This introduces a new 'ps2' feature which, when disabled, results in
no implicit PS/2 bus input devices being automatically added to the
domain and addition of the 'i8042=off' machine option to the QEMU
command-line.

A notable side effect of disabling the i8042 controller in QEMU is that
the vmport device won't be created. For this reason we will not allow
setting the vmport feature if the ps2 feature is explicitly disabled.

Signed-off-by: Kamil Szczęk <kamil@szczek.dev>
---
 docs/formatdomain.rst             |  6 ++++++
 src/conf/domain_conf.c            |  6 +++++-
 src/conf/domain_conf.h            |  1 +
 src/conf/domain_validate.c        | 23 +++++++++++++++++++++++
 src/conf/schemas/domaincommon.rng |  5 +++++
 src/qemu/qemu_command.c           |  5 +++++
 src/qemu/qemu_domain.c            |  3 ++-
 src/qemu/qemu_validate.c          | 23 +++++++++++++++++++++++
 8 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index e1e219bcb5..741405ec12 100644
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -2022,6 +2022,7 @@ Hypervisors may allow certain CPU / machine features to be toggled on/off.
      </tcg>
      <async-teardown enabled='yes'/>
      <ras state='on'/>
+     <ps2 state='on'/>
    </features>
    ...
 
@@ -2262,6 +2263,11 @@ are:
    exceptions when enabled (``on``). If the attribute is not defined, the
    hypervisor default will be used.
    :since:`Since 10.4.0` (QEMU/KVM and ARM virt guests only)
+``ps2``
+   Depending on the ``state`` attribute (values ``on``, ``off``) enable or
+   disable the emulation of a PS/2 controller used by ``ps2`` bus input devices.
+   If the attribute is not defined, the hypervisor default will be used.
+   :since:`Since 10.7.0` (QEMU only)
 
 Time keeping
 ------------
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index d950921667..a897b0b727 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -185,6 +185,7 @@ VIR_ENUM_IMPL(virDomainFeature,
               "tcg",
               "async-teardown",
               "ras",
+              "ps2",
 );
 
 VIR_ENUM_IMPL(virDomainCapabilitiesPolicy,
@@ -17019,7 +17020,8 @@ virDomainFeaturesDefParse(virDomainDef *def,
         case VIR_DOMAIN_FEATURE_HTM:
         case VIR_DOMAIN_FEATURE_NESTED_HV:
         case VIR_DOMAIN_FEATURE_CCF_ASSIST:
-        case VIR_DOMAIN_FEATURE_RAS: {
+        case VIR_DOMAIN_FEATURE_RAS:
+        case VIR_DOMAIN_FEATURE_PS2: {
             virTristateSwitch state;
 
             if (virXMLPropTristateSwitch(nodes[i], "state",
@@ -20883,6 +20885,7 @@ virDomainDefFeaturesCheckABIStability(virDomainDef *src,
         case VIR_DOMAIN_FEATURE_NESTED_HV:
         case VIR_DOMAIN_FEATURE_CCF_ASSIST:
         case VIR_DOMAIN_FEATURE_RAS:
+        case VIR_DOMAIN_FEATURE_PS2:
             if (src->features[i] != dst->features[i]) {
                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                                _("State of feature '%1$s' differs: source: '%2$s', destination: '%3$s'"),
@@ -27685,6 +27688,7 @@ virDomainDefFormatFeatures(virBuffer *buf,
         case VIR_DOMAIN_FEATURE_NESTED_HV:
         case VIR_DOMAIN_FEATURE_CCF_ASSIST:
         case VIR_DOMAIN_FEATURE_RAS:
+        case VIR_DOMAIN_FEATURE_PS2:
             switch ((virTristateSwitch) def->features[i]) {
             case VIR_TRISTATE_SWITCH_LAST:
             case VIR_TRISTATE_SWITCH_ABSENT:
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index eae621f900..f65cdd87b6 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2181,6 +2181,7 @@ typedef enum {
     VIR_DOMAIN_FEATURE_TCG,
     VIR_DOMAIN_FEATURE_ASYNC_TEARDOWN,
     VIR_DOMAIN_FEATURE_RAS,
+    VIR_DOMAIN_FEATURE_PS2,
 
     VIR_DOMAIN_FEATURE_LAST
 } virDomainFeature;
diff --git a/src/conf/domain_validate.c b/src/conf/domain_validate.c
index 39b8d67928..56f1092841 100644
--- a/src/conf/domain_validate.c
+++ b/src/conf/domain_validate.c
@@ -2744,6 +2744,29 @@ virDomainInputDefValidate(const virDomainInputDef *input,
         return -1;
     }
 
+    switch ((virDomainInputBus) input->bus) {
+    case VIR_DOMAIN_INPUT_BUS_PS2:
+        if (def->features[VIR_DOMAIN_FEATURE_PS2] == VIR_TRISTATE_SWITCH_OFF) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("ps2 bus inputs require the ps2 feature not to be disabled"));
+            return -1;
+        }
+        break;
+
+    case VIR_DOMAIN_INPUT_BUS_DEFAULT:
+    case VIR_DOMAIN_INPUT_BUS_USB:
+    case VIR_DOMAIN_INPUT_BUS_XEN:
+    case VIR_DOMAIN_INPUT_BUS_PARALLELS:
+    case VIR_DOMAIN_INPUT_BUS_VIRTIO:
+    case VIR_DOMAIN_INPUT_BUS_NONE:
+        break;
+
+    case VIR_DOMAIN_INPUT_BUS_LAST:
+    default:
+        virReportEnumRangeError(virDomainInputBus, input->bus);
+        return -1;
+    }
+
     return 0;
 }
 
diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng
index 05ba697924..a71f1d97b9 100644
--- a/src/conf/schemas/domaincommon.rng
+++ b/src/conf/schemas/domaincommon.rng
@@ -6917,6 +6917,11 @@
               <ref name="featurestate"/>
             </element>
           </optional>
+          <optional>
+            <element name="ps2">
+              <ref name="featurestate"/>
+            </element>
+          </optional>
         </interleave>
       </element>
     </optional>
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 28914c9c34..bb6fee4bfd 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6888,6 +6888,11 @@ qemuAppendDomainFeaturesMachineParam(virBuffer *buf,
         virBufferAsprintf(buf, ",ras=%s", str);
     }
 
+    if (def->features[VIR_DOMAIN_FEATURE_PS2] != VIR_TRISTATE_SWITCH_ABSENT) {
+        const char *str = virTristateSwitchTypeToString(def->features[VIR_DOMAIN_FEATURE_PS2]);
+        virBufferAsprintf(buf, ",i8042=%s", str);
+    }
+
     return 0;
 }
 
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 2b4bb54efc..d1767c326d 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -3928,7 +3928,8 @@ static int
 qemuDomainDefAddImplicitInputDevice(virDomainDef *def,
                                     virQEMUCaps *qemuCaps)
 {
-    if (virQEMUCapsSupportsI8042(qemuCaps, def)) {
+    if (virQEMUCapsSupportsI8042(qemuCaps, def) &&
+        def->features[VIR_DOMAIN_FEATURE_PS2] != VIR_TRISTATE_SWITCH_OFF) {
         if (virDomainDefMaybeAddInput(def,
                                       VIR_DOMAIN_INPUT_TYPE_MOUSE,
                                       VIR_DOMAIN_INPUT_BUS_PS2) < 0)
diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
index 6f7aeababe..88774f5383 100644
--- a/src/qemu/qemu_validate.c
+++ b/src/qemu/qemu_validate.c
@@ -143,6 +143,13 @@ qemuValidateDomainDefFeatures(const virDomainDef *def,
                                _("vmport is not available with this QEMU binary"));
                 return -1;
             }
+
+            if (def->features[i] == VIR_TRISTATE_SWITCH_ON &&
+                def->features[VIR_DOMAIN_FEATURE_PS2] == VIR_TRISTATE_SWITCH_OFF) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("vmport feature requires the ps2 feature not to be disabled"));
+                return -1;
+            }
             break;
 
         case VIR_DOMAIN_FEATURE_VMCOREINFO:
@@ -242,6 +249,22 @@ qemuValidateDomainDefFeatures(const virDomainDef *def,
             }
             break;
 
+        case VIR_DOMAIN_FEATURE_PS2:
+            if (def->features[i] != VIR_TRISTATE_SWITCH_ABSENT &&
+                !virQEMUCapsSupportsI8042(qemuCaps, def)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("ps2 feature is not available with this QEMU binary"));
+                return -1;
+            }
+
+            if (def->features[i] != VIR_TRISTATE_SWITCH_ABSENT &&
+                !virQEMUCapsSupportsI8042Toggle(qemuCaps, def)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("ps2 feature state cannot be controlled with this QEMU binary"));
+                return -1;
+            }
+            break;
+
         case VIR_DOMAIN_FEATURE_SMM:
         case VIR_DOMAIN_FEATURE_KVM:
         case VIR_DOMAIN_FEATURE_XEN:
-- 
2.45.0