kernel/git/stable/linux.git/virt/kvm/vfio.c, branch linux-7.2.y

KVM: VFIO: update coherency only if file was deleted

2026-05-13T18:12:40+00:00

When servicing a KVM_DEV_VFIO_FILE_DEL request, if a file is removed from kv->file_list, kv->noncoherent needs to be updated, in case we can revert to using coherent DMA. However, if we found no candidate to remove, there is no need to re-scan the list, so do it only if a matching file was found. To simplify the control flow, use a mutex guard so that we can return early from within the search loop if the maching file is found. Signed-off-by: Carlos López Reviewed-by: Alex Williamson Link: https://patch.msgid.link/20260313122040.1413091-7-clopez@suse.de Signed-off-by: Sean Christopherson

KVM: VFIO: deduplicate file release logic

2026-05-13T18:12:39+00:00

There are two callsites which destroy files in kv->file_list: the function servicing KVM_DEV_VFIO_FILE_DEL, and the relase of the whole KVM VFIO device. The process involves several steps, so move all those into a single function, removing duplicate code. Signed-off-by: Carlos López Reviewed-by: Alex Williamson Link: https://patch.msgid.link/20260313122040.1413091-6-clopez@suse.de Signed-off-by: Sean Christopherson

KVM: VFIO: use mutex guard in kvm_vfio_file_set_spapr_tce()

2026-05-13T18:12:36+00:00

Use a mutex guard to hold a lock for the entirety of the function, which removes the need for a goto (whose label even has a misleading name since 8152f8201088 ("fdget(), more trivial conversions")) Signed-off-by: Carlos López Reviewed-by: Alex Williamson Link: https://patch.msgid.link/20260313122040.1413091-5-clopez@suse.de Signed-off-by: Sean Christopherson

KVM: VFIO: clean up control flow in kvm_vfio_file_add()

2026-05-13T18:04:47+00:00

The struct file that this function fgets() is always passed to fput() before returning, so use automatic cleanup via __free() to avoid several jumps to the end of the function. Similarly, use a mutex guard to completely remove the need to use gotos. Signed-off-by: Carlos López Reviewed-by: Alex Williamson Link: https://patch.msgid.link/20260313122040.1413091-4-clopez@suse.de Signed-off-by: Sean Christopherson

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

VFIO: KVM: x86: Drop kvm_arch_{start,end}_assignment()

2025-06-25T16:51:33+00:00

Drop kvm_arch_{start,end}_assignment() and all associated code now that KVM x86 no longer consumes assigned_device_count. Tracking whether or not a VFIO-assigned device is formally associated with a VM is fundamentally flawed, as such an association is optional for general usage, i.e. is prone to false negatives. E.g. prior to commit 2edd9cb79fb3 ("kvm: detect assigned device via irqbypass manager"), device passthrough via VFIO would fail to enable IRQ bypass if userspace omitted the formal VFIO<=>KVM binding. And device drivers that *need* the VFIO<=>KVM connection, e.g. KVM-GT, shouldn't be relying on generic x86 tracking infrastructure. Cc: Jim Mattson Link: https://lore.kernel.org/r/20250523011756.3243624-6-seanjc@google.com Signed-off-by: Sean Christopherson

Merge tag 'vfio-v6.13-rc1' of https://github.com/awilliam/linux-vfio

2024-11-27T20:57:03+00:00

Pull VFIO updates from Alex Williamson: - Constify an unmodified structure used in linking vfio and kvm (Christophe JAILLET) - Add ID for an additional hardware SKU supported by the nvgrace-gpu vfio-pci variant driver (Ankit Agrawal) - Fix incorrect signed cast in QAT vfio-pci variant driver, negating test in check_add_overflow(), though still caught by later tests (Giovanni Cabiddu) - Additional debugfs attributes exposed in hisi_acc vfio-pci variant driver for migration debugging (Longfang Liu) - Migration support is added to the virtio vfio-pci variant driver, becoming the primary feature of the driver while retaining emulation of virtio legacy support as a secondary option (Yishai Hadas) - Fixes to a few unwind flows in the mlx5 vfio-pci driver discovered through reviews of the virtio variant driver (Yishai Hadas) - Fix an unlikely issue where a PCI device exposed to userspace with an unknown capability at the base of the extended capability chain can overflow an array index (Avihai Horon) * tag 'vfio-v6.13-rc1' of https://github.com/awilliam/linux-vfio: vfio/pci: Properly hide first-in-list PCIe extended capability vfio/mlx5: Fix unwind flows in mlx5vf_pci_save/resume_device_data() vfio/mlx5: Fix an unwind issue in mlx5vf_add_migration_pages() vfio/virtio: Enable live migration once VIRTIO_PCI was configured vfio/virtio: Add PRE_COPY support for live migration vfio/virtio: Add support for the basic live migration functionality virtio-pci: Introduce APIs to execute device parts admin commands virtio: Manage device and driver capabilities via the admin commands virtio: Extend the admin command to include the result size virtio_pci: Introduce device parts access commands Documentation: add debugfs description for hisi migration hisi_acc_vfio_pci: register debugfs for hisilicon migration driver hisi_acc_vfio_pci: create subfunction for data reading hisi_acc_vfio_pci: extract public functions for container_of vfio/qat: fix overflow check in qat_vf_resume_write() vfio/nvgrace-gpu: Add a new GH200 SKU to the devid table kvm/vfio: Constify struct kvm_device_ops

fdget(), more trivial conversions

2024-11-03T06:28:06+00:00

all failure exits prior to fdget() leave the scope, all matching fdput() are immediately followed by leaving the scope. [xfs_ioc_commit_range() chunk moved here as well] Reviewed-by: Christian Brauner Signed-off-by: Al Viro

fdget(), trivial conversions

2024-11-03T06:28:06+00:00

fdget() is the first thing done in scope, all matching fdput() are immediately followed by leaving the scope. Reviewed-by: Christian Brauner Signed-off-by: Al Viro

kvm/vfio: Constify struct kvm_device_ops

2024-10-30T19:31:26+00:00

'struct kvm_device_ops' is not modified in this driver. Constifying this structure moves some data to a read-only section, so increases overall security, especially when the structure holds some function pointers. On a x86_64, with allmodconfig: Before: ====== text data bss dec hex filename 2605 169 16 2790 ae6 virt/kvm/vfio.o After: ===== text data bss dec hex filename 2685 89 16 2790 ae6 virt/kvm/vfio.o Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/e7361a1bb7defbb0f7056b884e83f8d75ac9fe21.1727517084.git.christophe.jaillet@wanadoo.fr Signed-off-by: Alex Williamson