kernel.git/drivers/xen, branch linux-6.1.y

xenbus: Use .freeze/.thaw to handle xenbus devices

2026-03-04T12:20:15Z

[ Upstream commit e08dd1ee49838750a514e83c0aa60cd12ba6ecbb ] The goal is to fix s2idle and S3 for Xen PV devices. A domain resuming from s3 or s2idle disconnects its PV devices during resume. The backends are not expecting this and do not reconnect. b3e96c0c7562 ("xen: use freeze/restore/thaw PM events for suspend/ resume/chkpt") changed xen_suspend()/do_suspend() from PMSG_SUSPEND/PMSG_RESUME to PMSG_FREEZE/PMSG_THAW/PMSG_RESTORE, but the suspend/resume callbacks remained. .freeze/restore are used with hiberation where Linux restarts in a new place in the future. .suspend/resume are useful for runtime power management for the duration of a boot. The current behavior of the callbacks works for an xl save/restore or live migration where the domain is restored/migrated to a new location and connecting to a not-already-connected backend. Change xenbus_pm_ops to use .freeze/thaw/restore and drop the .suspend/resume hook. This matches the use in drivers/xen/manage.c for save/restore and live migration. With .suspend/resume empty, PV devices are left connected during s2idle and s3, so PV devices are not changed and work after resume. Signed-off-by: Jason Andryuk Acked-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <20251119224731.61497-2-jason.andryuk@amd.com> Signed-off-by: Sasha Levin

xen/virtio: Don't use grant-dma-ops when running as Dom0

2026-03-04T12:19:23Z

[ Upstream commit dc8ea8714311e549ee93a2b0bdd5487d20bfadbf ] Dom0 inherit devices from the machine and is usually in PV mode. If we are running in a virtual that has virtio devices, these devices would be considered as using grants with Dom0 as backend, while being the said Dom0 itself, while we want to use these devices like regular PCI devices. Fix this by preventing grant-dma-ops from being used when running as Dom0 (initial domain). We still keep the device-tree logic as-is. Signed-off-by: Teddy Astie Fixes: 61367688f1fb0 ("xen/virtio: enable grant based virtio on x86") Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <6698564dd2270a9f7377b78ebfb20cb425cabbe8.1767720955.git.teddy.astie@vates.tech> Signed-off-by: Sasha Levin

xen/virtio: Handle PCI devices which Host controller is described in DT

2026-03-04T12:19:23Z

[ Upstream commit ef8ae384b4c9ccefecf4754f34644bd9fb0105b7 ] Use the same "xen-grant-dma" device concept for the PCI devices behind device-tree based PCI Host controller, but with one modification. Unlike for platform devices, we cannot use generic IOMMU bindings (iommus property), as we need to support more flexible configuration. The problem is that PCI devices under the single PCI Host controller may have the backends running in different Xen domains and thus have different endpoints ID (backend domains ID). Add ability to deal with generic PCI-IOMMU bindings (iommu-map/ iommu-map-mask properties) which allows us to describe relationship between PCI devices and backend domains ID properly. To avoid having to look up for the PCI Host bridge twice and reduce the amount of checks pass an extra struct device_node *np to xen_dt_grant_init_backend_domid(). So with current patch the code expects iommus property for the platform devices and iommu-map/iommu-map-mask properties for PCI devices. The example of generated by the toolstack iommu-map property for two PCI devices 0000:00:01.0 and 0000:00:02.0 whose backends are running in different Xen domains with IDs 1 and 2 respectively: iommu-map = <0x08 0xfde9 0x01 0x08 0x10 0xfde9 0x02 0x08>; Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Xenia Ragiadakou Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/20221025162004.8501-3-olekstysh@gmail.com Signed-off-by: Juergen Gross Stable-dep-of: dc8ea8714311 ("xen/virtio: Don't use grant-dma-ops when running as Dom0") Signed-off-by: Sasha Levin

xen/virtio: Optimize the setup of "xen-grant-dma" devices

2026-03-04T12:19:23Z

[ Upstream commit 035e3a4321f73c352b6408ec2153fa5bc3feb459 ] This is needed to avoid having to parse the same device-tree several times for a given device. For this to work we need to install the xen_virtio_restricted_mem_acc callback in Arm's xen_guest_init() which is same callback as x86's PV and HVM modes already use and remove the manual assignment in xen_setup_dma_ops(). Also we need to split the code to initialize backend_domid into a separate function. Prior to current patch we parsed the device-tree three times: 1. xen_setup_dma_ops()->...->xen_is_dt_grant_dma_device() 2. xen_setup_dma_ops()->...->xen_dt_grant_init_backend_domid() 3. xen_virtio_mem_acc()->...->xen_is_dt_grant_dma_device() With current patch we parse the device-tree only once in xen_virtio_restricted_mem_acc()->...->xen_dt_grant_init_backend_domid() Other benefits are: - Not diverge from x86 when setting up Xen grant DMA ops - Drop several global functions Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Xenia Ragiadakou Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/20221025162004.8501-2-olekstysh@gmail.com Signed-off-by: Juergen Gross Stable-dep-of: dc8ea8714311 ("xen/virtio: Don't use grant-dma-ops when running as Dom0") Signed-off-by: Sasha Levin

scsi: xen: scsiback: Fix potential memory leak in scsiback_remove()

2026-02-06T15:44:18Z

[ Upstream commit 901a5f309daba412e2a30364d7ec1492fa11c32c ] Memory allocated for struct vscsiblk_info in scsiback_probe() is not freed in scsiback_remove() leading to potential memory leaks on remove, as well as in the scsiback_probe() error paths. Fix that by freeing it in scsiback_remove(). Cc: stable@vger.kernel.org Fixes: d9d660f6e562 ("xen-scsiback: Add Xen PV SCSI backend driver") Signed-off-by: Abdun Nihaal Reviewed-by: Juergen Gross Link: https://patch.msgid.link/20251223063012.119035-1-nihaal@cse.iitm.ac.in Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

xen: make remove callback of xen driver void returned

2026-02-06T15:44:18Z

[ Upstream commit 7cffcade57a429667447c4f41d8414bbcf1b3aaa ] Since commit fc7a6209d571 ("bus: Make remove callback return void") forces bus_type::remove be void-returned, it doesn't make much sense for any bus based driver implementing remove callbalk to return non-void to its caller. This change is for xen bus based drivers. Acked-by: Juergen Gross Signed-off-by: Dawei Li Link: https://lore.kernel.org/r/TYCP286MB23238119AB4DF190997075C9CAE39@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM Signed-off-by: Juergen Gross Stable-dep-of: 901a5f309dab ("scsi: xen: scsiback: Fix potential memory leak in scsiback_remove()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

xen/events: Update virq_to_irq on migration

2025-10-19T14:23:23Z

[ Upstream commit 3fcc8e146935415d69ffabb5df40ecf50e106131 ] VIRQs come in 3 flavors, per-VPU, per-domain, and global, and the VIRQs are tracked in per-cpu virq_to_irq arrays. Per-domain and global VIRQs must be bound on CPU 0, and bind_virq_to_irq() sets the per_cpu virq_to_irq at registration time Later, the interrupt can migrate, and info->cpu is updated. When calling __unbind_from_irq(), the per-cpu virq_to_irq is cleared for a different cpu. If bind_virq_to_irq() is called again with CPU 0, the stale irq is returned. There won't be any irq_info for the irq, so things break. Make xen_rebind_evtchn_to_cpu() update the per_cpu virq_to_irq mappings to keep them update to date with the current cpu. This ensures the correct virq_to_irq is cleared in __unbind_from_irq(). Fixes: e46cdb66c8fc ("xen: event channels") Cc: stable@vger.kernel.org Signed-off-by: Jason Andryuk Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <20250828003604.8949-4-jason.andryuk@amd.com> [ Adjust context ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

xen/manage: Fix suspend error path

2025-10-19T14:23:11Z

commit f770c3d858687252f1270265ba152d5c622e793f upstream. The device power management API has the following asymmetry: * dpm_suspend_start() does not clean up on failure (it requires a call to dpm_resume_end()) * dpm_suspend_end() does clean up on failure (it does not require a call to dpm_resume_start()) The asymmetry was introduced by commit d8f3de0d2412 ("Suspend-related patches for 2.6.27") in June 2008: It removed a call to device_resume() from device_suspend() (which was later renamed to dpm_suspend_start()). When Xen began using the device power management API in May 2008 with commit 0e91398f2a5d ("xen: implement save/restore"), the asymmetry did not yet exist. But since it was introduced, a call to dpm_resume_end() is missing in the error path of dpm_suspend_start(). Fix it. Fixes: d8f3de0d2412 ("Suspend-related patches for 2.6.27") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v2.6.27 Reviewed-by: "Rafael J. Wysocki (Intel)" Signed-off-by: Juergen Gross Message-ID: <22453676d1ddcebbe81641bb68ddf587fee7e21e.1756990799.git.lukas@wunner.de> Signed-off-by: Greg Kroah-Hartman

xen/events: Cleanup find_virq() return codes

2025-10-19T14:23:11Z

commit 08df2d7dd4ab2db8a172d824cda7872d5eca460a upstream. rc is overwritten by the evtchn_status hypercall in each iteration, so the return value will be whatever the last iteration is. This could incorrectly return success even if the event channel was not found. Change to an explicit -ENOENT for an un-found virq and return 0 on a successful match. Fixes: 62cc5fc7b2e0 ("xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports") Cc: stable@vger.kernel.org Signed-off-by: Jason Andryuk Reviewed-by: Jan Beulich Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <20250828003604.8949-2-jason.andryuk@amd.com> Signed-off-by: Greg Kroah-Hartman

xen/gntdev: remove struct gntdev_copy_batch from stack

2025-08-15T10:04:58Z

[ Upstream commit 70045cf6593cbf0740956ea9b7b4269142c6ee38 ] When compiling the kernel with LLVM, the following warning was issued: drivers/xen/gntdev.c:991: warning: stack frame size (1160) exceeds limit (1024) in function 'gntdev_ioctl' The main reason is struct gntdev_copy_batch which is located on the stack and has a size of nearly 1kb. For performance reasons it shouldn't by just dynamically allocated instead, so allocate a new instance when needed and instead of freeing it put it into a list of free structs anchored in struct gntdev_priv. Fixes: a4cdb556cae0 ("xen/gntdev: add ioctl for grant copy") Reported-by: Abinash Singh Reviewed-by: Stefano Stabellini Signed-off-by: Juergen Gross Message-ID: <20250703073259.17356-1-jgross@suse.com> Signed-off-by: Sasha Levin