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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] Fixes for x86/64 writable pagetables, including SMP
# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID a1f7e01b0990a378584e718e6d48eac38824fdb9
# Parent 663f0fb1e444239bae280d2867b80cea3f4bf7c1
Fixes for x86/64 writable pagetables, including SMP
guest support.
NOTE: I removed some x86/64 specific tests from get_page_type().
I can't see what good could come of them -- if they caused
things to work then I'm pretty sure there must be some underlying
bug that is what ought to be fixed.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
diff -r 663f0fb1e444 -r a1f7e01b0990 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Tue Aug 9 09:34:06 2005
+++ b/xen/arch/x86/mm.c Tue Aug 9 10:42:51 2005
@@ -138,7 +138,7 @@
* Returns the current foreign domain; defaults to the currently-executing
* domain if a foreign override hasn't been specified.
*/
-#define FOREIGNDOM (percpu_info[smp_processor_id()].foreign ? :
current->domain)
+#define FOREIGNDOM (percpu_info[smp_processor_id()].foreign ?: current->domain)
/* Private domain structs for DOMID_XEN and DOMID_IO. */
static struct domain *dom_xen, *dom_io;
@@ -903,7 +903,8 @@
return 1;
ASSERT(!shadow_mode_refcounts(d));
- for ( i = 0; i < L4_PAGETABLE_ENTRIES; i++ ) {
+ for ( i = 0; i < L4_PAGETABLE_ENTRIES; i++ )
+ {
if ( !l3_backptr(&vaddr, i, type) )
goto fail;
@@ -1122,10 +1123,9 @@
return 0;
}
}
- else
- {
- if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e)) )
- return 0;
+ else if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e)) )
+ {
+ return 0;
}
put_page_from_l2e(ol2e, pfn);
@@ -1188,23 +1188,16 @@
if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e)) )
{
- BUG_ON(!create_pae_xen_mappings(pl3e));
put_page_from_l3e(nl3e, pfn);
return 0;
}
-
- put_page_from_l3e(ol3e, pfn);
- return 1;
- }
- else
- {
- if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e)) )
- {
- BUG_ON(!create_pae_xen_mappings(pl3e));
- return 0;
- }
- }
-
+ }
+ else if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e)) )
+ {
+ return 0;
+ }
+
+ BUG_ON(!create_pae_xen_mappings(pl3e));
put_page_from_l3e(ol3e, pfn);
return 1;
}
@@ -1254,11 +1247,10 @@
return 0;
}
}
- else
- {
- if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e)) )
- return 0;
- }
+ else if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e)) )
+ {
+ return 0;
+ }
put_page_from_l4e(ol4e, pfn);
return 1;
@@ -1409,11 +1401,7 @@
}
else if ( unlikely((x & PGT_count_mask) == 0) )
{
-#ifdef CONFIG_X86_64
- if ( (x & (PGT_type_mask|PGT_va_mask)) != (type & ~PGT_va_mask))
-#else
if ( (x & (PGT_type_mask|PGT_va_mask)) != type )
-#endif
{
if ( (x & PGT_type_mask) != (type & PGT_type_mask) )
{
@@ -1445,17 +1433,14 @@
}
else
{
-#ifdef CONFIG_X86_64
- if ( unlikely((x & (PGT_type_mask|PGT_va_mask)) != (type &
~PGT_va_mask)) )
-#else
if ( unlikely((x & (PGT_type_mask|PGT_va_mask)) != type) )
-#endif
{
if ( unlikely((x & PGT_type_mask) != (type & PGT_type_mask) ) )
{
if ( ((x & PGT_type_mask) != PGT_l2_page_table) ||
((type & PGT_type_mask) != PGT_l1_page_table) )
- MEM_LOG("Bad type (saw %" PRtype_info "!= exp %"
PRtype_info ") for pfn %lx",
+ MEM_LOG("Bad type (saw %" PRtype_info
+ "!= exp %" PRtype_info ") for pfn %lx",
x, type, page_to_pfn(page));
return 0;
}
@@ -1718,9 +1703,6 @@
type = PGT_l1_page_table | PGT_va_mutable;
pin_page:
-#if CONFIG_PAGING_LEVELS >= 4
- type |= PGT_va_mutable;
-#endif
if ( shadow_mode_refcounts(FOREIGNDOM) )
type = PGT_writable_page;
@@ -1744,16 +1726,16 @@
#ifndef CONFIG_X86_PAE /* Unsafe on PAE because of Xen-private mappings. */
case MMUEXT_PIN_L2_TABLE:
- type = PGT_l2_page_table;
+ type = PGT_l2_page_table | PGT_va_mutable;
goto pin_page;
#endif
case MMUEXT_PIN_L3_TABLE:
- type = PGT_l3_page_table;
+ type = PGT_l3_page_table | PGT_va_mutable;
goto pin_page;
case MMUEXT_PIN_L4_TABLE:
- type = PGT_l4_page_table;
+ type = PGT_l4_page_table | PGT_va_mutable;
goto pin_page;
case MMUEXT_UNPIN_TABLE:
@@ -1946,9 +1928,9 @@
unlikely(_nd != _d) )
{
MEM_LOG("Bad page values %lx: ed=%p(%u), sd=%p,"
- " caf=%08x, taf=%" PRtype_info "\n",
page_to_pfn(page),
- d, d->domain_id, unpickle_domptr(_nd), x,
- page->u.inuse.type_info);
+ " caf=%08x, taf=%" PRtype_info "\n",
+ page_to_pfn(page), d, d->domain_id,
+ unpickle_domptr(_nd), x, page->u.inuse.type_info);
okay = 0;
goto reassign_fail;
}
@@ -2111,7 +2093,8 @@
l1e = l1e_from_intpte(req.val);
okay = mod_l1_entry(va, l1e);
if ( okay && unlikely(shadow_mode_enabled(d)) )
- shadow_l1_normal_pt_update(d, req.ptr, l1e,
&sh_mapcache);
+ shadow_l1_normal_pt_update(
+ d, req.ptr, l1e, &sh_mapcache);
put_page_type(page);
}
break;
@@ -2124,9 +2107,11 @@
/* FIXME: doesn't work with PAE */
l2e = l2e_from_intpte(req.val);
- okay = mod_l2_entry((l2_pgentry_t *)va, l2e, mfn,
type_info);
+ okay = mod_l2_entry(
+ (l2_pgentry_t *)va, l2e, mfn, type_info);
if ( okay && unlikely(shadow_mode_enabled(d)) )
- shadow_l2_normal_pt_update(d, req.ptr, l2e,
&sh_mapcache);
+ shadow_l2_normal_pt_update(
+ d, req.ptr, l2e, &sh_mapcache);
put_page_type(page);
}
break;
@@ -2142,7 +2127,8 @@
l3e = l3e_from_intpte(req.val);
okay = mod_l3_entry(va, l3e, mfn, type_info);
if ( okay && unlikely(shadow_mode_enabled(d)) )
- shadow_l3_normal_pt_update(d, req.ptr, l3e,
&sh_mapcache);
+ shadow_l3_normal_pt_update(
+ d, req.ptr, l3e, &sh_mapcache);
put_page_type(page);
}
break;
@@ -2158,7 +2144,8 @@
l4e = l4e_from_intpte(req.val);
okay = mod_l4_entry(va, l4e, mfn, type_info);
if ( okay && unlikely(shadow_mode_enabled(d)) )
- shadow_l4_normal_pt_update(d, req.ptr, l4e,
&sh_mapcache);
+ shadow_l4_normal_pt_update(
+ d, req.ptr, l4e, &sh_mapcache);
put_page_type(page);
}
break;
@@ -2205,7 +2192,8 @@
if ( unlikely(shadow_mode_translate(FOREIGNDOM) && IS_PRIV(d)) )
{
shadow_lock(FOREIGNDOM);
- printk("privileged guest dom%d requests pfn=%lx to map mfn=%lx
for dom%d\n",
+ printk("privileged guest dom%d requests pfn=%lx to "
+ "map mfn=%lx for dom%d\n",
d->domain_id, gpfn, mfn, FOREIGNDOM->domain_id);
set_machinetophys(mfn, gpfn);
set_p2m_entry(FOREIGNDOM, gpfn, mfn, &sh_mapcache, &mapcache);
@@ -2629,17 +2617,11 @@
#endif
/* Re-validate a given p.t. page, given its prior snapshot */
-int revalidate_l1(struct domain *d, l1_pgentry_t *l1page, l1_pgentry_t
*snapshot)
+int revalidate_l1(
+ struct domain *d, l1_pgentry_t *l1page, l1_pgentry_t *snapshot)
{
l1_pgentry_t ol1e, nl1e;
int modified = 0, i;
-
-#if 0
- if ( d->domain_id )
- printk("%s: l1page mfn=%lx snapshot mfn=%lx\n", __func__,
- l1e_get_pfn(linear_pg_table[l1_linear_offset((unsigned
long)l1page)]),
- l1e_get_pfn(linear_pg_table[l1_linear_offset((unsigned
long)snapshot)]));
-#endif
for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
{
@@ -2690,9 +2672,9 @@
l1_pgentry_t *pl1e;
l2_pgentry_t *pl2e;
unsigned int modified;
-#if defined(__x86_64__)
+
+#ifdef CONFIG_X86_64
struct vcpu *v = current;
- /* If in user mode, switch to kernel mode just to read LDT mapping. */
extern void toggle_guest_mode(struct vcpu *);
int user_mode = !(v->arch.flags & TF_kernel_mode);
#endif
@@ -2700,8 +2682,10 @@
ASSERT(!shadow_mode_enabled(d));
if ( unlikely(d->arch.ptwr[which].vcpu != current) )
- write_ptbase(d->arch.ptwr[which].vcpu);
- else
+ /* Don't use write_ptbase: it may switch to guest_user on x86/64! */
+ write_cr3(pagetable_get_paddr(
+ d->arch.ptwr[which].vcpu->arch.guest_table));
+ else
TOGGLE_MODE();
l1va = d->arch.ptwr[which].l1va;
@@ -2803,7 +2787,7 @@
/* Align address; read full word. */
addr &= ~(sizeof(physaddr_t)-1);
if ( (rc = x86_emulate_read_std(addr, (unsigned long *)&full,
- sizeof(physaddr_t))) )
+ sizeof(physaddr_t))) )
return rc;
/* Mask out bits provided by caller. */
full &= ~((((physaddr_t)1 << (bytes*8)) - 1) << (offset*8));
@@ -2829,7 +2813,8 @@
((page->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table) ||
(page_get_owner(page) != d) )
{
- MEM_LOG("ptwr_emulate: Page is mistyped or bad pte (%lx, %"
PRtype_info ")\n",
+ MEM_LOG("ptwr_emulate: Page is mistyped or bad pte "
+ "(%lx, %" PRtype_info ")\n",
l1e_get_pfn(pte), page->u.inuse.type_info);
return X86EMUL_UNHANDLEABLE;
}
@@ -2902,42 +2887,13 @@
.cmpxchg8b_emulated = ptwr_emulated_cmpxchg8b
};
-#if defined(__x86_64__)
-/*
- * Returns zero on if mapped, or -1 otherwise
- */
-static int __not_mapped(l2_pgentry_t *pl2e)
-{
- unsigned long page = read_cr3();
-
- page &= PAGE_MASK;
- page = ((unsigned long *) __va(page))[l4_table_offset((unsigned
long)pl2e)];
- if ( !(page & _PAGE_PRESENT) )
- return -1;
-
- page &= PAGE_MASK;
- page = ((unsigned long *) __va(page))[l3_table_offset((unsigned
long)pl2e)];
- if ( !(page & _PAGE_PRESENT) )
- return -1;
-
- page &= PAGE_MASK;
- page = ((unsigned long *) __va(page))[l2_table_offset((unsigned
long)pl2e)];
- if ( !(page & _PAGE_PRESENT) )
- return -1;
-
- return 0;
-}
-#else
-#define __not_mapped(p) (0)
-#endif
-
/* Write page fault handler: check if guest is trying to modify a PTE. */
int ptwr_do_page_fault(struct domain *d, unsigned long addr)
{
unsigned long pfn;
struct pfn_info *page;
l1_pgentry_t pte;
- l2_pgentry_t *pl2e;
+ l2_pgentry_t *pl2e, l2e;
int which;
unsigned long l2_idx;
@@ -2984,10 +2940,7 @@
pl2e = &__linear_l2_table[l2_idx];
which = PTWR_PT_INACTIVE;
- if ( unlikely(__not_mapped(pl2e)) )
- goto inactive;
-
- if ( (l2e_get_pfn(*pl2e)) == pfn )
+ if ( (__get_user(l2e.l2, &pl2e->l2) == 0) && (l2e_get_pfn(l2e) == pfn) )
{
/*
* Check the PRESENT bit to set ACTIVE mode.
@@ -2995,13 +2948,11 @@
* ACTIVE p.t. (it may be the same p.t. mapped at another virt addr).
* The ptwr_flush call below will restore the PRESENT bit.
*/
- if ( likely(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ||
+ if ( likely(l2e_get_flags(l2e) & _PAGE_PRESENT) ||
(d->arch.ptwr[PTWR_PT_ACTIVE].l1va &&
(l2_idx == d->arch.ptwr[PTWR_PT_ACTIVE].l2_idx)) )
which = PTWR_PT_ACTIVE;
}
-
- inactive:
/*
* If this is a multi-processor guest then ensure that the page is hooked
diff -r 663f0fb1e444 -r a1f7e01b0990 xen/include/asm-x86/page.h
--- a/xen/include/asm-x86/page.h Tue Aug 9 09:34:06 2005
+++ b/xen/include/asm-x86/page.h Tue Aug 9 10:42:51 2005
@@ -208,21 +208,21 @@
+ DOMAIN_ENTRIES_PER_L4_PAGETABLE)
#endif
-#define VA_LINEAR_PT_VIRT_START (LINEAR_PT_VIRT_START & VADDR_MASK)
-#define linear_l1_table \
+#define LINEAR_PT_OFFSET (LINEAR_PT_VIRT_START & VADDR_MASK)
+#define linear_l1_table \
((l1_pgentry_t *)(LINEAR_PT_VIRT_START))
-#define __linear_l2_table \
- ((l2_pgentry_t *)(LINEAR_PT_VIRT_START + \
- (VA_LINEAR_PT_VIRT_START >> (PAGETABLE_ORDER<<0))))
-#define __linear_l3_table \
- ((l3_pgentry_t *)(LINEAR_PT_VIRT_START + \
- (VA_LINEAR_PT_VIRT_START >> (PAGETABLE_ORDER<<0)) + \
- (VA_LINEAR_PT_VIRT_START >> (PAGETABLE_ORDER<<1))))
-#define __linear_l4_table \
- ((l4_pgentry_t *)(LINEAR_PT_VIRT_START + \
- (VA_LINEAR_PT_VIRT_START >> (PAGETABLE_ORDER<<0)) + \
- (VA_LINEAR_PT_VIRT_START >> (PAGETABLE_ORDER<<1)) + \
- (VA_LINEAR_PT_VIRT_START >> (PAGETABLE_ORDER<<2))))
+#define __linear_l2_table \
+ ((l2_pgentry_t *)(LINEAR_PT_VIRT_START + \
+ (LINEAR_PT_OFFSET >> (PAGETABLE_ORDER<<0))))
+#define __linear_l3_table \
+ ((l3_pgentry_t *)(LINEAR_PT_VIRT_START + \
+ (LINEAR_PT_OFFSET >> (PAGETABLE_ORDER<<0)) + \
+ (LINEAR_PT_OFFSET >> (PAGETABLE_ORDER<<1))))
+#define __linear_l4_table \
+ ((l4_pgentry_t *)(LINEAR_PT_VIRT_START + \
+ (LINEAR_PT_OFFSET >> (PAGETABLE_ORDER<<0)) + \
+ (LINEAR_PT_OFFSET >> (PAGETABLE_ORDER<<1)) + \
+ (LINEAR_PT_OFFSET >> (PAGETABLE_ORDER<<2))))
#define linear_pg_table linear_l1_table
#define linear_l2_table(_ed) ((_ed)->arch.guest_vtable)
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