Hi, Michael and the list, I observed this on windows 8 enterprise guests, when doing memory ballooning:
23892@1517298572.328354:virtio_balloon_to_target balloon target: 0x80000000 num_pages: 524288 23892@1517298638.542819:virtio_balloon_get_config num_pages: 524288 actual: 0 23892@1517298638.542974:virtio_balloon_handle_output section name: pc.ram gpa: 0x174604000 23892@1517298638.543059:virtio_balloon_handle_output section name: pc.ram gpa: 0x0 23892@1517298638.543135:virtio_balloon_handle_output section name: pc.ram gpa: 0x17460a000 23892@1517298638.543140:virtio_balloon_handle_output section name: pc.ram gpa: 0x0 23892@1517298638.543143:virtio_balloon_handle_output section name: pc.ram gpa: 0x17460b000 23892@1517298638.543146:virtio_balloon_handle_output section name: pc.ram gpa: 0x0 23892@1517298638.543148:virtio_balloon_handle_output section name: pc.ram gpa: 0x17460c000 23892@1517298638.543152:virtio_balloon_handle_output section name: pc.ram gpa: 0x0 23892@1517298638.543154:virtio_balloon_handle_output section name: pc.ram gpa: 0x17460d000 23892@1517298638.543159:virtio_balloon_handle_output section name: pc.ram gpa: 0x0 23892@1517298638.543162:virtio_balloon_handle_output section name: pc.ram gpa: 0x17460e000 23892@1517298638.543165:virtio_balloon_handle_output section name: pc.ram gpa: 0x0 23892@1517298638.543167:virtio_balloon_handle_output section name: pc.ram gpa: 0x17460f000 23892@1517298638.543170:virtio_balloon_handle_output section name: pc.ram gpa: 0x0 ... I think it's very possible that these zero addresses (please let me know what the first 4K page is used for if anyone knows, since IIUC that's what we throw away now) are half of the 64bit PFN. Or say, not sure whether this means a windows guest driver bug that is using 64bits for PFN rather than 32bits (and I suppose the protocol is using 32bit for PFNs). Michael, do you know what to do with this? Thanks, -- Peter Xu