linux-dev/arch/arm/xen, branch linus/master

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

Merge tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping

2022-05-26T02:18:36Z

Pull dma-mapping updates from Christoph Hellwig: - don't over-decrypt memory (Robin Murphy) - takes min align mask into account for the swiotlb max mapping size (Tianyu Lan) - use GFP_ATOMIC in dma-debug (Mikulas Patocka) - fix DMA_ATTR_NO_KERNEL_MAPPING on xen/arm (me) - don't fail on highmem CMA pages in dma_direct_alloc_pages (me) - cleanup swiotlb initialization and share more code with swiotlb-xen (me, Stefano Stabellini) * tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping: (23 commits) dma-direct: don't over-decrypt memory swiotlb: max mapping size takes min align mask into account swiotlb: use the right nslabs-derived sizes in swiotlb_init_late swiotlb: use the right nslabs value in swiotlb_init_remap swiotlb: don't panic when the swiotlb buffer can't be allocated dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC dma-direct: don't fail on highmem CMA pages in dma_direct_alloc_pages swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm x86: remove cruft from swiotlb: remove swiotlb_init_with_tbl and swiotlb_init_late_with_tbl swiotlb: merge swiotlb-xen initialization into swiotlb swiotlb: provide swiotlb_init variants that remap the buffer swiotlb: pass a gfp_mask argument to swiotlb_init_late swiotlb: add a SWIOTLB_ANY flag to lift the low memory restriction swiotlb: make the swiotlb_init interface more useful x86: centralize setting SWIOTLB_FORCE when guest memory encryption is enabled x86: remove the IOMMU table infrastructure MIPS/octeon: use swiotlb_init instead of open coding it arm/xen: don't check for xen_initial_domain() in xen_create_contiguous_region swiotlb: rename swiotlb_late_init_with_default_size ...

swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm

2022-05-11T17:48:32Z

swiotlb-xen uses very different ways to allocate coherent memory on x86 vs arm. On the former it allocates memory from the page allocator, while on the later it reuses the dma-direct allocator the handles the complexities of non-coherent DMA on arm platforms. Unfortunately the complexities of trying to deal with the two cases in the swiotlb-xen.c code lead to a bug in the handling of DMA_ATTR_NO_KERNEL_MAPPING on arm. With the DMA_ATTR_NO_KERNEL_MAPPING flag the coherent memory allocator does not actually allocate coherent memory, but just a DMA handle for some memory that is DMA addressable by the device, but which does not have to have a kernel mapping. Thus dereferencing the return value will lead to kernel crashed and memory corruption. Fix this by using the dma-direct allocator directly for arm, which works perfectly fine because on arm swiotlb-xen is only used when the domain is 1:1 mapped, and then simplifying the remaining code to only cater for the x86 case with DMA coherent device. Reported-by: Rahul Singh Signed-off-by: Christoph Hellwig Reviewed-by: Rahul Singh Reviewed-by: Stefano Stabellini Tested-by: Rahul Singh

arm/xen: Fix some refcount leaks

2022-04-22T20:33:33Z

The of_find_compatible_node() function returns a node pointer with refcount incremented, We should use of_node_put() on it when done Add the missing of_node_put() to release the refcount. Fixes: 9b08aaa3199a ("ARM: XEN: Move xen_early_init() before efi_init()") Fixes: b2371587fe0c ("arm/xen: Read extended regions from DT and init Xen resource") Signed-off-by: Miaoqian Lin Reviewed-by: Stefano Stabellini Signed-off-by: Stefano Stabellini

swiotlb: merge swiotlb-xen initialization into swiotlb

2022-04-18T05:21:13Z

Reuse the generic swiotlb initialization for xen-swiotlb. For ARM/ARM64 this works trivially, while for x86 xen_swiotlb_fixup needs to be passed as the remap argument to swiotlb_init_remap/swiotlb_init_late. Note that the lower bound of the swiotlb size is changed to the smaller IO_TLB_MIN_SLABS based value with this patch, but that is fine as the 2MB value used in Xen before was just an optimization and is not the hard lower bound. Signed-off-by: Christoph Hellwig Reviewed-by: Stefano Stabellini Reviewed-by: Konrad Rzeszutek Wilk Tested-by: Boris Ostrovsky

arm/xen: don't check for xen_initial_domain() in xen_create_contiguous_region

2022-04-18T05:21:09Z

It used to be that Linux enabled swiotlb-xen when running a dom0 on ARM. Since f5079a9a2a31 "xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped", Linux detects whether to enable or disable swiotlb-xen based on the new feature flags: XENFEAT_direct_mapped and XENFEAT_not_direct_mapped. However, there is still a leftover xen_initial_domain() check in xen_create_contiguous_region. Remove the check as xen_create_contiguous_region is only called by swiotlb-xen during initialization. If xen_create_contiguous_region is called, we know Linux is running 1:1 mapped so there is no need for additional checks. Also update the in-code comment. Signed-off-by: Stefano Stabellini Signed-off-by: Christoph Hellwig Reviewed-by: Konrad Rzeszutek Wilk

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

arm/xen: Switch to use gnttab_setup_auto_xlat_frames() for DT

2022-01-06T08:53:31Z

Read the start address of the grant table space from DT (region 0). This patch mostly restores behaviour before commit 3cf4095d7446 ("arm/xen: Use xen_xlate_map_ballooned_pages to setup grant table") but trying not to break the ACPI support added after that commit. So the patch touches DT part only and leaves the ACPI part with xen_xlate_map_ballooned_pages(). Also in order to make a code more resilient use a fallback to xen_xlate_map_ballooned_pages() if grant table region wasn't found. This is a preparation for using Xen extended region feature where unused regions of guest physical address space (provided by the hypervisor) will be used to create grant/foreign/whatever mappings instead of wasting real RAM pages from the domain memory for establishing these mappings. The immediate benefit of this change: - Avoid superpage shattering in Xen P2M when establishing stage-2 mapping (GFN <-> MFN) for the grant table space - Avoid wasting real RAM pages (reducing the amount of memory usuable) for mapping grant table space - The grant table space is always mapped at the exact same place (region 0 is reserved for the grant table) Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/1639080336-26573-3-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

xen: allow pv-only hypercalls only with CONFIG_XEN_PV

2021-11-02T13:11:01Z

Put the definitions of the hypercalls usable only by pv guests inside CONFIG_XEN_PV sections. On Arm two dummy functions related to pv hypercalls can be removed. While at it remove the no longer supported tmem hypercall definition. Signed-off-by: Juergen Gross Link: https://lore.kernel.org/r/20211028081221.2475-3-jgross@suse.com Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

2021-07-06T18:52:58Z

Pull ARM development updates from Russell King: - Make it clear __swp_entry_to_pte() uses PTE_TYPE_FAULT - Updates for setting vmalloc size via command line to resolve an issue with the 8MiB hole not properly being accounted for, and clean up the code. - ftrace support for module PLTs - Spelling fixes - kbuild updates for removing generated files and pattern rules for generating files - Clang/llvm updates - Change the way the kernel is mapped, placing it in vmalloc space instead. - Remove arm_pm_restart from arm and aarch64. * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (29 commits) ARM: 9098/1: ftrace: MODULE_PLT: Fix build problem without DYNAMIC_FTRACE ARM: 9097/1: mmu: Declare section start/end correctly ARM: 9096/1: Remove arm_pm_restart() ARM: 9095/1: ARM64: Remove arm_pm_restart() ARM: 9094/1: Register with kernel restart handler ARM: 9093/1: drivers: firmwapsci: Register with kernel restart handler ARM: 9092/1: xen: Register with kernel restart handler ARM: 9091/1: Revert "mm: qsd8x50: Fix incorrect permission faults" ARM: 9090/1: Map the lowmem and kernel separately ARM: 9089/1: Define kernel physical section start and end ARM: 9088/1: Split KERNEL_OFFSET from PAGE_OFFSET ARM: 9087/1: kprobes: test-thumb: fix for LLVM_IAS=1 ARM: 9086/1: syscalls: use pattern rules to generate syscall headers ARM: 9085/1: remove unneeded abi parameter to syscallnr.sh ARM: 9084/1: simplify the build rule of mach-types.h ARM: 9083/1: uncompress: atags_to_fdt: Spelling s/REturn/Return/ ARM: 9082/1: [v2] mark prepare_page_table as __init ARM: 9079/1: ftrace: Add MODULE_PLTS support ARM: 9078/1: Add warn suppress parameter to arm_gen_branch_link() ARM: 9077/1: PLT: Move struct plt_entries definition to header ...