From ee7a08d5310a92a168827f50fb0f9eafd9864ac9 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Mon, 13 Jul 2015 19:17:38 +0200 Subject: [PATCH 12/23] i386/acpi-build: more traditional _UID and _HID for PXB root buses Message-id: <1436815069-15106-2-git-send-email-lersek@redhat.com> Patchwork-id: 66992 O-Subject: [RHEV-7.2 qemu-kvm-rhev PATCH 01/12] i386/acpi-build: more traditional _UID and _HID for PXB root buses Bugzilla: 1242479 RH-Acked-by: Marcel Apfelbaum RH-Acked-by: Paolo Bonzini RH-Acked-by: Michael S. Tsirkin The ACPI specification permits the _HID and _UID objects to evaluate to strings. (See "6.1.5 _HID (Hardware ID)" and "6.1.12 _UID (Unique ID)" in the ACPI v6.0 spec.) With regard to related standards, the UEFI specification can also express a device address composed from string _HID and _UID identifiers, inside the Expanded ACPI Device Path Node. (See "9.3.3 ACPI Device Path", Table 49, in the UEFI v2.5 spec.) However, numeric (integer) contents for both _HID and _UID are more traditional. They are recommended by the UEFI spec for size reasons: [...] the ACPI Device Path node is smaller and should be used if possible to reduce the size of device paths that may potentially be stored in nonvolatile storage [...] External tools support them better (for example the --acpi_hid and --acpi_uid options of "efibootmgr" only take numeric identifiers). Finally, numeric _HID and _UID contents are existing practice in the QEMU source. This patch was tested with a Fedora 20 LiveCD and a preexistent Windows Server 2012 R2 guest. Using "acpidump" and "iasl" in the Fedora guest, we get, in the SSDT: > Scope (\_SB) > { > Device (PC04) > { > Name (_UID, 0x04) // _UID: Unique ID > Name (_HID, EisaId ("PNP0A03") /* PCI Bus */) // _HID: Hardware ID Cc: Marcel Apfelbaum Cc: Michael S. Tsirkin Signed-off-by: Laszlo Ersek Reviewed-by: Marcel Apfelbaum Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit c96d9286a6d70452e5fa4f1e3f840715e325be95) Signed-off-by: Miroslav Rezanina --- hw/i386/acpi-build.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 589534e..b84f4e6 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -942,9 +942,8 @@ build_ssdt(GArray *table_data, GArray *linker, scope = aml_scope("\\_SB"); dev = aml_device("PC%.02X", bus_num); - aml_append(dev, - aml_name_decl("_UID", aml_string("PC%.02X", bus_num))); - aml_append(dev, aml_name_decl("_HID", aml_string("PNP0A03"))); + aml_append(dev, aml_name_decl("_UID", aml_int(bus_num))); + aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03"))); aml_append(dev, aml_name_decl("_BBN", aml_int(bus_num))); if (numa_node != NUMA_NODE_UNASSIGNED) { -- 1.8.3.1