[libvirt] [PATCH v2 2/3] qemu: check the kvm host cpu max limits in virConnectGetDomainCapabilities

[Shivaprasad G Bhat]

The qemu limit and host limit both should be considered for
the domain vcpu max limits.

Signed-off-by: Shivaprasad G Bhat <sbhat at linux.vnet.ibm.com>
---
 src/qemu/qemu_capabilities.c |   11 ++++++++---
 src/qemu/qemu_capabilities.h |    3 ++-
 src/qemu/qemu_driver.c       |    2 +-
 tests/domaincapstest.c       |    3 ++-
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 01466fc..ff5ad19 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -38,6 +38,7 @@
 #include "virbitmap.h"
 #include "virnodesuspend.h"
 #include "virnuma.h"
+#include "virhostcpu.h"
 #include "qemu_monitor.h"
 #include "virstring.h"
 #include "qemu_hostdev.h"
@@ -4336,16 +4337,20 @@ int
 virQEMUCapsFillDomainCaps(virDomainCapsPtr domCaps,
                           virQEMUCapsPtr qemuCaps,
                           virFirmwarePtr *firmwares,
-                          size_t nfirmwares)
+                          size_t nfirmwares,
+                          virDomainVirtType virttype)
 {
     virDomainCapsOSPtr os = &domCaps->os;
     virDomainCapsDeviceDiskPtr disk = &domCaps->disk;
     virDomainCapsDeviceHostdevPtr hostdev = &domCaps->hostdev;
     virDomainCapsDeviceGraphicsPtr graphics = &domCaps->graphics;
     virDomainCapsDeviceVideoPtr video = &domCaps->video;
-    int maxvcpus = virQEMUCapsGetMachineMaxCpus(qemuCaps, domCaps->machine);
 
-    domCaps->maxvcpus = maxvcpus;
+    domCaps->maxvcpus = virQEMUCapsGetMachineMaxCpus(qemuCaps, domCaps->machine);
+    if (virttype == VIR_DOMAIN_VIRT_KVM) {
+        int hostmaxvcpus = virHostCPUGetKVMMaxVCPUs();
+        domCaps->maxvcpus = MIN(domCaps->maxvcpus, hostmaxvcpus);
+    }
 
     if (virQEMUCapsFillDomainOSCaps(os, firmwares, nfirmwares) < 0 ||
         virQEMUCapsFillDomainDeviceDiskCaps(qemuCaps,
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index affb639..9d891c8 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -492,6 +492,7 @@ int virQEMUCapsInitGuestFromBinary(virCapsPtr caps,
 int virQEMUCapsFillDomainCaps(virDomainCapsPtr domCaps,
                               virQEMUCapsPtr qemuCaps,
                               virFirmwarePtr *firmwares,
-                              size_t nfirmwares);
+                              size_t nfirmwares,
+                              virDomainVirtType virttype);
 
 #endif /* __QEMU_CAPABILITIES_H__*/
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 4e6e4c9..59b657b 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -18475,7 +18475,7 @@ qemuConnectGetDomainCapabilities(virConnectPtr conn,
         goto cleanup;
 
     if (virQEMUCapsFillDomainCaps(domCaps, qemuCaps,
-                                  cfg->firmwares, cfg->nfirmwares) < 0)
+                                  cfg->firmwares, cfg->nfirmwares, virttype) < 0)
         goto cleanup;
 
     ret = virDomainCapsFormat(domCaps);
diff --git a/tests/domaincapstest.c b/tests/domaincapstest.c
index ae31146..01ebfcc 100644
--- a/tests/domaincapstest.c
+++ b/tests/domaincapstest.c
@@ -129,7 +129,8 @@ fillQemuCaps(virDomainCapsPtr domCaps,
 
     if (virQEMUCapsFillDomainCaps(domCaps, qemuCaps,
                                   cfg->firmwares,
-                                  cfg->nfirmwares) < 0)
+                                  cfg->nfirmwares,
+                                  VIR_DOMAIN_VIRT_QEMU) < 0)
         goto cleanup;
 
     /* The function above tries to query host's KVM & VFIO capabilities by