On Mon, Sep 25, 2023 at 05:58:00PM +0200, Laszlo Ersek wrote: > On 9/25/23 16:04, Richard W.M. Jones wrote: > > Read HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation key > > "RealTimeIsUniversal" to see if the Windows guest is expecting BIOS > > set to localtime (not present) or UTC (present and set to 1). > > > > See: https://wiki.archlinux.org/title/System_time#UTC_in_Microsoft_Windows > > See: > > https://listman.redhat.com/archives/libguestfs/2023-September/thread.html#32556 > > Reported-by: Lee Garrett > > --- > > convert/convert_windows.ml | 38 +++++++++++++++++++++++++++++++++++++- > > tests/test-v2v-i-ova.xml | 2 +- > > 2 files changed, 38 insertions(+), 2 deletions(-) > > > > diff --git a/convert/convert_windows.ml b/convert/convert_windows.ml > > index f6e039be7e..84e8f7b7d3 100644 > > --- a/convert/convert_windows.ml > > +++ b/convert/convert_windows.ml > > @@ -103,6 +103,42 @@ let convert (g : G.guestfs) _ inspect i_firmware > > block_driver _ static_ips = > > (* If the Windows guest has AV installed. *) > > let has_antivirus = Windows.detect_antivirus inspect in > > > > + (* Does the guest expect the BIOS to be set to UTC or localtime? > > + * See > > https://wiki.archlinux.org/title/System_time#UTC_in_Microsoft_Windows > > + * Note this might be a QWORD on 64 bit Windows instances. > > + *) > > + let bios_utc = > > + Registry.with_hive_readonly g inspect.i_windows_system_hive > > + (fun reg -> > > + try > > + let key_path = [ "Control"; "TimeZoneInformation" ] in > > + let path = inspect.i_windows_current_control_set :: key_path in > > + let node = > > + match Registry.get_node reg path with > > + | None -> raise Not_found > > + | Some node -> node in > > + let valueh = g#hivex_node_get_value node "RealTimeIsUniversal" in > > + if valueh = 0L then raise Not_found; > > + let t = g#hivex_value_type valueh in > > + let data = g#hivex_value_value valueh in > > + let is_utc = > > + match t with > > + | 0_L (* REG_NONE *) -> false (* localtime *) > > + | 4_L (* REG_DWORD *) -> data = "\001\000\000\000" > > + | 11_L (* REG_QWORD *) -> data = > > "\001\000\000\000\000\000\000\000" > > + | _ (* who knows ... *) -> > > + warning (f_"unknown CurrentControlSet\\Control\\\ > > + TimeZoneInformation key RealTimeIsUniversal \ > > + type 0x%Lx, assuming BIOS set to UTC") t; > > + true in > > [*] > > > + is_utc > > + with Not_found -> > > + (* If the key is not found then by default we assume > > + * that Windows is expecting the BIOS to be set to localtime. > > + *) > > + false > > + ) in > > + > > (* Open the software hive (readonly) and find the Xen PV uninstaller, > > * if it exists. > > *) > > [*] Just guessing, but I'm not sure if assuming UTC is right when the > key is found but its type is unrecognized, in light of determining > localtime when the key is absent or has type REG_NONE. > > Either way, the warning is honest about it!
I don't know - I would need to examine lots of Windows machines to find out what they really do. But I expect that this field only ever contains dword:1 or hex(b):1 [qword:1], or is absent. > > @@ -275,7 +311,7 @@ let convert (g : G.guestfs) _ inspect i_firmware > > block_driver _ static_ips = > > gcaps_arch = Utils.kvm_arch inspect.i_arch; > > gcaps_arch_min_version = 0; > > gcaps_virtio_1_0 = virtio_win_installed.Inject_virtio_win.virtio_1_0; > > - gcaps_bios_utc = true; > > + gcaps_bios_utc = bios_utc; > > } in > > > > guestcaps > > diff --git a/tests/test-v2v-i-ova.xml b/tests/test-v2v-i-ova.xml > > index a41827bfd5..fa7b4dbfc5 100644 > > --- a/tests/test-v2v-i-ova.xml > > +++ b/tests/test-v2v-i-ova.xml > > @@ -18,7 +18,7 @@ > > <os> > > <type arch='x86_64' machine='q35'>hvm</type> > > </os> > > - <clock offset='utc'/> > > + <clock offset='localtime'/> > > <on_poweroff>destroy</on_poweroff> > > <on_reboot>restart</on_reboot> > > <on_crash>restart</on_crash> > > With the BIOS -> RTC typo (?) fixed everywhere: > > series > Reviewed-by: Laszlo Ersek <ler...@redhat.com> Thanks, I'll post v2 anyway since I've written it now. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
