On 07/09/2018 10:32 AM, Michal Privoznik wrote:
On 07/06/2018 08:50 PM, John Ferlan wrote:
> Prior to the hostdev being inserted in the hostdevs list,
> add a check during qemuDomainAttachDeviceConfig to determine
> whether the new/incoming <hostdev ...> device is providing
> the same <address> as some existing hostdev on the list
> and if so fail the cold attach.
>
> This cannot be done during virDomainHostdevDefPostParse
> because that is called after virDomainDefParseXML would
> have inserted a hostdev onto the hostdevs list and thus
> would have a "conflict" with itself. Therefore, the post
> parse processing can only compare if the current hostdev
> address conflicts with a SCSI <disk> address.
>
> By comparison this is similar to the validation phase
> checks in virDomainDefCheckDuplicateDriveAddresses that
> occur during define/startup processing but are not run
> during config attach of a live guest.
>
> Signed-off-by: John Ferlan <jferlan(a)redhat.com>
> ---
> src/qemu/qemu_driver.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 9a35e04a85..ef1abe3f68 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -8007,6 +8007,12 @@ qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef,
> _("device is already in the domain
configuration"));
> return -1;
> }
> + if (dev->data.hostdev->info->type !=
VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE &&
> + virDomainDefHasDeviceAddress(vmdef, dev->data.hostdev->info)) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("a device with the same address already exists
"));
> + return -1;
> + }
> if (virDomainHostdevInsert(vmdef, hostdev))
> return -1;
> dev->data.hostdev = NULL;
>
I think hostdevs are not the only type of device suffering from this. In
fact, I've just tested disks and libvirt accepts attaching another disk
onto same <address/> happily.
I wonder if this should go into virDomainDefCompatibleDevice() (now that
we have @action there ;-) ).
It's a case of myopia for the bug I'm working on as listed in patch2.
What I did is no different than the VIR_DOMAIN_DEVICE_RNG check in the
same function.
Still, if I change this patch to add:
if (action == VIR_DOMAIN_DEVICE_ACTION_ATTACH && !live &&
data.newInfo &&
data.newInfo->type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE &&
virDomainDefHasDeviceAddress(def, data.newInfo)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("a device with the same address already exists "));
return -1;
}
to virDomainDefCompatibleDevice and remove the (new)hostdev and
(existing)rng checks, then I believe it covers the existing cases.
Tks -
John