On Mon, Sep 14, 2015 at 02:16:49PM -0400, Gabriel L. Somlo wrote: > On Mon, Sep 14, 2015 at 01:09:41PM -0300, Eduardo Habkost wrote: > > On Mon, Sep 14, 2015 at 10:57:31AM -0400, Gabriel L. Somlo wrote: > > > Add a fw_cfg device node to the ACPI SSDT. While the guest-side > > > BIOS can't utilize this information (since it has to access the > > > hard-coded fw_cfg device to extract ACPI tables to begin with), > > > having fw_cfg listed in ACPI will help the guest kernel keep a > > > more accurate inventory of in-use IO port regions. > > > > > > Signed-off-by: Gabriel Somlo <so...@cmu.edu> > > > --- > > > hw/i386/acpi-build.c | 20 ++++++++++++++++++++ > > > 1 file changed, 20 insertions(+) > > > > > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > > > index 95e0c65..ecdb3a5 100644 > > > --- a/hw/i386/acpi-build.c > > > +++ b/hw/i386/acpi-build.c > > > @@ -1071,6 +1071,26 @@ build_ssdt(GArray *table_data, GArray *linker, > > > aml_append(scope, aml_name_decl("_S5", pkg)); > > > aml_append(ssdt, scope); > > > > > > + if (guest_info->fw_cfg) { > > > > I sent a reply to v1 a few minutes before seeing v2. Copying it here for > > reference: > > > > Is this function ever going to be called without fw_cfg set? > > acpi_setup() returns immediately if fw_cfg isn't available. > > You're right, build_ssdt() is called from acpi_build(), which is > called directly from acpi_setup(), and also indirectly via > acpi_build_update() via acpi_add_rom_blob(), but all that eventually > ties back to acpi_setup(), *after* it already established that > guest_info->fw_cfg is non-NULL. > > > Also, this changes guest ABI, so you will need to add some compat flag > > to PCMachineClass indicating if the device node should be added. > > So I'll replace the "if (guest_info->fw_cfg)" check with > "if machine-type >= (pc-q35-2.5 or pc-i440fx-2.5))", in v3, > as soon as the patches for the 2.5 machine type make it into > git master (I remember seeing a reviewed-by fly by for that > earlier today :)
Sounds good, assuming you are going to implement the "machine-type >= pc-2.5" check with something like: PC_MACHINE_GET_CLASS(machine)->acpi_no_fw_cfg_node. -- Eduardo