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Message-Id: <20181226133351.894160986@intel.com>
User-Agent: quilt/0.65
Date:   Wed, 26 Dec 2018 21:15:00 +0800
From:   Fengguang Wu <fengguang.wu@intel.com>
To:     Andrew Morton <akpm@linux-foundation.org>
cc:     Linux Memory Management List <linux-mm@kvack.org>,
        Nikita Leshenko <nikita.leshchenko@oracle.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Fengguang Wu <fengguang.wu@intel.com>
cc:     kvm@vger.kernel.org
Cc:     LKML <linux-kernel@vger.kernel.org>
cc:     Fan Du <fan.du@intel.com>
cc:     Yao Yuan <yuan.yao@intel.com>
cc:     Peng Dong <dongx.peng@intel.com>
cc:     Huang Ying <ying.huang@intel.com>
CC:     Liu Jingqi <jingqi.liu@intel.com>
cc:     Dong Eddie <eddie.dong@intel.com>
cc:     Dave Hansen <dave.hansen@intel.com>
cc:     Zhang Yi <yi.z.zhang@linux.intel.com>
cc:     Dan Williams <dan.j.williams@intel.com>
Subject: [RFC][PATCH v2 14/21] kvm: register in mm_struct
References: <20181226131446.330864849@intel.com>
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Content-Disposition: inline; filename=0009-kvm-register-in-mm_struct.patch
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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 <nikita.leshchenko@oracle.com>
CC: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
---
 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);