From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 905ED2D59E3 for ; Fri, 25 Jul 2025 09:54:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753437287; cv=none; b=XWqtz4FBxprdRfFS55kGfKNtn5twQuTyauLHlgTyzgMSRQFV1yCmMygOfiwOZlHJlRfQu5wkm3GTf8xRZS+JyYVoIFw6DIAqfrl2aGs/EFjqKCa+MOL/muSz+R1Z7nNlUrG7ZOaG4nVl4wFEAKGJ9TEYOOyCL8qqKPUX9bOnUbM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753437287; c=relaxed/simple; bh=KQiWoYwE4DtgGub2KVDrTmPEBdDunx+CvhNc03f/X8c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=DWUBtPBVDXbeEG29zGrBuDI7a3Q3bZedlxmd68sJofnyrqaRCe7egmXZfcHw9soNa5N9LSn2z8fmjW2xbClMRZlZcrTqEtuS1QwGIoiFj168ETS2ORJ0xUE2HSPERm5Q7w1eIMiD0+28LoC8gouGgjnYzH9KH1MlF0EVSywY0Ak= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=EVyzFiFq; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EVyzFiFq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753437284; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PgepI28mSFaDGrO5jO+/MtZDNqSsfZIqo5y5RNjR59U=; b=EVyzFiFqHAycMlKrLj2KqB4npWTVp1YNMT+0dPDJXgTWVtyyZyaDuI6D+z8y+DsCBI1spe rbvupyP3dNwKmlxjAfISFtukObJasZfOzXBXKTNpAIeSfceokRl+YuNGP+/gL0RP3WOlZj mFPr81RxjoftgRfUHXj8V9hfZWR6x5w= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-520-B8Wjw5u7PF29wgmtWrU0zg-1; Fri, 25 Jul 2025 05:54:41 -0400 X-MC-Unique: B8Wjw5u7PF29wgmtWrU0zg-1 X-Mimecast-MFC-AGG-ID: B8Wjw5u7PF29wgmtWrU0zg_1753437280 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0A2DE1800873 for ; Fri, 25 Jul 2025 09:54:40 +0000 (UTC) Received: from dell-r430-03.lab.eng.brq2.redhat.com (dell-r430-03.lab.eng.brq2.redhat.com [10.37.153.18]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0E5E019560AA; Fri, 25 Jul 2025 09:54:38 +0000 (UTC) From: Igor Mammedov To: kvm@vger.kernel.org Cc: pbonzini@redhat.com, peterx@redhat.com Subject: [kvm-unit-tests PATCH v4 5/5] x86: add HPET counter read micro benchmark and enable/disable torture tests Date: Fri, 25 Jul 2025 11:54:29 +0200 Message-ID: <20250725095429.1691734-6-imammedo@redhat.com> In-Reply-To: <20250725095429.1691734-1-imammedo@redhat.com> References: <20250725095429.1691734-1-imammedo@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 test is to be used for benchmarking/validating HPET main counter reading how to run: QEMU=/foo/qemu-system-x86_64 x86/run x86/hpet_read_test.flat -smp X where X is desired number of logical CPUs to test with it will 1st execute concurrent read benchmark and after that it will run torture test enabling/disabling HPET counter, while running readers in parallel. Goal is to verify counter that always goes up. Signed-off-by: Igor Mammedov --- v4: * use global for test cycles and siplify code a bit * use cpu number instead of APCI ID as index into latency array * report failure if a cpu measured 0 latency * replace on_cpus() with on_cpu_async() to avoid BSP interrupting itself * drop volatile v3: * measure lat inside threads so that, threads startup time wouldn't throw off results * fix BSP iterrupting itself by running read test and stalling other cpus as result. (fix it by exiting read test earlier if it's running on BSP) v2: * fix broken timer going backwards check * report # of fails * warn if number of vcpus is not sufficient for torture test and skip it * style fixups --- x86/Makefile.common | 2 + x86/hpet_read_test.c | 93 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 95 insertions(+) create mode 100644 x86/hpet_read_test.c diff --git a/x86/Makefile.common b/x86/Makefile.common index 5663a65d..ef0e09a6 100644 --- a/x86/Makefile.common +++ b/x86/Makefile.common @@ -101,6 +101,8 @@ tests-common += $(TEST_DIR)/realmode.$(exe) \ realmode_bits := $(if $(call cc-option,-m16,""),16,32) endif +tests-common += $(TEST_DIR)/hpet_read_test.$(exe) + test_cases: $(tests-common) $(tests) $(TEST_DIR)/%.o: CFLAGS += -std=gnu99 -ffreestanding -I $(SRCDIR)/lib -I $(SRCDIR)/lib/x86 -I lib diff --git a/x86/hpet_read_test.c b/x86/hpet_read_test.c new file mode 100644 index 00000000..a44cdac2 --- /dev/null +++ b/x86/hpet_read_test.c @@ -0,0 +1,93 @@ +#include "libcflat.h" +#include "smp.h" +#include "apic.h" +#include "asm/barrier.h" +#include "x86/atomic.h" +#include "vmalloc.h" +#include "alloc.h" + +#define HPET_ADDR 0xFED00000L +#define HPET_COUNTER_ADDR ((uint8_t *)HPET_ADDR + 0xF0UL) +#define HPET_CONFIG_ADDR ((uint8_t *)HPET_ADDR + 0x10UL) +#define HPET_ENABLE_BIT 0x01UL +#define HPET_CLK_PERIOD 10 + +#define TEST_CYCLES 100000 + +static atomic_t fail; +static uint64_t latency[MAX_TEST_CPUS]; + +static void hpet_reader(void *data) +{ + long i; + uint64_t old_counter = 0, new_counter; + long id = (long)data; + + latency[id] = *(uint64_t *)HPET_COUNTER_ADDR; + for (i = 0; i < TEST_CYCLES; ++i) { + new_counter = *(uint64_t *)HPET_COUNTER_ADDR; + if (new_counter < old_counter) + atomic_inc(&fail); + old_counter = new_counter; + } + /* claculate job latency in ns */ + latency[id] = (*(uint64_t *)HPET_COUNTER_ADDR - latency[id]) + * HPET_CLK_PERIOD / TEST_CYCLES; +} + +static void hpet_writer(void *data) +{ + int i; + + for (i = 0; i < TEST_CYCLES; ++i) + if (i % 2) + *(uint64_t *)HPET_CONFIG_ADDR |= HPET_ENABLE_BIT; + else + *(uint64_t *)HPET_CONFIG_ADDR &= ~HPET_ENABLE_BIT; +} + +int main(void) +{ + unsigned long cpu, time_ns, lat = 0; + uint64_t start, end; + int ncpus = cpu_count(); + + do { + printf("* starting concurrent read bench on %d cpus\n", ncpus); + *(uint64_t *)HPET_CONFIG_ADDR |= HPET_ENABLE_BIT; + start = *(uint64_t *)HPET_COUNTER_ADDR; + + for (cpu = cpu_count() - 1; cpu > 0; --cpu) + on_cpu_async(cpu, hpet_reader, (void *)cpu); + while (cpus_active() > 1) + pause(); + + end = (*(uint64_t *)HPET_COUNTER_ADDR); + time_ns = (end - start) * HPET_CLK_PERIOD; + + for (cpu = 1; cpu < ncpus; cpu++) + if (latency[cpu]) + lat += latency[cpu]; + else + report_fail("cpu %lu reported invalid latency (0)\n", cpu); + lat = lat / ncpus; + + report(time_ns && !atomic_read(&fail), + "read test took %lu ms, avg read: %lu ns\n", time_ns/1000000, lat); + } while (0); + + do { + printf("* starting enable/disable with concurrent readers torture\n"); + if (ncpus > 2) { + for (cpu = 2; cpu < ncpus; cpu++) + on_cpu_async(cpu, hpet_reader, (void *)TEST_CYCLES); + + on_cpu(1, hpet_writer, (void *)TEST_CYCLES); + report(!atomic_read(&fail), "torture test, fails: %u\n", + atomic_read(&fail)); + } else + printf("SKIP: torture test: '-smp X' should be greater than 2\n"); + } while (0); + + return report_summary(); +} -- 2.47.1