[libvirt] [PATCH 4/4] qemu: Limit refresh of CPU halted state to s390

Peter Krempa posted 4 patches 7 years, 3 months ago
[libvirt] [PATCH 4/4] qemu: Limit refresh of CPU halted state to s390
Posted by Peter Krempa 7 years, 3 months ago
From: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>

Refreshing the halted state can cause VM performance issues. Since
s390 is currently the only architecture with a known interest in
the halted state, we're avoiding to call QEMU on other platforms.

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
---
 src/qemu/qemu_domain.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 5395cd093c..aa652959ed 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -8726,6 +8726,11 @@ qemuDomainRefreshVcpuHalted(virQEMUDriverPtr driver,
     if (vm->def->virtType == VIR_DOMAIN_VIRT_QEMU)
         return 0;

+    /* The halted state is interresting only on s390(x). On other platforms
+     * the data would be stale at the time when it would be used. */
+    if (!ARCH_IS_S390(vm->def->os.arch))
+        return 0;
+
     if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
         return -1;

-- 
2.15.0

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