158 lines
3.6 KiB
C
158 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR MIT
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/******************************************************************************
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* grant_table.c
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* x86 specific part
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*
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* Granting foreign access to our memory reservation.
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*
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* Copyright (c) 2005-2006, Christopher Clark
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* Copyright (c) 2004-2005, K A Fraser
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* Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
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* VA Linux Systems Japan. Split out x86 specific part.
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*/
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <xen/interface/xen.h>
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#include <xen/page.h>
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#include <xen/grant_table.h>
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#include <xen/xen.h>
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#include <asm/pgtable.h>
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static struct gnttab_vm_area {
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struct vm_struct *area;
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pte_t **ptes;
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} gnttab_shared_vm_area, gnttab_status_vm_area;
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int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
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unsigned long max_nr_gframes,
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void **__shared)
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{
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void *shared = *__shared;
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unsigned long addr;
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unsigned long i;
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if (shared == NULL)
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*__shared = shared = gnttab_shared_vm_area.area->addr;
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addr = (unsigned long)shared;
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for (i = 0; i < nr_gframes; i++) {
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set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
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mfn_pte(frames[i], PAGE_KERNEL));
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addr += PAGE_SIZE;
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}
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return 0;
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}
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int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
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unsigned long max_nr_gframes,
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grant_status_t **__shared)
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{
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grant_status_t *shared = *__shared;
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unsigned long addr;
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unsigned long i;
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if (shared == NULL)
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*__shared = shared = gnttab_status_vm_area.area->addr;
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addr = (unsigned long)shared;
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for (i = 0; i < nr_gframes; i++) {
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set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
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mfn_pte(frames[i], PAGE_KERNEL));
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addr += PAGE_SIZE;
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}
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return 0;
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}
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void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
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{
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pte_t **ptes;
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unsigned long addr;
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unsigned long i;
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if (shared == gnttab_status_vm_area.area->addr)
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ptes = gnttab_status_vm_area.ptes;
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else
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ptes = gnttab_shared_vm_area.ptes;
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addr = (unsigned long)shared;
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for (i = 0; i < nr_gframes; i++) {
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set_pte_at(&init_mm, addr, ptes[i], __pte(0));
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addr += PAGE_SIZE;
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}
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}
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static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
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{
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area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL);
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if (area->ptes == NULL)
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return -ENOMEM;
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area->area = alloc_vm_area(PAGE_SIZE * nr_frames, area->ptes);
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if (area->area == NULL) {
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kfree(area->ptes);
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return -ENOMEM;
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}
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return 0;
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}
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static void arch_gnttab_vfree(struct gnttab_vm_area *area)
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{
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free_vm_area(area->area);
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kfree(area->ptes);
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}
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int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
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{
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int ret;
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if (!xen_pv_domain())
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return 0;
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ret = arch_gnttab_valloc(&gnttab_shared_vm_area, nr_shared);
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if (ret < 0)
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return ret;
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/*
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* Always allocate the space for the status frames in case
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* we're migrated to a host with V2 support.
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*/
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ret = arch_gnttab_valloc(&gnttab_status_vm_area, nr_status);
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if (ret < 0)
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goto err;
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return 0;
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err:
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arch_gnttab_vfree(&gnttab_shared_vm_area);
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return -ENOMEM;
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}
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#ifdef CONFIG_XEN_PVH
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#include <xen/events.h>
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#include <xen/xen-ops.h>
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static int __init xen_pvh_gnttab_setup(void)
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{
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if (!xen_pvh_domain())
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return -ENODEV;
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xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
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return xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
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&xen_auto_xlat_grant_frames.vaddr,
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xen_auto_xlat_grant_frames.count);
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}
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/* Call it _before_ __gnttab_init as we need to initialize the
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* xen_auto_xlat_grant_frames first. */
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core_initcall(xen_pvh_gnttab_setup);
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#endif
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