[PATCH v2 12/19] KVM: kvm_arch.c: Remove a global variable, hardware_enable_failed

isaku.yamahata
2022-08-30T12:02:50Z

A global variable hardware_enable_failed in kvm_arch.c is used only by
kvm_arch_add_vm() and hardware_enable(). It doesn't have to be a global
variable. Make it function local.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
virt/kvm/kvm_arch.c | 56 +++++++++++++++++++++------------------------
1 file changed, 26 insertions(+), 30 deletions(-)

diff --git a/virt/kvm/kvm_arch.c b/virt/kvm/kvm_arch.c
index 491e92ef9e3d..3990f85edab3 100644
--- a/virt/kvm/kvm_arch.c
+++ b/virt/kvm/kvm_arch.c
@@ -13,14 +13,13 @@
#include <linux/kvm_host.h>

static cpumask_t cpus_hardware_enabled = CPU_MASK_NONE;
-static atomic_t hardware_enable_failed;

__weak int kvm_arch_post_init_vm(struct kvm *kvm)
{
return 0;
}

-static void hardware_enable(void *junk)
+static int __hardware_enable(void)
{
int cpu = raw_smp_processor_id();
int r;
@@ -28,17 +27,21 @@ static void hardware_enable(void *junk)
WARN_ON_ONCE(preemptible());

if (cpumask_test_cpu(cpu, &cpus_hardware_enabled))
- return;
-
- cpumask_set_cpu(cpu, &cpus_hardware_enabled);
-
+ return 0;
r = kvm_arch_hardware_enable();
-
- if (r) {
- cpumask_clear_cpu(cpu, &cpus_hardware_enabled);
- atomic_inc(&hardware_enable_failed);
+ if (r)
pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
- }
+ else
+ cpumask_set_cpu(cpu, &cpus_hardware_enabled);
+ return r;
+}
+
+static void hardware_enable(void *arg)
+{
+ atomic_t *failed = arg;
+
+ if (__hardware_enable())
+ atomic_inc(failed);
}

static void hardware_disable(void *junk)
@@ -64,15 +67,16 @@ __weak void kvm_arch_pre_hardware_unsetup(void)
*/
__weak int kvm_arch_add_vm(struct kvm *kvm, int usage_count)
{
+ atomic_t failed;
int r = 0;

if (usage_count != 1)
return 0;

- atomic_set(&hardware_enable_failed, 0);
- on_each_cpu(hardware_enable, NULL, 1);
+ atomic_set(&failed, 0);
+ on_each_cpu(hardware_enable, &failed, 1);

- if (atomic_read(&hardware_enable_failed)) {
+ if (atomic_read(&failed)) {
r = -EBUSY;
goto err;
}
@@ -95,23 +99,15 @@ __weak int kvm_arch_del_vm(int usage_count)

__weak int kvm_arch_online_cpu(unsigned int cpu, int usage_count)
{
- int ret = 0;
-
- /*
- * Abort the CPU online process if hardware virtualization cannot
- * be enabled. Otherwise running VMs would encounter unrecoverable
- * errors when scheduled to this CPU.
- */
if (usage_count) {
- WARN_ON_ONCE(atomic_read(&hardware_enable_failed));
-
- hardware_enable(NULL);
- if (atomic_read(&hardware_enable_failed)) {
- atomic_set(&hardware_enable_failed, 0);
- ret = -EIO;
- }
+ /*
+ * Abort the CPU online process if hardware virtualization cannot
+ * be enabled. Otherwise running VMs would encounter unrecoverable
+ * errors when scheduled to this CPU.
+ */
+ return __hardware_enable();
}
- return ret;
+ return 0;
}

__weak int kvm_arch_offline_cpu(unsigned int cpu, int usage_count)
@@ -137,5 +133,5 @@ __weak int kvm_arch_suspend(int usage_count)
__weak void kvm_arch_resume(int usage_count)
{
if (usage_count)
- hardware_enable(NULL);
+ (void)__hardware_enable();
}
--
2.25.1