If we don't HAVE_LINUX_KVM_H, we can't query /dev/kvm to discover the limits on the number of vCPUs, so we report an error and return a negative value instead. --- src/util/virhostcpu.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/src/util/virhostcpu.c b/src/util/virhostcpu.c index 4ff4e72..a33932f 100644 --- a/src/util/virhostcpu.c +++ b/src/util/virhostcpu.c @@ -1299,6 +1299,7 @@ virHostCPUGetThreadsPerSubcore(virArch arch ATTRIBUTE_UNUSED) #endif /* HAVE_LINUX_KVM_H && defined(KVM_CAP_PPC_SMT) */ +#if HAVE_LINUX_KVM_H int virHostCPUGetKVMMaxVCPUs(void) { @@ -1310,11 +1311,11 @@ virHostCPUGetKVMMaxVCPUs(void) return -1; } -#ifdef KVM_CAP_MAX_VCPUS +# ifdef KVM_CAP_MAX_VCPUS /* at first try KVM_CAP_MAX_VCPUS to determine the maximum count */ if ((ret = ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS)) > 0) goto cleanup; -#endif /* KVM_CAP_MAX_VCPUS */ +# endif /* KVM_CAP_MAX_VCPUS */ /* as a fallback get KVM_CAP_NR_VCPUS (the recommended maximum number of * vcpus). Note that on most machines this is set to 160. */ @@ -1329,3 +1330,12 @@ virHostCPUGetKVMMaxVCPUs(void) VIR_FORCE_CLOSE(fd); return ret; } +#else +int +virHostCPUGetKVMMaxVCPUs(void) +{ + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("KVM is not supported on this platform")); + return -1; +} +#endif /* HAVE_LINUX_KVM_H */ -- 2.7.4

An error in virHostCPUGetKVMMaxVCPUs() means we've been unable to access /dev/kvm, or we're running on a platform that doesn't support KVM in the first place. If that's the case, we shouldn't ignore the error and report domcapabilities even though we know the user won't be able to start any KVM guest. --- src/qemu/qemu_capabilities.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 28d5321..ae54c94 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -4349,9 +4349,12 @@ virQEMUCapsFillDomainCaps(virDomainCapsPtr domCaps, domCaps->maxvcpus = virQEMUCapsGetMachineMaxCpus(qemuCaps, domCaps->machine); if (virttype == VIR_DOMAIN_VIRT_KVM) { - int hostmaxvcpus = virHostCPUGetKVMMaxVCPUs(); - if (hostmaxvcpus >= 0) - domCaps->maxvcpus = MIN(domCaps->maxvcpus, hostmaxvcpus); + int hostmaxvcpus; + + if ((hostmaxvcpus = virHostCPUGetKVMMaxVCPUs()) < 0) + return -1; + + domCaps->maxvcpus = MIN(domCaps->maxvcpus, hostmaxvcpus); } if (virQEMUCapsFillDomainOSCaps(os, firmwares, nfirmwares) < 0 || -- 2.7.4