From bb92c177684aa0faad0b9cee0657c3da7a5d146a Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Fri, 1 Feb 2019 12:39:26 +0000 Subject: [PATCH] x86/mm: drop lXe_to_lYe invocations in map_pages_to_xen Map and unmap page tables where necessary. Signed-off-by: Wei Liu Signed-off-by: Hongyan Xia --- Changed since v2: - Fix a leak in mapping l2t. --- xen/arch/x86/mm.c | 41 ++++++++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 11 deletions(-) diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 00b4ac5f21..f6564651dc 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -5308,8 +5308,10 @@ int map_pages_to_xen( else { l2_pgentry_t *l2t; + mfn_t l2t_mfn = l3e_get_mfn(ol3e); + + l2t = map_xen_pagetable_new(l2t_mfn); - l2t = l3e_to_l2e(ol3e); for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) { ol2e = l2t[i]; @@ -5321,10 +5323,12 @@ int map_pages_to_xen( { unsigned int j; l1_pgentry_t *l1t; + mfn_t l1t_mfn = l2e_get_mfn(ol2e); - l1t = l2e_to_l1e(ol2e); + l1t = map_xen_pagetable_new(l1t_mfn); for ( j = 0; j < L1_PAGETABLE_ENTRIES; j++ ) flush_flags(l1e_get_flags(l1t[j])); + UNMAP_XEN_PAGETABLE_NEW(l1t); } } flush_area(virt, flush_flags); @@ -5333,9 +5337,10 @@ int map_pages_to_xen( ol2e = l2t[i]; if ( (l2e_get_flags(ol2e) & _PAGE_PRESENT) && !(l2e_get_flags(ol2e) & _PAGE_PSE) ) - free_xen_pagetable(l2e_to_l1e(ol2e)); + free_xen_pagetable_new(l2e_get_mfn(ol2e)); } - free_xen_pagetable(l2t); + UNMAP_XEN_PAGETABLE_NEW(l2t); + free_xen_pagetable_new(l2t_mfn); } } @@ -5440,12 +5445,14 @@ int map_pages_to_xen( else { l1_pgentry_t *l1t; + mfn_t l1t_mfn = l2e_get_mfn(ol2e); - l1t = l2e_to_l1e(ol2e); + l1t = map_xen_pagetable_new(l1t_mfn); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) flush_flags(l1e_get_flags(l1t[i])); flush_area(virt, flush_flags); - free_xen_pagetable(l1t); + UNMAP_XEN_PAGETABLE_NEW(l1t); + free_xen_pagetable_new(l1t_mfn); } } @@ -5459,12 +5466,14 @@ int map_pages_to_xen( /* Normal page mapping. */ if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) { + /* XXX This forces page table to be populated */ pl1e = virt_to_xen_l1e(virt); if ( pl1e == NULL ) { ASSERT(rc == -ENOMEM); goto out; } + UNMAP_XEN_PAGETABLE_NEW(pl1e); } else if ( l2e_get_flags(*pl2e) & _PAGE_PSE ) { @@ -5527,9 +5536,11 @@ int map_pages_to_xen( } } - pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(virt); + pl1e = map_xen_pagetable_new(l2e_get_mfn((*pl2e))); + pl1e += l1_table_offset(virt); ol1e = *pl1e; l1e_write_atomic(pl1e, l1e_from_mfn(mfn, flags)); + UNMAP_XEN_PAGETABLE_NEW(pl1e); if ( (l1e_get_flags(ol1e) & _PAGE_PRESENT) ) { unsigned int flush_flags = FLUSH_TLB | FLUSH_ORDER(0); @@ -5550,6 +5561,7 @@ int map_pages_to_xen( { unsigned long base_mfn; l1_pgentry_t *l1t; + mfn_t l1t_mfn; if ( locking ) spin_lock(&map_pgdir_lock); @@ -5573,12 +5585,15 @@ int map_pages_to_xen( goto check_l3; } - l1t = l2e_to_l1e(ol2e); + l1t_mfn = l2e_get_mfn(ol2e); + l1t = map_xen_pagetable_new(l1t_mfn); + base_mfn = l1e_get_pfn(l1t[0]) & ~(L1_PAGETABLE_ENTRIES - 1); for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) if ( (l1e_get_pfn(l1t[i]) != (base_mfn + i)) || (l1e_get_flags(l1t[i]) != flags) ) break; + UNMAP_XEN_PAGETABLE_NEW(l1t); if ( i == L1_PAGETABLE_ENTRIES ) { l2e_write_atomic(pl2e, l2e_from_pfn(base_mfn, @@ -5588,7 +5603,7 @@ int map_pages_to_xen( flush_area(virt - PAGE_SIZE, FLUSH_TLB_GLOBAL | FLUSH_ORDER(PAGETABLE_ORDER)); - free_xen_pagetable(l2e_to_l1e(ol2e)); + free_xen_pagetable_new(l1t_mfn); } else if ( locking ) spin_unlock(&map_pgdir_lock); @@ -5604,6 +5619,7 @@ int map_pages_to_xen( { unsigned long base_mfn; l2_pgentry_t *l2t; + mfn_t l2t_mfn; if ( locking ) spin_lock(&map_pgdir_lock); @@ -5621,7 +5637,9 @@ int map_pages_to_xen( goto end_of_loop; } - l2t = l3e_to_l2e(ol3e); + l2t_mfn = l3e_get_mfn(ol3e); + l2t = map_xen_pagetable_new(l2t_mfn); + base_mfn = l2e_get_pfn(l2t[0]) & ~(L2_PAGETABLE_ENTRIES * L1_PAGETABLE_ENTRIES - 1); for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ ) @@ -5629,6 +5647,7 @@ int map_pages_to_xen( (base_mfn + (i << PAGETABLE_ORDER))) || (l2e_get_flags(l2t[i]) != l1f_to_lNf(flags)) ) break; + UNMAP_XEN_PAGETABLE_NEW(l2t); if ( i == L2_PAGETABLE_ENTRIES ) { l3e_write_atomic(pl3e, l3e_from_pfn(base_mfn, @@ -5638,7 +5657,7 @@ int map_pages_to_xen( flush_area(virt - PAGE_SIZE, FLUSH_TLB_GLOBAL | FLUSH_ORDER(2*PAGETABLE_ORDER)); - free_xen_pagetable(l3e_to_l2e(ol3e)); + free_xen_pagetable_new(l2t_mfn); } else if ( locking ) spin_unlock(&map_pgdir_lock); -- 2.39.5