diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index b8bc82953c..9024ab258b 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -5541,6 +5541,8 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) if ( l3e_get_flags(*pl3e) & _PAGE_PSE ) { + l2_pgentry_t *l2t; + if ( l2_table_offset(v) == 0 && l1_table_offset(v) == 0 && ((e - v) >= (1UL << L3_PAGETABLE_SHIFT)) ) @@ -5556,11 +5558,11 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) } /* PAGE1GB: shatter the superpage and fall through. */ - pl2e = alloc_xen_pagetable(); - if ( !pl2e ) + l2t = alloc_xen_pagetable(); + if ( !l2t ) return -ENOMEM; for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) - l2e_write(pl2e + i, + l2e_write(l2t + i, l2e_from_pfn(l3e_get_pfn(*pl3e) + (i << PAGETABLE_ORDER), l3e_get_flags(*pl3e))); @@ -5569,14 +5571,14 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) if ( (l3e_get_flags(*pl3e) & _PAGE_PRESENT) && (l3e_get_flags(*pl3e) & _PAGE_PSE) ) { - l3e_write_atomic(pl3e, l3e_from_mfn(virt_to_mfn(pl2e), + l3e_write_atomic(pl3e, l3e_from_mfn(virt_to_mfn(l2t), __PAGE_HYPERVISOR)); - pl2e = NULL; + l2t = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); - if ( pl2e ) - free_xen_pagetable(pl2e); + if ( l2t ) + free_xen_pagetable(l2t); } /* @@ -5610,12 +5612,14 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) } else { + l1_pgentry_t *l1t; + /* PSE: shatter the superpage and try again. */ - pl1e = alloc_xen_pagetable(); - if ( !pl1e ) + l1t = alloc_xen_pagetable(); + if ( !l1t ) return -ENOMEM; for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) - l1e_write(&pl1e[i], + l1e_write(&l1t[i], l1e_from_pfn(l2e_get_pfn(*pl2e) + i, l2e_get_flags(*pl2e) & ~_PAGE_PSE)); if ( locking ) @@ -5623,19 +5627,19 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) if ( (l2e_get_flags(*pl2e) & _PAGE_PRESENT) && (l2e_get_flags(*pl2e) & _PAGE_PSE) ) { - l2e_write_atomic(pl2e, l2e_from_mfn(virt_to_mfn(pl1e), + l2e_write_atomic(pl2e, l2e_from_mfn(virt_to_mfn(l1t), __PAGE_HYPERVISOR)); - pl1e = NULL; + l1t = NULL; } if ( locking ) spin_unlock(&map_pgdir_lock); - if ( pl1e ) - free_xen_pagetable(pl1e); + if ( l1t ) + free_xen_pagetable(l1t); } } else { - l1_pgentry_t nl1e; + l1_pgentry_t nl1e, *l1t; /* * Ordinary 4kB mapping: The L2 entry has been verified to be @@ -5682,9 +5686,9 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) continue; } - pl1e = l2e_to_l1e(*pl2e); + l1t = l2e_to_l1e(*pl2e); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) - if ( l1e_get_intpte(pl1e[i]) != 0 ) + if ( l1e_get_intpte(l1t[i]) != 0 ) break; if ( i == L1_PAGETABLE_ENTRIES ) { @@ -5693,7 +5697,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) if ( locking ) spin_unlock(&map_pgdir_lock); flush_area(NULL, FLUSH_TLB_GLOBAL); /* flush before free */ - free_xen_pagetable(pl1e); + free_xen_pagetable(l1t); } else if ( locking ) spin_unlock(&map_pgdir_lock); @@ -5722,21 +5726,25 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) continue; } - pl2e = l3e_to_l2e(*pl3e); - for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) - if ( l2e_get_intpte(pl2e[i]) != 0 ) - break; - if ( i == L2_PAGETABLE_ENTRIES ) { - /* Empty: zap the L3E and free the L2 page. */ - l3e_write_atomic(pl3e, l3e_empty()); - if ( locking ) + l2_pgentry_t *l2t; + + l2t = l3e_to_l2e(*pl3e); + for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) + if ( l2e_get_intpte(l2t[i]) != 0 ) + break; + if ( i == L2_PAGETABLE_ENTRIES ) + { + /* Empty: zap the L3E and free the L2 page. */ + l3e_write_atomic(pl3e, l3e_empty()); + if ( locking ) + spin_unlock(&map_pgdir_lock); + flush_area(NULL, FLUSH_TLB_GLOBAL); /* flush before free */ + free_xen_pagetable(l2t); + } + else if ( locking ) spin_unlock(&map_pgdir_lock); - flush_area(NULL, FLUSH_TLB_GLOBAL); /* flush before free */ - free_xen_pagetable(pl2e); } - else if ( locking ) - spin_unlock(&map_pgdir_lock); } flush_area(NULL, FLUSH_TLB_GLOBAL);