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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 7/8] x86/mm: handle foreign mappings in p2m_entry_modify
So that the specific handling can be removed from
atomic_write_ept_entry and be shared with npt and shadow code.
This commit also removes the check that prevent non-ept PVH dom0 from
mapping foreign pages.
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Jun Nakajima <jun.nakajima@xxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
---
xen/arch/x86/mm/hap/hap.c | 3 +-
xen/arch/x86/mm/p2m-ept.c | 108 +++++++-------------------------
xen/arch/x86/mm/p2m-pt.c | 7 ---
xen/arch/x86/mm/shadow/common.c | 3 +-
xen/include/asm-x86/p2m.h | 30 ++++++++-
5 files changed, 53 insertions(+), 98 deletions(-)
diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index dc46d5e14f..4f52639be5 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -735,7 +735,8 @@ hap_write_p2m_entry(struct domain *d, unsigned long gfn,
l1_pgentry_t *p,
}
p2m_entry_modify(p2m_get_hostp2m(d), p2m_flags_to_type(l1e_get_flags(new)),
- p2m_flags_to_type(old_flags), level);
+ p2m_flags_to_type(old_flags), l1e_get_mfn(new),
+ l1e_get_mfn(*p), level);
safe_write_pte(p, new);
if ( old_flags & _PAGE_PRESENT )
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 0ece6608cb..2b0c3ab265 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -45,65 +45,13 @@ static inline bool_t is_epte_valid(ept_entry_t *e)
return ((e->epte & ~(1ul << 63)) != 0 && e->sa_p2mt != p2m_invalid);
}
-/* returns : 0 for success, -errno otherwise */
-static int atomic_write_ept_entry(struct p2m_domain *p2m,
- ept_entry_t *entryptr, ept_entry_t new,
- int level)
+static void atomic_write_ept_entry(struct p2m_domain *p2m,
+ ept_entry_t *entryptr, ept_entry_t new,
+ int level)
{
- int rc;
- unsigned long oldmfn = mfn_x(INVALID_MFN);
- bool_t check_foreign = (new.mfn != entryptr->mfn ||
- new.sa_p2mt != entryptr->sa_p2mt);
-
- if ( level )
- {
- ASSERT(!is_epte_superpage(&new) || !p2m_is_foreign(new.sa_p2mt));
- write_atomic(&entryptr->epte, new.epte);
- return 0;
- }
-
- if ( unlikely(p2m_is_foreign(new.sa_p2mt)) )
- {
- rc = -EINVAL;
- if ( !is_epte_present(&new) )
- goto out;
-
- if ( check_foreign )
- {
- struct domain *fdom;
-
- if ( !mfn_valid(_mfn(new.mfn)) )
- goto out;
-
- rc = -ESRCH;
- fdom = page_get_owner(mfn_to_page(_mfn(new.mfn)));
- if ( fdom == NULL )
- goto out;
-
- /* get refcount on the page */
- rc = -EBUSY;
- if ( !get_page(mfn_to_page(_mfn(new.mfn)), fdom) )
- goto out;
- }
- }
-
- if ( unlikely(p2m_is_foreign(entryptr->sa_p2mt)) && check_foreign )
- oldmfn = entryptr->mfn;
-
- p2m_entry_modify(p2m, new.sa_p2mt, entryptr->sa_p2mt, level);
-
+ p2m_entry_modify(p2m, new.sa_p2mt, entryptr->sa_p2mt, _mfn(new.mfn),
+ _mfn(entryptr->mfn), level);
write_atomic(&entryptr->epte, new.epte);
-
- if ( unlikely(oldmfn != mfn_x(INVALID_MFN)) )
- put_page(mfn_to_page(_mfn(oldmfn)));
-
- rc = 0;
-
- out:
- if ( rc )
- gdprintk(XENLOG_ERR, "epte o:%"PRIx64" n:%"PRIx64" rc:%d\n",
- entryptr->epte, new.epte, rc);
- return rc;
}
static void ept_p2m_type_to_flags(struct p2m_domain *p2m, ept_entry_t *entry,
@@ -396,7 +344,6 @@ static int ept_next_level(struct p2m_domain *p2m, bool_t
read_only,
static bool_t ept_invalidate_emt(struct p2m_domain *p2m, mfn_t mfn,
bool_t recalc, int level)
{
- int rc;
ept_entry_t *epte = map_domain_page(mfn);
unsigned int i;
bool_t changed = 0;
@@ -412,8 +359,7 @@ static bool_t ept_invalidate_emt(struct p2m_domain *p2m,
mfn_t mfn,
e.emt = MTRR_NUM_TYPES;
if ( recalc )
e.recalc = 1;
- rc = atomic_write_ept_entry(p2m, &epte[i], e, level);
- ASSERT(rc == 0);
+ atomic_write_ept_entry(p2m, &epte[i], e, level);
changed = 1;
}
@@ -437,7 +383,7 @@ static int ept_invalidate_emt_range(struct p2m_domain *p2m,
ept_entry_t *table;
unsigned long gfn_remainder = first_gfn;
unsigned int i, index;
- int wrc, rc = 0, ret = GUEST_TABLE_MAP_FAILED;
+ int rc = 0, ret = GUEST_TABLE_MAP_FAILED;
table = map_domain_page(pagetable_get_mfn(p2m_get_pagetable(p2m)));
for ( i = p2m->ept.wl; i > target; --i )
@@ -463,8 +409,7 @@ static int ept_invalidate_emt_range(struct p2m_domain *p2m,
rc = -ENOMEM;
goto out;
}
- wrc = atomic_write_ept_entry(p2m, &table[index], split_ept_entry, i);
- ASSERT(wrc == 0);
+ atomic_write_ept_entry(p2m, &table[index], split_ept_entry, i);
for ( ; i > target; --i )
if ( !ept_next_level(p2m, 1, &table, &gfn_remainder, i) )
@@ -483,8 +428,7 @@ static int ept_invalidate_emt_range(struct p2m_domain *p2m,
{
e.emt = MTRR_NUM_TYPES;
e.recalc = 1;
- wrc = atomic_write_ept_entry(p2m, &table[index], e, target);
- ASSERT(wrc == 0);
+ atomic_write_ept_entry(p2m, &table[index], e, target);
rc = 1;
}
}
@@ -513,7 +457,7 @@ static int resolve_misconfig(struct p2m_domain *p2m,
unsigned long gfn)
unsigned int level = ept->wl;
unsigned long mfn = ept->mfn;
ept_entry_t *epte;
- int wrc, rc = 0;
+ int rc = 0;
if ( !mfn )
return 0;
@@ -557,8 +501,7 @@ static int resolve_misconfig(struct p2m_domain *p2m,
unsigned long gfn)
ept_p2m_type_to_flags(p2m, &e, e.sa_p2mt, e.access);
}
e.recalc = 0;
- wrc = atomic_write_ept_entry(p2m, &epte[i], e, level);
- ASSERT(wrc == 0);
+ atomic_write_ept_entry(p2m, &epte[i], e, level);
}
}
else
@@ -593,8 +536,7 @@ static int resolve_misconfig(struct p2m_domain *p2m,
unsigned long gfn)
{
if ( ept_split_super_page(p2m, &e, level, level - 1) )
{
- wrc = atomic_write_ept_entry(p2m, &epte[i], e, level);
- ASSERT(wrc == 0);
+ atomic_write_ept_entry(p2m, &epte[i], e, level);
unmap_domain_page(epte);
mfn = e.mfn;
continue;
@@ -608,8 +550,7 @@ static int resolve_misconfig(struct p2m_domain *p2m,
unsigned long gfn)
e.recalc = 0;
if ( recalc && p2m_is_changeable(e.sa_p2mt) )
ept_p2m_type_to_flags(p2m, &e, e.sa_p2mt, e.access);
- wrc = atomic_write_ept_entry(p2m, &epte[i], e, level);
- ASSERT(wrc == 0);
+ atomic_write_ept_entry(p2m, &epte[i], e, level);
}
rc = 1;
@@ -623,8 +564,7 @@ static int resolve_misconfig(struct p2m_domain *p2m,
unsigned long gfn)
smp_wmb();
e.emt = 0;
e.recalc = 0;
- wrc = atomic_write_ept_entry(p2m, &epte[i], e, level);
- ASSERT(wrc == 0);
+ atomic_write_ept_entry(p2m, &epte[i], e, level);
unmap_domain_page(epte);
rc = 1;
}
@@ -784,8 +724,7 @@ ept_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t mfn,
/* now install the newly split ept sub-tree */
/* NB: please make sure domian is paused and no in-fly VT-d DMA. */
- rc = atomic_write_ept_entry(p2m, ept_entry, split_ept_entry, i);
- ASSERT(rc == 0);
+ atomic_write_ept_entry(p2m, ept_entry, split_ept_entry, i);
/* then move to the level we want to make real changes */
for ( ; i > target; i-- )
@@ -831,18 +770,13 @@ ept_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t
mfn,
new_entry.suppress_ve = is_epte_valid(&old_entry) ?
old_entry.suppress_ve : 1;
- rc = atomic_write_ept_entry(p2m, ept_entry, new_entry, target);
- if ( unlikely(rc) )
- old_entry.epte = 0;
- else
- {
- entry_written = 1;
+ atomic_write_ept_entry(p2m, ept_entry, new_entry, target);
+ entry_written = 1;
- if ( p2mt != p2m_invalid &&
- (gfn + (1UL << order) - 1 > p2m->max_mapped_pfn) )
- /* Track the highest gfn for which we have ever had a valid
mapping */
- p2m->max_mapped_pfn = gfn + (1UL << order) - 1;
- }
+ if ( p2mt != p2m_invalid &&
+ (gfn + (1UL << order) - 1 > p2m->max_mapped_pfn) )
+ /* Track the highest gfn for which we have ever had a valid mapping */
+ p2m->max_mapped_pfn = gfn + (1UL << order) - 1;
out:
if ( needs_sync )
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index c8905a5597..6238043aa6 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -523,13 +523,6 @@ p2m_pt_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t
mfn,
__trace_var(TRC_MEM_SET_P2M_ENTRY, 0, sizeof(t), &t);
}
- if ( unlikely(p2m_is_foreign(p2mt)) )
- {
- /* hvm fixme: foreign types are only supported on ept at present */
- gdprintk(XENLOG_WARNING, "Unimplemented foreign p2m type.\n");
- return -EINVAL;
- }
-
/* Carry out any eventually pending earlier changes first. */
rc = do_recalc(p2m, gfn);
if ( rc < 0 )
diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index b210c7447e..7f0e05045e 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -3186,7 +3186,8 @@ shadow_write_p2m_entry(struct domain *d, unsigned long
gfn,
sh_unshadow_for_p2m_change(d, gfn, p, new, level);
p2m_entry_modify(p2m_get_hostp2m(d), p2m_flags_to_type(l1e_get_flags(new)),
- p2m_flags_to_type(l1e_get_flags(*p)), level);
+ p2m_flags_to_type(l1e_get_flags(*p)), l1e_get_mfn(new),
+ l1e_get_mfn(*p), level);
/* Update the entry with new content */
safe_write_pte(p, new);
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 834d49d2d4..1cc8acb3fe 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -933,9 +933,12 @@ struct hvm_ioreq_server *p2m_get_ioreq_server(struct
domain *d,
unsigned int *flags);
static inline void p2m_entry_modify(struct p2m_domain *p2m, p2m_type_t nt,
- p2m_type_t ot, unsigned int level)
+ p2m_type_t ot, mfn_t nfn, mfn_t ofn,
+ unsigned int level)
{
- if ( level != 1 || nt == ot )
+ struct page_info *pg;
+
+ if ( level != 1 || (nt == ot && mfn_eq(nfn, ofn)) )
return;
switch ( nt )
@@ -948,6 +951,17 @@ static inline void p2m_entry_modify(struct p2m_domain
*p2m, p2m_type_t nt,
p2m->ioreq.entry_count++;
break;
+ case p2m_map_foreign:
+ pg = mfn_to_page(nfn);
+
+ if ( !pg || !page_get_owner_and_reference(pg) )
+ {
+ ASSERT_UNREACHABLE();
+ return;
+ }
+
+ break;
+
default:
break;
}
@@ -959,6 +973,18 @@ static inline void p2m_entry_modify(struct p2m_domain
*p2m, p2m_type_t nt,
p2m->ioreq.entry_count--;
break;
+ case p2m_map_foreign:
+ pg = mfn_to_page(ofn);
+
+ if ( !pg )
+ {
+ ASSERT_UNREACHABLE();
+ return;
+ }
+ put_page(pg);
+
+ break;
+
default:
break;
}
--
2.20.1
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