[PATCH 0/2] DEVICE_UNPLUG_GUEST_ERROR support

[Michal Prívozník]

On 11/1/21 1:27 AM, Daniel Henrique Barboza wrote:
> Hi,
> 
> This small series adds support to a new QMP event called
> DEVICE_UNPLUG_GUEST_SUPPORT introduced recently in upstream QEMU.
> This event is emitted when a device removal error is detected in the guest
> side. Libvirt can use this event to to abort the removal operation
> immediately instead of waiting for the operation to timeout.
> 
> Upstream QEMU is emitting this event in the following cases:
> 
> - memory removal errors in ACPI and pseries guests
> - CPU removal errors in pseries guests
> 
> Adding support to DEVICE_UNPLUG_GUEST_ERROR will allow Libvirt to
> detect all device removal errors that QEMU might add in the future.
> 
> The patches were tested using a common scenario where CPU removal will
> fail everytime in a pseries guest:
> 
> - start a pseries guest with 1 CPU
> - add one CPU
> - offline vcpu0 in the guest kernel
> - try to remove the recently added CPU (vcpu1). The kernel will refuse the
> unplug because vcpu1 is the last online CPU
> 
> This test case will cause 'setvcpus' to hang until the timeout is fired:
> 
> [danielhb at ltc-boston118 build]$ sudo ./run tools/virsh setvcpus f34 1
> error: Timed out during operation: vcpu unplug request timed out. Unplug result must be manually inspected in the domain
> 
> With this series applied, 'setvcpus' will report the error as soon as
> the DEVICE_UNPLUG_GUEST_ERROR event is received:
> 
> [danielhb at ltc-boston118 build]$ sudo ./run tools/virsh setvcpus f34 1
> error: operation failed: unplug of device was rejected by the guest                                  
> 
> 
> I haven't add any documentation because I didn't find a good place to
> document this change, and I'm not sure if this is necessary either since
> this doesn't change user ABI. If this requires a doc change please let
> me know.

Right, this is an internal implementation and your patches just emit an
already existing event, so I think no additional doc is needed. Except
maybe a NEWS.rst?

> 
> 
> 
> Daniel Henrique Barboza (2):
>   tests: update QEMU and domain ppc64 capabilities for qemu 6.2
>   qemu: add DEVICE_UNPLUG_GUEST_ERROR event support
> 
>  src/qemu/qemu_monitor.c                       |    12 +
>  src/qemu/qemu_monitor.h                       |     9 +
>  src/qemu/qemu_monitor_json.c                  |    19 +
>  src/qemu/qemu_process.c                       |    37 +
>  tests/domaincapsdata/qemu_6.2.0.ppc64.xml     |   138 +
>  .../caps_6.2.0.ppc64.replies                  | 31062 ++++++++++++++++
>  .../qemucapabilitiesdata/caps_6.2.0.ppc64.xml |  1167 +
>  ...default-video-type-ppc64.ppc64-latest.args |    13 +-
>  ...ault-cpu-kvm-pseries-2.7.ppc64-latest.args |    13 +-
>  ...ault-cpu-kvm-pseries-3.1.ppc64-latest.args |    13 +-
>  ...ault-cpu-kvm-pseries-4.2.ppc64-latest.args |    13 +-
>  ...ault-cpu-tcg-pseries-2.7.ppc64-latest.args |    13 +-
>  ...ault-cpu-tcg-pseries-3.1.ppc64-latest.args |    13 +-
>  ...ault-cpu-tcg-pseries-4.2.ppc64-latest.args |    13 +-
>  .../ppc64-pseries-graphics.ppc64-latest.args  |    29 +-
>  .../ppc64-pseries-headless.ppc64-latest.args  |    23 +-
>  .../ppc64-tpmproxy-single.ppc64-latest.args   |    11 +-
>  .../ppc64-tpmproxy-with-tpm.ppc64-latest.args |    13 +-
>  .../tpm-emulator-spapr.ppc64-latest.args      |    19 +-
>  19 files changed, 32531 insertions(+), 99 deletions(-)
>  create mode 100644 tests/domaincapsdata/qemu_6.2.0.ppc64.xml
>  create mode 100644 tests/qemucapabilitiesdata/caps_6.2.0.ppc64.replies
>  create mode 100644 tests/qemucapabilitiesdata/caps_6.2.0.ppc64.xml
> 

Reviewed-by: Michal Privoznik <mprivozn at redhat.com>

Michal