Hi Wei,
I didn't review the important part of this test, i.e. what it's
testing and how, so below are just some nits.
On Thu, Aug 03, 2017 at 11:24:30PM -0500, Wei Huang wrote:
> AMD PMU implementation is very different from Intel. This patch adds
> a new test case, called amd_pmu, to x86 architecture. The
> implementation of amd_pmu.c is based on intel_pmu.c, with focus on
> AMD's general-purpose registers. To avoid running on Intel CPUs,
> we check the CPU's vendor name before executing the tests.
>
> Signed-off-by: Wei Huang <wei@xxxxxxxxxx>
> ---
> x86/Makefile.common | 3 +-
> x86/amd_pmu.c | 265 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> x86/unittests.cfg | 4 +
> 3 files changed, 271 insertions(+), 1 deletion(-)
> create mode 100644 x86/amd_pmu.c
>
> diff --git a/x86/Makefile.common b/x86/Makefile.common
> index d0f4ed1..36bcf90 100644
> --- a/x86/Makefile.common
> +++ b/x86/Makefile.common
> @@ -45,7 +45,8 @@ tests-common = $(TEST_DIR)/vmexit.flat $(TEST_DIR)/tsc.flat \
> $(TEST_DIR)/realmode.flat $(TEST_DIR)/msr.flat \
> $(TEST_DIR)/hypercall.flat $(TEST_DIR)/sieve.flat \
> $(TEST_DIR)/kvmclock_test.flat $(TEST_DIR)/eventinj.flat \
> - $(TEST_DIR)/s3.flat $(TEST_DIR)/intel_pmu.flat $(TEST_DIR)/setjmp.flat \
> + $(TEST_DIR)/s3.flat $(TEST_DIR)/intel_pmu.flat \
> + $(TEST_DIR)/amd_pmu.flat $(TEST_DIR)/setjmp.flat \
mixing tabs and spaces here
> $(TEST_DIR)/tsc_adjust.flat $(TEST_DIR)/asyncpf.flat \
> $(TEST_DIR)/init.flat $(TEST_DIR)/smap.flat \
> $(TEST_DIR)/hyperv_synic.flat $(TEST_DIR)/hyperv_stimer.flat \
> diff --git a/x86/amd_pmu.c b/x86/amd_pmu.c
> new file mode 100644
> index 0000000..006eccf
> --- /dev/null
> +++ b/x86/amd_pmu.c
> @@ -0,0 +1,265 @@
> +/*
> + * vPMU testing for AMD CPUs
> + *
> + * Copyright (c) 2017 Red Hat Inc
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
> + */
> +
> +#include "x86/msr.h"
> +#include "x86/processor.h"
> +#include "x86/apic-defs.h"
> +#include "x86/apic.h"
apic-defs is included by apic
> +#include "x86/desc.h"
> +#include "x86/isr.h"
> +#include "x86/vm.h"
> +
> +#include "libcflat.h"
> +#include "pmu.h"
> +#include <stdint.h>
stdint is included by libcflat
> +
> +#define AMD64_NUM_COUNTERS 4
> +
> +#define CPUID_VENDOR_AMD_1 0x68747541 /* "Auth" */
> +#define CPUID_VENDOR_AMD_2 0x69746e65 /* "enti" */
> +#define CPUID_VENDOR_AMD_3 0x444d4163 /* "cAMD" */
> +
> +struct pmu_event gp_events[] = {
> + {"core cycles", 0x0076, 1*N, 50*N},
> + {"instructions", 0x00c0, 10*N, 10.2*N},
> + {"cache reference", 0x077d, 1, 2*N},
> + {"cache misses", 0x077e, 0, 1*N},
> + {"branches", 0x00c2, 1*N, 1.1*N},
> + {"branch misses", 0x00c3, 0, 0.1*N},
> + {"stalls frontend", 0x00d0, 0, 0.1*N},
> + {"stalls backend", 0x00d1, 0, 30*N},
> +};
> +
> +char *buf;
> +static int num_counters;
> +volatile uint64_t irq_received;
all above globals can be static
> +
> +static bool check_irq(void)
> +{
> + int i;
> + irq_received = 0;
> +
> + irq_enable();
> + for (i = 0; i < 100000 && !irq_received; i++)
> + asm volatile("pause");
> + irq_disable();
> +
> + return irq_received;
> +}
> +
> +static inline void loop()
> +{
> + unsigned long tmp, tmp2, tmp3;
> +
> + asm volatile("1: mov (%1), %2\n\t"
> + " add $64, %1\n\t"
> + " nop\n\t"
> + " nop\n\t"
> + " nop\n\t"
> + " nop\n\t"
> + " nop\n\t"
> + " nop\n\t"
> + " nop\n\t"
> + " loop 1b"
> + : "=c"(tmp), "=r"(tmp2), "=r"(tmp3)
> + : "0"(N), "1"(buf));
> +}
> +
> +static struct pmu_event* get_counter_event(pmu_counter_t *cnt)
> +{
> + int i;
> +
> + for (i = 0; i < sizeof(gp_events)/sizeof(gp_events[0]); i++)
> + if (gp_events[i].unit_sel == (cnt->config & 0xffff))
> + return &gp_events[i];
> +
> + return (void*)0;
NULL
> +}
> +
> +static void cnt_overflow(isr_regs_t *regs)
> +{
> + irq_received++;
> + apic_write(APIC_EOI, 0);
> +}
> +
> +static int event_to_global_idx(pmu_counter_t *cnt)
> +{
> + return cnt->ctr - MSR_K7_PERFCTR0;
> +}
> +
> +static bool verify_event(uint64_t count, struct pmu_event *e)
> +{
> + return count >= e->min && count <= e->max;
> +}
> +
> +static bool verify_counter(pmu_counter_t *cnt)
> +{
> + return verify_event(cnt->count, get_counter_event(cnt));
> +}
> +
> +static void start_event(pmu_counter_t *evt)
> +{
> + wrmsr(evt->ctr, evt->count);
> + wrmsr(MSR_K7_EVNTSEL0 + event_to_global_idx(evt),
> + evt->config | EVNTSEL_EN);
> +}
> +
> +static void stop_event(pmu_counter_t *evt)
> +{
> + wrmsr(MSR_K7_EVNTSEL0 + event_to_global_idx(evt),
> + evt->config & ~EVNTSEL_EN);
> + evt->count = rdmsr(evt->ctr);
> +}
> +
> +static void measure(pmu_counter_t *evt, int count)
> +{
> + int i;
> +
> + for (i = 0; i < count; i++)
> + start_event(&evt[i]);
> +
> + loop();
> +
> + for (i = 0; i < count; i++)
> + stop_event(&evt[i]);
> +}
> +
> +static void check_gp_counter(struct pmu_event *evt)
> +{
> + int i;
> +
> + pmu_counter_t cnt = {
> + .ctr = MSR_K7_PERFCTR0,
> + .config = EVNTSEL_OS | EVNTSEL_USR | evt->unit_sel,
> + };
> +
> + for (i = 0; i < num_counters; i++, cnt.ctr++) {
> + cnt.count = 0;
> + measure(&cnt, 1);
> + report("%s-%d", verify_event(cnt.count, evt), evt->name, i);
> + }
> +}
> +
> +static void check_gp_counters(void)
> +{
> + int i;
> +
> + for (i = 0; i < sizeof(gp_events)/sizeof(gp_events[0]); i++) {
> + check_gp_counter(&gp_events[i]);
> + }
> +}
> +
> +static void check_counter_overflow(void)
> +{
> + uint64_t count;
> + int i;
> + pmu_counter_t cnt = {
> + .ctr = MSR_K7_PERFCTR0,
> + .config = EVNTSEL_OS | EVNTSEL_USR | gp_events[1].unit_sel,
> + .count = 0,
> + };
> +
> + measure(&cnt, 1);
> + count = cnt.count;
> +
> + report_prefix_push("overflow");
> +
> + for (i = 0; i < num_counters; i++, cnt.ctr++) {
> + if (i % 2)
> + cnt.config |= EVNTSEL_INT;
> + else
> + cnt.config &= ~EVNTSEL_INT;
> + cnt.count = 1 - count;
> + measure(&cnt, 1);
> + report("cntr-%d", cnt.count < 20, i);
> + report("irq-%d", check_irq() == (i % 2), i);
> + }
> +
> + report_prefix_pop();
> +}
> +
> +static void check_gp_counter_cmask(void)
> +{
> + pmu_counter_t cnt = {
> + .ctr = MSR_K7_PERFCTR0,
> + .config = EVNTSEL_OS | EVNTSEL_USR | gp_events[1].unit_sel,
> + .count = 0,
> + };
> +
> + cnt.config |= (0x2 << EVNTSEL_CMASK_SHIFT);
> + measure(&cnt, 1);
> + report("cmask", cnt.count < gp_events[1].min);
> +}
> +
> +static void check_rdpmc(void)
> +{
> + uint64_t val = 0x1f3456789ull;
> + int i;
> +
> + report_prefix_push("rdpmc");
> +
> + for (i = 0; i < num_counters; i++) {
> + uint64_t x = val;
> + wrmsr(MSR_K7_PERFCTR0 + i, val);
> + report("cntr-%d", rdpmc(i) == x, i);
> + }
> +
> + report_prefix_pop();
> +}
> +
> +static void check_counters_many(void)
> +{
> + pmu_counter_t cnt[10];
> + int i, n;
> +
> + for (n = 0; n < num_counters; n++) {
> + cnt[n].count = 0;
> + cnt[n].ctr = MSR_K7_PERFCTR0 + n;
> + cnt[n].config = EVNTSEL_OS | EVNTSEL_USR | gp_events[n].unit_sel;
> + }
> +
> + measure(cnt, n);
> +
> + for (i = 0; i < n; i++)
> + if (!verify_counter(&cnt[i]))
> + break;
{} for the for loop, might be nice here
> +
> + report("all counters", i == n);
> +}
> +
> +#define IS_AMD_CPU(cpuid) ((cpuid).b == CPUID_VENDOR_AMD_1 && \
> + (cpuid).d == CPUID_VENDOR_AMD_2 && \
> + (cpuid).c == CPUID_VENDOR_AMD_3)
should add a blank line here
> +int main(int ac, char **av)
> +{
> + struct cpuid id = cpuid(0);
> +
> + setup_vm();
> + setup_idt();
> + handle_irq(PC_VECTOR, cnt_overflow);
> + buf = vmalloc(N * 64);
> +
> + if (!IS_AMD_CPU(id)) {
> + printf("No AMD PMU detected!\n");
> + return report_summary();
> + }
> +
> + num_counters = AMD64_NUM_COUNTERS;
> + if (num_counters > ARRAY_SIZE(gp_events))
> + num_counters = ARRAY_SIZE(gp_events);
> +
> + apic_write(APIC_LVTPC, PC_VECTOR);
> +
> + check_gp_counters();
> + check_rdpmc();
> + check_counters_many();
> + check_counter_overflow();
> + check_gp_counter_cmask();
> +
> + return report_summary();
> +}
> diff --git a/x86/unittests.cfg b/x86/unittests.cfg
> index 74156fa..98fb3e9 100644
> --- a/x86/unittests.cfg
> +++ b/x86/unittests.cfg
> @@ -145,6 +145,10 @@ file = intel_pmu.flat
> extra_params = -cpu host
> check = /proc/sys/kernel/nmi_watchdog=0
>
> +[amd_pmu]
> +file = amd_pmu.flat
> +extra_params = -cpu host
maybe add 'arch = x86_64', since AMD only supports 64 bit.
> +
> [port80]
> file = port80.flat
>
> --
> 2.7.5
>
Thanks,
drew
