Prepare kvm options to support -device for disks
Prepare kvm options to support -device for disks

Newer kvm version support -device driver,... option where available
drivers can be found by running kvm -device ? command. Currently
ganeti uses `if` property of driver to define the disk type to use
which is also passed as hvparam. This patch prepares the use of
-device option only for paravirtual disks. To support other drivers
as well we must create a mapping between the values passed now as
disk_type hvparam and existing drivers. Note that if -device is used
`if` property of `drive` option should be `none`.

Signed-off-by: Dimitris Aragiorgis <4514117c4a99256e19437c7e3407c4ecbf98aec0@grnet.gr>
Signed-off-by: Thomas Thrainer <98bdeac947eb8ca18146e9ce7f092788ec242cd1@google.com>
Reviewed-by: Thomas Thrainer <98bdeac947eb8ca18146e9ce7f092788ec242cd1@google.com>

mbakke/ganeti,mbakke/ganeti,yiannist/ganeti,ganeti/ganeti,ganeti-github-testing/ganeti-test-1,leshchevds/ganeti,andir/ganeti,grnet/snf-ganeti,mbakke/ganeti,andir/ganeti,onponomarev/ganeti,leshchevds/ganeti,dimara/ganeti,ganeti/ganeti,yiannist/ganeti,apyrgio/ganeti,ganeti/ganeti,apyrgio/ganeti,dimara/ganeti,andir/ganeti,leshchevds/ganeti,bitemyapp/ganeti,apyrgio/snf-ganeti,bitemyapp/ganeti,grnet/snf-ganeti,yiannist/ganeti,onponomarev/ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/snf-ganeti