nvdimm acpi: drop the lock of fit buffer

as there is a global lock to protect vm-exit handlers and
QMP/monitor, this lock can be dropped

Suggested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

1 files changed, 5 insertions, 12 deletions

diff --git a/include/hw/mem/nvdimm.h b/include/hw/mem/nvdimm.h
index 33cd421..d3ffb25 100644
--- a/include/hw/mem/nvdimm.h
+++ b/include/hw/mem/nvdimm.h
@@ -99,20 +99,13 @@ typedef struct NVDIMMClass NVDIMMClass;
 #define NVDIMM_ACPI_IO_LEN      4
 
 /*
- * The buffer, @fit, saves the FIT info for all the presented NVDIMM
- * devices which is updated after the NVDIMM device is plugged or
- * unplugged.
- *
- * Rules to use the buffer:
- *    1) the user should hold the @lock to access the buffer.
- *    2) mark @dirty whenever the buffer is updated.
- *
- * These rules preserve NVDIMM ACPI _FIT method to read incomplete
- * or obsolete fit info if fit update happens during multiple RFIT
- * calls.
+ * NvdimmFitBuffer:
+ * @fit: FIT structures for present NVDIMMs. It is updated when
+ *   the NVDIMM device is plugged or unplugged.
+ * @dirty: It allows OSPM to detect change and restart read in
+ *   progress if there is any.
  */
 struct NvdimmFitBuffer {
-    QemuMutex lock;
     GArray *fit;
     bool dirty;
 };