linux-dev/include/xen/arm, branch master

arm/xen: Assign xen-grant DMA ops for xen-grant DMA devices

2022-06-06T14:07:30Z

By assigning xen-grant DMA ops we will restrict memory access for passed device using Xen grant mappings. This is needed for using any virtualized device (e.g. virtio) in Xen guests in a safe manner. Please note, for the virtio devices the XEN_VIRTIO config should be enabled (it forces ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS). Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/1654197833-25362-9-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

arm/xen: Introduce xen_setup_dma_ops()

2022-06-06T06:54:33Z

This patch introduces new helper and places it in new header. The helper's purpose is to assign any Xen specific DMA ops in a single place. For now, we deal with xen-swiotlb DMA ops only. The one of the subsequent commits in current series will add xen-grant DMA ops case. Also re-use the xen_swiotlb_detect() check on Arm32. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini [For arm64] Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/1654197833-25362-2-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

Merge tag 'for-linus-5.19-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2022-06-04T20:42:53Z

Pull more xen updates from Juergen Gross: "Two cleanup patches for Xen related code and (more important) an update of MAINTAINERS for Xen, as Boris Ostrovsky decided to step down" * tag 'for-linus-5.19-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: replace xen_remap() with memremap() MAINTAINERS: Update Xen maintainership xen: switch gnttab_end_foreign_access() to take a struct page pointer

xen: replace xen_remap() with memremap()

2022-06-01T05:24:17Z

xen_remap() is used to establish mappings for frames not under direct control of the kernel: for Xenstore and console ring pages, and for grant pages of non-PV guests. Today xen_remap() is defined to use ioremap() on x86 (doing uncached mappings), and ioremap_cache() on Arm (doing cached mappings). Uncached mappings for those use cases are bad for performance, so they should be avoided if possible. As all use cases of xen_remap() don't require uncached mappings (the mapped area is always physical RAM), a mapping using the standard WB cache mode is fine. As sparse is flagging some of the xen_remap() use cases to be not appropriate for iomem(), as the result is not annotated with the __iomem modifier, eliminate xen_remap() completely and replace all use cases with memremap() specifying the MEMREMAP_WB caching mode. xen_unmap() can be replaced with memunmap(). Reported-by: kernel test robot Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Acked-by: Stefano Stabellini Link: https://lore.kernel.org/r/20220530082634.6339-1-jgross@suse.com Signed-off-by: Juergen Gross

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

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

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

xen/arm: move xen_swiotlb_detect to arm/swiotlb-xen.h

2021-05-14T13:52:05Z

Move xen_swiotlb_detect to a static inline function to make it available to !CONFIG_XEN builds. CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Stefano Stabellini Reviewed-by: Christoph Hellwig Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20210512201823.1963-1-sstabellini@kernel.org Signed-off-by: Juergen Gross

xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped

2021-04-23T09:33:50Z

Newer Xen versions expose two Xen feature flags to tell us if the domain is directly mapped or not. Only when a domain is directly mapped it makes sense to enable swiotlb-xen on ARM. Introduce a function on ARM to check the new Xen feature flags and also to deal with the legacy case. Call the function xen_swiotlb_detect. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210319200140.12512-1-sstabellini@kernel.org Signed-off-by: Juergen Gross

arm/arm64: xen: Fix to convert percpu address to gfn correctly

2020-10-07T05:08:43Z

Use per_cpu_ptr_to_phys() instead of virt_to_phys() for per-cpu address conversion. In xen_starting_cpu(), per-cpu xen_vcpu_info address is converted to gfn by virt_to_gfn() macro. However, since the virt_to_gfn(v) assumes the given virtual address is in linear mapped kernel memory area, it can not convert the per-cpu memory if it is allocated on vmalloc area. This depends on CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK. If it is enabled, the first chunk of percpu memory is linear mapped. In the other case, that is allocated from vmalloc area. Moreover, if the first chunk of percpu has run out until allocating xen_vcpu_info, it will be allocated on the 2nd chunk, which is based on kernel memory or vmalloc memory (depends on CONFIG_NEED_PER_CPU_KM). Without this fix and kernel configured to use vmalloc area for the percpu memory, the Dom0 kernel will fail to boot with following errors. [ 0.466172] Xen: initializing cpu0 [ 0.469601] ------------[ cut here ]------------ [ 0.474295] WARNING: CPU: 0 PID: 1 at arch/arm64/xen/../../arm/xen/enlighten.c:153 xen_starting_cpu+0x160/0x180 [ 0.484435] Modules linked in: [ 0.487565] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc4+ #4 [ 0.493895] Hardware name: Socionext Developer Box (DT) [ 0.499194] pstate: 00000005 (nzcv daif -PAN -UAO BTYPE=--) [ 0.504836] pc : xen_starting_cpu+0x160/0x180 [ 0.509263] lr : xen_starting_cpu+0xb0/0x180 [ 0.513599] sp : ffff8000116cbb60 [ 0.516984] x29: ffff8000116cbb60 x28: ffff80000abec000 [ 0.522366] x27: 0000000000000000 x26: 0000000000000000 [ 0.527754] x25: ffff80001156c000 x24: fffffdffbfcdb600 [ 0.533129] x23: 0000000000000000 x22: 0000000000000000 [ 0.538511] x21: ffff8000113a99c8 x20: ffff800010fe4f68 [ 0.543892] x19: ffff8000113a9988 x18: 0000000000000010 [ 0.549274] x17: 0000000094fe0f81 x16: 00000000deadbeef [ 0.554655] x15: ffffffffffffffff x14: 0720072007200720 [ 0.560037] x13: 0720072007200720 x12: 0720072007200720 [ 0.565418] x11: 0720072007200720 x10: 0720072007200720 [ 0.570801] x9 : ffff8000100fbdc0 x8 : ffff800010715208 [ 0.576182] x7 : 0000000000000054 x6 : ffff00001b790f00 [ 0.581564] x5 : ffff800010bbf880 x4 : 0000000000000000 [ 0.586945] x3 : 0000000000000000 x2 : ffff80000abec000 [ 0.592327] x1 : 000000000000002f x0 : 0000800000000000 [ 0.597716] Call trace: [ 0.600232] xen_starting_cpu+0x160/0x180 [ 0.604309] cpuhp_invoke_callback+0xac/0x640 [ 0.608736] cpuhp_issue_call+0xf4/0x150 [ 0.612728] __cpuhp_setup_state_cpuslocked+0x128/0x2c8 [ 0.618030] __cpuhp_setup_state+0x84/0xf8 [ 0.622192] xen_guest_init+0x324/0x364 [ 0.626097] do_one_initcall+0x54/0x250 [ 0.630003] kernel_init_freeable+0x12c/0x2c8 [ 0.634428] kernel_init+0x1c/0x128 [ 0.637988] ret_from_fork+0x10/0x18 [ 0.641635] ---[ end trace d95b5309a33f8b27 ]--- [ 0.646337] ------------[ cut here ]------------ [ 0.651005] kernel BUG at arch/arm64/xen/../../arm/xen/enlighten.c:158! [ 0.657697] Internal error: Oops - BUG: 0 [#1] SMP [ 0.662548] Modules linked in: [ 0.665676] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.9.0-rc4+ #4 [ 0.673398] Hardware name: Socionext Developer Box (DT) [ 0.678695] pstate: 00000005 (nzcv daif -PAN -UAO BTYPE=--) [ 0.684338] pc : xen_starting_cpu+0x178/0x180 [ 0.688765] lr : xen_starting_cpu+0x144/0x180 [ 0.693188] sp : ffff8000116cbb60 [ 0.696573] x29: ffff8000116cbb60 x28: ffff80000abec000 [ 0.701955] x27: 0000000000000000 x26: 0000000000000000 [ 0.707344] x25: ffff80001156c000 x24: fffffdffbfcdb600 [ 0.712718] x23: 0000000000000000 x22: 0000000000000000 [ 0.718107] x21: ffff8000113a99c8 x20: ffff800010fe4f68 [ 0.723481] x19: ffff8000113a9988 x18: 0000000000000010 [ 0.728863] x17: 0000000094fe0f81 x16: 00000000deadbeef [ 0.734245] x15: ffffffffffffffff x14: 0720072007200720 [ 0.739626] x13: 0720072007200720 x12: 0720072007200720 [ 0.745008] x11: 0720072007200720 x10: 0720072007200720 [ 0.750390] x9 : ffff8000100fbdc0 x8 : ffff800010715208 [ 0.755771] x7 : 0000000000000054 x6 : ffff00001b790f00 [ 0.761153] x5 : ffff800010bbf880 x4 : 0000000000000000 [ 0.766534] x3 : 0000000000000000 x2 : 00000000deadbeef [ 0.771916] x1 : 00000000deadbeef x0 : ffffffffffffffea [ 0.777304] Call trace: [ 0.779819] xen_starting_cpu+0x178/0x180 [ 0.783898] cpuhp_invoke_callback+0xac/0x640 [ 0.788325] cpuhp_issue_call+0xf4/0x150 [ 0.792317] __cpuhp_setup_state_cpuslocked+0x128/0x2c8 [ 0.797619] __cpuhp_setup_state+0x84/0xf8 [ 0.801779] xen_guest_init+0x324/0x364 [ 0.805683] do_one_initcall+0x54/0x250 [ 0.809590] kernel_init_freeable+0x12c/0x2c8 [ 0.814016] kernel_init+0x1c/0x128 [ 0.817583] ret_from_fork+0x10/0x18 [ 0.821226] Code: d0006980 f9427c00 cb000300 17ffffea (d4210000) [ 0.827415] ---[ end trace d95b5309a33f8b28 ]--- [ 0.832076] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 0.839815] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]--- Signed-off-by: Masami Hiramatsu Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/160196697165.60224.17470743378683334995.stgit@devnote2 Signed-off-by: Juergen Gross