From: Juergen Gross Date: Wed, 29 Jun 2016 15:50:48 +0000 (+0200) Subject: xen: use native disk xenbus protocol if possible X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4ada797b05a52ac824a710c67216b37739026a64;p=qemu.git xen: use native disk xenbus protocol if possible The qdisk implementation is using the native xenbus protocol only in case of no protocol specified at all. As using the explicit 32- or 64-bit protocol is slower than the native one due to copying requests not by memcpy but element for element, this is not optimal. Correct this by using the native protocol in case word sizes of frontend and backend match. Signed-off-by: Juergen Gross Reviewed-by: Anthony PERARD Signed-off-by: Stefano Stabellini --- diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 3b8ad33fc5..342868904d 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -976,14 +976,16 @@ static int blk_connect(struct XenDevice *xendev) blkdev->feature_persistent = !!pers; } - blkdev->protocol = BLKIF_PROTOCOL_NATIVE; - if (blkdev->xendev.protocol) { - if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { - blkdev->protocol = BLKIF_PROTOCOL_X86_32; - } - if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { - blkdev->protocol = BLKIF_PROTOCOL_X86_64; - } + if (!blkdev->xendev.protocol) { + blkdev->protocol = BLKIF_PROTOCOL_NATIVE; + } else if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_NATIVE) == 0) { + blkdev->protocol = BLKIF_PROTOCOL_NATIVE; + } else if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { + blkdev->protocol = BLKIF_PROTOCOL_X86_32; + } else if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { + blkdev->protocol = BLKIF_PROTOCOL_X86_64; + } else { + blkdev->protocol = BLKIF_PROTOCOL_NATIVE; } blkdev->sring = xengnttab_map_grant_ref(blkdev->xendev.gnttabdev,