linux/drivers/xen/xlate_mmu.c

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/*
* 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 <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>
/* map fgmfn of domid to lpfn in the current domain */
static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
unsigned int domid)
{
int rc;
struct xen_add_to_physmap_range xatp = {
.domid = DOMID_SELF,
.foreign_domid = domid,
.size = 1,
.space = XENMAPSPACE_gmfn_foreign,
};
xen_ulong_t idx = fgmfn;
xen_pfn_t gpfn = lpfn;
int err = 0;
set_xen_guest_handle(xatp.idxs, &idx);
set_xen_guest_handle(xatp.gpfns, &gpfn);
set_xen_guest_handle(xatp.errs, &err);
rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
return rc < 0 ? rc : err;
}
struct remap_data {
xen_pfn_t *fgmfn; /* foreign domain's gmfn */
pgprot_t prot;
domid_t domid;
struct vm_area_struct *vma;
int index;
struct page **pages;
struct xen_remap_mfn_info *info;
int *err_ptr;
int mapped;
};
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++];
unsigned long pfn = page_to_pfn(page);
pte_t pte = pte_mkspecial(pfn_pte(pfn, info->prot));
int rc;
rc = map_foreign_page(pfn, *info->fgmfn, info->domid);
*info->err_ptr++ = rc;
if (!rc) {
set_pte_at(info->vma->vm_mm, addr, ptep, pte);
info->mapped++;
}
info->fgmfn++;
return 0;
}
int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t *mfn, int nr,
int *err_ptr, pgprot_t prot,
unsigned domid,
struct page **pages)
{
int err;
struct remap_data data;
unsigned long range = nr << 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.fgmfn = mfn;
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);
int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
int nr, struct page **pages)
{
int i;
for (i = 0; i < nr; i++) {
struct xen_remove_from_physmap xrp;
unsigned long pfn;
pfn = page_to_pfn(pages[i]);
xrp.domid = DOMID_SELF;
xrp.gpfn = pfn;
(void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
}
return 0;
}
EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);