From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 256E1361679 for ; Fri, 3 Apr 2026 05:12:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775193122; cv=none; b=lgL+HQ4A91b1S/J5++R6PdoBK1dGpF/zLq+V3otuAhfWjM0BMVopF/XLnshfS8OEZ7vTLK65uzwPXrv/4gvKYZETMNUzZ1jt1B2SrAad9A4xGOe3RMtO3UqNtt9BAR4xY1uQpjB7sTCBRWpWCaas9VYbGebwksXiFuOFHbn8DWU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775193122; c=relaxed/simple; bh=V31Q3Af4wdCYq4VTT4ChM3OKL1fBC/ih/e2pbKE1f2M=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bmf7O6Uj7egAIrZqcQFH+lVtPHEqPN/sqvnw1n5PJFC68gDrNaekY7yVyzmR6W3OpNxvaqtHIbzFgdtYtDCMbV/zQgDkaUDb6ODXKhG6+hrC9ZGj9h1rt+cqAxgRNnnEx6HT7BI3KYd4ZVxcUseYiWobQpif56oE8JYwaSeLYUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=m/KYJqbj; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="m/KYJqbj" Received: from DESKTOP-0403QTC.corp.microsoft.com (unknown [52.148.171.5]) by linux.microsoft.com (Postfix) with ESMTPSA id 3C14420B700D; Thu, 2 Apr 2026 22:11:59 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 3C14420B700D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1775193120; bh=Kwjfymmh3pQiKj6OmsaX+cYDKLyC7WNs0YCS0m8B5TQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m/KYJqbjOAIpmvmxkmNAge4PDjzaNe9SjRqOegjC8PqJtj2qbT42g5Ihi3F4poBKv hR+wC+6oqw0Nwdh25gUZpmKEXNa1ozhwlK6tofv5UoDQv6GMHOJj1N951pr2fCZKLF lNJIRdBqQ9MBHPsQZUkc7cuh6sJaJDaMbSTMCEOg= From: Jacob Pan To: linux-kernel@vger.kernel.org, "iommu@lists.linux.dev" , Jason Gunthorpe , Alex Williamson , Joerg Roedel , Mostafa Saleh , David Matlack , Robin Murphy , Nicolin Chen , "Tian, Kevin" , Yi Liu Cc: skhawaja@google.com, pasha.tatashin@soleen.com, Will Deacon , Jacob Pan , Baolu Lu Subject: [PATCH V3 08/10] vfio:selftest: Handle VFIO noiommu cdev Date: Thu, 2 Apr 2026 22:11:44 -0700 Message-Id: <20260403051146.10210-9-jacob.pan@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260403051146.10210-1-jacob.pan@linux.microsoft.com> References: <20260403051146.10210-1-jacob.pan@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit With unsafe DMA noiommu mode, the vfio devices are prefixed with noiommu-, e.g. /dev/vfio/ |-- devices | `-- noiommu-vfio0 |-- noiommu-0 `-- vfio Let vfio tests, such as luo kexec test, accommodate the noiommu device files. Signed-off-by: Jacob Pan --- .../lib/include/libvfio/vfio_pci_device.h | 1 + .../selftests/vfio/lib/vfio_pci_device.c | 32 ++++++++++++++++--- .../vfio/vfio_pci_liveupdate_kexec_test.c | 9 ++++++ 3 files changed, 38 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h index 2389c7698335..e2721e36b37e 100644 --- a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h +++ b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h @@ -124,6 +124,7 @@ static inline bool vfio_pci_device_match(struct vfio_pci_device *device, } const char *vfio_pci_get_cdev_path(const char *bdf); +int vfio_pci_noiommu_mode_enabled(void); /* Low-level routines for setting up a struct vfio_pci_device */ struct vfio_pci_device *vfio_pci_device_alloc(const char *bdf, struct iommu *iommu); diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c index 66ee268110e2..1ba81d169208 100644 --- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c +++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c @@ -225,11 +225,14 @@ void vfio_pci_group_setup(struct vfio_pci_device *device) struct vfio_group_status group_status = { .argsz = sizeof(group_status), }; - char group_path[32]; + char group_path[64]; int group; group = vfio_pci_get_group_from_dev(device->bdf); - snprintf(group_path, sizeof(group_path), "/dev/vfio/%d", group); + if (vfio_pci_noiommu_mode_enabled()) + snprintf(group_path, sizeof(group_path), "/dev/vfio/noiommu-%d", group); + else + snprintf(group_path, sizeof(group_path), "/dev/vfio/%d", group); device->group_fd = open(group_path, O_RDWR); VFIO_ASSERT_GE(device->group_fd, 0, "open(%s) failed\n", group_path); @@ -294,6 +297,24 @@ static void vfio_pci_device_setup(struct vfio_pci_device *device) device->msi_eventfds[i] = -1; } + +int vfio_pci_noiommu_mode_enabled(void) +{ + const char *path = "/sys/module/vfio/parameters/enable_unsafe_noiommu_mode"; + FILE *f; + int c; + + f = fopen(path, "re"); + if (!f) + return 0; + + c = fgetc(f); + fclose(f); + if (c == 'Y' || c == 'y') + return 1; + return 0; +} + const char *vfio_pci_get_cdev_path(const char *bdf) { char dir_path[PATH_MAX]; @@ -310,8 +331,11 @@ const char *vfio_pci_get_cdev_path(const char *bdf) VFIO_ASSERT_NOT_NULL(dir, "Failed to open directory %s\n", dir_path); while ((entry = readdir(dir)) != NULL) { - /* Find the file that starts with "vfio" */ - if (strncmp("vfio", entry->d_name, 4)) + /* Find the file that starts with "noiommu-vfio" or "vfio" */ + if (vfio_pci_noiommu_mode_enabled()) { + if (strncmp("noiommu-vfio", entry->d_name, strlen("noiommu-vfio"))) + continue; + } else if (strncmp("vfio", entry->d_name, 4)) continue; snprintf(cdev_path, PATH_MAX, "/dev/vfio/devices/%s", entry->d_name); diff --git a/tools/testing/selftests/vfio/vfio_pci_liveupdate_kexec_test.c b/tools/testing/selftests/vfio/vfio_pci_liveupdate_kexec_test.c index 36bddfbb88ed..d72f6a58e3e6 100644 --- a/tools/testing/selftests/vfio/vfio_pci_liveupdate_kexec_test.c +++ b/tools/testing/selftests/vfio/vfio_pci_liveupdate_kexec_test.c @@ -159,6 +159,15 @@ static void check_open_vfio_device_fails(void) VFIO_ASSERT_EQ(errno, EBUSY); free((void *)cdev_path); + /* + * In no-IOMMU mode the group lives at /dev/vfio/noiommu- and + * cannot be added to a Type1 IOMMU container, so the container-based + * access check below doesn't apply. The cdev check above already + * covers that the device is inaccessible in this mode. + */ + if (vfio_pci_noiommu_mode_enabled()) + return; + for (i = 0; i < nr_iommu_modes; i++) { if (!iommu_modes[i].container_path) continue; -- 2.34.1