[PATCH] tpm_crb: mark command buffer as dirty on request completion

[Anthony PERARD]

From: Anthony PERARD <anthony.perard@citrix.com>

At the moment, there doesn't seems to be any way to know that QEMU
made modification to the command buffer. This is potentially an issue
on Xen while migrating a guest, as modification to the buffer after
the migration as started could be ignored and not transfered to the
destination.

Mark the memory region of the command buffer as dirty once a request
is completed.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---

I have only read code to find out whether the tpm-crb device was fine
with regards to migration, and I don't think there's anything that
could mark the memory region as dirty once a request is completed.

There is one call to memory_region_get_ram_ptr(), but nothing seems to
be done with the pointer is regards to ram migration. Am I wrong?

Thanks.
---
 hw/tpm/tpm_crb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
index aa9c00aad3..67db594c48 100644
--- a/hw/tpm/tpm_crb.c
+++ b/hw/tpm/tpm_crb.c
@@ -197,6 +197,7 @@ static void tpm_crb_request_completed(TPMIf *ti, int ret)
         ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
                          tpmSts, 1); /* fatal error */
     }
+    memory_region_set_dirty(&s->cmdmem, 0, CRB_CTRL_CMD_SIZE);
 }
 
 static enum TPMVersion tpm_crb_get_version(TPMIf *ti)
-- 
Anthony PERARD