Re: [libvirt PATCH v4 3/3] add virQEMUCapsProbeQMPTCGState function to set QEMU_CAPS_TCG_DISABLED

[Michal Privoznik]

On 4/24/20 9:58 AM, Peter Krempa wrote:
On Wed, Apr 22, 2020 at 17:50:44 -0400, Tobin Feldman-Fitzthum wrote:
Add virQEMUCapsProbeQMPTCGState to set TCG_DISABLED cap if version
is > 2.10, KVM is enabled, and tcg-accel is not present in
qom-list-types result.
Signed-off-by: Tobin Feldman-Fitzthum <to...@linux.vnet.ibm.com>
---
  src/qemu/qemu_capabilities.c | 34 ++++++++++++++++++++++++++++++++--
  1 file changed, 32 insertions(+), 2 deletions(-)

I don't feel comfortable reviewing the other two patches which deal with
the actual use of the capability, so I'll leave those for somebody else.

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index e7179ea048..4a3170fc5c 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -2576,7 +2576,35 @@ virQEMUCapsProbeQMPGenericProps(virQEMUCapsPtr qemuCaps,
  }
  
  static int
-virQEMUCapsProbeQMPDevices(virQEMUCapsPtr qemuCaps,
+virQEMUCapsProbeQMPTCGState(virQEMUCapsPtr qemuCaps,

Returned value of the new function is not used, so please define it as
'void'

+                            char **values,
+                            int nvalues)
+{
+    size_t i;
+    bool found = false;
+    /*
+     * As of version 2.10, QEMU can be built without the TCG.
+     * */
+    if (qemuCaps->version < 2010000)
+        return 0;
+    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM))
+        return 0;
+
+    for (i = 0; i < nvalues; i++) {
+        if (STREQ(values[i], "tcg-accel")) {
+            found = true;

You can set the capability here without intermediate variable and just
return.

I'm not quite sure what you mean. The capability tracks lack of 
tcg-accel. So what can be done here is return and drop the check before 
setting the capability below.


+            break;
+        }
+    }
+
+    if (!found)
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_TCG_DISABLED);
+
+    return 0;
+}
+
+static int
+virQEMUCapsProbeQMPTypes(virQEMUCapsPtr qemuCaps,
                             qemuMonitorPtr mon)
  {
      int nvalues;

With the above resolved:

Reviewed-by: Peter Krempa <pkre...@redhat.com>


Michal