>
> return true;
> }
> +
> +unsigned long get_host_sbi_impl_version(void)
> +{
> + struct sbiret ret;
> +
> + ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_IMP_VERSION, 0,
> + 0, 0, 0, 0, 0);
> +
> + GUEST_ASSERT(!ret.error);
> +
> + return ret.value;
> +}
> diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu.c b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
> index fc1fc5eea99e..8ea2a6db6610 100644
> --- a/tools/testing/selftests/kvm/riscv/sbi_pmu.c
> +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu.c
> @@ -21,6 +21,11 @@
> #define RISCV_MAX_PMU_COUNTERS 64
> union sbi_pmu_ctr_info ctrinfo_arr[RISCV_MAX_PMU_COUNTERS];
>
> +/* Snapshot shared memory data */
> +#define PMU_SNAPSHOT_GPA_BASE (1 << 30)
> +static void *snapshot_gva;
> +static vm_paddr_t snapshot_gpa;
> +
> /* Cache the available counters in a bitmask */
> static unsigned long counter_mask_available;
>
> @@ -173,6 +178,20 @@ static void stop_counter(unsigned long counter, unsigned long stop_flags)
> counter, ret.error);
> }
>
> +static void snapshot_set_shmem(vm_paddr_t gpa, unsigned long flags)
> +{
> + unsigned long lo = (unsigned long)gpa;
> +#if __riscv_xlen == 32
> + unsigned long hi = (unsigned long)(gpa >> 32);
> +#else
> + unsigned long hi = gpa == -1 ? -1 : 0;
> +#endif
> + struct sbiret ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
> + lo, hi, flags, 0, 0, 0);
> +
> + GUEST_ASSERT(ret.value == 0 && ret.error == 0);
> +}
> +
> static void test_pmu_event(unsigned long event)
> {
> unsigned long counter;
> @@ -207,6 +226,43 @@ static void test_pmu_event(unsigned long event)
> stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
> }
>
> +static void test_pmu_event_snapshot(unsigned long event)
> +{
> + unsigned long counter;
> + unsigned long counter_value_pre, counter_value_post;
> + unsigned long counter_init_value = 100;
> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
> +
> + counter = get_counter_index(0, counter_mask_available, 0, event);
> + counter_value_pre = read_counter(counter, ctrinfo_arr[counter]);
> +
> + /* Do not set the initial value */
> + start_counter(counter, 0, 0);
> + dummy_func_loop(10000);
> +
> + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
> +
> + /* The counter value is updated w.r.t relative index of cbase */
> + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
> + __GUEST_ASSERT(counter_value_post > counter_value_pre,
> + "counter_value_post %lx counter_value_pre %lx\n",
> + counter_value_post, counter_value_pre);
> +
> + /* Now set the initial value and compare */
> + WRITE_ONCE(snapshot_data->ctr_values[0], counter_init_value);
> + start_counter(counter, SBI_PMU_START_FLAG_INIT_FROM_SNAPSHOT, 0);
> + dummy_func_loop(10000);
> +
> + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT);
> +
> + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]);
> + __GUEST_ASSERT(counter_value_post > counter_init_value,
> + "counter_value_post %lx counter_init_value %lx for counter\n",
> + counter_value_post, counter_init_value);
> +
> + stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);
> +}
> +
> static void test_invalid_event(void)
> {
> struct sbiret ret;
> @@ -270,6 +326,41 @@ static void test_pmu_basic_sanity(int cpu)
> GUEST_DONE();
> }
>
> +static void test_pmu_events_snaphost(int cpu)
> +{
> + long out_val = 0;
> + bool probe;
> + int num_counters = 0;
> + unsigned long sbi_impl_version;
> + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva;
> + int i;
> +
> + probe = guest_sbi_probe_extension(SBI_EXT_PMU, &out_val);
> + GUEST_ASSERT(probe && out_val == 1);
> +
> + sbi_impl_version = get_host_sbi_impl_version();
> + if (sbi_impl_version >= sbi_mk_version(2, 0))
> + __GUEST_ASSERT(0, "SBI implementation version doesn't support PMU Snapshot");
> +
> + snapshot_set_shmem(snapshot_gpa, 0);
> +
> + /* Get the counter details */
> + num_counters = get_num_counters();
> + update_counter_info(num_counters);
> +
> + /* Validate shared memory access */
> + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_overflow_mask), 0);
> + for (i = 0; i < num_counters; i++) {
> + if (counter_mask_available & (1UL << i))
> + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_values[i]), 0);
> + }
> + /* Only these two events are guranteed to be present */
> + test_pmu_event_snapshot(SBI_PMU_HW_CPU_CYCLES);
> + test_pmu_event_snapshot(SBI_PMU_HW_INSTRUCTIONS);
> +
> + GUEST_DONE();
> +}
> +
> static void run_vcpu(struct kvm_vcpu *vcpu)
> {
> struct ucall uc;
> @@ -328,6 +419,36 @@ static void test_vm_events_test(void *guest_code)
> test_vm_destroy(vm);
> }
>
> +static void test_vm_setup_snapshot_mem(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
> +{
> + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, PMU_SNAPSHOT_GPA_BASE, 1, 1, 0);
> + /* PMU Snapshot requires single page only */
> + virt_map(vm, PMU_SNAPSHOT_GPA_BASE, PMU_SNAPSHOT_GPA_BASE, 1);
> +
> + /* PMU_SNAPSHOT_GPA_BASE is identity mapped */
> + snapshot_gva = (void *)(PMU_SNAPSHOT_GPA_BASE);
> + snapshot_gpa = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)snapshot_gva);
> + sync_global_to_guest(vcpu->vm, snapshot_gva);
> + sync_global_to_guest(vcpu->vm, snapshot_gpa);
> +}
> +
> +static void test_vm_events_snapshot_test(void *guest_code)
> +{
> + struct kvm_vm *vm = NULL;
> + struct kvm_vcpu *vcpu = NULL;
> +
> + vm = vm_create_with_one_vcpu(&vcpu, guest_code);
> + __TEST_REQUIRE(__vcpu_has_ext(vcpu, RISCV_ISA_EXT_REG(KVM_RISCV_SBI_EXT_PMU)),
> + "SBI PMU not available, skipping test");
> +
> + test_vm_setup_snapshot_mem(vm, vcpu);
> +
> + vcpu_args_set(vcpu, 1, 0);
> + run_vcpu(vcpu);
> +
> + test_vm_destroy(vm);
> +}
> +
> int main(void)
> {
> test_vm_basic_test(test_pmu_basic_sanity);
> @@ -336,5 +457,8 @@ int main(void)
> test_vm_events_test(test_pmu_events);
> pr_info("SBI PMU event verification test : PASS\n");
>
> + test_vm_events_snapshot_test(test_pmu_events_snaphost);
> + pr_info("SBI PMU event verification with snapshot test : PASS\n");
> +
> return 0;
> }
> --
> 2.34.1
>
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