[libvirt] [PATCH v2 1/3] adding QEMU_CAPS_QUERY_CURRENT_MACHINE and QEMU_CAPS_PM_WAKEUP_SUPPORT

[Daniel Henrique Barboza]

QEMU commit 46ea94ca9cf ("qmp: query-current-machine with
wakeup-suspend-support") added a new QMP command called
'query-current-machine' that retrieves guest parameters that
can vary in the same machine model (e.g. ACPI support for x86 VMs
depends on the '--no-acpi' option). Currently, this API has a single
flag, 'wakeup-suspend-support', that indicates whether the guest has
the capability of waking up from suspended state.

The original intent of this new API is to avoid situations such as [1],
where an user can execute "virsh dompmsuspend" in a guest that
can't wake up due to lack of support, making the guest unusable.
This is currently the case for any non-x86 arch guests and for
some x86 guests that starts with --no-acpi (q35 machines implements
suspend support even with the --no-acpi flag).

This is the Libvirt side of this API that will be available in
QEMU 4.0. QEMU_CAPS_QUERY_CURRENT_MACHINE is a new
virQEMUCapsCommands that will indicate if the QEMU binary
supports the 'query-current-machine' API. QEMU_CAPS_PM_WAKEUP_SUPPORT
is a flag that reflects the 'wakeup-suspend-support' value
for the current QEMU instance. In the next patches these
two caps will be populated and used in qemu_driver.c,
'qemuDomainPMSuspendForDuration', to complete the fix
for [1].

[1] https://github.com/open-power-host-os/qemu/issues/31

Signed-off-by: Daniel Henrique Barboza <danielhb413 at gmail.com>
---
 src/qemu/qemu_capabilities.c                      | 5 +++++
 src/qemu/qemu_capabilities.h                      | 4 ++++
 tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml | 1 +
 tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml | 1 +
 tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml  | 1 +
 5 files changed, 12 insertions(+)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 71d4c01296..5c1b41aa3e 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -523,6 +523,10 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "nvdimm.unarmed",
               "scsi-disk.device_id",
               "virtio-pci-non-transitional",
+              "query-current-machine",
+
+              /* 330 */
+              "wakeup-suspend-support",
     );
 
 
@@ -968,6 +972,7 @@ struct virQEMUCapsStringFlags virQEMUCapsCommands[] = {
     { "query-cpus-fast", QEMU_CAPS_QUERY_CPUS_FAST },
     { "qom-list-properties", QEMU_CAPS_QOM_LIST_PROPERTIES },
     { "blockdev-del", QEMU_CAPS_BLOCKDEV_DEL },
+    { "query-current-machine", QEMU_CAPS_QUERY_CURRENT_MACHINE },
 };
 
 struct virQEMUCapsStringFlags virQEMUCapsMigration[] = {
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index c6f6980684..85d0c653fa 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -506,6 +506,10 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */
     QEMU_CAPS_DEVICE_NVDIMM_UNARMED, /* -device nvdimm,unarmed= */
     QEMU_CAPS_SCSI_DISK_DEVICE_ID, /* 'device_id' property of scsi disk */
     QEMU_CAPS_VIRTIO_PCI_TRANSITIONAL, /* virtio *-pci-{non-}transitional devices */
+    QEMU_CAPS_QUERY_CURRENT_MACHINE, /* query-current-machine command */
+
+    /* 330 */
+    QEMU_CAPS_PM_WAKEUP_SUPPORT, /* dynamic capability that shows if the running domain has wake-up from suspend support */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml b/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml
index a8b5eb61c5..9d20be128a 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml
@@ -163,6 +163,7 @@
   <flag name='memory-backend-file.pmem'/>
   <flag name='scsi-disk.device_id'/>
   <flag name='virtio-pci-non-transitional'/>
+  <flag name='query-current-machine'/>
   <version>3001091</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>0</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml
index 311740f34f..a1a59e14cb 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml
@@ -163,6 +163,7 @@
   <flag name='memory-backend-file.pmem'/>
   <flag name='scsi-disk.device_id'/>
   <flag name='virtio-pci-non-transitional'/>
+  <flag name='query-current-machine'/>
   <version>3001091</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>0</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml
index 4585ff9e07..899c0cf7c8 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml
@@ -201,6 +201,7 @@
   <flag name='nvdimm.unarmed'/>
   <flag name='scsi-disk.device_id'/>
   <flag name='virtio-pci-non-transitional'/>
+  <flag name='query-current-machine'/>
   <version>3001050</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>43100758</microcodeVersion>
-- 
2.20.1