diff mbox series

[02/24] accel/tcg: Make page_alloc_target_data allocation constant

Message ID 20221006031113.1139454-3-richard.henderson@linaro.org
State Superseded
Headers show
Series accel/tcg: Rewrite user-only vma tracking | expand

Commit Message

Richard Henderson Oct. 6, 2022, 3:10 a.m. UTC 
Use a constant target data allocation size for all pages.
This will be necessary to reduce overhead of page tracking.
Since TARGET_PAGE_DATA_SIZE is now required, we can use this
to omit data tracking for targets that don't require it.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/exec/cpu-all.h    | 9 ++++-----
 target/arm/cpu.h          | 8 ++++++++
 target/arm/internals.h    | 4 ----
 accel/tcg/translate-all.c | 8 ++++++--
 target/arm/mte_helper.c   | 3 +--
 5 files changed, 19 insertions(+), 13 deletions(-)

Comments

Alex Bennée Oct. 25, 2022, 8:45 a.m. UTC | #1 
Richard Henderson <richard.henderson@linaro.org> writes:

> Use a constant target data allocation size for all pages.
> This will be necessary to reduce overhead of page tracking.
> Since TARGET_PAGE_DATA_SIZE is now required, we can use this
> to omit data tracking for targets that don't require it.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
diff mbox series

Patch

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 16b7df41bf..854adc4ac2 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -281,19 +281,18 @@  void page_reset_target_data(target_ulong start, target_ulong end);
 int page_check_range(target_ulong start, target_ulong len, int flags);
 
 /**
- * page_alloc_target_data(address, size)
+ * page_alloc_target_data(address)
  * @address: guest virtual address
- * @size: size of data to allocate
  *
- * Allocate @size bytes of out-of-band data to associate with the
- * guest page at @address.  If the page is not mapped, NULL will
+ * Allocate TARGET_PAGE_DATA_SIZE bytes of out-of-band data to associate
+ * with the guest page at @address.  If the page is not mapped, NULL will
  * be returned.  If there is existing data associated with @address,
  * no new memory will be allocated.
  *
  * The memory will be freed when the guest page is deallocated,
  * e.g. with the munmap system call.
  */
-void *page_alloc_target_data(target_ulong address, size_t size);
+void *page_alloc_target_data(target_ulong address);
 
 /**
  * page_get_target_data(address)
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 429ed42eec..2f44f7afc7 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3423,6 +3423,14 @@  static inline MemTxAttrs *typecheck_memtxattrs(MemTxAttrs *x)
 #define PAGE_MTE            PAGE_TARGET_2
 #define PAGE_TARGET_STICKY  PAGE_MTE
 
+/* We associate one allocation tag per 16 bytes, the minimum.  */
+#define LOG2_TAG_GRANULE 4
+#define TAG_GRANULE      (1 << LOG2_TAG_GRANULE)
+
+#ifdef CONFIG_USER_ONLY
+#define TARGET_PAGE_DATA_SIZE (TARGET_PAGE_SIZE >> (LOG2_TAG_GRANULE + 1))
+#endif
+
 #ifdef TARGET_TAGGED_ADDRESSES
 /**
  * cpu_untagged_addr:
diff --git a/target/arm/internals.h b/target/arm/internals.h
index 307a596505..d94efbaf5b 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1165,10 +1165,6 @@  void arm_log_exception(CPUState *cs);
  */
 #define GMID_EL1_BS  6
 
-/* We associate one allocation tag per 16 bytes, the minimum.  */
-#define LOG2_TAG_GRANULE 4
-#define TAG_GRANULE      (1 << LOG2_TAG_GRANULE)
-
 /*
  * SVE predicates are 1/8 the size of SVE vectors, and cannot use
  * the same simd_desc() encoding due to restrictions on size.
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 4ed75a13e1..64a2601f9f 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -2271,6 +2271,7 @@  void page_set_flags(target_ulong start, target_ulong end, int flags)
 
 void page_reset_target_data(target_ulong start, target_ulong end)
 {
+#ifdef TARGET_PAGE_DATA_SIZE
     target_ulong addr, len;
 
     /*
@@ -2293,15 +2294,17 @@  void page_reset_target_data(target_ulong start, target_ulong end)
         g_free(p->target_data);
         p->target_data = NULL;
     }
+#endif
 }
 
+#ifdef TARGET_PAGE_DATA_SIZE
 void *page_get_target_data(target_ulong address)
 {
     PageDesc *p = page_find(address >> TARGET_PAGE_BITS);
     return p ? p->target_data : NULL;
 }
 
-void *page_alloc_target_data(target_ulong address, size_t size)
+void *page_alloc_target_data(target_ulong address)
 {
     PageDesc *p = page_find(address >> TARGET_PAGE_BITS);
     void *ret = NULL;
@@ -2309,11 +2312,12 @@  void *page_alloc_target_data(target_ulong address, size_t size)
     if (p->flags & PAGE_VALID) {
         ret = p->target_data;
         if (!ret) {
-            p->target_data = ret = g_malloc0(size);
+            p->target_data = ret = g_malloc0(TARGET_PAGE_DATA_SIZE);
         }
     }
     return ret;
 }
+#endif /* TARGET_PAGE_DATA_SIZE */
 
 int page_check_range(target_ulong start, target_ulong len, int flags)
 {
diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
index fdd23ab3f8..62d36c127f 100644
--- a/target/arm/mte_helper.c
+++ b/target/arm/mte_helper.c
@@ -96,8 +96,7 @@  static uint8_t *allocation_tag_mem(CPUARMState *env, int ptr_mmu_idx,
 
     tags = page_get_target_data(clean_ptr);
     if (tags == NULL) {
-        size_t alloc_size = TARGET_PAGE_SIZE >> (LOG2_TAG_GRANULE + 1);
-        tags = page_alloc_target_data(clean_ptr, alloc_size);
+        tags = page_alloc_target_data(clean_ptr);
         assert(tags != NULL);
     }