/*
* 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/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, pgtable_t token, 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 = alloc_xenballooned_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);
free_xenballooned_pages(nr_pages, pages);
kfree(pages);
kfree(pfns);
return -ENOMEM;
}
kfree(pages);
*gfns = pfns;
*virt = vaddr;
return 0;
}
EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages);
