KVM: debugfs: expose pid of vcpu threads

Add a new debugfs file to expose the pid of each vcpu threads. This
is very helpful for userland tools to get the vcpu pids without
worrying about thread naming conventions of the VMM.

Signed-off-by: Vineeth Pillai (Google) <vineeth@bitbyteword.org>
Message-Id: <20220523190327.2658-1-vineeth@bitbyteword.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Vineeth Pillai 2022-05-23 15:03:27 -04:00 committed by Paolo Bonzini
parent 4de5c54f8c
commit e36de87d34
2 changed files with 15 additions and 2 deletions

View File

@ -1435,6 +1435,8 @@ int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state);
#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
#else
static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
#endif
int kvm_arch_hardware_enable(void);

View File

@ -3822,9 +3822,18 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu)
return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
}
#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
static int vcpu_get_pid(void *data, u64 *val)
{
struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
*val = pid_nr(rcu_access_pointer(vcpu->pid));
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(vcpu_get_pid_fops, vcpu_get_pid, NULL, "%llu\n");
static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
{
#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
struct dentry *debugfs_dentry;
char dir_name[ITOA_MAX_LEN * 2];
@ -3834,10 +3843,12 @@ static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id);
debugfs_dentry = debugfs_create_dir(dir_name,
vcpu->kvm->debugfs_dentry);
debugfs_create_file("pid", 0444, debugfs_dentry, vcpu,
&vcpu_get_pid_fops);
kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry);
#endif
}
#endif
/*
* Creates some virtual cpus. Good luck creating more than one.