From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/vfio/Kconfig | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 drivers/vfio/Kconfig (limited to 'drivers/vfio/Kconfig') diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig new file mode 100644 index 000000000..b9d6e1c22 --- /dev/null +++ b/drivers/vfio/Kconfig @@ -0,0 +1,101 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig VFIO + tristate "VFIO Non-Privileged userspace driver framework" + select IOMMU_API + depends on IOMMUFD || !IOMMUFD + select INTERVAL_TREE + select VFIO_GROUP if SPAPR_TCE_IOMMU || IOMMUFD=n + select VFIO_DEVICE_CDEV if !VFIO_GROUP + select VFIO_CONTAINER if IOMMUFD=n + help + VFIO provides a framework for secure userspace device drivers. + See Documentation/driver-api/vfio.rst for more details. + + If you don't know what to do here, say N. + +if VFIO +config VFIO_DEVICE_CDEV + bool "Support for the VFIO cdev /dev/vfio/devices/vfioX" + depends on IOMMUFD && !SPAPR_TCE_IOMMU + default !VFIO_GROUP + help + The VFIO device cdev is another way for userspace to get device + access. Userspace gets device fd by opening device cdev under + /dev/vfio/devices/vfioX, and then bind the device fd with an iommufd + to set up secure DMA context for device access. + + If you don't know what to do here, say N. + +config VFIO_GROUP + bool "Support for the VFIO group /dev/vfio/$group_id" + default y + help + VFIO group support provides the traditional model for accessing + devices through VFIO and is used by the majority of userspace + applications and drivers making use of VFIO. + + If you don't know what to do here, say Y. + +config VFIO_CONTAINER + bool "Support for the VFIO container /dev/vfio/vfio" + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64) + depends on VFIO_GROUP + default y + help + The VFIO container is the classic interface to VFIO for establishing + IOMMU mappings. If N is selected here then IOMMUFD must be used to + manage the mappings. + + Unless testing IOMMUFD say Y here. + +if VFIO_CONTAINER +config VFIO_IOMMU_TYPE1 + tristate + default n + +config VFIO_IOMMU_SPAPR_TCE + tristate + depends on SPAPR_TCE_IOMMU + default VFIO +endif + +config VFIO_NOIOMMU + bool "VFIO No-IOMMU support" + depends on VFIO_GROUP || (VFIO_DEVICE_CDEV && !GENERIC_ATOMIC64) + depends on !VFIO_GROUP || VFIO_CONTAINER || IOMMUFD_VFIO_CONTAINER + select IOMMUFD_NOIOMMU if VFIO_DEVICE_CDEV && !GENERIC_ATOMIC64 + help + VFIO is built on the ability to isolate devices using the IOMMU. + Only with an IOMMU can userspace access to DMA capable devices be + considered secure. VFIO No-IOMMU mode enables IOMMU groups for + devices without IOMMU backing for the purpose of re-using the VFIO + infrastructure in a non-secure mode. Use of this mode will result + in an unsupportable kernel and will therefore taint the kernel. + Device assignment to virtual machines is also not possible with + this mode since there is no IOMMU to provide DMA translation. + + If you don't know what to do here, say N. + +config VFIO_VIRQFD + bool + select EVENTFD + default n + +config VFIO_DEBUGFS + bool "Export VFIO internals in DebugFS" + depends on DEBUG_FS + help + Allows exposure of VFIO device internals. This option enables + the use of debugfs by VFIO drivers as required. The device can + cause the VFIO code create a top-level debug/vfio directory + during initialization, and then populate a subdirectory with + entries as required. + +source "drivers/vfio/pci/Kconfig" +source "drivers/vfio/platform/Kconfig" +source "drivers/vfio/mdev/Kconfig" +source "drivers/vfio/fsl-mc/Kconfig" +source "drivers/vfio/cdx/Kconfig" +endif + +source "virt/lib/Kconfig" -- cgit v1.3.1