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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 11/13] memory: add get_paged_gfn() as a wrapper...
...for some uses of get_page_from_gfn().
There are many occurences of the following pattern in the code:
q = <readonly look-up> ? P2M_ALLOC : P2M_UNSHARE;
page = get_page_from_gfn(d, gfn, &p2mt, q);
if ( p2m_is_paging(p2mt) )
{
if ( page )
put_page(page);
p2m_mem_paging_populate(d, gfn);
return <-ENOENT or equivalent>;
}
if ( (q & P2M_UNSHARE) && p2m_is_shared(p2mt) )
{
if ( page )
put_page(page);
return <-ENOENT or equivalent>;
}
if ( !page )
return <-EINVAL or equivalent>;
if ( !p2m_is_ram(p2mt) ||
(!<readonly look-up> && p2m_is_readonly(p2mt)) )
{
put_page(page);
return <-EINVAL or equivalent>;
}
There are some small differences between the exact way the occurrences are
coded but the desired semantic is the same.
This patch introduces a new common implementation of this code in
get_paged_gfn() and then converts the various open-coded patterns into
calls to this new function.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
v2:
- New in v2.
---
xen/arch/x86/hvm/emulate.c | 32 +++++++-------------------------
xen/arch/x86/hvm/hvm.c | 16 ++--------------
xen/common/grant_table.c | 38 +++++++++++---------------------------
xen/common/memory.c | 42 ++++++++++++++++++++++++++++++++++--------
xen/include/asm-arm/p2m.h | 3 +++
xen/include/asm-x86/p2m.h | 2 ++
6 files changed, 59 insertions(+), 74 deletions(-)
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index 8385c62145..ad9bc4f251 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -332,34 +332,16 @@ static int hvmemul_do_io_buffer(
static int hvmemul_acquire_page(unsigned long gmfn, struct page_info **page)
{
- struct domain *curr_d = current->domain;
- p2m_type_t p2mt;
-
- *page = get_page_from_gfn(curr_d, gmfn, &p2mt, P2M_UNSHARE);
-
- if ( *page == NULL )
- return X86EMUL_UNHANDLEABLE;
-
- if ( p2m_is_paging(p2mt) )
- {
- put_page(*page);
- p2m_mem_paging_populate(curr_d, gmfn);
- return X86EMUL_RETRY;
- }
-
- if ( p2m_is_shared(p2mt) )
+ switch ( get_paged_gfn(current->domain, _gfn(gmfn), false, NULL, page) )
{
- put_page(*page);
+ case -ENOENT:
return X86EMUL_RETRY;
- }
-
- /* This code should not be reached if the gmfn is not RAM */
- if ( p2m_is_mmio(p2mt) )
- {
- domain_crash(curr_d);
-
- put_page(*page);
+ case -EINVAL:
return X86EMUL_UNHANDLEABLE;
+ default:
+ ASSERT_UNREACHABLE();
+ case 0:
+ break;
}
return X86EMUL_OKAY;
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index c23983cdff..906235932d 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2573,24 +2573,12 @@ static void *_hvm_map_guest_frame(unsigned long gfn,
bool_t permanent,
bool_t *writable)
{
void *map;
- p2m_type_t p2mt;
struct page_info *page;
struct domain *d = current->domain;
+ p2m_type_t p2mt;
- page = get_page_from_gfn(d, gfn, &p2mt,
- writable ? P2M_UNSHARE : P2M_ALLOC);
- if ( (p2m_is_shared(p2mt) && writable) || !page )
- {
- if ( page )
- put_page(page);
- return NULL;
- }
- if ( p2m_is_paging(p2mt) )
- {
- put_page(page);
- p2m_mem_paging_populate(d, gfn);
+ if ( get_paged_gfn(d, _gfn(gfn), !writable, &p2mt, &page) )
return NULL;
- }
if ( writable )
{
diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index c6b99c4116..510f37f100 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -375,39 +375,23 @@ static int get_paged_frame(unsigned long gfn, mfn_t *mfn,
struct page_info **page, bool readonly,
struct domain *rd)
{
- int rc = GNTST_okay;
- p2m_type_t p2mt;
-
- *mfn = INVALID_MFN;
- *page = get_page_from_gfn(rd, gfn, &p2mt,
- readonly ? P2M_ALLOC : P2M_UNSHARE);
- if ( !*page )
- {
-#ifdef P2M_SHARED_TYPES
- if ( p2m_is_shared(p2mt) )
- return GNTST_eagain;
-#endif
-#ifdef P2M_PAGES_TYPES
- if ( p2m_is_paging(p2mt) )
- {
- p2m_mem_paging_populate(rd, gfn);
- return GNTST_eagain;
- }
-#endif
- return GNTST_bad_page;
- }
+ int rc;
- if ( p2m_is_foreign(p2mt) )
+ rc = get_paged_gfn(rd, _gfn(gfn), readonly, NULL, page);
+ switch ( rc )
{
- put_page(*page);
- *page = NULL;
-
+ case -ENOENT:
+ return GNTST_eagain;
+ case -EINVAL:
return GNTST_bad_page;
+ default:
+ ASSERT_UNREACHABLE();
+ case 0:
+ break;
}
*mfn = page_to_mfn(*page);
-
- return rc;
+ return GNTST_okay;
}
static inline void
diff --git a/xen/common/memory.c b/xen/common/memory.c
index 35da9ca80e..419b76ac38 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -1574,30 +1574,31 @@ void destroy_ring_for_helper(
}
}
-int prepare_ring_for_helper(
- struct domain *d, unsigned long gmfn, struct page_info **_page,
- void **_va)
+int get_paged_gfn(struct domain *d, gfn_t gfn, bool readonly,
+ p2m_type_t *p2mt_p, struct page_info **page_p)
{
- struct page_info *page;
+ p2m_query_t q = readonly ? P2M_ALLOC : P2M_UNSHARE;
p2m_type_t p2mt;
- void *va;
+ struct page_info *page;
- page = get_page_from_gfn(d, gmfn, &p2mt, P2M_UNSHARE);
+ page = get_page_from_gfn(d, gfn_x(gfn), &p2mt, q);
#ifdef CONFIG_HAS_MEM_PAGING
if ( p2m_is_paging(p2mt) )
{
if ( page )
put_page(page);
- p2m_mem_paging_populate(d, gmfn);
+
+ p2m_mem_paging_populate(d, gfn_x(gfn));
return -ENOENT;
}
#endif
#ifdef CONFIG_HAS_MEM_SHARING
- if ( p2m_is_shared(p2mt) )
+ if ( (q & P2M_UNSHARE) && p2m_is_shared(p2mt) )
{
if ( page )
put_page(page);
+
return -ENOENT;
}
#endif
@@ -1605,6 +1606,31 @@ int prepare_ring_for_helper(
if ( !page )
return -EINVAL;
+ if ( !p2m_is_ram(p2mt) || (!readonly && p2m_is_readonly(p2mt)) )
+ {
+ put_page(page);
+ return -EINVAL;
+ }
+
+ if ( p2mt_p )
+ *p2mt_p = p2mt;
+
+ *page_p = page;
+ return 0;
+}
+
+int prepare_ring_for_helper(
+ struct domain *d, unsigned long gmfn, struct page_info **_page,
+ void **_va)
+{
+ struct page_info *page;
+ void *va;
+ int rc;
+
+ rc = get_paged_gfn(d, _gfn(gmfn), false, NULL, &page);
+ if ( rc )
+ return rc;
+
if ( !get_page_type(page, PGT_writable_page) )
{
put_page(page);
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index 8823707c17..a39a4faabd 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -303,6 +303,9 @@ static inline struct page_info *get_page_from_gfn(
return page;
}
+int get_paged_gfn(struct domain *d, gfn_t gfn, bool readonly,
+ p2m_type_t *p2mt_p, struct page_info **page_p);
+
int get_page_type(struct page_info *page, unsigned long type);
bool is_iomem_page(mfn_t mfn);
static inline int get_page_and_type(struct page_info *page,
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index d4b3cfcb6e..e890bcd3e1 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -492,6 +492,8 @@ static inline struct page_info *get_page_from_gfn(
return mfn_valid(_mfn(gfn)) && get_page(page, d) ? page : NULL;
}
+int get_paged_gfn(struct domain *d, gfn_t gfn, bool readonly,
+ p2m_type_t *p2mt_p, struct page_info **page_p);
/* General conversion function from mfn to gfn */
static inline unsigned long mfn_to_gfn(struct domain *d, mfn_t mfn)
--
2.11.0
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