Thanks. On Fri, Sep 27, 2013 at 3:40 PM, Stefan Hajnoczi <stefanha@xxxxxxxxx> wrote: > On Fri, Sep 27, 2013 at 03:19:28AM +0530, Piyus Kedia wrote: >> I am working on record replay in KVM. I just want to confirm that KVM >> doesn't access guest memory except for DMA. The functions >> kvm_read_guest_page() and kvm_write_guest_page() in kvm_main.c are >> only used for mmio emulation which access memory that is always >> emulated. It will be nice if somebody else also confirm this. > > kvmclock comes to mind, I think it has a shared page between the guest > and the host kernel where clock updates are published from host -> > guest. I think kvmclock can be disabled by choosing another clocksource > in the guest Linux kernel. > > There are other exceptions like the ivshmem device which is rarely used > but can provide shared memory between guest <-> host or guest <-> guest. > I think that memory is an MMIO PCI BAR in the guest just that neither > kvm.ko nor QEMU may be catch the update if another process on the host > is writing to it. > > 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
