From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH 6/6] KVM: assigned dev: MSI-X mask support Date: Thu, 18 Nov 2010 14:39:28 +0800 Message-ID: <201011181439.28299.sheng@linux.intel.com> References: <1289812532-3227-1-git-send-email-sheng@linux.intel.com> <201011180958.55773.sheng@linux.intel.com> <20101118062140.GB8731@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Marcelo Tosatti , kvm@vger.kernel.org, Alex Williamson To: "Michael S. Tsirkin" Return-path: Received: from mga09.intel.com ([134.134.136.24]:64840 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751331Ab0KRGja (ORCPT ); Thu, 18 Nov 2010 01:39:30 -0500 In-Reply-To: <20101118062140.GB8731@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thursday 18 November 2010 14:21:40 Michael S. Tsirkin wrote: > On Thu, Nov 18, 2010 at 09:58:55AM +0800, Sheng Yang wrote: > > > > +static int msix_mmio_write(struct kvm_io_device *this, gpa_t addr, > > > > int len, + const void *val) > > > > +{ > > > > + struct kvm_assigned_dev_kernel *adev = > > > > + container_of(this, struct kvm_assigned_dev_kernel, > > > > + msix_mmio_dev); > > > > + int idx, r = 0; > > > > + unsigned long new_val = *(unsigned long *)val; > > > > > > What if it's a 64-bit write on a 32-bit host? > > > > In fact we haven't support QWORD(64bit) accessing now. The reason is we > > haven't seen any OS is using it in this way now, so I think we can leave > > it later. > > > > Also seems QEmu doesn't got the way to handle 64bit MMIO. > > I think it does. I think it simply splits these to 32-bit transactions > and handles as such. That seems to be spec-compilant. I wouldn't want us > to regress. Yes, you're right... I think I have to add it. :shrug: -- regards Yang, Sheng