On 23/09/2016 10:51, Herongguang (Stephen) wrote: > > > On 2016/9/23 15:17, Paolo Bonzini wrote: >> >> >> On 22/09/2016 15:16, Herongguang (Stephen) wrote: >>> I have some concern: >>> 1. For example, vhost does not know about as_id, I wonder if guests in >>> SMM can operate disk or ether card, as in >>> that case vhost would not logging dirty pages correctly, without knowing >>> as_id. >> >> In the end memory is logged by ram_addr_t, not by address space. So if >> vhost_sync_dirty_bitmap is called on the right region everything works. >> >> Guests in SMM can operate on storage devices, but storage devices cannot >> write to 0xA0000-0xBFFFF so that's safe. > You are right, as vhost does not have a smram address space listener. So > is this a qemu's flaw that virtual devices can not write to SMRAM?
No, it's how it works in real hardware. However, it is a (minor) bug that vhost doesn't have the equivalent of kvm_set_phys_mem's call to kvm_physical_sync_dirty_bitmap. > Fine, your patch is simpler than I thought and functions right. Great! > Reviewed-by: He Rongguang <herongguang...@huawei.com> Also Tested-by? Thanks, Paolo > >> . >> >
