[PATCH v4 05/26] KVM: Provide more information in kernel log if hardware enabling fails

From: isaku . yamahata
Date: Thu Sep 08 2022 - 19:26:31 EST


From: Sean Christopherson <seanjc@xxxxxxxxxx>

Provide the name of the calling function to hardware_enable_nolock() and
include it in the error message to provide additional information on
exactly what path failed.

Opportunistically bump the pr_info() to pr_warn(), failure to enable
virtualization support is warn-worthy as _something_ is wrong with the
system.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220216031528.92558-4-chao.gao@xxxxxxxxx
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Reviewed-by: Yuan Yao <yuan.yao@xxxxxxxxx>
---
virt/kvm/kvm_main.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4243a9541543..278eb6cc7cbe 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4991,7 +4991,7 @@ static struct miscdevice kvm_dev = {
&kvm_chardev_ops,
};

-static void hardware_enable_nolock(void *junk)
+static void hardware_enable_nolock(void *caller_name)
{
int cpu = raw_smp_processor_id();
int r;
@@ -5006,7 +5006,8 @@ static void hardware_enable_nolock(void *junk)
if (r) {
cpumask_clear_cpu(cpu, cpus_hardware_enabled);
atomic_inc(&hardware_enable_failed);
- pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
+ pr_warn("kvm: enabling virtualization on CPU%d failed during %s()\n",
+ cpu, (const char *)caller_name);
}
}

@@ -5014,7 +5015,7 @@ static int kvm_starting_cpu(unsigned int cpu)
{
raw_spin_lock(&kvm_count_lock);
if (kvm_usage_count)
- hardware_enable_nolock(NULL);
+ hardware_enable_nolock((void *)__func__);
raw_spin_unlock(&kvm_count_lock);
return 0;
}
@@ -5063,7 +5064,7 @@ static int hardware_enable_all(void)
kvm_usage_count++;
if (kvm_usage_count == 1) {
atomic_set(&hardware_enable_failed, 0);
- on_each_cpu(hardware_enable_nolock, NULL, 1);
+ on_each_cpu(hardware_enable_nolock, (void *)__func__, 1);

if (atomic_read(&hardware_enable_failed)) {
hardware_disable_all_nolock();
@@ -5686,7 +5687,7 @@ static void kvm_resume(void)
{
if (kvm_usage_count) {
lockdep_assert_not_held(&kvm_count_lock);
- hardware_enable_nolock(NULL);
+ hardware_enable_nolock((void *)__func__);
}
}

--
2.25.1