Commit 918baead authored by Apollon Oikonomopoulos's avatar Apollon Oikonomopoulos Committed by Thomas Thrainer
Browse files

KVM: use running HVPs to calc blockdev options

Commit 0fe22ad2

 moved the call to _GenerateKVMBlockDevicesOptions() from
_GenerateKVMRuntime() to _ExecuteKvmRuntime. However, while in
_GenerateKVMRuntime() there is only one set of HVPs, those of the
instance's configuration, in _ExecuteKVMRuntime there are two sets of

  - The instance's configured HVPs
  - The HVPs the instance used when it was started

Currently, _GenerateKVMBlockDevicesOptions() uses the first set of HVPs
only, meaning that it will always read the configured HVPs. Since
_ExecuteKVMRuntime() is also called at migration time, it should use the
instance's running HVPs, otherwise migration while fail.

The following scenario will lead to a crash on migration:

 1. Start the instance (assuming 'paravirtual' disk_type)
 2. gnt-instance modify -H disk_type=scsi <instance_name>
 3. gnt-instance migrate <instance_name>

Step 3 will start the instance on the remote node with all disks
configured as 'scsi' and qemu will crash post-migration.

We fix this by making sure _GenerateKVMBlockDevicesOptions gets the
running HVPs as well.
Signed-off-by: default avatarApollon Oikonomopoulos <>
Signed-off-by: default avatarThomas Thrainer <>
Reviewed-by: default avatarThomas Thrainer <>
parent 5e6d16ab
......@@ -1236,12 +1236,14 @@ class KVMHypervisor(hv_base.BaseHypervisor):
return data
def _GenerateKVMBlockDevicesOptions(self, instance, kvm_disks,
def _GenerateKVMBlockDevicesOptions(self, instance, up_hvp, kvm_disks,
kvmhelp, devlist):
"""Generate KVM options regarding instance's block devices.
@type instance: L{objects.Instance}
@param instance: the instance object
@type up_hvp: dict
@param up_hvp: the instance's runtime hypervisor parameters
@type kvm_disks: list of tuples
@param kvm_disks: list of tuples [(disk, link_name, uri)..]
@type kvmhelp: string
......@@ -1252,12 +1254,11 @@ class KVMHypervisor(hv_base.BaseHypervisor):
@return: list of command line options eventually used by kvm executable
hvp = instance.hvparams
kernel_path = hvp[constants.HV_KERNEL_PATH]
kernel_path = up_hvp[constants.HV_KERNEL_PATH]
if kernel_path:
boot_disk = False
boot_disk = hvp[constants.HV_BOOT_ORDER] == constants.HT_BO_DISK
boot_disk = up_hvp[constants.HV_BOOT_ORDER] == constants.HT_BO_DISK
# whether this is an older KVM version that uses the boot=on flag
# on devices
......@@ -1265,7 +1266,7 @@ class KVMHypervisor(hv_base.BaseHypervisor):
dev_opts = []
device_driver = None
disk_type = hvp[constants.HV_DISK_TYPE]
disk_type = up_hvp[constants.HV_DISK_TYPE]
if disk_type == constants.HT_DISK_PARAVIRTUAL:
if_val = ",if=%s" % self._VIRTIO
......@@ -1278,7 +1279,7 @@ class KVMHypervisor(hv_base.BaseHypervisor):
if_val = ",if=%s" % disk_type
# Cache mode
disk_cache = hvp[constants.HV_DISK_CACHE]
disk_cache = up_hvp[constants.HV_DISK_CACHE]
if instance.disk_template in constants.DTS_EXT_MIRROR:
if disk_cache != "none":
# TODO: make this a hard error, instead of a silent overwrite
......@@ -1914,6 +1915,7 @@ class KVMHypervisor(hv_base.BaseHypervisor):
self._ConfigureNIC(instance, nic_seq, nic, taps[nic_seq])
bdev_opts = self._GenerateKVMBlockDevicesOptions(instance,
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