[libvirt] [PATCH 2/4] Rename and move kvmGetMaxVCPUs to utils and extend it

[Shivaprasad G Bhat]

This function needs to be used at two different places and make it global
now. Also, extend it to return the NR_CPUs when needed.

Signed-off-by: Shivaprasad G Bhat <sbhat at linux.vnet.ibm.com>
---
 src/libvirt_private.syms |    1 +
 src/qemu/qemu_driver.c   |   52 +---------------------------------------------
 src/util/virhostcpu.c    |   37 +++++++++++++++++++++++++++++++++
 src/util/virhostcpu.h    |    7 ++++++
 4 files changed, 46 insertions(+), 51 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index e939de3..569f8e8 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1066,6 +1066,7 @@ virLogManagerNew;
 nodeCapsInitNUMA;
 nodeGetInfo;
 virHostCPUGetCount;
+virHostCPUGetKVMVCPUs;
 virHostCPUGetMap;
 virHostCPUGetOnlineBitmap;
 virHostCPUGetPresentBitmap;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index a45fd55..65ef68c 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -122,24 +122,6 @@ VIR_LOG_INIT("qemu.qemu_driver");
 #define QEMU_SCHED_MIN_QUOTA               1000LL
 #define QEMU_SCHED_MAX_QUOTA  18446744073709551LL
 
-#if HAVE_LINUX_KVM_H
-# include <linux/kvm.h>
-#endif
-
-/* device for kvm ioctls */
-#define KVM_DEVICE "/dev/kvm"
-
-/* add definitions missing in older linux/kvm.h */
-#ifndef KVMIO
-# define KVMIO 0xAE
-#endif
-#ifndef KVM_CHECK_EXTENSION
-# define KVM_CHECK_EXTENSION       _IO(KVMIO,   0x03)
-#endif
-#ifndef KVM_CAP_NR_VCPUS
-# define KVM_CAP_NR_VCPUS 9       /* returns max vcpus per vm */
-#endif
-
 #define QEMU_NB_BLKIO_PARAM  6
 
 #define QEMU_NB_BANDWIDTH_PARAM 7
@@ -1269,38 +1251,6 @@ static int qemuConnectIsAlive(virConnectPtr conn ATTRIBUTE_UNUSED)
 }
 
 
-static int
-kvmGetMaxVCPUs(void)
-{
-    int fd;
-    int ret;
-
-    if ((fd = open(KVM_DEVICE, O_RDONLY)) < 0) {
-        virReportSystemError(errno, _("Unable to open %s"), KVM_DEVICE);
-        return -1;
-    }
-
-#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 */
-
-    /* as a fallback get KVM_CAP_NR_VCPUS (the recommended maximum number of
-     * vcpus). Note that on most machines this is set to 160. */
-    if ((ret = ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_NR_VCPUS)) > 0)
-        goto cleanup;
-
-    /* if KVM_CAP_NR_VCPUS doesn't exist either, kernel documentation states
-     * that 4 should be used as the maximum number of cpus */
-    ret = 4;
-
- cleanup:
-    VIR_FORCE_CLOSE(fd);
-    return ret;
-}
-
-
 static char *
 qemuConnectGetSysinfo(virConnectPtr conn, unsigned int flags)
 {
@@ -1338,7 +1288,7 @@ qemuConnectGetMaxVcpus(virConnectPtr conn ATTRIBUTE_UNUSED, const char *type)
         return 16;
 
     if (STRCASEEQ(type, "kvm"))
-        return kvmGetMaxVCPUs();
+        return virHostCPUGetKVMVCPUs(VIR_HOSTCPU_KVM_MAXVCPUS);
 
     if (STRCASEEQ(type, "kqemu"))
         return 1;
diff --git a/src/util/virhostcpu.c b/src/util/virhostcpu.c
index 00c09cd..5712eda 100644
--- a/src/util/virhostcpu.c
+++ b/src/util/virhostcpu.c
@@ -37,6 +37,7 @@
 #if HAVE_LINUX_KVM_H
 # include <linux/kvm.h>
 #endif
+#define KVM_DEVICE "/dev/kvm"
 
 #if defined(__FreeBSD__) || defined(__APPLE__)
 # include <sys/time.h>
@@ -1297,3 +1298,39 @@ virHostCPUGetThreadsPerSubcore(virArch arch ATTRIBUTE_UNUSED)
 }
 
 #endif /* HAVE_LINUX_KVM_H && defined(KVM_CAP_PPC_SMT) */
+
+#ifndef KVM_CAP_NR_VCPUS
+# define KVM_CAP_NR_VCPUS 9       /* returns max vcpus per vm */
+#endif
+
+int
+virHostCPUGetKVMVCPUs(virHostCPUKVMWrapperFlags flag)
+{
+    int fd;
+    int ret;
+
+    if ((fd = open(KVM_DEVICE, O_RDONLY)) < 0) {
+        virReportSystemError(errno, _("Unable to open %s"), KVM_DEVICE);
+        return -1;
+    }
+
+#ifdef KVM_CAP_MAX_VCPUS
+    /* at first try KVM_CAP_MAX_VCPUS to determine the maximum count */
+    if (flag & VIR_HOSTCPU_KVM_MAXVCPUS &&
+        (ret = ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS)) > 0)
+        goto cleanup;
+#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. */
+    if ((flag & VIR_HOSTCPU_KVM_MAXVCPUS || flag & VIR_HOSTCPU_KVM_NR_VCPUS) &&
+        (ret = ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_NR_VCPUS)) > 0)
+                 goto cleanup;
+    /* if KVM_CAP_NR_VCPUS doesn't exist either, kernel documentation states
+     * that 4 should be used as the maximum number of cpus */
+    ret = 4;
+
+ cleanup:
+    VIR_FORCE_CLOSE(fd);
+    return ret;
+}
diff --git a/src/util/virhostcpu.h b/src/util/virhostcpu.h
index e5ffc70..c1b855a 100644
--- a/src/util/virhostcpu.h
+++ b/src/util/virhostcpu.h
@@ -51,4 +51,11 @@ int virHostCPUGetInfo(virArch hostarch,
                       unsigned int *cores,
                       unsigned int *threads);
 
+typedef enum {
+    VIR_HOSTCPU_KVM_MAXVCPUS   = (1 << 0),
+    VIR_HOSTCPU_KVM_NR_VCPUS = (1 << 1),
+} virHostCPUKVMWrapperFlags;
+
+int virHostCPUGetKVMVCPUs(virHostCPUKVMWrapperFlags flag);
+
 #endif /* __VIR_HOSTCPU_H__*/