diff options
| -rw-r--r-- | arch/x86/include/asm/xen/page.h | 5 | ||||
| -rw-r--r-- | arch/x86/xen/p2m.c | 10 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 31 |
3 files changed, 31 insertions, 15 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index c61934f..64a619d 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -47,8 +47,9 @@ extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); extern unsigned long set_phys_range_identity(unsigned long pfn_s, unsigned long pfn_e); -extern int m2p_add_override(unsigned long mfn, struct page *page); -extern int m2p_remove_override(struct page *page); +extern int m2p_add_override(unsigned long mfn, struct page *page, + bool clear_pte); +extern int m2p_remove_override(struct page *page, bool clear_pte); 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 141eb0d..2d2b32a 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -650,7 +650,7 @@ static unsigned long mfn_hash(unsigned long mfn) } /* Add an MFN override for a particular page */ -int m2p_add_override(unsigned long mfn, struct page *page) +int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte) { unsigned long flags; unsigned long pfn; @@ -662,7 +662,6 @@ int m2p_add_override(unsigned long mfn, struct page *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; @@ -674,10 +673,9 @@ int m2p_add_override(unsigned long mfn, struct page *page) if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) return -ENOMEM; - if (!PageHighMem(page)) + if (clear_pte && !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); @@ -685,7 +683,7 @@ int m2p_add_override(unsigned long mfn, struct page *page) return 0; } -int m2p_remove_override(struct page *page) +int m2p_remove_override(struct page *page, bool clear_pte) { unsigned long flags; unsigned long mfn; @@ -713,7 +711,7 @@ int m2p_remove_override(struct page *page) spin_unlock_irqrestore(&m2p_override_lock, flags); set_phys_to_machine(pfn, page->index); - if (!PageHighMem(page)) + if (clear_pte && !PageHighMem(page)) set_pte_at(&init_mm, address, ptep, pfn_pte(pfn, PAGE_KERNEL)); /* No tlb flush necessary because the caller already diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 3745a31..fd725cd 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -466,13 +466,30 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, if (map_ops[i].status) continue; - /* m2p override only supported for GNTMAP_contains_pte mappings */ - if (!(map_ops[i].flags & GNTMAP_contains_pte)) - continue; - pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + + if (map_ops[i].flags & GNTMAP_contains_pte) { + pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + (map_ops[i].host_addr & ~PAGE_MASK)); - mfn = pte_mfn(*pte); - ret = m2p_add_override(mfn, pages[i]); + mfn = pte_mfn(*pte); + } else { + /* If you really wanted to do this: + * mfn = PFN_DOWN(map_ops[i].dev_bus_addr); + * + * The reason we do not implement it is b/c on the + * unmap path (gnttab_unmap_refs) we have no means of + * checking whether the page is !GNTMAP_contains_pte. + * + * That is without some extra data-structure to carry + * the struct page, bool clear_pte, and list_head next + * tuples and deal with allocation/delallocation, etc. + * + * The users of this API set the GNTMAP_contains_pte + * flag so lets just return not supported until it + * becomes neccessary to implement. + */ + return -EOPNOTSUPP; + } + ret = m2p_add_override(mfn, pages[i], + map_ops[i].flags & GNTMAP_contains_pte); if (ret) return ret; } @@ -494,7 +511,7 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, return ret; for (i = 0; i < count; i++) { - ret = m2p_remove_override(pages[i]); + ret = m2p_remove_override(pages[i], true /* clear the PTE */); if (ret) return ret; } |