From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: [PATCH 3/3] vhost: make default mapping empty by default Date: Sun, 20 Dec 2009 19:16:32 +0200 Message-ID: <20091220171632.GD31713@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Rusty Russell , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: Al Viro List-Id: virtualization@lists.linuxfoundation.org vhost now validates each region with access_ok in calling process context before access. Since this fails on a full 64 bit 1:1 mapping that vhost had by default, we can't support such a mapping: users will have to set up a table with real addresses that actually matches their address space. Make the default mapping empty. Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 13 +++---------- 1 files changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 33e06bf..2b65d9b 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -170,21 +170,14 @@ long vhost_dev_reset_owner(struct vhost_dev *dev) { struct vhost_memory *memory; - /* Restore memory to default 1:1 mapping. */ - memory = kmalloc(offsetof(struct vhost_memory, regions) + - 2 * sizeof *memory->regions, GFP_KERNEL); + /* Restore memory to default empty mapping. */ + memory = kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL); if (!memory) return -ENOMEM; vhost_dev_cleanup(dev); - memory->nregions = 2; - memory->regions[0].guest_phys_addr = 1; - memory->regions[0].userspace_addr = 1; - memory->regions[0].memory_size = ~0ULL; - memory->regions[1].guest_phys_addr = 0; - memory->regions[1].userspace_addr = 0; - memory->regions[1].memory_size = 1; + memory->nregions = 0; dev->memory = memory; return 0; } -- 1.6.6.rc1.43.gf55cc