From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v6 00/12] KVM: introduce readonly memslot Date: Wed, 22 Aug 2012 15:09:35 +0300 Message-ID: <5034CBFF.5020608@redhat.com> References: <5032F8FD.2020306@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM To: Xiao Guangrong Return-path: In-Reply-To: <5032F8FD.2020306@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 08/21/2012 05:57 AM, Xiao Guangrong wrote: > Changelog: > - fix endless retrying for unhandleable instruction which accesses on readonly > host memory > - divide slot->flags by 16:16, the lower part is visible for userspace, the > reset is internally used in kvm, and document this in the code > - check slot->flags for gfn_to_hva_memslot > > The test case can be found at: > http://lkml.indiana.edu/hypermail/linux/kernel/1207.2/00819/migrate-perf.tar.bz2 > > In current code, if we map a readonly memory space from host to guest > and the page is not currently mapped in the host, we will get a fault-pfn > and async is not allowed, then the vm will crash. > > As Avi's suggestion, We introduce readonly memory region to map ROM/ROMD > to the guest, read access is happy for readonly memslot, write access on > readonly memslot will cause KVM_EXIT_MMIO exit. Thanks, applied 1-11. -- error compiling committee.c: too many arguments to function