On Tue, Apr 16, 2013 at 03:54:15PM +0800, Wenchao Xia wrote: > 于 2013-4-16 13:51, Stefan Hajnoczi 写道: > >On Mon, Apr 15, 2013 at 09:03:36PM +0800, Wenchao Xia wrote: > >> I'd like to add/export an function which allow userspace program > >>to take snapshot for a region of memory. Since it is not implemented yet > >>I will describe it as C APIs, it is quite simple now and if it is worthy > >>I'll improve the interface later: > > > >We talked about a simple approach using fork(2) on IRC yesterday. > > > >Is this email outdated? > > > >Stefan > > > No, after the discuss on IRC, I agree that fork() is a simpler > method to do it, which can comes to qemu fast, since user wants it. > With a more consideration, still I think a KVM's mem snapshot would > be an long term solution for it: > The source of the problem comes from acceleration module, kvm.ko, when > qemu does not use it, no troubles. This means an acceleration module > missed a function while caller requires. My instinct idea is: when > acceleration module replace a pure software one, it should try provide > all parts or not stop software filling the gap, and doing so brings > benefits, so hope to add it. > My API description is old, the core is COW pages, maybe redesign if > reasonable. QEMU is a userspace process that has guest RAM mmapped. You want to snapshot that mmap region but there is no Linux system call to do that. Maybe a new mremap(2) flag is what you want. But I don't see the connection to kvm.ko which you mention. The feature you're wishing for has nothing to do with kvm.ko. Stefan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
