[PATCH 5/9] accel: Move CPUTLB to CPUState and assert offset

[Anton Johansson]

As CPUTLB is now target-agnostic it can be moved from
CPUNegativeOffsetState to CPUState, and the negative offset from
CPUArchState can instead be statically asserted to be greater than
CPU_MAX_NEGATIVE_ENV_OFFSET.

This also opens up the door for reducing the dependency of common code
on CPUArchState.

Signed-off-by: Anton Johansson <anjo@rev.ng>
---
 include/exec/cpu-all.h    |  2 +-
 include/exec/cpu-defs.h   |  2 --
 include/exec/tlb-common.h |  4 ++--
 include/hw/core/cpu.h     |  7 +++++++
 accel/tcg/translate-all.c | 13 +++++++++++--
 5 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 8018ce783e..706daa49ec 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -453,7 +453,7 @@ static inline CPUNegativeOffsetState *cpu_neg(CPUState *cpu)
  */
 static inline CPUTLB *env_tlb(CPUArchState *env)
 {
-    return &env_neg(env)->tlb;
+    return &env_cpu(env)->tlb;
 }
 
 #endif /* CPU_ALL_H */
diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
index dff6c37f6b..add0f3c541 100644
--- a/include/exec/cpu-defs.h
+++ b/include/exec/cpu-defs.h
@@ -25,7 +25,6 @@
 
 #include "qemu/host-utils.h"
 #include "qemu/thread.h"
-#include "exec/tlb-common.h"
 #include "hw/core/cpu.h"
 
 #include "cpu-param.h"
@@ -83,7 +82,6 @@
  * before CPUArchState, as a field named "neg".
  */
 typedef struct CPUNegativeOffsetState {
-    CPUTLB tlb;
     IcountDecr icount_decr;
 } CPUNegativeOffsetState;
 
diff --git a/include/exec/tlb-common.h b/include/exec/tlb-common.h
index 838a1f0d2a..450c0156bf 100644
--- a/include/exec/tlb-common.h
+++ b/include/exec/tlb-common.h
@@ -190,8 +190,8 @@ typedef struct CPUTLBCommon {
 /*
  * The entire softmmu tlb, for all MMU modes.
  * The meaning of each of the MMU modes is defined in the target code.
- * Since this is placed within CPUNegativeOffsetState, the smallest
- * negative offsets are at the end of the struct.
+ * Since this is placed within CPUState, the smallest negative offsets
+ * are at the end of the struct.
  */
 
 typedef struct CPUTLB {
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 0377f74d48..adf6158899 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -448,6 +448,13 @@ struct CPUState {
 
     /* track IOMMUs whose translations we've cached in the TCG TLB */
     GArray *iommu_notifiers;
+
+    /*
+     * The following fields needs to be within CPU_MAX_NEGATIVE_ENV_OFFSET of
+     * CPUArchState.  As CPUArchState is assumed to follow CPUState in the
+     * ArchCPU struct these are placed last.  This is checked statically.
+     */
+    CPUTLB tlb;
 };
 
 typedef QTAILQ_HEAD(CPUTailQ, CPUState) CPUTailQ;
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index d3d4fbc1a4..5582aaf653 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -339,8 +339,17 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
     tcg_ctx->page_bits = TARGET_PAGE_BITS;
     tcg_ctx->page_mask = TARGET_PAGE_MASK;
     tcg_ctx->tlb_dyn_max_bits = CPU_TLB_DYN_MAX_BITS;
-    tcg_ctx->tlb_fast_offset =
-        (int)offsetof(ArchCPU, neg.tlb.f) - (int)offsetof(ArchCPU, env);
+
+#define TLB_FAST_OFFSET \
+    ((int)offsetof(ArchCPU, parent_obj.tlb.f) - (int)offsetof(ArchCPU, env))
+
+    QEMU_BUILD_BUG_ON(TLB_FAST_OFFSET < CPU_MAX_NEGATIVE_ENV_OFFSET ||
+                      TLB_FAST_OFFSET > 0);
+
+    tcg_ctx->tlb_fast_offset = TLB_FAST_OFFSET;
+
+#undef TLB_FAST_OFFSET
+
 #endif
     tcg_ctx->insn_start_words = TARGET_INSN_START_WORDS;
 #ifdef TCG_GUEST_DEFAULT_MO
-- 
2.41.0