[linux-block.git] / arch / x86 / xen / grant-table.c

// SPDX-License-Identifier: GPL-2.0 OR MIT
/******************************************************************************
 * grant_table.c
 * x86 specific part
 *
 * Granting foreign access to our memory reservation.
 *
 * Copyright (c) 2005-2006, Christopher Clark
 * Copyright (c) 2004-2005, K A Fraser
 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
 *                    VA Linux Systems Japan. Split out x86 specific part.
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <xen/interface/xen.h>
#include <xen/page.h>
#include <xen/grant_table.h>
#include <xen/xen.h>


static struct gnttab_vm_area {
	struct vm_struct *area;
	pte_t **ptes;
	int idx;
} gnttab_shared_vm_area, gnttab_status_vm_area;

int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
			   unsigned long max_nr_gframes,
			   void **__shared)
{
	void *shared = *__shared;
	unsigned long addr;
	unsigned long i;

	if (shared == NULL)
		*__shared = shared = gnttab_shared_vm_area.area->addr;

	addr = (unsigned long)shared;

	for (i = 0; i < nr_gframes; i++) {
		set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
			   mfn_pte(frames[i], PAGE_KERNEL));
		addr += PAGE_SIZE;
	}

	return 0;
}

int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
			   unsigned long max_nr_gframes,
			   grant_status_t **__shared)
{
	grant_status_t *shared = *__shared;
	unsigned long addr;
	unsigned long i;

	if (shared == NULL)
		*__shared = shared = gnttab_status_vm_area.area->addr;

	addr = (unsigned long)shared;

	for (i = 0; i < nr_gframes; i++) {
		set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
			   mfn_pte(frames[i], PAGE_KERNEL));
		addr += PAGE_SIZE;
	}

	return 0;
}

void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
{
	pte_t **ptes;
	unsigned long addr;
	unsigned long i;

	if (shared == gnttab_status_vm_area.area->addr)
		ptes = gnttab_status_vm_area.ptes;
	else
		ptes = gnttab_shared_vm_area.ptes;

	addr = (unsigned long)shared;

	for (i = 0; i < nr_gframes; i++) {
		set_pte_at(&init_mm, addr, ptes[i], __pte(0));
		addr += PAGE_SIZE;
	}
}

static int gnttab_apply(pte_t *pte, unsigned long addr, void *data)
{
	struct gnttab_vm_area *area = data;

	area->ptes[area->idx++] = pte;
	return 0;
}

static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
{
	area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL);
	if (area->ptes == NULL)
		return -ENOMEM;
	area->area = get_vm_area(PAGE_SIZE * nr_frames, VM_IOREMAP);
	if (!area->area)
		goto out_free_ptes;
	if (apply_to_page_range(&init_mm, (unsigned long)area->area->addr,
			PAGE_SIZE * nr_frames, gnttab_apply, area))
		goto out_free_vm_area;
	return 0;
out_free_vm_area:
	free_vm_area(area->area);
out_free_ptes:
	kfree(area->ptes);
	return -ENOMEM;
}

static void arch_gnttab_vfree(struct gnttab_vm_area *area)
{
	free_vm_area(area->area);
	kfree(area->ptes);
}

int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
{
	int ret;

	if (!xen_pv_domain())
		return 0;

	ret = arch_gnttab_valloc(&gnttab_shared_vm_area, nr_shared);
	if (ret < 0)
		return ret;

	/*
	 * Always allocate the space for the status frames in case
	 * we're migrated to a host with V2 support.
	 */
	ret = arch_gnttab_valloc(&gnttab_status_vm_area, nr_status);
	if (ret < 0)
		goto err;

	return 0;
err:
	arch_gnttab_vfree(&gnttab_shared_vm_area);
	return -ENOMEM;
}

#ifdef CONFIG_XEN_PVH
#include <xen/events.h>
#include <xen/xen-ops.h>
static int __init xen_pvh_gnttab_setup(void)
{
	if (!xen_pvh_domain())
		return -ENODEV;

	xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();

	return xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
					     &xen_auto_xlat_grant_frames.vaddr,
					     xen_auto_xlat_grant_frames.count);
}
/* Call it _before_ __gnttab_init as we need to initialize the
 * xen_auto_xlat_grant_frames first. */
core_initcall(xen_pvh_gnttab_setup);
#endif
Commit	Line	Data
901d209a	1	// SPDX-License-Identifier: GPL-2.0 OR MIT
8d3d2106 IY	2	/******************************************************************************
	3	* grant_table.c
	4	* x86 specific part
	5	*
	6	* Granting foreign access to our memory reservation.
	7	*
	8	* Copyright (c) 2005-2006, Christopher Clark
	9	* Copyright (c) 2004-2005, K A Fraser
	10	* Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
	11	* VA Linux Systems Japan. Split out x86 specific part.
8d3d2106 IY	12	*/
	13
	14	#include <linux/sched.h>
	15	#include <linux/mm.h>
162e3717	16	#include <linux/slab.h>
8d3d2106 IY	17	#include <linux/vmalloc.h>
	18
	19	#include <xen/interface/xen.h>
	20	#include <xen/page.h>
	21	#include <xen/grant_table.h>
162e3717	22	#include <xen/xen.h>
8d3d2106	23
8d3d2106	24
162e3717 DV	25	static struct gnttab_vm_area {
	26	struct vm_struct *area;
	27	pte_t **ptes;
5dd63bf1	28	int idx;
b988b8ff	29	} gnttab_shared_vm_area, gnttab_status_vm_area;
162e3717 DV	30
	31	int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
	32	unsigned long max_nr_gframes,
	33	void **__shared)
8d3d2106	34	{
162e3717 DV	35	void shared = __shared;
	36	unsigned long addr;
	37	unsigned long i;
8d3d2106	38
162e3717 DV	39	if (shared == NULL)
162e3717 DV	40	*__shared = shared = gnttab_shared_vm_area.area->addr;
8d3d2106	41
162e3717 DV	42	addr = (unsigned long)shared;
	43
	44	for (i = 0; i < nr_gframes; i++) {
	45	set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
	46	mfn_pte(frames[i], PAGE_KERNEL));
	47	addr += PAGE_SIZE;
	48	}
85ff6acb	49
85ff6acb AL	50	return 0;
	51	}
	52
b988b8ff JG	53	int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
	54	unsigned long max_nr_gframes,
	55	grant_status_t **__shared)
	56	{
	57	grant_status_t shared = __shared;
	58	unsigned long addr;
	59	unsigned long i;
	60
	61	if (shared == NULL)
	62	*__shared = shared = gnttab_status_vm_area.area->addr;
	63
	64	addr = (unsigned long)shared;
	65
	66	for (i = 0; i < nr_gframes; i++) {
	67	set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
	68	mfn_pte(frames[i], PAGE_KERNEL));
	69	addr += PAGE_SIZE;
	70	}
	71
	72	return 0;
	73	}
	74
162e3717	75	void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
8d3d2106	76	{
b988b8ff	77	pte_t **ptes;
162e3717 DV	78	unsigned long addr;
162e3717 DV	79	unsigned long i;
8d3d2106	80
b988b8ff JG	81	if (shared == gnttab_status_vm_area.area->addr)
	82	ptes = gnttab_status_vm_area.ptes;
	83	else
	84	ptes = gnttab_shared_vm_area.ptes;
	85
162e3717 DV	86	addr = (unsigned long)shared;
	87
	88	for (i = 0; i < nr_gframes; i++) {
b988b8ff	89	set_pte_at(&init_mm, addr, ptes[i], __pte(0));
162e3717 DV	90	addr += PAGE_SIZE;
162e3717 DV	91	}
8d3d2106 IY	92	}
8d3d2106 IY	93
5dd63bf1 CH	94	static int gnttab_apply(pte_t pte, unsigned long addr, void data)
	95	{
	96	struct gnttab_vm_area *area = data;
	97
	98	area->ptes[area->idx++] = pte;
	99	return 0;
	100	}
	101
162e3717	102	static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
85ff6acb	103	{
4f0fbdf2	104	area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL);
162e3717 DV	105	if (area->ptes == NULL)
162e3717 DV	106	return -ENOMEM;
5dd63bf1 CH	107	area->area = get_vm_area(PAGE_SIZE * nr_frames, VM_IOREMAP);
	108	if (!area->area)
	109	goto out_free_ptes;
	110	if (apply_to_page_range(&init_mm, (unsigned long)area->area->addr,
	111	PAGE_SIZE * nr_frames, gnttab_apply, area))
	112	goto out_free_vm_area;
162e3717	113	return 0;
5dd63bf1 CH	114	out_free_vm_area:
	115	free_vm_area(area->area);
	116	out_free_ptes:
	117	kfree(area->ptes);
	118	return -ENOMEM;
85ff6acb AL	119	}
85ff6acb AL	120
b988b8ff	121	static void arch_gnttab_vfree(struct gnttab_vm_area *area)
162e3717	122	{
b988b8ff JG	123	free_vm_area(area->area);
	124	kfree(area->ptes);
	125	}
	126
	127	int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
	128	{
	129	int ret;
	130
162e3717 DV	131	if (!xen_pv_domain())
	132	return 0;
	133
b988b8ff JG	134	ret = arch_gnttab_valloc(&gnttab_shared_vm_area, nr_shared);
	135	if (ret < 0)
	136	return ret;
	137
	138	/*
	139	* Always allocate the space for the status frames in case
	140	* we're migrated to a host with V2 support.
	141	*/
	142	ret = arch_gnttab_valloc(&gnttab_status_vm_area, nr_status);
	143	if (ret < 0)
	144	goto err;
	145
	146	return 0;
	147	err:
	148	arch_gnttab_vfree(&gnttab_shared_vm_area);
	149	return -ENOMEM;
8d3d2106	150	}
162e3717	151
6926f6d6	152	#ifdef CONFIG_XEN_PVH
6926f6d6	153	#include <xen/events.h>
243848fc	154	#include <xen/xen-ops.h>
6926f6d6 KRW	155	static int __init xen_pvh_gnttab_setup(void)
	156	{
	157	if (!xen_pvh_domain())
	158	return -ENODEV;
	159
243848fc SZ	160	xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
	161
	162	return xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
	163	&xen_auto_xlat_grant_frames.vaddr,
	164	xen_auto_xlat_grant_frames.count);
6926f6d6 KRW	165	}
	166	/* Call it _before_ __gnttab_init as we need to initialize the
	167	* xen_auto_xlat_grant_frames first. */
	168	core_initcall(xen_pvh_gnttab_setup);
	169	#endif