From 45b5939e50746b92fd4cb47c02524f79ba8fabe6 Mon Sep 17 00:00:00 2001 From: Luiz Capitulino Date: Fri, 16 Sep 2016 10:27:35 -0400 Subject: kvm: create per-vcpu dirs in debugfs This commit adds the ability for archs to export per-vcpu information via a new per-vcpu dir in the VM's debugfs directory. If kvm_arch_has_vcpu_debugfs() returns true, then KVM will create a vcpu dir for each vCPU in the VM's debugfs directory. Then kvm_arch_create_vcpu_debugfs() is responsible for populating each vcpu directory with arch specific entries. The per-vcpu path in debugfs will look like: /sys/kernel/debug/kvm/29162-10/vcpu0 /sys/kernel/debug/kvm/29162-10/vcpu1 This is all arch specific for now because the only user of this interface (x86) wants to export x86-specific per-vcpu information to user-space. Signed-off-by: Luiz Capitulino Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a6e864c67e35..81dfc73d3df3 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2371,6 +2371,7 @@ static int kvm_vcpu_release(struct inode *inode, struct file *filp) { struct kvm_vcpu *vcpu = filp->private_data; + debugfs_remove_recursive(vcpu->debugfs_dentry); kvm_put_kvm(vcpu->kvm); return 0; } @@ -2393,6 +2394,32 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu) return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC); } +static int kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) +{ + char dir_name[ITOA_MAX_LEN * 2]; + int ret; + + if (!kvm_arch_has_vcpu_debugfs()) + return 0; + + if (!debugfs_initialized()) + return 0; + + snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id); + vcpu->debugfs_dentry = debugfs_create_dir(dir_name, + vcpu->kvm->debugfs_dentry); + if (!vcpu->debugfs_dentry) + return -ENOMEM; + + ret = kvm_arch_create_vcpu_debugfs(vcpu); + if (ret < 0) { + debugfs_remove_recursive(vcpu->debugfs_dentry); + return ret; + } + + return 0; +} + /* * Creates some virtual cpus. Good luck creating more than one. */ @@ -2425,6 +2452,10 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) if (r) goto vcpu_destroy; + r = kvm_create_vcpu_debugfs(vcpu); + if (r) + goto vcpu_destroy; + mutex_lock(&kvm->lock); if (kvm_get_vcpu_by_id(kvm, id)) { r = -EEXIST; @@ -2456,6 +2487,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) unlock_vcpu_destroy: mutex_unlock(&kvm->lock); + debugfs_remove_recursive(vcpu->debugfs_dentry); vcpu_destroy: kvm_arch_vcpu_destroy(vcpu); vcpu_decrement: -- cgit v1.2.3