[libvirt] [PATCH v4 4/6] qemu: Save various defaults for shmem

Martin Kletzander mkletzan at redhat.com
Wed Oct 26 10:51:35 UTC 2016


We're keeping some things at default and that's not something we want to
do intentionally.  Let's save some sensible defaults upfront in order to
avoid having problems later.  The details for the defaults (of the newer
implementation) can be found in qemu's commit 5400c02b90bb:

  http://git.qemu.org/?p=qemu.git;a=commit;h=5400c02b90bb

Since we are merely saving the defaults it will not change the guest ABI
and thanks to the fact that we're doing it in the PostParse callback it
will not break the ABI stability checks.

Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
---
 src/qemu/qemu_domain.c                             | 54 ++++++++++++++++++++++
 tests/qemuxml2argvdata/qemuxml2argv-shmem.args     |  2 +-
 .../qemuxml2xmlout-shmem-plain-doorbell.xml        |  5 +-
 tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem.xml  |  1 +
 4 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 94f793e8ce9c..ee3bf8cae3a2 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2671,6 +2671,56 @@ qemuDomainChrDefDropDefaultPath(virDomainChrDefPtr chr,


 static int
+qemuDomainShmemDefPostParse(virDomainShmemDefPtr shm)
+{
+    /* This was the default since the introduction of this device. */
+    if (shm->model != VIR_DOMAIN_SHMEM_MODEL_IVSHMEM_DOORBELL && !shm->size)
+        shm->size = 4 << 20;
+
+    /* Nothing more to check/change for IVSHMEM */
+    if (shm->model == VIR_DOMAIN_SHMEM_MODEL_IVSHMEM)
+        return 0;
+
+    if (!shm->server.enabled) {
+        if (shm->model == VIR_DOMAIN_SHMEM_MODEL_IVSHMEM_DOORBELL) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("shmem model '%s' is supported "
+                             "only with server option enabled"),
+                           virDomainShmemModelTypeToString(shm->model));
+            return -1;
+        }
+
+        if (shm->msi.enabled) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("shmem model '%s' doesn't support "
+                             "msi"),
+                           virDomainShmemModelTypeToString(shm->model));
+        }
+    } else {
+        if (shm->model == VIR_DOMAIN_SHMEM_MODEL_IVSHMEM_PLAIN) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("shmem model '%s' is supported "
+                             "only with server option disabled"),
+                           virDomainShmemModelTypeToString(shm->model));
+            return -1;
+        }
+
+        if (shm->size) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("shmem model '%s' does not support size setting"),
+                           virDomainShmemModelTypeToString(shm->model));
+            return -1;
+        }
+        shm->msi.enabled = true;
+        if (!shm->msi.ioeventfd)
+            shm->msi.ioeventfd = VIR_TRISTATE_SWITCH_ON;
+    }
+
+    return 0;
+}
+
+
+static int
 qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
                              const virDomainDef *def,
                              virCapsPtr caps,
@@ -2874,6 +2924,10 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
         }
     }

+    if (dev->type == VIR_DOMAIN_DEVICE_SHMEM &&
+        qemuDomainShmemDefPostParse(dev->data.shmem) < 0)
+        goto cleanup;
+
     ret = 0;

  cleanup:
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-shmem.args b/tests/qemuxml2argvdata/qemuxml2argv-shmem.args
index 99fac119b04c..bdf660a3c435 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-shmem.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-shmem.args
@@ -17,7 +17,7 @@ QEMU_AUDIO_DRV=none \
 -no-acpi \
 -boot c \
 -usb \
--device ivshmem,id=shmem0,shm=shmem0,bus=pci.0,addr=0x3 \
+-device ivshmem,id=shmem0,size=4m,shm=shmem0,bus=pci.0,addr=0x3 \
 -device ivshmem,id=shmem1,size=128m,shm=shmem1,bus=pci.0,addr=0x5 \
 -device ivshmem,id=shmem2,size=256m,shm=shmem2,bus=pci.0,addr=0x4 \
 -device ivshmem,id=shmem3,size=512m,chardev=charshmem3,bus=pci.0,addr=0x6 \
diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem-plain-doorbell.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem-plain-doorbell.xml
index ab9c69bfccd4..7872e1c8a102 100644
--- a/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem-plain-doorbell.xml
+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem-plain-doorbell.xml
@@ -23,6 +23,7 @@
     <memballoon model='none'/>
     <shmem name='shmem0'>
       <model type='ivshmem-plain'/>
+      <size unit='M'>4</size>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
     </shmem>
     <shmem name='shmem1'>
@@ -38,11 +39,13 @@
     <shmem name='shmem3'>
       <model type='ivshmem-doorbell'/>
       <server/>
+      <msi ioeventfd='on'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
     </shmem>
     <shmem name='shmem4'>
       <model type='ivshmem-doorbell'/>
       <server path='/tmp/shmem4-sock'/>
+      <msi ioeventfd='on'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
     </shmem>
     <shmem name='shmem5'>
@@ -54,7 +57,7 @@
     <shmem name='shmem6'>
       <model type='ivshmem-doorbell'/>
       <server path='/tmp/shmem6-sock'/>
-      <msi vectors='16'/>
+      <msi vectors='16' ioeventfd='on'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>
     </shmem>
     <shmem name='shmem7'>
diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem.xml
index 5602913648bc..04b463a27892 100644
--- a/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem.xml
+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-shmem.xml
@@ -23,6 +23,7 @@
     <memballoon model='none'/>
     <shmem name='shmem0'>
       <model type='ivshmem'/>
+      <size unit='M'>4</size>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
     </shmem>
     <shmem name='shmem1'>
-- 
2.10.1




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