diff options
Diffstat (limited to 'drivers/xen/xlate_mmu.c')
| -rw-r--r-- | drivers/xen/xlate_mmu.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c new file mode 100644 index 000000000..f17c4c03d --- /dev/null +++ b/drivers/xen/xlate_mmu.c @@ -0,0 +1,295 @@ +/* + * MMU operations common to all auto-translated physmap guests. + * + * Copyright (C) 2015 Citrix Systems R&D Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include <asm/xen/hypercall.h> +#include <asm/xen/hypervisor.h> + +#include <xen/xen.h> +#include <xen/xen-ops.h> +#include <xen/page.h> +#include <xen/interface/xen.h> +#include <xen/interface/memory.h> +#include <xen/balloon.h> + +typedef void (*xen_gfn_fn_t)(unsigned long gfn, void *data); + +/* Break down the pages in 4KB chunk and call fn for each gfn */ +static void xen_for_each_gfn(struct page **pages, unsigned nr_gfn, + xen_gfn_fn_t fn, void *data) +{ + unsigned long xen_pfn = 0; + struct page *page; + int i; + + for (i = 0; i < nr_gfn; i++) { + if ((i % XEN_PFN_PER_PAGE) == 0) { + page = pages[i / XEN_PFN_PER_PAGE]; + xen_pfn = page_to_xen_pfn(page); + } + fn(pfn_to_gfn(xen_pfn++), data); + } +} + +struct remap_data { + xen_pfn_t *fgfn; /* foreign domain's gfn */ + int nr_fgfn; /* Number of foreign gfn left to map */ + pgprot_t prot; + domid_t domid; + struct vm_area_struct *vma; + int index; + struct page **pages; + struct xen_remap_gfn_info *info; + int *err_ptr; + int mapped; + + /* Hypercall parameters */ + int h_errs[XEN_PFN_PER_PAGE]; + xen_ulong_t h_idxs[XEN_PFN_PER_PAGE]; + xen_pfn_t h_gpfns[XEN_PFN_PER_PAGE]; + + int h_iter; /* Iterator */ +}; + +static void setup_hparams(unsigned long gfn, void *data) +{ + struct remap_data *info = data; + + info->h_idxs[info->h_iter] = *info->fgfn; + info->h_gpfns[info->h_iter] = gfn; + info->h_errs[info->h_iter] = 0; + + info->h_iter++; + info->fgfn++; +} + +static int remap_pte_fn(pte_t *ptep, unsigned long addr, void *data) +{ + struct remap_data *info = data; + struct page *page = info->pages[info->index++]; + pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), info->prot)); + int rc, nr_gfn; + uint32_t i; + struct xen_add_to_physmap_range xatp = { + .domid = DOMID_SELF, + .foreign_domid = info->domid, + .space = XENMAPSPACE_gmfn_foreign, + }; + + nr_gfn = min_t(typeof(info->nr_fgfn), XEN_PFN_PER_PAGE, info->nr_fgfn); + info->nr_fgfn -= nr_gfn; + + info->h_iter = 0; + xen_for_each_gfn(&page, nr_gfn, setup_hparams, info); + BUG_ON(info->h_iter != nr_gfn); + + set_xen_guest_handle(xatp.idxs, info->h_idxs); + set_xen_guest_handle(xatp.gpfns, info->h_gpfns); + set_xen_guest_handle(xatp.errs, info->h_errs); + xatp.size = nr_gfn; + + rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp); + + /* info->err_ptr expect to have one error status per Xen PFN */ + for (i = 0; i < nr_gfn; i++) { + int err = (rc < 0) ? rc : info->h_errs[i]; + + *(info->err_ptr++) = err; + if (!err) + info->mapped++; + } + + /* + * Note: The hypercall will return 0 in most of the case if even if + * all the fgmfn are not mapped. We still have to update the pte + * as the userspace may decide to continue. + */ + if (!rc) + set_pte_at(info->vma->vm_mm, addr, ptep, pte); + + return 0; +} + +int xen_xlate_remap_gfn_array(struct vm_area_struct *vma, + unsigned long addr, + xen_pfn_t *gfn, int nr, + int *err_ptr, pgprot_t prot, + unsigned domid, + struct page **pages) +{ + int err; + struct remap_data data; + unsigned long range = DIV_ROUND_UP(nr, XEN_PFN_PER_PAGE) << PAGE_SHIFT; + + /* Kept here for the purpose of making sure code doesn't break + x86 PVOPS */ + BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO))); + + data.fgfn = gfn; + data.nr_fgfn = nr; + data.prot = prot; + data.domid = domid; + data.vma = vma; + data.pages = pages; + data.index = 0; + data.err_ptr = err_ptr; + data.mapped = 0; + + err = apply_to_page_range(vma->vm_mm, addr, range, + remap_pte_fn, &data); + return err < 0 ? err : data.mapped; +} +EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array); + +static void unmap_gfn(unsigned long gfn, void *data) +{ + struct xen_remove_from_physmap xrp; + + xrp.domid = DOMID_SELF; + xrp.gpfn = gfn; + (void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp); +} + +int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma, + int nr, struct page **pages) +{ + xen_for_each_gfn(pages, nr, unmap_gfn, NULL); + + return 0; +} +EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range); + +struct map_balloon_pages { + xen_pfn_t *pfns; + unsigned int idx; +}; + +static void setup_balloon_gfn(unsigned long gfn, void *data) +{ + struct map_balloon_pages *info = data; + + info->pfns[info->idx++] = gfn; +} + +/** + * xen_xlate_map_ballooned_pages - map a new set of ballooned pages + * @gfns: returns the array of corresponding GFNs + * @virt: returns the virtual address of the mapped region + * @nr_grant_frames: number of GFNs + * @return 0 on success, error otherwise + * + * This allocates a set of ballooned pages and maps them into the + * kernel's address space. + */ +int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt, + unsigned long nr_grant_frames) +{ + struct page **pages; + xen_pfn_t *pfns; + void *vaddr; + struct map_balloon_pages data; + int rc; + unsigned long nr_pages; + + BUG_ON(nr_grant_frames == 0); + nr_pages = DIV_ROUND_UP(nr_grant_frames, XEN_PFN_PER_PAGE); + pages = kcalloc(nr_pages, sizeof(pages[0]), GFP_KERNEL); + if (!pages) + return -ENOMEM; + + pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL); + if (!pfns) { + kfree(pages); + return -ENOMEM; + } + rc = xen_alloc_unpopulated_pages(nr_pages, pages); + if (rc) { + pr_warn("%s Couldn't balloon alloc %ld pages rc:%d\n", __func__, + nr_pages, rc); + kfree(pages); + kfree(pfns); + return rc; + } + + data.pfns = pfns; + data.idx = 0; + xen_for_each_gfn(pages, nr_grant_frames, setup_balloon_gfn, &data); + + vaddr = vmap(pages, nr_pages, 0, PAGE_KERNEL); + if (!vaddr) { + pr_warn("%s Couldn't map %ld pages rc:%d\n", __func__, + nr_pages, rc); + xen_free_unpopulated_pages(nr_pages, pages); + kfree(pages); + kfree(pfns); + return -ENOMEM; + } + kfree(pages); + + *gfns = pfns; + *virt = vaddr; + + return 0; +} + +struct remap_pfn { + struct mm_struct *mm; + struct page **pages; + pgprot_t prot; + unsigned long i; +}; + +static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data) +{ + struct remap_pfn *r = data; + struct page *page = r->pages[r->i]; + pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot)); + + set_pte_at(r->mm, addr, ptep, pte); + r->i++; + + return 0; +} + +/* Used by the privcmd module, but has to be built-in on ARM */ +int xen_remap_vma_range(struct vm_area_struct *vma, unsigned long addr, unsigned long len) +{ + struct remap_pfn r = { + .mm = vma->vm_mm, + .pages = vma->vm_private_data, + .prot = vma->vm_page_prot, + }; + + return apply_to_page_range(vma->vm_mm, addr, len, remap_pfn_fn, &r); +} +EXPORT_SYMBOL_GPL(xen_remap_vma_range); |