Anthony Liguori wrote: > Cam Macdonell wrote: >> Hello, >> >> Is it possible to share a memory (a page perhaps) between the host and >> guest? > > Yes, the host always has access to all of the guests memory. All of the > virtio drivers depend on this fact. With KVM, the userspace (in this > case, QEMU), just tells the kernel about a virtual address region and > the kernel uses that region of virtual memory for the guest's physical > memory. Whatever you (as userspace) maps into that region is totally up > to you. > >> More precisely, could a host and guest share a memory-mapped file? > > It will be a lot easier once we have MMU notifiers upstream. You'll be > able to simply mmap(MAP_FIXED) a file into the guest's physical address > space even while it's running. For now, you have to setup these > mappings before the VM starts. > >> If one were crazy enough to want to do this, where should they look >> first? >> > > If you look at the -mem-file implementation in the latest git, you'll > see that all the guest's memory can be an mmap()'d file.
Hi Anthony, In setting up the guest memory to share a page, I need to make the kernel aware of that page. Is the best way to do this through a little virtio-like PCI device or is there an easier to get dynamic info into the guest kernel? Also, is the mem-file implementation in a specific branch of the latest GIT or is it within the main branch somewhere, I've been unable to find it? Thanks a bunch, Cam ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
