From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.214.198 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793633844; b=KogOUmGQmyOgAanHYwZjcL49rSMLQ8EunZ/4QnxaHpxLPb3BoJDbzW0MNTWFHQbkCQ8D 6/MNdK0wCRdBi7XtiDislRKCz2xBrBRrkR+htqngmTYLs0ecD79paNpv5Bx3OXriKy1NY r3zy3T4WYNzN+VXeexD23yDm6W0Lbry3faSa2IMd66erakQOYrqib1kGAWakFCAHStaN/ TW+9HAnu7PlfksoziTXTbUPUUI72t0yLsPl6ihPZsa7RdZWI1kphkvpntV27ngffWEIUd E0Uu0UhHvtKghbU9s+ZgQurdNhSUgKW4/0yMkaMHAbIHf8j+XQK1hI+tud2Jke/CfhQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793633844; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Received:Date:In-Reply-To: Mime-Version:References:X-Mailer:Message-ID:Subject:From:To:Cc: Content-Type; bh=9juNA68D1pfuFQpRVNDQa7dR4Pnf/xhC+K8NWgBMU/E=; b=oe+y+SG2/hW79aHgEb7eRG4ugzXyMpOhhzghYeljxCO8Ze0FCodSTsVxwddedaUscHJ4 NLXIXjVnFvq2ywF2JMzXHN1Vl1v9gtEhewFwmJ2vpm7/m+o43fl/MLwRhWOexyL9HvLcn ZegO7DzSZhLfdp0cSCpV3gUqypVAbZYPlnsrBZV53ooliMr8CyR29ijGHnJ6tNQy6UTNQ SANZXTp67LxUCQMtrqbDtbFgQKKfPJZk3Q9kzy42EpISw32brj+tqyL5zrAhRKBEJTqye xRMCl548zVMvU2ZL0ZYiH1s6WDyqgJEiQcPfj/N9ZrgIKVJSrTZrpGxMkmHPIAqkFWw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=google.com; spf=pass smtp.mailfrom=flex--vipinsh.bounces.google.com; dkim=pass header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b="ne/GrZZB"; arc=none smtp.remote-ip=209.85.214.198 Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 414F260EC3CD for ; Mon, 2 Nov 2026 15:37:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 414F260EC3CD 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--vipinsh.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=ne/GrZZB Received: by mail-pl1-f198.google.com with SMTP id d9443c01a7336-2e832c03576so48291315ad.1 for ; Mon, 02 Nov 2026 07:37:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20260707; t=1793633844; x=1794238644; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=9juNA68D1pfuFQpRVNDQa7dR4Pnf/xhC+K8NWgBMU/E=; b=ne/GrZZBB6RQdxM5E5YlzCX2uHuyM90n+ZGH0IzIs+RtSEMzmn90zvFc5wu6L4ndX2 UUhYANfqHwY9O0/LpiVnAW59obokAICWZsCfC5WHHR1HIaMtz+dRALHpK3ADpuJceALG fsaZ//B9E3RtbSa8iPpz62QhQ6adoNp+TPCcOkXQEIyVAiQSoyYihqWGqsvnqLJZBIJV Afm6D4Y3dlUWSNqWt5G6WkVgUP7C//FKusN0Z4aTz7GP8GqhyUvlw+Oc/IUJ7byuVaCm 41fz1DQe/LHfkRbcy2VviRmHuZ9rbBx7MM6z2thnxzPs3vs3PljyXpUddS/NNIQh9Wm+ +tsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793633844; x=1794238644; h=content-type: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:content-type; bh=9juNA68D1pfuFQpRVNDQa7dR4Pnf/xhC+K8NWgBMU/E=; b=fjLQ+R5sHYSW6L7/J5l7a/QRyDmzJQtuRoiY/wkNi9q1rLHBxG6qzjjISkn71MCp91 9EN0FAt4Am9OE7jQYfWBVEoI3QjpHBnXBuLG+iTgx1qxwimMlA8zn0bSr9ymBZe3XUTn p3VNEeCOA+V8wk1p8ERmEubocN8q1RvB5uf4ZWkvzgiZwvC3tqnDV6FjEXXrmBDGfTBi sceGtZtKcsVWPe3Ko6NEBychttOSLXPPC1K2fh8KbZY4xSRL2+zGyMSkEcyILEeKvWEX eQcLTegpH5bS+YI4VqntJu7EDIclgsLmwri6is4fKcyNskJxAkHpt0v+c2UvQ82A8h2U 9U1w== X-Forwarded-Encrypted: i=1; AKwUvByToooszD3VbeElmKRFOcedWbVZXtEFFCywNKWqwv03hK3+B1K7BvQpwXrlpzVC8tKJ7g1im/3jYqOEWNc=@vger.kernel.org X-Gm-Message-State: APuU4Z9t1aV/w066tEJ7kW9E65vqhJaeG4C0S9v9crI41Zf/JZY4NQnW pN4vVWyeZh1UtYn5HEjcNc6v9dQXSzfn73T8kVzNymTR/v2+p6qUNaqAKRAwfCCHmZR+Z9+jcVu 5xxg04iLbfg== X-Received: from plkz4.prod.google.com ([2002:a17:902:7084:b0:2eb:4f47:5748]) (user=vipinsh job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:f642:b0:2e9:5772:9ab2 with SMTP id d9443c01a7336-2eb364ec93fmr97906535ad.41.1793633843417; Mon, 02 Nov 2026 07:37:23 -0800 (PST) Date: Mon, 2 Nov 2026 07:36:51 -0800 In-Reply-To: <20261102153656.1431701-1-vipinsh@google.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 References: <20261102153656.1431701-1-vipinsh@google.com> X-Mailer: git-send-email 2.56.0.317.g454f8302e1-goog Message-ID: <20261102153656.1431701-23-vipinsh@google.com> Subject: [PATCH v6 22/27] vfio: selftests: Add helpers for Live Update DMA memory and sysfs state From: Vipin Sharma To: kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-pci@vger.kernel.org Cc: ajayachandra@nvidia.com, alex@shazbot.org, amastro@fb.com, ankita@nvidia.com, apopple@nvidia.com, bhelgaas@google.com, chrisl@kernel.org, christian.koenig@amd.com, corbet@lwn.net, dmatlack@google.com, graf@amazon.com, jacob.pan@linux.microsoft.com, jgg@nvidia.com, jgg@ziepe.ca, jrhilke@google.com, julianr@linux.ibm.com, kees@kernel.org, kevin.tian@intel.com, leon@kernel.org, leonro@nvidia.com, lukas@wunner.de, mattev@meta.com, michal.winiarski@intel.com, parav@nvidia.com, pasha.tatashin@soleen.com, praan@google.com, pratyush@kernel.org, rananta@google.com, rdunlap@infradead.org, rientjes@google.com, rodrigo.vivi@intel.com, rppt@kernel.org, saeedm@nvidia.com, schnelle@linux.ibm.com, skhan@linuxfoundation.org, skhawaja@google.com, vipinsh@google.com, vivek.kasireddy@intel.com, witu@nvidia.com, yanjun.zhu@linux.dev, yi.l.liu@intel.com Content-Type: text/plain; charset="UTF-8" Add shared libvfio helpers used by the Live Update kexec selftest: - vfio_thp_memfd_alloc() and vfio_memfd_mmap_aligned() to allocate a shmem memfd, map it at a 2MB-aligned virtual address, and back it with 2MB THP folios via MADV_HUGEPAGE, write-fault population, and MADV_COLLAPSE. - __sysfs_iommu_group_get(), a variant of sysfs_iommu_group_get() that returns an error instead of asserting when the device has no IOMMU group. Signed-off-by: Vipin Sharma --- .../selftests/vfio/lib/include/libvfio.h | 3 ++ .../vfio/lib/include/libvfio/sysfs.h | 1 + tools/testing/selftests/vfio/lib/libvfio.c | 54 +++++++++++++++++++ tools/testing/selftests/vfio/lib/sysfs.c | 22 ++++++-- 4 files changed, 77 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/vfio/lib/include/libvfio.h b/tools/testing/selftests/vfio/lib/include/libvfio.h index 07862b470777..1c245962525b 100644 --- a/tools/testing/selftests/vfio/lib/include/libvfio.h +++ b/tools/testing/selftests/vfio/lib/include/libvfio.h @@ -33,4 +33,7 @@ char **vfio_selftests_get_bdfs(int *argc, char *argv[], int *nr_bdfs); */ void *mmap_reserve(size_t size, size_t align, size_t offset); +int vfio_thp_memfd_alloc(size_t size, void **vaddr_out); +void *vfio_memfd_mmap_aligned(int fd, size_t size, size_t align); + #endif /* SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_H */ diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h b/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h index c9ab1ea8f5a9..b9d6f6f69f88 100644 --- a/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h +++ b/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h @@ -6,6 +6,7 @@ int sysfs_sriov_totalvfs_get(const char *bdf); int sysfs_sriov_numvfs_get(const char *bdf); void sysfs_sriov_numvfs_set(const char *bdf, int numvfs); char *sysfs_sriov_vf_bdf_get(const char *pf_bdf, int i); +int __sysfs_iommu_group_get(const char *bdf, int *group); int sysfs_iommu_group_get(const char *bdf); char *sysfs_driver_get(const char *bdf); diff --git a/tools/testing/selftests/vfio/lib/libvfio.c b/tools/testing/selftests/vfio/lib/libvfio.c index 3a3d1ed635c1..00369fe7d074 100644 --- a/tools/testing/selftests/vfio/lib/libvfio.c +++ b/tools/testing/selftests/vfio/lib/libvfio.c @@ -1,14 +1,23 @@ // SPDX-License-Identifier: GPL-2.0-only +#include #include #include +#include +#include #include #include +#include +#include #include "../../../kselftest.h" #include +#ifndef MADV_COLLAPSE +#define MADV_COLLAPSE 25 +#endif + static bool is_bdf(const char *str) { unsigned int s, b, d, f; @@ -101,3 +110,48 @@ void *mmap_reserve(size_t size, size_t align, size_t offset) return map_align; } + +void *vfio_memfd_mmap_aligned(int fd, size_t size, size_t align) +{ + void *vaddr; + + vaddr = mmap_reserve(size, align, 0); + vaddr = mmap(vaddr, size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_FIXED, fd, 0); + VFIO_ASSERT_NE(vaddr, MAP_FAILED); + + return vaddr; +} + +int vfio_thp_memfd_alloc(size_t size, void **vaddr_out) +{ + void *vaddr; + int fd; + + VFIO_ASSERT_TRUE(IS_ALIGNED(size, SZ_2M)); + + fd = memfd_create("vfio-lu-dma", 0); + VFIO_ASSERT_GE(fd, 0); + + VFIO_ASSERT_EQ(ftruncate(fd, size), 0); + + vaddr = vfio_memfd_mmap_aligned(fd, size, SZ_2M); + + if (madvise(vaddr, size, MADV_HUGEPAGE)) + ksft_exit_skip("madvise(MADV_HUGEPAGE) failed: %s\n", + strerror(errno)); + + /* + * Write-fault the mapping rather than using fallocate() so that shmem + * allocates PMD-sized THP folios when shmem_enabled is always, + * within_size, or advise, then collapse in case shmem_enabled is never. + */ + memset(vaddr, 0, size); + + if (madvise(vaddr, size, MADV_COLLAPSE)) + ksft_exit_skip("madvise(MADV_COLLAPSE) failed: %s\n", + strerror(errno)); + + *vaddr_out = vaddr; + return fd; +} diff --git a/tools/testing/selftests/vfio/lib/sysfs.c b/tools/testing/selftests/vfio/lib/sysfs.c index 98a46a2543cd..219db6aaa101 100644 --- a/tools/testing/selftests/vfio/lib/sysfs.c +++ b/tools/testing/selftests/vfio/lib/sysfs.c @@ -115,14 +115,30 @@ char *sysfs_sriov_vf_bdf_get(const char *pf_bdf, int i) return out_vf_bdf; } -int sysfs_iommu_group_get(const char *bdf) +int __sysfs_iommu_group_get(const char *bdf, int *group) { + char rl_path[PATH_MAX]; char path[PATH_MAX]; - int group; + char *end; + int ret; snprintf_assert(path, PATH_MAX, "/sys/bus/pci/devices/%s/iommu_group", bdf); - readlink_base(path, "%d", &group); + ret = readlink_safe(path, rl_path); + if (ret == -1) + return -errno; + + errno = 0; + *group = strtol(basename(rl_path), &end, 10); + VFIO_ASSERT_EQ(errno, 0); + VFIO_ASSERT_EQ(*end, '\0'); + return 0; +} + +int sysfs_iommu_group_get(const char *bdf) +{ + int group; + VFIO_ASSERT_EQ(__sysfs_iommu_group_get(bdf, &group), 0); return group; } -- 2.56.0.317.g454f8302e1-goog