linux-dev/drivers/xen/Kconfig, branch master

xen: Kconfig: Fix spelling mistake "Maxmium" -> "Maximum"

2022-10-12T06:39:50Z

There is a spelling mistake in a Kconfig description. Fix it. Signed-off-by: Colin Ian King Acked-by: Stefano Stabellini Link: https://lore.kernel.org/r/20221007203500.2756787-1-colin.i.king@gmail.com Signed-off-by: Juergen Gross

xen: don't require virtio with grants for non-PV guests

2022-08-01T05:43:03Z

Commit fa1f57421e0b ("xen/virtio: Enable restricted memory access using Xen grant mappings") introduced a new requirement for using virtio devices: the backend now needs to support the VIRTIO_F_ACCESS_PLATFORM feature. This is an undue requirement for non-PV guests, as those can be operated with existing backends without any problem, as long as those backends are running in dom0. Per default allow virtio devices without grant support for non-PV guests. On Arm require VIRTIO_F_ACCESS_PLATFORM for devices having been listed in the device tree to use grants. Add a new config item to always force use of grants for virtio. Fixes: fa1f57421e0b ("xen/virtio: Enable restricted memory access using Xen grant mappings") Reported-by: Viresh Kumar Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Tested-by: Oleksandr Tyshchenko # Arm64 guest using Xen Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/20220622063838.8854-4-jgross@suse.com Signed-off-by: Juergen Gross

xen/grant-dma-ops: Retrieve the ID of backend's domain for DT devices

2022-06-06T14:07:30Z

Use the presence of "iommus" property pointed to the IOMMU node with recently introduced "xen,grant-dma" compatible as a clear indicator of enabling Xen grant mappings scheme for that device and read the ID of Xen domain where the corresponding backend is running. The domid (domain ID) is used as an argument to the Xen grant mapping APIs. To avoid the deferred probe timeout which takes place after reusing generic IOMMU device tree bindings (because the IOMMU device never becomes available) enable recently introduced stub IOMMU driver by selecting XEN_GRANT_DMA_IOMMU. Also introduce xen_is_grant_dma_device() to check whether xen-grant DMA ops need to be set for a passed device. Remove the hardcoded domid 0 in xen_grant_setup_dma_ops(). Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/1654197833-25362-8-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

xen/grant-dma-iommu: Introduce stub IOMMU driver

2022-06-06T14:07:30Z

In order to reuse generic IOMMU device tree bindings by Xen grant DMA-mapping layer we need to add this stub driver from a fw_devlink perspective (grant-dma-ops cannot be converted into the proper IOMMU driver). Otherwise, just reusing IOMMU bindings (without having a corresponding driver) leads to the deferred probe timeout afterwards, because the IOMMU device never becomes available. This stub driver does nothing except registering empty iommu_ops, the upper layer "of_iommu" will treat this as NO_IOMMU condition and won't return -EPROBE_DEFER. As this driver is quite different from the most hardware IOMMU implementations and only needed in Xen guests, place it in drivers/xen directory. The subsequent commit will make use of it. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/1654197833-25362-7-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

xen/virtio: Enable restricted memory access using Xen grant mappings

2022-06-06T14:07:30Z

In order to support virtio in Xen guests add a config option XEN_VIRTIO enabling the user to specify whether in all Xen guests virtio should be able to access memory via Xen grant mappings only on the host side. Also set PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS feature from the guest initialization code on Arm and x86 if CONFIG_XEN_VIRTIO is enabled. Signed-off-by: Juergen Gross Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/1654197833-25362-5-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

xen/grant-dma-ops: Add option to restrict memory access under Xen

2022-06-06T06:54:52Z

Introduce Xen grant DMA-mapping layer which contains special DMA-mapping routines for providing grant references as DMA addresses to be used by frontends (e.g. virtio) in Xen guests. Add the needed functionality by providing a special set of DMA ops handling the needed grant operations for the I/O pages. The subsequent commit will introduce the use case for xen-grant DMA ops layer to enable using virtio devices in Xen guests in a safe manner. Signed-off-by: Juergen Gross Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/1654197833-25362-4-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

arm/xen: Read extended regions from DT and init Xen resource

2022-01-06T08:53:41Z

This patch implements arch_xen_unpopulated_init() on Arm where the extended regions (if any) are gathered from DT and inserted into specific Xen resource to be used as unused address space for Xen scratch pages by unpopulated-alloc code. The extended region (safe range) is a region of guest physical address space which is unused and could be safely used to create grant/foreign mappings instead of wasting real RAM pages from the domain memory for establishing these mappings. The extended regions are chosen by the hypervisor at the domain creation time and advertised to it via "reg" property under hypervisor node in the guest device-tree. As region 0 is reserved for grant table space (always present), the indexes for extended regions are 1...N. If arch_xen_unpopulated_init() fails for some reason the default behaviour will be restored (allocate xenballooned pages). This patch also removes XEN_UNPOPULATED_ALLOC dependency on x86. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/1639080336-26573-6-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

xen/privcmd: make option visible in Kconfig

2021-11-16T22:13:31Z

This configuration option provides a misc device as an API to userspace. Make this API usable without having to select the module as a transitive dependency. This also fixes an issue where localyesconfig would select CONFIG_XEN_PRIVCMD=m because it was not visible and defaulted to building as module. [boris: clarified help message per Jan's suggestion] Based-on-patch-by: Thomas Weißschuh Signed-off-by: Juergen Gross Link: https://lore.kernel.org/r/20211116143323.18866-1-jgross@suse.com Reviewed-by: Jan Beulich Reviewed-by: Thomas Weißschuh Signed-off-by: Boris Ostrovsky

xen-pciback: allow compiling on other archs than x86

2021-11-02T13:03:43Z

Xen-pciback driver was designed to be built for x86 only. But it can also be used by other architectures, e.g. Arm. Currently PCI backend implements multiple functionalities at a time, such as: 1. It is used as a database for assignable PCI devices, e.g. xl pci-assignable-{add|remove|list} manipulates that list. So, whenever the toolstack needs to know which PCI devices can be passed through it reads that from the relevant sysfs entries of the pciback. 2. It is used to hold the unbound PCI devices list, e.g. when passing through a PCI device it needs to be unbound from the relevant device driver and bound to pciback (strictly speaking it is not required that the device is bound to pciback, but pciback is again used as a database of the passed through PCI devices, so we can re-bind the devices back to their original drivers when guest domain shuts down) 3. Device reset for the devices being passed through 4. Para-virtualised use-cases support The para-virtualised part of the driver is not always needed as some architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend model for PCI device passthrough. For such use-cases make the very first step in splitting the xen-pciback driver into two parts: Xen PCI stub and PCI PV backend drivers. For that add new configuration options CONFIG_XEN_PCI_STUB and CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its functionality, e.g. no support for para-virtualised scenario. x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the fully featured backend driver. Signed-off-by: Oleksandr Andrushchenko Signed-off-by: Anastasiia Lukianenko Reviewed-by: Stefano Stabellini Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20211028143620.144936-1-andr2000@gmail.com Signed-off-by: Boris Ostrovsky

xen/x86: allow PVH Dom0 without XEN_PV=y

2021-10-05T06:35:56Z

Decouple XEN_DOM0 from XEN_PV, converting some existing uses of XEN_DOM0 to a new XEN_PV_DOM0. (I'm not convinced all are really / should really be PV-specific, but for starters I've tried to be conservative.) For PVH Dom0 the hypervisor populates MADT with only x2APIC entries, so without x2APIC support enabled in the kernel things aren't going to work very well. (As opposed, DomU-s would only ever see LAPIC entries in MADT as of now.) Note that this then requires PVH Dom0 to be 64-bit, as X86_X2APIC depends on X86_64. In the course of this xen_running_on_version_or_later() needs to be available more broadly. Move it from a PV-specific to a generic file, considering that what it does isn't really PV-specific at all anyway. Note that xen/interface/version.h cannot be included on its own; in enlighten.c, which uses SCHEDOP_* anyway, include xen/interface/sched.h first to resolve the apparently sole missing type (xen_ulong_t). Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/983bb72f-53df-b6af-14bd-5e088bd06a08@suse.com Signed-off-by: Juergen Gross