From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DC6E9370AC5 for ; Wed, 1 Jul 2026 20:33:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782938009; cv=none; b=tEU8LhycOsUy1v2gryxCzizDwAJE4+KCsLpH/Zb+4tkujeelkkvxxBPwALAjDNWm+1i0v1ZpSNyAO+iE34ZcYdkIZ/TfUKhcGztLVWyxXVVMHOBrjw+jQbR/FsAmwhrAJa1+J9x25Hsn+uQtgz8c4o4gTIO72fE4mnaQQgw7G/A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782938009; c=relaxed/simple; bh=4KEfuHRJpFYT5jEmjcFTuOijhwJ/hoaYjh0Y17dUgSA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=D8t3JxMfN9FtK+Etq/66eGymndss/snjPlKX4ATbVsB2UK3LFjaAwmK+eYTUIwFBcILoUkbTKcBRWF0gx4M0Uz3CtIYOjSqSwD31Zx3FiNrTKRKyoFaR3eE9NbVUbegEBOMroy7i3DkOvpSoJEOoXeAnpKujewEXjHdhXhEUfMQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aaronlewis.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=DZ5cK595; arc=none smtp.client-ip=209.85.215.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aaronlewis.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DZ5cK595" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-c9aa197d5easo1851257a12.1 for ; Wed, 01 Jul 2026 13:33:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782938007; x=1783542807; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=8UgSSY8WUFGu6h80kFLXB2vQvMpiDB5sWsAbO0KnBss=; b=DZ5cK595lI6HP7ohW6s8qa2xm0tfuhEaLSfq9mXgxDs1f68DDGDuEOdmlgsd9bwC8+ kE3N3PzNopJz/Bqn0BKsRbxKyTK+keKKRTV08+ta/U1OjBndRrL3qWrCBWT/veKH4op4 hRLFxObejVGpujCtO2L4cJDxyCmj3PbfR6sncM/N2O3pElZ5L/mC7fw3nowOleW6mR0G D7nC92hy6hT1dIBwDG39FrKc4BTnzFjD9qmGpkc+Z6jJeQQ4yUOMYtoWaZFAlRTx2E8B xa3Z4q6pukcJYe5eKoYeOddIEmvJ92t1frSXbruQTZF/AbAY+jg1/hVNVl7FAvezg6rx cG5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782938007; x=1783542807; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=8UgSSY8WUFGu6h80kFLXB2vQvMpiDB5sWsAbO0KnBss=; b=VWhy8TC51uNg+EgCBBucB5U7irM6GG13Z7ZE5rDf+IyqRd2P7oQQB7OyLOgRuL5Uzi 2TjYBKYnmZqhPjl7lM099brC59aiblsSOzP0CWUxsrB7ha+Y8pSvIdmT5oEYCbGQOsji vTwrNeKOxMklzBYoSfWuCdQEgZfG5oVEa5DPKIsiS2aclCmgGodev0Vku+Qb8NhiEyr5 9WXNQCf/pDBa/syr8aksVz05We+Xzcuh727F41VOzXhcyVuVBdYS8GJF1G97xrnviII2 ITaT3airKGy7dY4J1VmVpxcqZCW9e+/sSnG+OhfnaqWwpC7SvXgM/InKM/Dl7YTqiK+w wBAg== X-Gm-Message-State: AOJu0YxcoS4ejicqpqlkduC4m/M6hMLvLSw6VxdYV9GWaJJ8DfFOtwTk /M1eyLab5p1bxBvPVEaOtfhG7XT74C2aJZVgp84DzI6IkEEnSKLAEz0hU0q2kxUrjrxWlcX06WK 3wtTM7qxpFkYQ3hVd6vqa7AQ7U4fYZE26tgPST3X2Kox15yq4EuqFamQhU1+jnxq2buOm1q0NJ0 x/1d6cRgQFjz3wkNlva+jYVI+qqgocnMPpwS+Xnb9uEQMJl6crsJNEpw== X-Received: from dlbrn2.prod.google.com ([2002:a05:7022:1502:b0:135:dd6a:be57]) (user=aaronlewis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:e292:b0:39b:bc11:9ec5 with SMTP id adf61e73a8af0-3bfd26883b5mr6283219637.13.1782938006657; Wed, 01 Jul 2026 13:33:26 -0700 (PDT) Date: Wed, 1 Jul 2026 20:33:08 +0000 In-Reply-To: <20260701203311.326798-1-aaronlewis@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260701203311.326798-1-aaronlewis@google.com> X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog Message-ID: <20260701203311.326798-2-aaronlewis@google.com> Subject: [PATCH 1/4] vfio: selftests: Introduce vfio_dma_mapping_perf_test From: Aaron Lewis To: kvm@vger.kernel.org Cc: alex@shazbot.org, dmatlack@google.com, jgg@nvidia.com, Aaron Lewis Content-Type: text/plain; charset="UTF-8" Introduce a tool to aid in latency testing rather than a traditional pass/fail test. The goal is to make the test configurable to expose latency issues and make them easy to reproduce and share. Start with a basic test that performs a simple DMA map/unmap and reports the duration of each operation. Report the following four metrics: 1. Time taken by mmap(). 2. Time taken to map a DMA region. 3. Time taken to unmap a DMA region. 4. Time taken by munmap(). Subsequent commits in this series will introduce more features to allow for a wider variety of testing. Signed-off-by: Aaron Lewis --- tools/testing/selftests/vfio/Makefile | 1 + .../vfio/vfio_dma_mapping_perf_test.c | 124 ++++++++++++++++++ 2 files changed, 125 insertions(+) create mode 100644 tools/testing/selftests/vfio/vfio_dma_mapping_perf_test.c diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile index e6e8cb52ab03..9f620c5ef6ab 100644 --- a/tools/testing/selftests/vfio/Makefile +++ b/tools/testing/selftests/vfio/Makefile @@ -8,6 +8,7 @@ else CFLAGS = $(KHDR_INCLUDES) TEST_GEN_PROGS += vfio_dma_mapping_test TEST_GEN_PROGS += vfio_dma_mapping_mmio_test +TEST_GEN_PROGS += vfio_dma_mapping_perf_test TEST_GEN_PROGS += vfio_iommufd_setup_test TEST_GEN_PROGS += vfio_pci_device_test TEST_GEN_PROGS += vfio_pci_device_init_perf_test diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_perf_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_perf_test.c new file mode 100644 index 000000000000..87d84450fc47 --- /dev/null +++ b/tools/testing/selftests/vfio/vfio_dma_mapping_perf_test.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "kselftest_harness.h" + +static const char *device_bdf; + +struct iommu_mapping { + u64 pgd; + u64 p4d; + u64 pud; + u64 pmd; + u64 pte; +}; + +static void timer_start(struct timespec *start) { + clock_gettime(CLOCK_MONOTONIC, start); +} + +static double timer_elapsed_ms(struct timespec start) +{ + struct timespec end; + + clock_gettime(CLOCK_MONOTONIC, &end); + + return (double)(end.tv_sec - start.tv_sec) * MSEC_PER_SEC + + (double)(end.tv_nsec - start.tv_nsec) / NSEC_PER_MSEC; +} + +FIXTURE(vfio_dma_mapping_perf_test) { + struct iommu *iommu; + struct vfio_pci_device *device; + struct iova_allocator *iova_allocator; +}; + +FIXTURE_VARIANT(vfio_dma_mapping_perf_test) { + const char *iommu_mode; + int mmap_flags; +}; + +#define FIXTURE_VARIANT_ADD_IOMMU_MODE(_iommu_mode, _name, _mmap_flags) \ +FIXTURE_VARIANT_ADD(vfio_dma_mapping_perf_test, _iommu_mode ## _ ## _name) { \ + .iommu_mode = #_iommu_mode, \ + .mmap_flags = MAP_ANONYMOUS | MAP_PRIVATE | (_mmap_flags), \ +} + +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(anonymous, 0); +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(anonymous_hugetlb_2mb, MAP_HUGETLB | MAP_HUGE_2MB); +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(anonymous_hugetlb_1gb, MAP_HUGETLB | MAP_HUGE_1GB); + +#undef FIXTURE_VARIANT_ADD_IOMMU_MODE + +FIXTURE_SETUP(vfio_dma_mapping_perf_test) +{ + self->iommu = iommu_init(variant->iommu_mode); + self->device = vfio_pci_device_init(device_bdf, self->iommu); + self->iova_allocator = iova_allocator_init(self->iommu); +} + +FIXTURE_TEARDOWN(vfio_dma_mapping_perf_test) +{ + iova_allocator_cleanup(self->iova_allocator); + vfio_pci_device_cleanup(self->device); + iommu_cleanup(self->iommu); +} + +TEST_F(vfio_dma_mapping_perf_test, dma_map_unmap) +{ + const u64 size = SZ_1G; + const int flags = variant->mmap_flags; + struct dma_region region; + struct timespec start; + u64 unmapped; + int rc; + + timer_start(&start); + region.vaddr = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0); + printf("Completed mmap() in %.2lfms\n", timer_elapsed_ms(start)); + + /* Skip the test if there aren't enough HugeTLB pages available. */ + if (flags & MAP_HUGETLB && region.vaddr == MAP_FAILED) + SKIP(return, "mmap() failed: %s (%d)\n", strerror(errno), errno); + else + ASSERT_NE(region.vaddr, MAP_FAILED); + + region.iova = iova_allocator_alloc(self->iova_allocator, size); + region.size = size; + + timer_start(&start); + iommu_map(self->iommu, ®ion); + printf("Mapped HVA %p (size %luG) at IOVA 0x%lx in %.2lfms\n", + region.vaddr, size / SZ_1G, region.iova, timer_elapsed_ms(start)); + ASSERT_EQ(region.iova, to_iova(self->device, region.vaddr)); + + timer_start(&start); + rc = __iommu_unmap(self->iommu, ®ion, &unmapped); + printf("Unmapped IOVA 0x%lx in %.2lfms\n", region.iova, timer_elapsed_ms(start)); + ASSERT_EQ(rc, 0); + ASSERT_EQ(unmapped, region.size); + + timer_start(&start); + ASSERT_TRUE(!munmap(region.vaddr, size)); + printf("Completed munmap() in %.2lfms\n", timer_elapsed_ms(start)); +} + +int main(int argc, char *argv[]) +{ + device_bdf = vfio_selftests_get_bdf(&argc, argv); + return test_harness_run(argc, argv); +} -- 2.55.0.rc0.799.gd6f94ed593-goog