Prevent target code getting out of sync with Translation Blocks.

Fixes a problem where the target code gets out of sync
with the Translation Blocks (TB). LTP tests crash and QEMU
itself will crash eventually when generating new TB code
while searching for a PC in an existing TB. Debugging code
that checks that the target code and TB's are in sync confirm
that this change fixes the problem.

This is an import from git://git.qemu.org/qemu.git
    -----------------------------------------------------------------------
    commit 0b57e287138728f72d88b06e69b970c5d745c44a
    Author: David Gibson <david@gibson.dropbear.id.au>
    Date:   Mon Sep 10 12:30:57 2012 +1000

    cpu_physical_memory_write_rom() needs to do TB invalidates

    cpu_physical_memory_write_rom(), despite the name, can also be used to
    write images into RAM - and will often be used that way if the machine
    uses load_image_targphys() into RAM addresses.

    However, cpu_physical_memory_write_rom(), unlike cpu_physical_memory_rw()
    doesn't invalidate any cached TBs which might be affected by the region
    written.

    This was breaking reset (under full emu) on the pseries machine - we loaded
    our firmware image into RAM, and while executing it rewrite the code at
    the entry point (correctly causing a TB invalidate/refresh).  When we
    reset the firmware image was reloaded, but the TB from the rewrite was
    still active and caused us to get an illegal instruction trap.

    This patch fixes the bug by duplicating the tb invalidate code from
    cpu_physical_memory_rw() in cpu_physical_memory_write_rom().

    Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    -----------------------------------------------------------------------

Change-Id: I2f0eeb512a289b0c9cae2e11e02c7d68eba96f05
Signed-off-by: Chris Dearman <Chris.Dearman@imgtec.com>
Signed-off-by: Pete Delaney <piet.delaney@imgtec.com>
Signed-off-by: Duane Sand <Duane.Sand@imgtec.com>
diff --git a/exec.c b/exec.c
index c71ef66..90c5c6b 100644
--- a/exec.c
+++ b/exec.c
@@ -3439,6 +3439,13 @@
             /* ROM/RAM case */
             ptr = qemu_get_ram_ptr(addr1);
             memcpy(ptr, buf, l);
+           if (!cpu_physical_memory_is_dirty(addr1)) {
+               /* invalidate code */
+               tb_invalidate_phys_page_range(addr1, addr1 + l, 0);
+               /* set dirty bit */
+               cpu_physical_memory_set_dirty_flags(
+                   addr1, (0xff & ~CODE_DIRTY_FLAG));
+           }
         }
         len -= l;
         buf += l;