Re: [libvirt] [PATCH 1/2] qemu: add capabilities flags related to SG_IO

This patch adds two capabilities flags to deal with various aspects of supporting SG_IO commands on virtio-blk-pci devices: QEMU_CAPS_VIRTIO_BLK_SCSI set if -device virtio-blk-pci accepts the scsi="on|off" option When present, this is on by default, but can be set to off to disable SG_IO functions. QEMU_CAPS_VIRTIO_BLK_SG_IO set if SG_IO commands are supported in the virtio-blk-pci driver (present since qemu 0.11 according to a qemu developer, if I understood correctly) --- src/qemu/qemu_capabilities.c | 8 ++++++++ src/qemu/qemu_capabilities.h | 3 +++ 2 files changed, 11 insertions(+), 0 deletions(-)

+++ b/src/qemu/qemu_capabilities.h @@ -118,6 +118,9 @@ enum qemuCapsFlags { QEMU_CAPS_NO_ACPI = 78, /* -no-acpi */ QEMU_CAPS_FSDEV_READONLY =79, /* -fsdev readonly supported */

+ QEMU_CAPS_VIRTIO_BLK_SCSI = 80, /* virtio-blk-pci.scsi */ + QEMU_CAPS_VIRTIO_BLK_SG_IO = 81, /* support for SG_IO commands, reportedly added in 0.11 */ + QEMU_CAPS_LAST, /* this must always be the last item */ };