On 25.07.2016 22:48, Eric Farman wrote:
> Open /dev/vhost-scsi, and record the resulting file descriptor, so that
> the guest has access to the host device outside of the libvirt daemon.
> Pass this information, along with data parsed from the XML file, to build
> a device string for the qemu command line. That device string will be
> for either a vhost-scsi-ccw device in the case of an s390 machine, or
> vhost-scsi-pci for any others.
>
> Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Boris Fiuczynski <fiuczy@xxxxxxxxxxxxxxxxxx>
> ---
> src/libvirt_private.syms | 1 +
> src/qemu/qemu_command.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++-
> src/qemu/qemu_command.h | 5 ++++
> src/util/virscsi.c | 26 +++++++++++++++++++
> src/util/virscsi.h | 1 +
> 5 files changed, 99 insertions(+), 1 deletion(-)
>
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 9396c4e..b91c7a8 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -2253,6 +2253,7 @@ virSCSIDeviceListNew;
> virSCSIDeviceListSteal;
> virSCSIDeviceNew;
> virSCSIDeviceSetUsedBy;
> +virSCSIOpenVhost;
>
>
> # util/virseclabel.h
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index dd15ff8..31b30a4 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -4533,6 +4533,67 @@ qemuBuildSCSIiSCSIHostdevDrvStr(virDomainHostdevDefPtr dev)
> }
>
> char *
> +qemuBuildSCSIVhostHostdevDevStr(const virDomainDef *def,
> + virDomainHostdevDefPtr dev,
> + virQEMUCapsPtr qemuCaps,
> + virCommandPtr cmd)
> +{
> + size_t i;
> + virBuffer buf = VIR_BUFFER_INITIALIZER;
> + virDomainHostdevSubsysSCSIPtr scsisrc = &dev->source.subsys.u.scsi;
> + virDomainHostdevSubsysSCSIVhostPtr vhostsrc = &scsisrc->u.vhost;
> + int *vhostfd = NULL;
> + size_t vhostfdSize = 1;
> +
> + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VHOST_SCSI)) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("This QEMU doesn't support vhost-scsi devices"));
> + goto cleanup;
> + }
> +
> + if (ARCH_IS_S390(def->os.arch))
> + virBufferAddLit(&buf, "vhost-scsi-ccw");
> + else
> + virBufferAddLit(&buf, "vhost-scsi-pci");
> +
> + virBufferAsprintf(&buf, ",wwpn=%s", vhostsrc->wwpn);
> +
> + if (VIR_ALLOC_N(vhostfd, vhostfdSize) < 0)
> + goto cleanup;
> +
> + memset(vhostfd, -1, sizeof(*vhostfd) * vhostfdSize);
> +
> + if (virSCSIOpenVhost(vhostfd, &vhostfdSize) < 0)
> + goto cleanup;
> +
> + for (i = 0; i < vhostfdSize; i++) {
> + if (cmd) {
If cmd == NULL here we are in way bigger trouble. Just drop the check.
> + virCommandPassFD(cmd, vhostfd[i],
> + VIR_COMMAND_PASS_FD_CLOSE_PARENT);
> + }
> + }
> +
> + if (vhostfdSize == 1) {
> + virBufferAsprintf(&buf, ",vhostfd=%d", vhostfd[0]);
> + } else {
> + /* FIXME if 'vhostfds' became a valid vhost-scsi property in QEMU */
> + goto cleanup;
Instead of failing here silently, we should report an error. I'll leave
the error message up to you ;-)
> + }
> +
> + virBufferAsprintf(&buf, ",id=%s", dev->info->alias);
Here we should check if there has been an error while constructing @buf.
For instance an OOM might have occurred.
if (virBufferCheckError(&buf) < 0)
goto cleanup;
> +
> + VIR_FREE(vhostfd);
> + return virBufferContentAndReset(&buf);
> +
> + cleanup:
> + for (i = 0; vhostfd && i < vhostfdSize; i++)
> + VIR_FORCE_CLOSE(vhostfd[i]);
> + VIR_FREE(vhostfd);
> + virBufferFreeAndReset(&buf);
> + return NULL;
> +}
The rest looks okay. Perhaps, if you want you can introduce
virSCSIOpenVhost() in a separate patch. But only if you want. I don't
care that much.
Michal
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list