[Qemu-devel] [PATCH v15 24/24] icount: clean up cpu_can_io before jumping to the next block

Pavel Dovgalyuk posted 24 patches 6 years, 7 months ago
Maintainers: "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Laurent Vivier <lvivier@redhat.com>, Max Reitz <mreitz@redhat.com>, Fam Zheng <fam@euphon.net>, Stefan Hajnoczi <stefanha@redhat.com>, Eric Blake <eblake@redhat.com>, Richard Henderson <rth@twiddle.net>, Michael Roth <mdroth@linux.vnet.ibm.com>, Kevin Wolf <kwolf@redhat.com>, Peter Lieven <pl@kamp.de>, Josh Durgin <jdurgin@redhat.com>, Markus Armbruster <armbru@redhat.com>, Juan Quintela <quintela@redhat.com>, Thomas Huth <thuth@redhat.com>, Ronnie Sahlberg <ronniesahlberg@gmail.com>, Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
[Qemu-devel] [PATCH v15 24/24] icount: clean up cpu_can_io before jumping to the next block
Posted by Pavel Dovgalyuk 6 years, 7 months ago
Most of IO instructions can be executed only at the end of the block in
icount mode. Therefore translator can set cpu_can_io flag when translating
the last instruction.
But when the blocks are chained, then this flag is not reset and may
remain set at the beginning of the next block.
This patch resets the flag before "chaining" the translation blocks.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
---
 accel/tcg/tcg-runtime.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/accel/tcg/tcg-runtime.c b/accel/tcg/tcg-runtime.c
index d0d4484406..5871f5aba2 100644
--- a/accel/tcg/tcg-runtime.c
+++ b/accel/tcg/tcg-runtime.c
@@ -151,6 +151,8 @@ void *HELPER(lookup_tb_ptr)(CPUArchState *env)
     target_ulong cs_base, pc;
     uint32_t flags;
 
+    /* We are going to jump to the next block. can_do_io should be reset */
+    cpu->can_do_io = !use_icount;
     tb = tb_lookup__cpu_state(cpu, &pc, &cs_base, &flags, curr_cflags());
     if (tb == NULL) {
         return tcg_ctx->code_gen_epilogue;