diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 247f32f4eef5ce8b58b24a16471de25882c721bd..727f4331c048688e0b0059f2118b343bcd9eba7e 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -93,6 +93,7 @@ struct XenBlkDev { char *type; char *dev; char *devtype; + bool directiosafe; const char *fileproto; const char *filename; int ring_ref; @@ -701,6 +702,7 @@ static int blk_init(struct XenDevice *xendev) { struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); int info = 0; + char *directiosafe = NULL; /* read xenstore entries */ if (blkdev->params == NULL) { @@ -733,6 +735,8 @@ static int blk_init(struct XenDevice *xendev) if (blkdev->devtype == NULL) { blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type"); } + directiosafe = xenstore_read_be_str(&blkdev->xendev, "direct-io-safe"); + blkdev->directiosafe = (directiosafe && atoi(directiosafe)); /* do we have all we need? */ if (blkdev->params == NULL || @@ -760,6 +764,8 @@ static int blk_init(struct XenDevice *xendev) xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1); xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1); xenstore_write_be_int(&blkdev->xendev, "info", info); + + g_free(directiosafe); return 0; out_error: @@ -773,6 +779,8 @@ out_error: blkdev->dev = NULL; g_free(blkdev->devtype); blkdev->devtype = NULL; + g_free(directiosafe); + blkdev->directiosafe = false; return -1; } @@ -783,7 +791,11 @@ static int blk_connect(struct XenDevice *xendev) bool readonly = true; /* read-only ? */ - qflags = BDRV_O_CACHE_WB | BDRV_O_NATIVE_AIO; + if (blkdev->directiosafe) { + qflags = BDRV_O_NOCACHE | BDRV_O_NATIVE_AIO; + } else { + qflags = BDRV_O_CACHE_WB; + } if (strcmp(blkdev->mode, "w") == 0) { qflags |= BDRV_O_RDWR; readonly = false;