From 9d2c60799271d605f82dfd4bfa6ed7d14ad87e26 Mon Sep 17 00:00:00 2001

From: Eric Blake <eblake@redhat.com>

Date: Mon, 27 Sep 2010 09:37:22 -0600

Subject: [PATCH 04/15] vcpu: implement the public APIs

Factors common checks (such as nonzero vcpu count) up front, but

drivers will still need to do additional flag checks.

* src/libvirt.c (virDomainSetVcpusFlags, virDomainGetVcpusFlags):

New functions.

(virDomainSetVcpus, virDomainGetMaxVcpus): Refer to new API.

---

 src/libvirt.c |  140 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---

 1 files changed, 134 insertions(+), 6 deletions(-)

diff --git a/src/libvirt.c b/src/libvirt.c

index 629d97b..1b39210 100644

--- a/src/libvirt.c

+++ b/src/libvirt.c

@@ -5192,7 +5192,9 @@ error:

  * This function requires privileged access to the hypervisor.

  *

  * This command only changes the runtime configuration of the domain,

- * so can only be called on an active domain.

+ * so can only be called on an active domain.  It is hypervisor-dependent

+ * whether it also affects persistent configuration; for more control,

+ * use virDomainSetVcpusFlags().

  *

  * Returns 0 in case of success, -1 in case of failure.

  */

@@ -5237,13 +5239,139 @@ error:

 }

 /**

+ * virDomainSetVcpusFlags:

+ * @domain: pointer to domain object, or NULL for Domain0

+ * @nvcpus: the new number of virtual CPUs for this domain, must be at least 1

+ * @flags: an OR'ed set of virDomainVcpuFlags

+ *

+ * Dynamically change the number of virtual CPUs used by the domain.

+ * Note that this call may fail if the underlying virtualization hypervisor

+ * does not support it or if growing the number is arbitrary limited.

+ * This function requires privileged access to the hypervisor.

+ *

+ * @flags must include VIR_DOMAIN_VCPU_LIVE to affect a running

+ * domain (which may fail if domain is not active), or

+ * VIR_DOMAIN_VCPU_CONFIG to affect the next boot via the XML

+ * description of the domain.  Both flags may be set.

+ *

+ * If @flags includes VIR_DOMAIN_VCPU_MAXIMUM, then

+ * VIR_DOMAIN_VCPU_LIVE must be clear, and only the maximum virtual

+ * CPU limit is altered; generally, this value must be less than or

+ * equal to virConnectGetMaxVcpus().  Otherwise, this call affects the

+ * current virtual CPU limit, which must be less than or equal to the

+ * maximum limit.

+ *

+ * Returns 0 in case of success, -1 in case of failure.

+ */

+

+int

+virDomainSetVcpusFlags(virDomainPtr domain, unsigned int nvcpus,

+                       unsigned int flags)

+{

+    virConnectPtr conn;

+    VIR_DEBUG("domain=%p, nvcpus=%u, flags=%u", domain, nvcpus, flags);

+

+    virResetLastError();

+

+    if (!VIR_IS_CONNECTED_DOMAIN(domain)) {

+        virLibDomainError(NULL, VIR_ERR_INVALID_DOMAIN, __FUNCTION__);

+        virDispatchError(NULL);

+        return (-1);

+    }

+    if (domain->conn->flags & VIR_CONNECT_RO) {

+        virLibDomainError(domain, VIR_ERR_OPERATION_DENIED, __FUNCTION__);

+        goto error;

+    }

+

+    /* Perform some argument validation common to all implementations.  */

+    if (nvcpus < 1 || (unsigned short) nvcpus != nvcpus ||

+        (flags & (VIR_DOMAIN_VCPU_LIVE | VIR_DOMAIN_VCPU_CONFIG)) == 0) {

+        virLibDomainError(domain, VIR_ERR_INVALID_ARG, __FUNCTION__);

+        goto error;

+    }

+    conn = domain->conn;

+

+    if (conn->driver->domainSetVcpusFlags) {

+        int ret;

+        ret = conn->driver->domainSetVcpusFlags (domain, nvcpus, flags);

+        if (ret < 0)

+            goto error;

+        return ret;

+    }

+

+    virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);

+

+error:

+    virDispatchError(domain->conn);

+    return -1;

+}

+

+/**

+ * virDomainGetVcpusFlags:

+ * @domain: pointer to domain object, or NULL for Domain0

+ * @flags: an OR'ed set of virDomainVcpuFlags

+ *

+ * Query the number of virtual CPUs used by the domain.  Note that

+ * this call may fail if the underlying virtualization hypervisor does

+ * not support it.  This function requires privileged access to the

+ * hypervisor.

+ *

+ * @flags must include either VIR_DOMAIN_VCPU_ACTIVE to query a

+ * running domain (which will fail if domain is not active), or

+ * VIR_DOMAIN_VCPU_PERSISTENT to query the XML description of the

+ * domain.  It is an error to set both flags.

+ *

+ * If @flags includes VIR_DOMAIN_VCPU_MAXIMUM, then the maximum

+ * virtual CPU limit is queried.  Otherwise, this call queries the

+ * current virtual CPU limit.

+ *

+ * Returns 0 in case of success, -1 in case of failure.

+ */

+

+int

+virDomainGetVcpusFlags(virDomainPtr domain, unsigned int flags)

+{

+    virConnectPtr conn;

+    VIR_DEBUG("domain=%p, flags=%u", domain, flags);

+

+    virResetLastError();

+

+    if (!VIR_IS_CONNECTED_DOMAIN(domain)) {

+        virLibDomainError(NULL, VIR_ERR_INVALID_DOMAIN, __FUNCTION__);

+        virDispatchError(NULL);

+        return (-1);

+    }

+

+    /* Exactly one of these two flags should be set.  */

+    if (!(flags & VIR_DOMAIN_VCPU_LIVE) == !(flags & VIR_DOMAIN_VCPU_CONFIG)) {

+        virLibDomainError(domain, VIR_ERR_INVALID_ARG, __FUNCTION__);

+        goto error;

+    }

+    conn = domain->conn;

+

+    if (conn->driver->domainGetVcpusFlags) {

+        int ret;

+        ret = conn->driver->domainGetVcpusFlags (domain, flags);

+        if (ret < 0)

+            goto error;

+        return ret;

+    }

+

+    virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);

+

+error:

+    virDispatchError(domain->conn);

+    return -1;

+}

+

+/**

  * virDomainPinVcpu:

  * @domain: pointer to domain object, or NULL for Domain0

  * @vcpu: virtual CPU number

  * @cpumap: pointer to a bit map of real CPUs (in 8-bit bytes) (IN)

- * 	Each bit set to 1 means that corresponding CPU is usable.

- * 	Bytes are stored in little-endian order: CPU0-7, 8-15...

- * 	In each byte, lowest CPU number is least significant bit.

+ *      Each bit set to 1 means that corresponding CPU is usable.

+ *      Bytes are stored in little-endian order: CPU0-7, 8-15...

+ *      In each byte, lowest CPU number is least significant bit.

  * @maplen: number of bytes in cpumap, from 1 up to size of CPU map in

  *	underlying virtualization system (Xen...).

  *	If maplen < size, missing bytes are set to zero.

@@ -5371,9 +5499,9 @@ error:

  *

  * Provides the maximum number of virtual CPUs supported for

  * the guest VM. If the guest is inactive, this is basically

- * the same as virConnectGetMaxVcpus. If the guest is running

+ * the same as virConnectGetMaxVcpus(). If the guest is running

  * this will reflect the maximum number of virtual CPUs the

- * guest was booted with.

+ * guest was booted with.  For more details, see virDomainGetVcpusFlags().

  *

  * Returns the maximum of virtual CPU or -1 in case of error.

  */

-- 

1.7.2.3