Commit acba648d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'stable/for-linus-3.16-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fix from David Vrabel:
 "Fix BUG when trying to expand the grant table.  This seems to occur
  often during boot with Ubuntu 14.04 PV guests"

* tag 'stable/for-linus-3.16-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: safely map and unmap grant frames when in atomic context
parents d8772157 b7dd0e35
......@@ -51,3 +51,8 @@ int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
{
return -ENOSYS;
}
int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
{
return 0;
}
......@@ -36,99 +36,133 @@
#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>
#include <asm/pgtable.h>
static int map_pte_fn(pte_t *pte, struct page *pmd_page,
unsigned long addr, void *data)
static struct gnttab_vm_area {
struct vm_struct *area;
pte_t **ptes;
} 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)
{
unsigned long **frames = (unsigned long **)data;
void *shared = *__shared;
unsigned long addr;
unsigned long i;
set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
(*frames)++;
return 0;
}
if (shared == NULL)
*__shared = shared = gnttab_shared_vm_area.area->addr;
/*
* This function is used to map shared frames to store grant status. It is
* different from map_pte_fn above, the frames type here is uint64_t.
*/
static int map_pte_fn_status(pte_t *pte, struct page *pmd_page,
unsigned long addr, void *data)
{
uint64_t **frames = (uint64_t **)data;
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;
}
set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
(*frames)++;
return 0;
}
static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
unsigned long addr, void *data)
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;
}
set_pte_at(&init_mm, addr, pte, __pte(0));
return 0;
}
int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
unsigned long max_nr_gframes,
void **__shared)
void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
{
int rc;
void *shared = *__shared;
pte_t **ptes;
unsigned long addr;
unsigned long i;
if (shared == NULL) {
struct vm_struct *area =
alloc_vm_area(PAGE_SIZE * max_nr_gframes, NULL);
BUG_ON(area == NULL);
shared = area->addr;
*__shared = shared;
}
if (shared == gnttab_status_vm_area.area->addr)
ptes = gnttab_status_vm_area.ptes;
else
ptes = gnttab_shared_vm_area.ptes;
rc = apply_to_page_range(&init_mm, (unsigned long)shared,
PAGE_SIZE * nr_gframes,
map_pte_fn, &frames);
return rc;
addr = (unsigned long)shared;
for (i = 0; i < nr_gframes; i++) {
set_pte_at(&init_mm, addr, ptes[i], __pte(0));
addr += PAGE_SIZE;
}
}
int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
unsigned long max_nr_gframes,
grant_status_t **__shared)
static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
{
int rc;
grant_status_t *shared = *__shared;
area->ptes = kmalloc(sizeof(pte_t *) * nr_frames, GFP_KERNEL);
if (area->ptes == NULL)
return -ENOMEM;
if (shared == NULL) {
/* No need to pass in PTE as we are going to do it
* in apply_to_page_range anyhow. */
struct vm_struct *area =
alloc_vm_area(PAGE_SIZE * max_nr_gframes, NULL);
BUG_ON(area == NULL);
shared = area->addr;
*__shared = shared;
area->area = alloc_vm_area(PAGE_SIZE * nr_frames, area->ptes);
if (area->area == NULL) {
kfree(area->ptes);
return -ENOMEM;
}
rc = apply_to_page_range(&init_mm, (unsigned long)shared,
PAGE_SIZE * nr_gframes,
map_pte_fn_status, &frames);
return rc;
return 0;
}
void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
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)
{
apply_to_page_range(&init_mm, (unsigned long)shared,
PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);
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/balloon.h>
#include <xen/events.h>
#include <xen/xen.h>
#include <linux/slab.h>
static int __init xlated_setup_gnttab_pages(void)
{
......
......@@ -1195,18 +1195,20 @@ static int gnttab_expand(unsigned int req_entries)
int gnttab_init(void)
{
int i;
unsigned long max_nr_grant_frames;
unsigned int max_nr_glist_frames, nr_glist_frames;
unsigned int nr_init_grefs;
int ret;
gnttab_request_version();
max_nr_grant_frames = gnttab_max_grant_frames();
nr_grant_frames = 1;
/* Determine the maximum number of frames required for the
* grant reference free list on the current hypervisor.
*/
BUG_ON(grefs_per_grant_frame == 0);
max_nr_glist_frames = (gnttab_max_grant_frames() *
max_nr_glist_frames = (max_nr_grant_frames *
grefs_per_grant_frame / RPP);
gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *),
......@@ -1223,6 +1225,11 @@ int gnttab_init(void)
}
}
ret = arch_gnttab_init(max_nr_grant_frames,
nr_status_frames(max_nr_grant_frames));
if (ret < 0)
goto ini_nomem;
if (gnttab_setup() < 0) {
ret = -ENODEV;
goto ini_nomem;
......
......@@ -170,6 +170,7 @@ gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
unmap->dev_bus_addr = 0;
}
int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status);
int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes,
unsigned long max_nr_gframes,
void **__shared);
......
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