[mirror_ubuntu-artful-kernel.git] / drivers / xen / xlate_mmu.c

/*
 * 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);
Commit	Line	Data
628c28ee DV	1	/*
	2	* MMU operations common to all auto-translated physmap guests.
	3	*
	4	* Copyright (C) 2015 Citrix Systems R&D Ltd.
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License version 2
	8	* as published by the Free Software Foundation; or, when distributed
	9	* separately from the Linux kernel or incorporated into other
	10	* software packages, subject to the following license:
	11	*
	12	* Permission is hereby granted, free of charge, to any person obtaining a copy
	13	* of this source file (the "Software"), to deal in the Software without
	14	* restriction, including without limitation the rights to use, copy, modify,
	15	* merge, publish, distribute, sublicense, and/or sell copies of the Software,
	16	* and to permit persons to whom the Software is furnished to do so, subject to
	17	* the following conditions:
	18	*
	19	* The above copyright notice and this permission notice shall be included in
	20	* all copies or substantial portions of the Software.
	21	*
	22	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	23	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	24	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	25	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	26	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	27	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	28	* IN THE SOFTWARE.
	29	*/
	30	#include <linux/kernel.h>
	31	#include <linux/mm.h>
243848fc SZ	32	#include <linux/slab.h>
243848fc SZ	33	#include <linux/vmalloc.h>
628c28ee DV	34
	35	#include <asm/xen/hypercall.h>
	36	#include <asm/xen/hypervisor.h>
	37
	38	#include <xen/xen.h>
	39	#include <xen/page.h>
	40	#include <xen/interface/xen.h>
	41	#include <xen/interface/memory.h>
243848fc	42	#include <xen/balloon.h>
628c28ee	43
5995a68a	44	typedef void (xen_gfn_fn_t)(unsigned long gfn, void data);
628c28ee	45
5995a68a JG	46	/* Break down the pages in 4KB chunk and call fn for each gfn */
	47	static void xen_for_each_gfn(struct page **pages, unsigned nr_gfn,
	48	xen_gfn_fn_t fn, void *data)
	49	{
	50	unsigned long xen_pfn = 0;
	51	struct page *page;
	52	int i;
628c28ee	53
5995a68a JG	54	for (i = 0; i < nr_gfn; i++) {
	55	if ((i % XEN_PFN_PER_PAGE) == 0) {
	56	page = pages[i / XEN_PFN_PER_PAGE];
	57	xen_pfn = page_to_xen_pfn(page);
	58	}
	59	fn(pfn_to_gfn(xen_pfn++), data);
	60	}
628c28ee DV	61	}
	62
	63	struct remap_data {
a13d7201	64	xen_pfn_t fgfn; / foreign domain's gfn */
5995a68a	65	int nr_fgfn; /* Number of foreign gfn left to map */
628c28ee DV	66	pgprot_t prot;
	67	domid_t domid;
	68	struct vm_area_struct *vma;
	69	int index;
	70	struct page **pages;
a13d7201	71	struct xen_remap_gfn_info *info;
4e8c0c8c DV	72	int *err_ptr;
4e8c0c8c DV	73	int mapped;
5995a68a JG	74
	75	/* Hypercall parameters */
	76	int h_errs[XEN_PFN_PER_PAGE];
	77	xen_ulong_t h_idxs[XEN_PFN_PER_PAGE];
	78	xen_pfn_t h_gpfns[XEN_PFN_PER_PAGE];
	79
	80	int h_iter; /* Iterator */
628c28ee DV	81	};
628c28ee DV	82
5995a68a JG	83	static void setup_hparams(unsigned long gfn, void *data)
	84	{
	85	struct remap_data *info = data;
	86
	87	info->h_idxs[info->h_iter] = *info->fgfn;
	88	info->h_gpfns[info->h_iter] = gfn;
	89	info->h_errs[info->h_iter] = 0;
	90
	91	info->h_iter++;
	92	info->fgfn++;
	93	}
	94
628c28ee DV	95	static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
	96	void *data)
	97	{
	98	struct remap_data *info = data;
	99	struct page *page = info->pages[info->index++];
5995a68a JG	100	pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), info->prot));
	101	int rc, nr_gfn;
	102	uint32_t i;
	103	struct xen_add_to_physmap_range xatp = {
	104	.domid = DOMID_SELF,
	105	.foreign_domid = info->domid,
	106	.space = XENMAPSPACE_gmfn_foreign,
	107	};
628c28ee	108
5995a68a JG	109	nr_gfn = min_t(typeof(info->nr_fgfn), XEN_PFN_PER_PAGE, info->nr_fgfn);
	110	info->nr_fgfn -= nr_gfn;
	111
	112	info->h_iter = 0;
	113	xen_for_each_gfn(&page, nr_gfn, setup_hparams, info);
	114	BUG_ON(info->h_iter != nr_gfn);
	115
	116	set_xen_guest_handle(xatp.idxs, info->h_idxs);
	117	set_xen_guest_handle(xatp.gpfns, info->h_gpfns);
	118	set_xen_guest_handle(xatp.errs, info->h_errs);
	119	xatp.size = nr_gfn;
	120
	121	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
	122
	123	/* info->err_ptr expect to have one error status per Xen PFN */
	124	for (i = 0; i < nr_gfn; i++) {
	125	int err = (rc < 0) ? rc : info->h_errs[i];
	126
	127	*(info->err_ptr++) = err;
	128	if (!err)
	129	info->mapped++;
4e8c0c8c	130	}
5995a68a JG	131
	132	/*
	133	* Note: The hypercall will return 0 in most of the case if even if
	134	* all the fgmfn are not mapped. We still have to update the pte
	135	* as the userspace may decide to continue.
	136	*/
	137	if (!rc)
	138	set_pte_at(info->vma->vm_mm, addr, ptep, pte);
628c28ee DV	139
	140	return 0;
	141	}
	142
4e8c0c8c	143	int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
628c28ee	144	unsigned long addr,
a13d7201	145	xen_pfn_t *gfn, int nr,
4e8c0c8c DV	146	int *err_ptr, pgprot_t prot,
4e8c0c8c DV	147	unsigned domid,
628c28ee DV	148	struct page **pages)
	149	{
	150	int err;
	151	struct remap_data data;
5995a68a	152	unsigned long range = DIV_ROUND_UP(nr, XEN_PFN_PER_PAGE) << PAGE_SHIFT;
628c28ee	153
4e8c0c8c DV	154	/* Kept here for the purpose of making sure code doesn't break
	155	x86 PVOPS */
	156	BUG_ON(!((vma->vm_flags & (VM_PFNMAP \| VM_IO)) == (VM_PFNMAP \| VM_IO)));
628c28ee	157
a13d7201	158	data.fgfn = gfn;
5995a68a	159	data.nr_fgfn = nr;
4e8c0c8c	160	data.prot = prot;
628c28ee	161	data.domid = domid;
4e8c0c8c	162	data.vma = vma;
628c28ee	163	data.pages = pages;
4e8c0c8c DV	164	data.index = 0;
	165	data.err_ptr = err_ptr;
	166	data.mapped = 0;
	167
	168	err = apply_to_page_range(vma->vm_mm, addr, range,
628c28ee	169	remap_pte_fn, &data);
4e8c0c8c	170	return err < 0 ? err : data.mapped;
628c28ee	171	}
4e8c0c8c	172	EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array);
628c28ee	173
5995a68a	174	static void unmap_gfn(unsigned long gfn, void *data)
628c28ee	175	{
5995a68a	176	struct xen_remove_from_physmap xrp;
628c28ee	177
5995a68a JG	178	xrp.domid = DOMID_SELF;
	179	xrp.gpfn = gfn;
	180	(void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
	181	}
628c28ee	182
5995a68a JG	183	int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
	184	int nr, struct page **pages)
	185	{
	186	xen_for_each_gfn(pages, nr, unmap_gfn, NULL);
628c28ee	187
628c28ee DV	188	return 0;
	189	}
	190	EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);
243848fc	191
975fac3c SZ	192	struct map_balloon_pages {
	193	xen_pfn_t *pfns;
	194	unsigned int idx;
	195	};
	196
	197	static void setup_balloon_gfn(unsigned long gfn, void *data)
	198	{
	199	struct map_balloon_pages *info = data;
	200
	201	info->pfns[info->idx++] = gfn;
	202	}
	203
243848fc SZ	204	/**
	205	* xen_xlate_map_ballooned_pages - map a new set of ballooned pages
	206	* @gfns: returns the array of corresponding GFNs
	207	* @virt: returns the virtual address of the mapped region
	208	* @nr_grant_frames: number of GFNs
	209	* @return 0 on success, error otherwise
	210	*
	211	* This allocates a set of ballooned pages and maps them into the
	212	* kernel's address space.
	213	*/
	214	int __init xen_xlate_map_ballooned_pages(xen_pfn_t gfns, void virt,
	215	unsigned long nr_grant_frames)
	216	{
	217	struct page **pages;
	218	xen_pfn_t *pfns;
	219	void *vaddr;
975fac3c	220	struct map_balloon_pages data;
243848fc	221	int rc;
975fac3c	222	unsigned long nr_pages;
243848fc SZ	223
243848fc SZ	224	BUG_ON(nr_grant_frames == 0);
975fac3c SZ	225	nr_pages = DIV_ROUND_UP(nr_grant_frames, XEN_PFN_PER_PAGE);
975fac3c SZ	226	pages = kcalloc(nr_pages, sizeof(pages[0]), GFP_KERNEL);
243848fc SZ	227	if (!pages)
	228	return -ENOMEM;
	229
	230	pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
	231	if (!pfns) {
	232	kfree(pages);
	233	return -ENOMEM;
	234	}
975fac3c	235	rc = alloc_xenballooned_pages(nr_pages, pages);
243848fc	236	if (rc) {
975fac3c SZ	237	pr_warn("%s Couldn't balloon alloc %ld pages rc:%d\n", __func__,
975fac3c SZ	238	nr_pages, rc);
243848fc SZ	239	kfree(pages);
	240	kfree(pfns);
	241	return rc;
	242	}
243848fc	243
975fac3c SZ	244	data.pfns = pfns;
	245	data.idx = 0;
	246	xen_for_each_gfn(pages, nr_grant_frames, setup_balloon_gfn, &data);
	247
	248	vaddr = vmap(pages, nr_pages, 0, PAGE_KERNEL);
243848fc	249	if (!vaddr) {
975fac3c SZ	250	pr_warn("%s Couldn't map %ld pages rc:%d\n", __func__,
	251	nr_pages, rc);
	252	free_xenballooned_pages(nr_pages, pages);
243848fc SZ	253	kfree(pages);
	254	kfree(pfns);
	255	return -ENOMEM;
	256	}
	257	kfree(pages);
	258
	259	*gfns = pfns;
	260	*virt = vaddr;
	261
	262	return 0;
	263	}
	264	EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages);