From: Hongyan Xia <hx242@xen.org>
To: xen-devel@lists.xenproject.org
Cc: jgrall@amazon.com, "Jan Beulich" <jbeulich@suse.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>
Subject: [PATCH v10 02/13] x86/mm: switch to new APIs in map_pages_to_xen
Date: Wed, 21 Apr 2021 15:15:30 +0100 [thread overview]
Message-ID: <f8a422d4da4a93cd9b2f788c4594a1efe82bf389.1619014052.git.hongyxia@amazon.com> (raw)
In-Reply-To: <cover.1619014052.git.hongyxia@amazon.com>
In-Reply-To: <cover.1619014052.git.hongyxia@amazon.com>
From: Wei Liu <wei.liu2@citrix.com>
Page tables allocated in that function should be mapped and unmapped
now.
Take the opportunity to avoid a potential double map in
map_pages_to_xen() by initialising pl1e to NULL and only map it if it
was not mapped earlier.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Hongyan Xia <hongyxia@amazon.com>
---
Changed in v10:
- avoid a potential double map.
- drop RoB due to this change.
---
xen/arch/x86/mm.c | 64 ++++++++++++++++++++++++++++-------------------
1 file changed, 38 insertions(+), 26 deletions(-)
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 5944ef19dc50..8a68da26f45f 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5215,7 +5215,7 @@ int map_pages_to_xen(
}
else
{
- l2_pgentry_t *l2t = l3e_to_l2e(ol3e);
+ l2_pgentry_t *l2t = map_l2t_from_l3e(ol3e);
for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
{
@@ -5227,10 +5227,11 @@ int map_pages_to_xen(
else
{
unsigned int j;
- const l1_pgentry_t *l1t = l2e_to_l1e(ol2e);
+ const l1_pgentry_t *l1t = map_l1t_from_l2e(ol2e);
for ( j = 0; j < L1_PAGETABLE_ENTRIES; j++ )
flush_flags(l1e_get_flags(l1t[j]));
+ unmap_domain_page(l1t);
}
}
flush_area(virt, flush_flags);
@@ -5239,9 +5240,10 @@ 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_domain_page(l2t);
+ free_xen_pagetable_new(l3e_get_mfn(ol3e));
}
}
@@ -5258,6 +5260,7 @@ int map_pages_to_xen(
unsigned int flush_flags =
FLUSH_TLB | FLUSH_ORDER(2 * PAGETABLE_ORDER);
l2_pgentry_t *l2t;
+ mfn_t l2mfn;
/* Skip this PTE if there is no change. */
if ( ((l3e_get_pfn(ol3e) & ~(L2_PAGETABLE_ENTRIES *
@@ -5279,15 +5282,17 @@ int map_pages_to_xen(
continue;
}
- l2t = alloc_xen_pagetable();
- if ( l2t == NULL )
+ l2mfn = alloc_xen_pagetable_new();
+ if ( mfn_eq(l2mfn, INVALID_MFN) )
goto out;
+ l2t = map_domain_page(l2mfn);
for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
l2e_write(l2t + i,
l2e_from_pfn(l3e_get_pfn(ol3e) +
(i << PAGETABLE_ORDER),
l3e_get_flags(ol3e)));
+ UNMAP_DOMAIN_PAGE(l2t);
if ( l3e_get_flags(ol3e) & _PAGE_GLOBAL )
flush_flags |= FLUSH_TLB_GLOBAL;
@@ -5297,15 +5302,15 @@ int map_pages_to_xen(
if ( (l3e_get_flags(*pl3e) & _PAGE_PRESENT) &&
(l3e_get_flags(*pl3e) & _PAGE_PSE) )
{
- l3e_write_atomic(pl3e, l3e_from_mfn(virt_to_mfn(l2t),
- __PAGE_HYPERVISOR));
- l2t = NULL;
+ l3e_write_atomic(pl3e,
+ l3e_from_mfn(l2mfn, __PAGE_HYPERVISOR));
+ l2mfn = INVALID_MFN;
}
if ( locking )
spin_unlock(&map_pgdir_lock);
flush_area(virt, flush_flags);
- if ( l2t )
- free_xen_pagetable(l2t);
+
+ free_xen_pagetable_new(l2mfn);
}
pl2e = virt_to_xen_l2e(virt);
@@ -5333,12 +5338,13 @@ int map_pages_to_xen(
}
else
{
- l1_pgentry_t *l1t = l2e_to_l1e(ol2e);
+ l1_pgentry_t *l1t = map_l1t_from_l2e(ol2e);
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_domain_page(l1t);
+ free_xen_pagetable_new(l2e_get_mfn(ol2e));
}
}
@@ -5349,20 +5355,20 @@ int map_pages_to_xen(
}
else
{
+ pl1e = NULL;
/* Normal page mapping. */
if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) )
{
pl1e = virt_to_xen_l1e(virt);
if ( pl1e == NULL )
goto out;
-
- UNMAP_DOMAIN_PAGE(pl1e);
}
else if ( l2e_get_flags(*pl2e) & _PAGE_PSE )
{
unsigned int flush_flags =
FLUSH_TLB | FLUSH_ORDER(PAGETABLE_ORDER);
l1_pgentry_t *l1t;
+ mfn_t l1mfn;
/* Skip this PTE if there is no change. */
if ( (((l2e_get_pfn(*pl2e) & ~(L1_PAGETABLE_ENTRIES - 1)) +
@@ -5382,14 +5388,16 @@ int map_pages_to_xen(
goto check_l3;
}
- l1t = alloc_xen_pagetable();
- if ( l1t == NULL )
+ l1mfn = alloc_xen_pagetable_new();
+ if ( mfn_eq(l1mfn, INVALID_MFN) )
goto out;
+ l1t = map_domain_page(l1mfn);
for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
l1e_write(&l1t[i],
l1e_from_pfn(l2e_get_pfn(*pl2e) + i,
lNf_to_l1f(l2e_get_flags(*pl2e))));
+ UNMAP_DOMAIN_PAGE(l1t);
if ( l2e_get_flags(*pl2e) & _PAGE_GLOBAL )
flush_flags |= FLUSH_TLB_GLOBAL;
@@ -5399,20 +5407,22 @@ int map_pages_to_xen(
if ( (l2e_get_flags(*pl2e) & _PAGE_PRESENT) &&
(l2e_get_flags(*pl2e) & _PAGE_PSE) )
{
- l2e_write_atomic(pl2e, l2e_from_mfn(virt_to_mfn(l1t),
+ l2e_write_atomic(pl2e, l2e_from_mfn(l1mfn,
__PAGE_HYPERVISOR));
- l1t = NULL;
+ l1mfn = INVALID_MFN;
}
if ( locking )
spin_unlock(&map_pgdir_lock);
flush_area(virt, flush_flags);
- if ( l1t )
- free_xen_pagetable(l1t);
+
+ free_xen_pagetable_new(l1mfn);
}
- pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(virt);
+ if ( !pl1e )
+ pl1e = map_l1t_from_l2e(*pl2e) + l1_table_offset(virt);
ol1e = *pl1e;
l1e_write_atomic(pl1e, l1e_from_mfn(mfn, flags));
+ UNMAP_DOMAIN_PAGE(pl1e);
if ( (l1e_get_flags(ol1e) & _PAGE_PRESENT) )
{
unsigned int flush_flags = FLUSH_TLB | FLUSH_ORDER(0);
@@ -5456,12 +5466,13 @@ int map_pages_to_xen(
goto check_l3;
}
- l1t = l2e_to_l1e(ol2e);
+ l1t = map_l1t_from_l2e(ol2e);
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_DOMAIN_PAGE(l1t);
if ( i == L1_PAGETABLE_ENTRIES )
{
l2e_write_atomic(pl2e, l2e_from_pfn(base_mfn,
@@ -5471,7 +5482,7 @@ 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(l2e_get_mfn(ol2e));
}
else if ( locking )
spin_unlock(&map_pgdir_lock);
@@ -5504,7 +5515,7 @@ int map_pages_to_xen(
continue;
}
- l2t = l3e_to_l2e(ol3e);
+ l2t = map_l2t_from_l3e(ol3e);
base_mfn = l2e_get_pfn(l2t[0]) & ~(L2_PAGETABLE_ENTRIES *
L1_PAGETABLE_ENTRIES - 1);
for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
@@ -5512,6 +5523,7 @@ int map_pages_to_xen(
(base_mfn + (i << PAGETABLE_ORDER))) ||
(l2e_get_flags(l2t[i]) != l1f_to_lNf(flags)) )
break;
+ UNMAP_DOMAIN_PAGE(l2t);
if ( i == L2_PAGETABLE_ENTRIES )
{
l3e_write_atomic(pl3e, l3e_from_pfn(base_mfn,
@@ -5521,7 +5533,7 @@ 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(l3e_get_mfn(ol3e));
}
else if ( locking )
spin_unlock(&map_pgdir_lock);
--
2.23.4
next prev parent reply other threads:[~2021-04-21 14:16 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 14:15 [PATCH v10 00/13] switch to domheap for Xen page tables Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 01/13] x86/mm: rewrite virt_to_xen_l*e Hongyan Xia
2021-04-22 11:54 ` Jan Beulich
2021-04-21 14:15 ` Hongyan Xia [this message]
2021-04-22 12:01 ` [PATCH v10 02/13] x86/mm: switch to new APIs in map_pages_to_xen Jan Beulich
2021-04-21 14:15 ` [PATCH v10 03/13] x86/mm: switch to new APIs in modify_xen_mappings Hongyan Xia
2021-04-22 13:10 ` Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 04/13] x86_64/mm: introduce pl2e in paging_init Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 05/13] x86_64/mm: switch to new APIs " Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 06/13] x86_64/mm: switch to new APIs in setup_m2p_table Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 07/13] efi: use new page table APIs in copy_mapping Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 08/13] efi: switch to new APIs in EFI code Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 09/13] x86/smpboot: add exit path for clone_mapping() Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 10/13] x86/smpboot: switch clone_mapping() to new APIs Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 11/13] x86/mm: drop old page table APIs Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 12/13] x86: switch to use domheap page for page tables Hongyan Xia
2021-04-21 14:15 ` [PATCH v10 13/13] x86/mm: drop _new suffix for page table APIs Hongyan Xia
2021-04-22 16:21 ` [PATCH v10 00/13] switch to domheap for Xen page tables Andrew Cooper
2021-04-22 16:35 ` Hongyan Xia
2021-04-22 17:27 ` Julien Grall
2021-04-22 17:28 ` Andrew Cooper
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