From e0207366b173c78a92603ed2519a0e5eb04b0dc0 Mon Sep 17 00:00:00 2001
From: David Hunt <david.hunt@intel.com>
Date: Wed, 17 Oct 2018 14:05:25 +0100
Subject: [PATCH] examples/power: add checks around hypervisor

Allow vm_power_manager to run without requiring qemu to be present
on the machine. This will be required for instances where the JSON
interface is used for commands and polices, without any VMs present.
A use case for this is a container enviromnent.

Signed-off-by: David Hunt <david.hunt@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 examples/vm_power_manager/channel_manager.c | 71 +++++++++++++--------
 1 file changed, 43 insertions(+), 28 deletions(-)

diff --git a/examples/vm_power_manager/channel_manager.c b/examples/vm_power_manager/channel_manager.c
index 927fc35ab5..2e471d0c16 100644
--- a/examples/vm_power_manager/channel_manager.c
+++ b/examples/vm_power_manager/channel_manager.c
@@ -43,7 +43,8 @@ static unsigned char *global_cpumaps;
 static virVcpuInfo *global_vircpuinfo;
 static size_t global_maplen;
 
-static unsigned global_n_host_cpus;
+static unsigned int global_n_host_cpus;
+static bool global_hypervisor_available;
 
 /*
  * Represents a single Virtual Machine
@@ -198,7 +199,11 @@ get_pcpus_mask(struct channel_info *chan_info, unsigned vcpu)
 {
 	struct virtual_machine_info *vm_info =
 			(struct virtual_machine_info *)chan_info->priv_info;
-	return rte_atomic64_read(&vm_info->pcpu_mask[vcpu]);
+
+	if (global_hypervisor_available && (vm_info != NULL))
+		return rte_atomic64_read(&vm_info->pcpu_mask[vcpu]);
+	else
+		return 0;
 }
 
 static inline int
@@ -559,6 +564,8 @@ get_all_vm(int *num_vm, int *num_vcpu)
 				VIR_CONNECT_LIST_DOMAINS_PERSISTENT;
 	unsigned int domain_flag = VIR_DOMAIN_VCPU_CONFIG;
 
+	if (!global_hypervisor_available)
+		return;
 
 	memset(global_cpumaps, 0, CHANNEL_CMDS_MAX_CPUS*global_maplen);
 	if (virNodeGetInfo(global_vir_conn_ptr, &node_info)) {
@@ -768,38 +775,42 @@ connect_hypervisor(const char *path)
 	}
 	return 0;
 }
-
 int
-channel_manager_init(const char *path)
+channel_manager_init(const char *path __rte_unused)
 {
 	virNodeInfo info;
 
 	LIST_INIT(&vm_list_head);
 	if (connect_hypervisor(path) < 0) {
-		RTE_LOG(ERR, CHANNEL_MANAGER, "Unable to initialize channel manager\n");
-		return -1;
-	}
-
-	global_maplen = VIR_CPU_MAPLEN(CHANNEL_CMDS_MAX_CPUS);
+		global_n_host_cpus = 64;
+		global_hypervisor_available = 0;
+		RTE_LOG(INFO, CHANNEL_MANAGER, "Unable to initialize channel manager\n");
+	} else {
+		global_hypervisor_available = 1;
+
+		global_maplen = VIR_CPU_MAPLEN(CHANNEL_CMDS_MAX_CPUS);
+
+		global_vircpuinfo = rte_zmalloc(NULL,
+				sizeof(*global_vircpuinfo) *
+				CHANNEL_CMDS_MAX_CPUS, RTE_CACHE_LINE_SIZE);
+		if (global_vircpuinfo == NULL) {
+			RTE_LOG(ERR, CHANNEL_MANAGER, "Error allocating memory for CPU Info\n");
+			goto error;
+		}
+		global_cpumaps = rte_zmalloc(NULL,
+				CHANNEL_CMDS_MAX_CPUS * global_maplen,
+				RTE_CACHE_LINE_SIZE);
+		if (global_cpumaps == NULL)
+			goto error;
 
-	global_vircpuinfo = rte_zmalloc(NULL, sizeof(*global_vircpuinfo) *
-			CHANNEL_CMDS_MAX_CPUS, RTE_CACHE_LINE_SIZE);
-	if (global_vircpuinfo == NULL) {
-		RTE_LOG(ERR, CHANNEL_MANAGER, "Error allocating memory for CPU Info\n");
-		goto error;
-	}
-	global_cpumaps = rte_zmalloc(NULL, CHANNEL_CMDS_MAX_CPUS * global_maplen,
-			RTE_CACHE_LINE_SIZE);
-	if (global_cpumaps == NULL) {
-		goto error;
+		if (virNodeGetInfo(global_vir_conn_ptr, &info)) {
+			RTE_LOG(ERR, CHANNEL_MANAGER, "Unable to retrieve node Info\n");
+			goto error;
+		}
+		global_n_host_cpus = (unsigned int)info.cpus;
 	}
 
-	if (virNodeGetInfo(global_vir_conn_ptr, &info)) {
-		RTE_LOG(ERR, CHANNEL_MANAGER, "Unable to retrieve node Info\n");
-		goto error;
-	}
 
-	global_n_host_cpus = (unsigned)info.cpus;
 
 	if (global_n_host_cpus > CHANNEL_CMDS_MAX_CPUS) {
 		RTE_LOG(WARNING, CHANNEL_MANAGER, "The number of host CPUs(%u) exceeds the "
@@ -811,7 +822,8 @@ channel_manager_init(const char *path)
 
 	return 0;
 error:
-	disconnect_hypervisor();
+	if (global_hypervisor_available)
+		disconnect_hypervisor();
 	return -1;
 }
 
@@ -838,7 +850,10 @@ channel_manager_exit(void)
 		rte_free(vm_info);
 	}
 
-	rte_free(global_cpumaps);
-	rte_free(global_vircpuinfo);
-	disconnect_hypervisor();
+	if (global_hypervisor_available) {
+		/* Only needed if hypervisor available */
+		rte_free(global_cpumaps);
+		rte_free(global_vircpuinfo);
+		disconnect_hypervisor();
+	}
 }
-- 
2.20.1