VM is associated with an address space and not a specific thread. >>From Documentation/virtual/kvm/api.txt: Only run VM ioctls from the same process (address space) that was used to create the VM. CC: Nikita Leshenko CC: Christian Borntraeger Signed-off-by: Fengguang Wu --- include/linux/mm_types.h | 11 +++++++++++ virt/kvm/kvm_main.c | 3 +++ 2 files changed, 14 insertions(+) --- linux.orig/include/linux/mm_types.h 2018-12-23 19:58:06.993417137 +0800 +++ linux/include/linux/mm_types.h 2018-12-23 19:58:06.993417137 +0800 @@ -27,6 +27,7 @@ typedef int vm_fault_t; struct address_space; struct mem_cgroup; struct hmm; +struct kvm; /* * Each physical page in the system has a struct page associated with @@ -496,6 +497,10 @@ struct mm_struct { /* HMM needs to track a few things per mm */ struct hmm *hmm; #endif + +#if IS_ENABLED(CONFIG_KVM) + struct kvm *kvm; +#endif } __randomize_layout; /* @@ -507,6 +512,12 @@ struct mm_struct { extern struct mm_struct init_mm; +#if IS_ENABLED(CONFIG_KVM) +static inline struct kvm *mm_kvm(struct mm_struct *mm) { return mm->kvm; } +#else +static inline struct kvm *mm_kvm(struct mm_struct *mm) { return NULL; } +#endif + /* Pointer magic because the dynamic array size confuses some compilers. */ static inline void mm_init_cpumask(struct mm_struct *mm) { --- linux.orig/virt/kvm/kvm_main.c 2018-12-23 19:58:06.993417137 +0800 +++ linux/virt/kvm/kvm_main.c 2018-12-23 19:58:06.993417137 +0800 @@ -727,6 +727,7 @@ static void kvm_destroy_vm(struct kvm *k struct mm_struct *mm = kvm->mm; kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm); + mm->kvm = NULL; kvm_destroy_vm_debugfs(kvm); kvm_arch_sync_events(kvm); spin_lock(&kvm_lock); @@ -3224,6 +3225,8 @@ static int kvm_dev_ioctl_create_vm(unsig fput(file); return -ENOMEM; } + + kvm->mm->kvm = kvm; kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm); fd_install(r, file);