From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933185AbXDAOrT (ORCPT ); Sun, 1 Apr 2007 10:47:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933257AbXDAOpz (ORCPT ); Sun, 1 Apr 2007 10:45:55 -0400 Received: from il.qumranet.com ([82.166.9.18]:47561 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933217AbXDAOfn (ORCPT ); Sun, 1 Apr 2007 10:35:43 -0400 From: Avi Kivity To: kvm-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, Avi Kivity Subject: [PATCH 18/41] KVM: Allow kernel to select size of mmap() buffer Date: Sun, 1 Apr 2007 17:35:15 +0300 Message-Id: <11754381392921-git-send-email-avi@qumranet.com> X-Mailer: git-send-email 1.5.0.5 In-Reply-To: <1175438139872-git-send-email-avi@qumranet.com> References: <1175438138288-git-send-email-avi@qumranet.com> <11754381381990-git-send-email-avi@qumranet.com> <11754381384009-git-send-email-avi@qumranet.com> <1175438138805-git-send-email-avi@qumranet.com> <11754381382515-git-send-email-avi@qumranet.com> <11754381383730-git-send-email-avi@qumranet.com> <11754381383144-git-send-email-avi@qumranet.com> <11754381381597-git-send-email-avi@qumranet.com> <1175438139242-git-send-email-avi@qumranet.com> <1175438139494-git-send-email-avi@qumranet.com> <11754381392046-git-send-email-avi@qumranet.com> <1175438139795-git-send-email-avi@qumranet.com> <1175438139430-git-send-email-avi@qumranet.com> <11754381393496-git-send-email-avi@qumranet.com> <11754381391514-git-send-email-avi@qumranet.com> <11754381392382-git-send-email-avi@qumranet.com> <11754381392358-git-send-email-avi@qumranet.com> <1175438139872-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This allows us to store offsets in the kernel/user kvm_run area, and be sure that userspace has them mapped. As offsets can be outside the kvm_run struct, userspace has no way of knowing how much to mmap. Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 8 +++++++- include/linux/kvm.h | 4 ++++ 2 files changed, 11 insertions(+), 1 deletions(-) diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index df85f5f..cba0b87 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -2436,7 +2436,7 @@ static long kvm_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { void __user *argp = (void __user *)arg; - int r = -EINVAL; + long r = -EINVAL; switch (ioctl) { case KVM_GET_API_VERSION: @@ -2478,6 +2478,12 @@ static long kvm_dev_ioctl(struct file *filp, */ r = 0; break; + case KVM_GET_VCPU_MMAP_SIZE: + r = -EINVAL; + if (arg) + goto out; + r = PAGE_SIZE; + break; default: ; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index c0d10cd..dad9081 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -253,6 +253,10 @@ struct kvm_signal_mask { * return is 1 (yes) or 0 (no, sorry). */ #define KVM_CHECK_EXTENSION _IO(KVMIO, 0x03) +/* + * Get size for mmap(vcpu_fd) + */ +#define KVM_GET_VCPU_MMAP_SIZE _IO(KVMIO, 0x04) /* in bytes */ /* * ioctls for VM fds -- 1.5.0.5