[PATCH] tcg: gdbstub: Fix missing breakpoint issue

[Changbin Du <changbin.du@gmail.com>]

When inserting breakpoints, we need to invalidate related TBs to apply
helper call. This is done by breakpoint_invalidate(). But many users
found the BPs sometimes never hit.

In system mode emulation, the BPs are global in guest but not particular
address space. The issue is that the current implementation only trys to
invalidate TB of paddr corresponding to the target vaddr in current MMU
context. Then some cached TBs continue running without BPs applied.

To fix this issue, we can just invalidate all TBs as what step mode does.
(For old version users, issuing a step command can workaround this problem.)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 exec.c | 29 +----------------------------
 1 file changed, 1 insertion(+), 28 deletions(-)

diff --git a/exec.c b/exec.c
index 67e520d18e..9d9fd48519 100644
--- a/exec.c
+++ b/exec.c
@@ -997,36 +997,9 @@ static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
     tb_invalidate_phys_addr(pc);
 }
 #else
-void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr, MemTxAttrs attrs)
-{
-    ram_addr_t ram_addr;
-    MemoryRegion *mr;
-    hwaddr l = 1;
-
-    if (!tcg_enabled()) {
-        return;
-    }
-
-    RCU_READ_LOCK_GUARD();
-    mr = address_space_translate(as, addr, &addr, &l, false, attrs);
-    if (!(memory_region_is_ram(mr)
-          || memory_region_is_romd(mr))) {
-        return;
-    }
-    ram_addr = memory_region_get_ram_addr(mr) + addr;
-    tb_invalidate_phys_page_range(ram_addr, ram_addr + 1);
-}
-
 static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
 {
-    MemTxAttrs attrs;
-    hwaddr phys = cpu_get_phys_page_attrs_debug(cpu, pc, &attrs);
-    int asidx = cpu_asidx_from_attrs(cpu, attrs);
-    if (phys != -1) {
-        /* Locks grabbed by tb_invalidate_phys_addr */
-        tb_invalidate_phys_addr(cpu->cpu_ases[asidx].as,
-                                phys | (pc & ~TARGET_PAGE_MASK), attrs);
-    }
+    tb_flush(cpu);
 }
 #endif
 
-- 
2.24.0