Commit e36de87d authored by Vineeth Pillai's avatar Vineeth Pillai Committed by Paolo Bonzini
Browse files

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: default avatarVineeth Pillai (Google) <vineeth@bitbyteword.org>
Message-Id: <20220523190327.2658-1-vineeth@bitbyteword.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4de5c54f

include/linux/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

virt/kvm/kvm_main.c

+13 −2
Original line number Diff line number Diff line
@@ -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.