diff options
| -rw-r--r-- | arch/x86/include/asm/xen/page.h | 4 | ||||
| -rw-r--r-- | arch/x86/xen/p2m.c | 49 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 16 |
3 files changed, 60 insertions, 9 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 50f0a0f6bd6a..f25bdf238a33 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -42,8 +42,8 @@ extern unsigned int machine_to_phys_order; extern unsigned long get_phys_to_machine(unsigned long pfn); extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); -extern void m2p_add_override(unsigned long mfn, struct page *page); -extern void m2p_remove_override(struct page *page); +extern int m2p_add_override(unsigned long mfn, struct page *page); +extern int m2p_remove_override(struct page *page); extern struct page *m2p_find_override(unsigned long mfn); extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index b3b19d43b951..40d51225ff08 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -29,6 +29,7 @@ #include <linux/module.h> #include <linux/list.h> #include <linux/hash.h> +#include <linux/sched.h> #include <asm/cache.h> #include <asm/setup.h> @@ -404,34 +405,74 @@ static unsigned long mfn_hash(unsigned long mfn) } /* Add an MFN override for a particular page */ -void m2p_add_override(unsigned long mfn, struct page *page) +int m2p_add_override(unsigned long mfn, struct page *page) { unsigned long flags; - unsigned long pfn = page_to_pfn(page); + unsigned long pfn; + unsigned long address; + unsigned level; + pte_t *ptep = NULL; + + pfn = page_to_pfn(page); + if (!PageHighMem(page)) { + address = (unsigned long)__va(pfn << PAGE_SHIFT); + ptep = lookup_address(address, &level); + + if (WARN(ptep == NULL || level != PG_LEVEL_4K, + "m2p_add_override: pfn %lx not mapped", pfn)) + return -EINVAL; + } + page->private = mfn; page->index = pfn_to_mfn(pfn); __set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)); + if (!PageHighMem(page)) + /* Just zap old mapping for now */ + pte_clear(&init_mm, address, ptep); + spin_lock_irqsave(&m2p_override_lock, flags); list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]); spin_unlock_irqrestore(&m2p_override_lock, flags); + + return 0; } -void m2p_remove_override(struct page *page) +int m2p_remove_override(struct page *page) { unsigned long flags; unsigned long mfn; unsigned long pfn; + unsigned long address; + unsigned level; + pte_t *ptep = NULL; pfn = page_to_pfn(page); mfn = get_phys_to_machine(pfn); if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) - return; + return -EINVAL; + + if (!PageHighMem(page)) { + address = (unsigned long)__va(pfn << PAGE_SHIFT); + ptep = lookup_address(address, &level); + + if (WARN(ptep == NULL || level != PG_LEVEL_4K, + "m2p_remove_override: pfn %lx not mapped", pfn)) + return -EINVAL; + } spin_lock_irqsave(&m2p_override_lock, flags); list_del(&page->lru); spin_unlock_irqrestore(&m2p_override_lock, flags); __set_phys_to_machine(pfn, page->index); + + if (!PageHighMem(page)) + set_pte_at(&init_mm, address, ptep, + pfn_pte(pfn, PAGE_KERNEL)); + /* No tlb flush necessary because the caller already + * left the pte unmapped. */ + + return 0; } struct page *m2p_find_override(unsigned long mfn) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 1afd5690858c..9ef54ebc1194 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -455,6 +455,8 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, unsigned long mfn; ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); + if (ret) + return ret; for (i = 0; i < count; i++) { /* m2p override only supported for GNTMAP_contains_pte mappings */ @@ -463,7 +465,9 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + (map_ops[i].host_addr & ~PAGE_MASK)); mfn = pte_mfn(*pte); - m2p_add_override(mfn, pages[i]); + ret = m2p_add_override(mfn, pages[i]); + if (ret) + return ret; } return ret; @@ -476,8 +480,14 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, int i, ret; ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); - for (i = 0; i < count; i++) - m2p_remove_override(pages[i]); + if (ret) + return ret; + + for (i = 0; i < count; i++) { + ret = m2p_remove_override(pages[i]); + if (ret) + return ret; + } return ret; } |