[Qemu-devel] [PATCH v2] exec: Fix MAP_RAM for cached access

[Eric Auger <eric.auger@redhat.com>]

When an IOMMUMemoryRegion is in front of a virtio device,
address_space_cache_init does not set cache->ptr as the memory
region is not RAM. However when the device performs an access,
we end up in glue() which performs the translation and then uses
MAP_RAM. This latter uses the unset ptr and returns a wrong value
which leads to a SIGSEV in address_space_lduw_internal_cached_slow,
for instance.

In slow path cache->ptr is NULL and MAP_RAM must redirect to
qemu_map_ram_ptr((mr)->ram_block, ofs).

As MAP_RAM, IS_DIRECT and INVALIDATE are the same in _cached_slow
and non cached mode, let's remove those macros.

This fixes the use cases featuring vIOMMU (Intel and ARM SMMU)
which lead to a SIGSEV.

Fixes: 48564041a73a (exec: reintroduce MemoryRegion caching)
Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v1 -> v2:
- directly use qemu_map_ram_ptr in place for MAP_RAM,
  memory_access_is_direct in place of IS_DIRECT and
  invalidate_and_set_dirty in place of INVALIDATE. The
  macros are removed.
---
 exec.c            |  6 ------
 memory_ldst.inc.c | 47 ++++++++++++++++++++++-------------------------
 2 files changed, 22 insertions(+), 31 deletions(-)

diff --git a/exec.c b/exec.c
index f6645ed..f5a7caf 100644
--- a/exec.c
+++ b/exec.c
@@ -3660,9 +3660,6 @@ void cpu_physical_memory_unmap(void *buffer, hwaddr len,
 #define ARG1                     as
 #define SUFFIX
 #define TRANSLATE(...)           address_space_translate(as, __VA_ARGS__)
-#define IS_DIRECT(mr, is_write)  memory_access_is_direct(mr, is_write)
-#define MAP_RAM(mr, ofs)         qemu_map_ram_ptr((mr)->ram_block, ofs)
-#define INVALIDATE(mr, ofs, len) invalidate_and_set_dirty(mr, ofs, len)
 #define RCU_READ_LOCK(...)       rcu_read_lock()
 #define RCU_READ_UNLOCK(...)     rcu_read_unlock()
 #include "memory_ldst.inc.c"
@@ -3799,9 +3796,6 @@ address_space_write_cached_slow(MemoryRegionCache *cache, hwaddr addr,
 #define ARG1                     cache
 #define SUFFIX                   _cached_slow
 #define TRANSLATE(...)           address_space_translate_cached(cache, __VA_ARGS__)
-#define IS_DIRECT(mr, is_write)  memory_access_is_direct(mr, is_write)
-#define MAP_RAM(mr, ofs)         (cache->ptr + (ofs - cache->xlat))
-#define INVALIDATE(mr, ofs, len) invalidate_and_set_dirty(mr, ofs, len)
 #define RCU_READ_LOCK()          ((void)0)
 #define RCU_READ_UNLOCK()        ((void)0)
 #include "memory_ldst.inc.c"
diff --git a/memory_ldst.inc.c b/memory_ldst.inc.c
index 1548398..acf865b 100644
--- a/memory_ldst.inc.c
+++ b/memory_ldst.inc.c
@@ -34,7 +34,7 @@ static inline uint32_t glue(address_space_ldl_internal, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, false, attrs);
-    if (l < 4 || !IS_DIRECT(mr, false)) {
+    if (l < 4 || !memory_access_is_direct(mr, false)) {
         release_lock |= prepare_mmio_access(mr);
 
         /* I/O case */
@@ -50,7 +50,7 @@ static inline uint32_t glue(address_space_ldl_internal, SUFFIX)(ARG1_DECL,
 #endif
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             val = ldl_le_p(ptr);
@@ -110,7 +110,7 @@ static inline uint64_t glue(address_space_ldq_internal, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, false, attrs);
-    if (l < 8 || !IS_DIRECT(mr, false)) {
+    if (l < 8 || !memory_access_is_direct(mr, false)) {
         release_lock |= prepare_mmio_access(mr);
 
         /* I/O case */
@@ -126,7 +126,7 @@ static inline uint64_t glue(address_space_ldq_internal, SUFFIX)(ARG1_DECL,
 #endif
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             val = ldq_le_p(ptr);
@@ -184,14 +184,14 @@ uint32_t glue(address_space_ldub, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, false, attrs);
-    if (!IS_DIRECT(mr, false)) {
+    if (!memory_access_is_direct(mr, false)) {
         release_lock |= prepare_mmio_access(mr);
 
         /* I/O case */
         r = memory_region_dispatch_read(mr, addr1, &val, 1, attrs);
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         val = ldub_p(ptr);
         r = MEMTX_OK;
     }
@@ -220,7 +220,7 @@ static inline uint32_t glue(address_space_lduw_internal, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, false, attrs);
-    if (l < 2 || !IS_DIRECT(mr, false)) {
+    if (l < 2 || !memory_access_is_direct(mr, false)) {
         release_lock |= prepare_mmio_access(mr);
 
         /* I/O case */
@@ -236,7 +236,7 @@ static inline uint32_t glue(address_space_lduw_internal, SUFFIX)(ARG1_DECL,
 #endif
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             val = lduw_le_p(ptr);
@@ -297,12 +297,12 @@ void glue(address_space_stl_notdirty, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, true, attrs);
-    if (l < 4 || !IS_DIRECT(mr, true)) {
+    if (l < 4 || !memory_access_is_direct(mr, true)) {
         release_lock |= prepare_mmio_access(mr);
 
         r = memory_region_dispatch_write(mr, addr1, val, 4, attrs);
     } else {
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         stl_p(ptr, val);
 
         dirty_log_mask = memory_region_get_dirty_log_mask(mr);
@@ -334,7 +334,7 @@ static inline void glue(address_space_stl_internal, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, true, attrs);
-    if (l < 4 || !IS_DIRECT(mr, true)) {
+    if (l < 4 || !memory_access_is_direct(mr, true)) {
         release_lock |= prepare_mmio_access(mr);
 
 #if defined(TARGET_WORDS_BIGENDIAN)
@@ -349,7 +349,7 @@ static inline void glue(address_space_stl_internal, SUFFIX)(ARG1_DECL,
         r = memory_region_dispatch_write(mr, addr1, val, 4, attrs);
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             stl_le_p(ptr, val);
@@ -361,7 +361,7 @@ static inline void glue(address_space_stl_internal, SUFFIX)(ARG1_DECL,
             stl_p(ptr, val);
             break;
         }
-        INVALIDATE(mr, addr1, 4);
+        invalidate_and_set_dirty(mr, addr1, 4);
         r = MEMTX_OK;
     }
     if (result) {
@@ -406,14 +406,14 @@ void glue(address_space_stb, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, true, attrs);
-    if (!IS_DIRECT(mr, true)) {
+    if (!memory_access_is_direct(mr, true)) {
         release_lock |= prepare_mmio_access(mr);
         r = memory_region_dispatch_write(mr, addr1, val, 1, attrs);
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         stb_p(ptr, val);
-        INVALIDATE(mr, addr1, 1);
+        invalidate_and_set_dirty(mr, addr1, 1);
         r = MEMTX_OK;
     }
     if (result) {
@@ -439,7 +439,7 @@ static inline void glue(address_space_stw_internal, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, true, attrs);
-    if (l < 2 || !IS_DIRECT(mr, true)) {
+    if (l < 2 || !memory_access_is_direct(mr, true)) {
         release_lock |= prepare_mmio_access(mr);
 
 #if defined(TARGET_WORDS_BIGENDIAN)
@@ -454,7 +454,7 @@ static inline void glue(address_space_stw_internal, SUFFIX)(ARG1_DECL,
         r = memory_region_dispatch_write(mr, addr1, val, 2, attrs);
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             stw_le_p(ptr, val);
@@ -466,7 +466,7 @@ static inline void glue(address_space_stw_internal, SUFFIX)(ARG1_DECL,
             stw_p(ptr, val);
             break;
         }
-        INVALIDATE(mr, addr1, 2);
+        invalidate_and_set_dirty(mr, addr1, 2);
         r = MEMTX_OK;
     }
     if (result) {
@@ -512,7 +512,7 @@ static void glue(address_space_stq_internal, SUFFIX)(ARG1_DECL,
 
     RCU_READ_LOCK();
     mr = TRANSLATE(addr, &addr1, &l, true, attrs);
-    if (l < 8 || !IS_DIRECT(mr, true)) {
+    if (l < 8 || !memory_access_is_direct(mr, true)) {
         release_lock |= prepare_mmio_access(mr);
 
 #if defined(TARGET_WORDS_BIGENDIAN)
@@ -527,7 +527,7 @@ static void glue(address_space_stq_internal, SUFFIX)(ARG1_DECL,
         r = memory_region_dispatch_write(mr, addr1, val, 8, attrs);
     } else {
         /* RAM case */
-        ptr = MAP_RAM(mr, addr1);
+        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             stq_le_p(ptr, val);
@@ -539,7 +539,7 @@ static void glue(address_space_stq_internal, SUFFIX)(ARG1_DECL,
             stq_p(ptr, val);
             break;
         }
-        INVALIDATE(mr, addr1, 8);
+        invalidate_and_set_dirty(mr, addr1, 8);
         r = MEMTX_OK;
     }
     if (result) {
@@ -576,8 +576,5 @@ void glue(address_space_stq_be, SUFFIX)(ARG1_DECL,
 #undef ARG1
 #undef SUFFIX
 #undef TRANSLATE
-#undef IS_DIRECT
-#undef MAP_RAM
-#undef INVALIDATE
 #undef RCU_READ_LOCK
 #undef RCU_READ_UNLOCK
-- 
2.5.5