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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-07-30 16:00:20 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-07-30 16:00:20 (GMT) |
commit | acba648dca67c6a224991a9e9f935b2bdec8dc17 (patch) | |
tree | 2c9a08e4ae279850ac8e47010401be5095fdb957 | |
parent | d8772157ef7b5f4fe208f3e8da7b9c6800495698 (diff) | |
parent | b7dd0e350e0bd4c0fddcc9b8958342700b00b168 (diff) | |
download | linux-acba648dca67c6a224991a9e9f935b2bdec8dc17.tar.xz |
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.c | 5 | ||||
-rw-r--r-- | arch/x86/xen/grant-table.c | 148 | ||||
-rw-r--r-- | drivers/xen/grant-table.c | 9 | ||||
-rw-r--r-- | include/xen/grant_table.h | 1 |
4 files changed, 105 insertions, 58 deletions
diff --git a/arch/arm/xen/grant-table.c b/arch/arm/xen/grant-table.c index 859a9bb..91cf08b 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 c985835..ebfa9b2 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 5d4de88..eeba754 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 a5af2a2..5c1aba1 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); |