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Message-ID: <bb50e7ce-4953-0299-ffc7-7f1e843fcdb0@redhat.com>
Date:   Wed, 29 Nov 2023 14:58:34 +0800
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Subject: Re: [PATCH v1 3/3] KVM: selftests: aarch64: Introduce
 pmu_event_filter_test
Content-Language: en-US
To:     Eric Auger <eauger@redhat.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Marc Zyngier <maz@kernel.org>, kvmarm@lists.linux.dev
Cc:     Paolo Bonzini <pbonzini@redhat.com>, Shuah Khan <shuah@kernel.org>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Zenghui Yu <yuzenghui@huawei.com>,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        linux-kselftest@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
References: <20231123063750.2176250-1-shahuang@redhat.com>
 <20231123063750.2176250-4-shahuang@redhat.com>
 <3c18a04a-2834-43ef-b857-e6ad8f0c5f41@redhat.com>
From:   Shaoqin Huang <shahuang@redhat.com>
In-Reply-To: <3c18a04a-2834-43ef-b857-e6ad8f0c5f41@redhat.com>
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Precedence: bulk

Hi Eric,

On 11/27/23 16:10, Eric Auger wrote:
> Hi Shaoqin,
> 
> On 11/23/23 07:37, Shaoqin Huang wrote:
>> Introduce pmu_event_filter_test for arm64 platforms. The test configures
>> PMUv3 for a vCPU, and sets different pmu event filter for the vCPU, and
> filters
>> check if the guest can use those events which user allow and can't use
>> those events which use deny.
>>
>> This test refactor the create_vpmu_vm() and make it a wrapper for
>> __create_vpmu_vm(), which can let we do some extra init before
> which can let we do -> which allows some extra init code.

Copy that.

>> KVM_ARM_VCPU_PMU_V3_INIT.
>>
>> This test choose the branches_retired and the instructions_retired
>> event, and let guest use the two events in pmu. And check if the result
> Are you sure those events are supported?
>> is expected.
>>
>> Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
>> ---
>>   tools/testing/selftests/kvm/Makefile          |   1 +
>>   .../kvm/aarch64/pmu_event_filter_test.c       | 227 ++++++++++++++++++
>>   .../selftests/kvm/include/aarch64/vpmu.h      |   4 +
>>   .../testing/selftests/kvm/lib/aarch64/vpmu.c  |  14 +-
>>   4 files changed, 244 insertions(+), 2 deletions(-)
>>   create mode 100644 tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
>>
>> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
>> index b60852c222ac..5f126e1a1dbf 100644
>> --- a/tools/testing/selftests/kvm/Makefile
>> +++ b/tools/testing/selftests/kvm/Makefile
>> @@ -155,6 +155,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/arch_timer
>>   TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
>>   TEST_GEN_PROGS_aarch64 += aarch64/hypercalls
>>   TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test
>> +TEST_GEN_PROGS_aarch64 += aarch64/pmu_event_filter_test
>>   TEST_GEN_PROGS_aarch64 += aarch64/psci_test
>>   TEST_GEN_PROGS_aarch64 += aarch64/set_id_regs
>>   TEST_GEN_PROGS_aarch64 += aarch64/smccc_filter
>> diff --git a/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
>> new file mode 100644
>> index 000000000000..a876f5c2033b
>> --- /dev/null
>> +++ b/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
>> @@ -0,0 +1,227 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * pmu_event_filter_test - Test user limit pmu event for guest.
>> + *
>> + * Copyright (c) 2023 Red Hat, Inc.
>> + *
>> + * This test checks if the guest only see the limited pmu event that userspace
> sees
>> + * sets, if the gust can use those events which user allow, and if the guest
> s/gust/guest

Thanks, will correct it.

>> + * can't use those events which user deny.
>> + * It also checks set invalid filter return the expected error.
> it also checks that setting invalid filter ranges ...
>> + * This test runs only when KVM_CAP_ARM_PMU_V3 is supported on the host.
>> + */
>> +#include <kvm_util.h>
>> +#include <processor.h>
>> +#include <vgic.h>
>> +#include <vpmu.h>
>> +#include <test_util.h>
>> +#include <perf/arm_pmuv3.h>
>> +
>> +struct {
>> +	uint64_t branches_retired;
>> +	uint64_t instructions_retired;
>> +} pmc_results;
>> +
>> +static struct vpmu_vm *vpmu_vm;
>> +
>> +#define FILTER_NR 10
>> +
>> +struct test_desc {
>> +	const char *name;
>> +	void (*check_result)(void);
>> +	struct kvm_pmu_event_filter filter[FILTER_NR];
>> +};
>> +
>> +#define __DEFINE_FILTER(base, num, act)		\
>> +	((struct kvm_pmu_event_filter) {	\
>> +		.base_event	= base,		\
>> +		.nevents	= num,		\
>> +		.action		= act,		\
>> +	})
>> +
>> +#define DEFINE_FILTER(base, act) __DEFINE_FILTER(base, 1, act)
>> +
>> +#define EMPTY_FILTER	{ 0 }
>> +
>> +#define SW_INCR		0x0
>> +#define INST_RETIRED	0x8
>> +#define BR_RETIERD	0x21
> looks like a typo

It's a typo error. Fixed it.

>> +
>> +#define NUM_BRANCHES	10
>> +
>> +static void run_and_measure_loop(void)
>> +{
>> +	asm volatile(
>> +		"	mov	x10, %[loop]\n"
>> +		"1:	sub	x10, x10, #1\n"
>> +		"	cmp	x10, #0x0\n"
>> +		"	b.gt	1b\n"
>> +		:
>> +		: [loop] "r" (NUM_BRANCHES)
>> +		: "x10", "cc");
>> +}
>> +
>> +static void guest_code(void)
>> +{
>> +	uint64_t pmcr = read_sysreg(pmcr_el0);
>> +
>> +	pmu_disable_reset();
>> +
>> +	write_pmevtypern(0, BR_RETIERD);
>> +	write_pmevtypern(1, INST_RETIRED);
>> +	enable_counter(0);
>> +	enable_counter(1);
>> +	write_sysreg(pmcr | ARMV8_PMU_PMCR_E, pmcr_el0);
>> +
>> +	run_and_measure_loop();
>> +
>> +	write_sysreg(pmcr, pmcr_el0);
>> +
>> +	pmc_results.branches_retired = read_sysreg(pmevcntr0_el0);
>> +	pmc_results.instructions_retired = read_sysreg(pmevcntr1_el0);
>> +
>> +	GUEST_DONE();
> another direct way to see if the guest can use those filters is to read
> the PMCEIDx that indicates whether an event is supported.
> 

Yes. That's the easist way. Why I do this is because I follow the x86 
design.

>> +}
>> +
>> +static void pmu_event_filter_init(struct vpmu_vm *vm, void *arg)
>> +{
>> +	struct kvm_device_attr attr = {
>> +		.group	= KVM_ARM_VCPU_PMU_V3_CTRL,
>> +		.attr	= KVM_ARM_VCPU_PMU_V3_FILTER,
>> +	};
>> +	struct kvm_pmu_event_filter *filter = (struct kvm_pmu_event_filter *)arg;
>> +
>> +	while (filter && filter->nevents != 0) {
>> +		attr.addr = (uint64_t)filter;
>> +		vcpu_ioctl(vm->vcpu, KVM_SET_DEVICE_ATTR, &attr);
>> +		filter++;
>> +	}
>> +}
>> +
>> +static void create_vpmu_vm_with_filter(void *guest_code,
>> +				       struct kvm_pmu_event_filter *filter)
>> +{
>> +	vpmu_vm = __create_vpmu_vm(guest_code, pmu_event_filter_init, filter);
>> +}
>> +
>> +static void run_vcpu(struct kvm_vcpu *vcpu)
>> +{
>> +	struct ucall uc;
>> +
>> +	while (1) {
>> +		vcpu_run(vcpu);
>> +		switch (get_ucall(vcpu, &uc)) {
>> +		case UCALL_DONE:
>> +			return;
>> +		default:
>> +			TEST_FAIL("Unknown ucall %lu", uc.cmd);
>> +		}
>> +	}
>> +}
>> +
>> +static void check_pmc_counting(void)
>> +{
>> +	uint64_t br = pmc_results.branches_retired;
>> +	uint64_t ir = pmc_results.instructions_retired;
>> +
>> +	TEST_ASSERT(br && br == NUM_BRANCHES, "Branch instructions retired = "
>> +		    "%lu (expected %u)", br, NUM_BRANCHES);
>> +	TEST_ASSERT(ir, "Instructions retired = %lu (expected > 0)", ir);
>> +}
>> +
>> +static void check_pmc_not_counting(void)
>> +{
>> +	uint64_t br = pmc_results.branches_retired;
>> +	uint64_t ir = pmc_results.instructions_retired;
>> +
>> +	TEST_ASSERT(!br, "Branch instructions retired = %lu (expected 0)", br);
>> +	TEST_ASSERT(!ir, "Instructions retired = %lu (expected 0)", ir);
>> +}
>> +
>> +static void run_vcpu_and_sync_pmc_results(void)
>> +{
>> +	memset(&pmc_results, 0, sizeof(pmc_results));
>> +	sync_global_to_guest(vpmu_vm->vm, pmc_results);
>> +
>> +	run_vcpu(vpmu_vm->vcpu);
>> +
>> +	sync_global_from_guest(vpmu_vm->vm, pmc_results);
>> +}
>> +
>> +static void run_test(struct test_desc *t)
>> +{
>> +	pr_debug("Test: %s\n", t->name);
>> +
>> +	create_vpmu_vm_with_filter(guest_code, t->filter);
>> +
>> +	run_vcpu_and_sync_pmc_results();
>> +
>> +	t->check_result();
>> +
>> +	destroy_vpmu_vm(vpmu_vm);
>> +}
>> +
>> +static struct test_desc tests[] = {
>> +	{"without_filter", check_pmc_counting, { EMPTY_FILTER }},
>> +	{"member_allow_filter", check_pmc_counting,
>> +	 {DEFINE_FILTER(SW_INCR, 0), DEFINE_FILTER(INST_RETIRED, 0),
>> +	  DEFINE_FILTER(BR_RETIERD, 0), EMPTY_FILTER}},
>> +	{"member_deny_filter", check_pmc_not_counting,
>> +	 {DEFINE_FILTER(SW_INCR, 1), DEFINE_FILTER(INST_RETIRED, 1),
>> +	  DEFINE_FILTER(BR_RETIERD, 1), EMPTY_FILTER}},
>> +	{"not_member_deny_filter", check_pmc_counting,
>> +	 {DEFINE_FILTER(SW_INCR, 1), EMPTY_FILTER}},
>> +	{"not_member_allow_filter", check_pmc_not_counting,
>> +	 {DEFINE_FILTER(SW_INCR, 0), EMPTY_FILTER}},
>> +	{ 0 }
>> +};
>> +
>> +static void for_each_test(void)
>> +{
>> +	struct test_desc *t;
>> +
>> +	for (t = &tests[0]; t->name; t++)
>> +		run_test(t);
>> +}
>> +
>> +static void set_invalid_filter(struct vpmu_vm *vm, void *arg)
>> +{
>> +	struct kvm_pmu_event_filter invalid;
>> +	struct kvm_device_attr attr = {
>> +		.group	= KVM_ARM_VCPU_PMU_V3_CTRL,
>> +		.attr	= KVM_ARM_VCPU_PMU_V3_FILTER,
>> +		.addr	= (uint64_t)&invalid,
>> +	};
>> +	int ret = 0;
>> +
>> +	/* The max event number is (1 << 16), set a range large than it. */
>> +	invalid = __DEFINE_FILTER(BIT(15), BIT(15)+1, 0);
>> +	ret = __vcpu_ioctl(vm->vcpu, KVM_SET_DEVICE_ATTR, &attr);
>> +	TEST_ASSERT(ret && errno == EINVAL, "Set Invalid filter range "
>> +		    "ret = %d, errno = %d (expected ret = -1, errno = EINVAL)",
>> +		    ret, errno);
>> +
>> +	ret = 0;
>> +
>> +	/* Set the Invalid action. */
>> +	invalid = __DEFINE_FILTER(0, 1, 3);
>> +	ret = __vcpu_ioctl(vm->vcpu, KVM_SET_DEVICE_ATTR, &attr);
>> +	TEST_ASSERT(ret && errno == EINVAL, "Set Invalid filter action "
>> +		    "ret = %d, errno = %d (expected ret = -1, errno = EINVAL)",
>> +		    ret, errno);
>> +}
>> +
>> +static void test_invalid_filter(void)
>> +{
>> +	vpmu_vm = __create_vpmu_vm(guest_code, set_invalid_filter, NULL);
>> +	destroy_vpmu_vm(vpmu_vm);
>> +}
>> +
>> +int main(void)
>> +{
>> +	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_PMU_V3));
>> +
>> +	for_each_test();
>> +
>> +	test_invalid_filter();
> I would introduce test_invalid_filter in a separate patch

Ok. I can split it into two.

Thanks,
Shaoqin

>> +}
>> diff --git a/tools/testing/selftests/kvm/include/aarch64/vpmu.h b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
>> index e0cc1ca1c4b7..db97bfb07996 100644
>> --- a/tools/testing/selftests/kvm/include/aarch64/vpmu.h
>> +++ b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
>> @@ -18,6 +18,10 @@ struct vpmu_vm {
>>   	int gic_fd;
>>   };
>>   
>> +struct vpmu_vm *__create_vpmu_vm(void *guest_code,
>> +				 void (*init_pmu)(struct vpmu_vm *vm, void *arg),
>> +				 void *arg);
>> +
>>   struct vpmu_vm *create_vpmu_vm(void *guest_code);
>>   
>>   void destroy_vpmu_vm(struct vpmu_vm *vpmu_vm);
>> diff --git a/tools/testing/selftests/kvm/lib/aarch64/vpmu.c b/tools/testing/selftests/kvm/lib/aarch64/vpmu.c
>> index b3de8fdc555e..76ea03d607f1 100644
>> --- a/tools/testing/selftests/kvm/lib/aarch64/vpmu.c
>> +++ b/tools/testing/selftests/kvm/lib/aarch64/vpmu.c
>> @@ -7,8 +7,9 @@
>>   #include <vpmu.h>
>>   #include <perf/arm_pmuv3.h>
>>   
>> -/* Create a VM that has one vCPU with PMUv3 configured. */
>> -struct vpmu_vm *create_vpmu_vm(void *guest_code)
>> +struct vpmu_vm *__create_vpmu_vm(void *guest_code,
>> +				 void (*init_pmu)(struct vpmu_vm *vm, void *arg),
>> +				 void *arg)
>>   {
>>   	struct kvm_vcpu_init init;
>>   	uint8_t pmuver;
>> @@ -50,12 +51,21 @@ struct vpmu_vm *create_vpmu_vm(void *guest_code)
>>   		    "Unexpected PMUVER (0x%x) on the vCPU with PMUv3", pmuver);
>>   
>>   	/* Initialize vPMU */
>> +	if (init_pmu)
>> +		init_pmu(vpmu_vm, arg);
>> +
>>   	vcpu_ioctl(vpmu_vm->vcpu, KVM_SET_DEVICE_ATTR, &irq_attr);
>>   	vcpu_ioctl(vpmu_vm->vcpu, KVM_SET_DEVICE_ATTR, &init_attr);
>>   
>>   	return vpmu_vm;
>>   }
>>   
>> +/* Create a VM that has one vCPU with PMUv3 configured. */
>> +struct vpmu_vm *create_vpmu_vm(void *guest_code)
>> +{
>> +	return __create_vpmu_vm(guest_code, NULL, NULL);
>> +}
>> +
>>   void destroy_vpmu_vm(struct vpmu_vm *vpmu_vm)
>>   {
>>   	close(vpmu_vm->gic_fd);
> Thanks
> 
> Eric
> 

-- 
Shaoqin