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authorLinus Torvalds <torvalds@linux-foundation.org>2014-07-30 09:00:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-07-30 09:00:20 -0700
commitacba648dca67c6a224991a9e9f935b2bdec8dc17 (patch)
tree2c9a08e4ae279850ac8e47010401be5095fdb957
parentd8772157ef7b5f4fe208f3e8da7b9c6800495698 (diff)
parentb7dd0e350e0bd4c0fddcc9b8958342700b00b168 (diff)
downloadlinux-acba648dca67c6a224991a9e9f935b2bdec8dc17.tar.gz
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
-rw-r--r--arch/arm/xen/grant-table.c5
-rw-r--r--arch/x86/xen/grant-table.c148
-rw-r--r--drivers/xen/grant-table.c9
-rw-r--r--include/xen/grant_table.h1
4 files changed, 105 insertions, 58 deletions
diff --git a/arch/arm/xen/grant-table.c b/arch/arm/xen/grant-table.c
index 859a9bb002d..91cf08ba1e9 100644
--- a/arch/arm/xen/grant-table.c
+++ b/arch/arm/xen/grant-table.c
@@ -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;
+}
diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
index c9858358858..ebfa9b2c871 100644
--- a/arch/x86/xen/grant-table.c
+++ b/arch/x86/xen/grant-table.c
@@ -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)
{
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 5d4de88fe5b..eeba7544f0c 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -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;
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index a5af2a26d94..5c1aba154b6 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -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);