include/exec: Improve probe_access_full{, _mmu} documentation

Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20241013184733.1423747-2-richard.henderson@linaro.org>

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 72240ef4263ccb7ba1c37a0aa0ad3bebdeed271e..2e4c4cc4b46361a4e9be98a27e032f085c1959ff 100644 (file)
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -368,6 +368,13 @@ int probe_access_flags(CPUArchState *env, vaddr addr, int size,
  * The CPUTLBEntryFull structure returned via @pfull is transient
  * and must be consumed or copied immediately, before any further
  * access or changes to TLB @mmu_idx.
+ *
+ * This function will not fault if @nonfault is set, but will
+ * return TLB_INVALID_MASK if the page is not mapped, or is not
+ * accessible with @access_type.
+ *
+ * This function will return TLB_MMIO in order to force the access
+ * to be handled out-of-line if plugins wish to instrument the access.
  */
 int probe_access_full(CPUArchState *env, vaddr addr, int size,
                       MMUAccessType access_type, int mmu_idx,
@@ -375,22 +382,14 @@ int probe_access_full(CPUArchState *env, vaddr addr, int size,
                       CPUTLBEntryFull **pfull, uintptr_t retaddr);
 
 /**
- * probe_access_mmu() - Like probe_access_full except cannot fault and
- * doesn't trigger instrumentation.
- *
- * @env: CPUArchState
- * @vaddr: virtual address to probe
- * @size: size of the probe
- * @access_type: read, write or execute permission
- * @mmu_idx: softmmu index
- * @phost: ptr to return value host address or NULL
- * @pfull: ptr to return value CPUTLBEntryFull structure or NULL
- *
- * The CPUTLBEntryFull structure returned via @pfull is transient
- * and must be consumed or copied immediately, before any further
- * access or changes to TLB @mmu_idx.
- *
- * Returns: TLB flags as per probe_access_flags()
+ * probe_access_full_mmu:
+ * Like probe_access_full, except:
+ *
+ * This function is intended to be used for page table accesses by
+ * the target mmu itself.  Since such page walking happens while
+ * handling another potential mmu fault, this function never raises
+ * exceptions (akin to @nonfault true for probe_access_full).
+ * Likewise this function does not trigger plugin instrumentation.
  */
 int probe_access_full_mmu(CPUArchState *env, vaddr addr, int size,
                           MMUAccessType access_type, int mmu_idx,