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Re: [Qemu-devel] [kvm-unit-tests PATCHv7 1/3] arm: Add PMU test
From: |
Andrew Jones |
Subject: |
Re: [Qemu-devel] [kvm-unit-tests PATCHv7 1/3] arm: Add PMU test |
Date: |
Thu, 3 Nov 2016 11:14:27 +0100 |
User-agent: |
Mutt/1.6.0.1 (2016-04-01) |
On Wed, Nov 02, 2016 at 05:22:15PM -0500, Wei Huang wrote:
Missing
From: Christopher Covington <address@hidden>
> Beginning with a simple sanity check of the control register, add
> a unit test for the ARM Performance Monitors Unit (PMU).
>
> Signed-off-by: Christopher Covington <address@hidden>
Missing
Signed-off-by: Wei Huang <address@hidden>
> ---
> arm/Makefile.common | 3 +-
> arm/pmu.c | 82
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
> arm/unittests.cfg | 20 +++++++++++++
> 3 files changed, 104 insertions(+), 1 deletion(-)
> create mode 100644 arm/pmu.c
>
> diff --git a/arm/Makefile.common b/arm/Makefile.common
> index ccb554d..f98f422 100644
> --- a/arm/Makefile.common
> +++ b/arm/Makefile.common
> @@ -11,7 +11,8 @@ endif
>
> tests-common = \
> $(TEST_DIR)/selftest.flat \
> - $(TEST_DIR)/spinlock-test.flat
> + $(TEST_DIR)/spinlock-test.flat \
> + $(TEST_DIR)/pmu.flat
>
> all: test_cases
>
> diff --git a/arm/pmu.c b/arm/pmu.c
> new file mode 100644
> index 0000000..42d0ee1
> --- /dev/null
> +++ b/arm/pmu.c
> @@ -0,0 +1,82 @@
> +/*
> + * Test the ARM Performance Monitors Unit (PMU).
> + *
> + * Copyright 2015 The Linux Foundation. All rights reserved.
Is the Linux Foundation correct for codeaurora patches? Should bump
the year to 2016.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU Lesser General Public License version 2.1 and
> + * only version 2.1 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
> License
> + * for more details.
> + */
> +#include "libcflat.h"
> +
> +#if defined(__arm__)
> +static inline uint32_t get_pmcr(void)
> +{
> + uint32_t ret;
> +
> + asm volatile("mrc p15, 0, %0, c9, c12, 0" : "=r" (ret));
> + return ret;
> +}
> +#elif defined(__aarch64__)
> +static inline uint32_t get_pmcr(void)
> +{
> + uint32_t ret;
> +
> + asm volatile("mrs %0, pmcr_el0" : "=r" (ret));
> + return ret;
> +}
> +#endif
> +
> +struct pmu_data {
> + union {
> + uint32_t pmcr_el0;
> + struct {
> + uint32_t enable:1;
> + uint32_t event_counter_reset:1;
> + uint32_t cycle_counter_reset:1;
> + uint32_t cycle_counter_clock_divider:1;
> + uint32_t event_counter_export:1;
> + uint32_t cycle_counter_disable_when_prohibited:1;
> + uint32_t cycle_counter_long:1;
> + uint32_t reserved:4;
> + uint32_t counters:5;
> + uint32_t identification_code:8;
> + uint32_t implementer:8;
> + };
> + };
> +};
I know I already reviewed/agreed to this bitfield, but I'm having second
thoughts. I think I'd prefer a bunch of defined shifts like the kernel uses.
> +
> +/*
> + * As a simple sanity check on the PMCR_EL0, ensure the implementer field
> isn't
> + * null. Also print out a couple other interesting fields for diagnostic
> + * purposes. For example, as of fall 2015, QEMU TCG mode doesn't implement
s/2015/2016/ how time flies...
> + * event counters and therefore reports zero event counters, but hopefully
> + * support for at least the instructions event will be added in the future
> and
> + * the reported number of event counters will become nonzero.
> + */
> +static bool check_pmcr(void)
> +{
> + struct pmu_data pmu;
> +
> + pmu.pmcr_el0 = get_pmcr();
> +
> + printf("PMU implementer: %c\n", pmu.implementer);
> + printf("Identification code: 0x%x\n", pmu.identification_code);
> + printf("Event counters: %d\n", pmu.counters);
> +
> + return pmu.implementer != 0;
> +}
> +
> +int main(void)
> +{
> + report_prefix_push("pmu");
> +
> + report("Control register", check_pmcr());
> +
> + return report_summary();
> +}
> diff --git a/arm/unittests.cfg b/arm/unittests.cfg
> index 3f6fa45..b647b69 100644
> --- a/arm/unittests.cfg
> +++ b/arm/unittests.cfg
> @@ -54,3 +54,23 @@ file = selftest.flat
> smp = $MAX_SMP
> extra_params = -append 'smp'
> groups = selftest
> +
> +# Test PMU support (KVM)
> +[pmu-kvm]
> +file = pmu.flat
> +groups = pmu
> +accel = kvm
No need to specify kvm when it works for both. Both is assumed.
tcg-only or kvm-only tests are exceptions requiring the 'accel'
parameter and a comment explaining why it doesn't work on the
other.
> +
> +# Test PMU support (TCG) with -icount IPC=1
> +[pmu-tcg-icount-1]
> +file = pmu.flat
> +extra_params = -icount 0 -append '1'
> +groups = pmu
> +accel = tcg
> +
> +# Test PMU support (TCG) with -icount IPC=256
> +[pmu-tcg-icount-256]
> +file = pmu.flat
> +extra_params = -icount 8 -append '256'
> +groups = pmu
> +accel = tcg
Why are these entries added now. These tests aren't yet implemented.
Thanks,
drew
[Qemu-devel] [kvm-unit-tests PATCHv7 3/3] arm: pmu: Add CPI checking, Wei Huang, 2016/11/02
Re: [Qemu-devel] [kvm-unit-tests PATCHv7 0/3] ARM PMU tests, Andrew Jones, 2016/11/03