[Qemu-devel] [PATCH] hw/acpi: fix Q35 support for legacy Windows OS

[Marcel Apfelbaum <marcel@redhat.com>]

Legacy Windows operating systems like Windows XP and Windows 2003
require _DIS method to be present for all interrupt links.

PC machines already have a no-op implemented for GSI links, add
it also in Q35.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---

Hi,

I tested this patch with WinXP and Win 2003, but also with Win 10, and Fedora.
This solves a BSOD early in the setup process.

WinXP/2003 can be tested using:
     -device piix3-ide,id=legacyide \
     -drive file=winxp-q35.qcow2,if=none,id=disk -device ide-hd,drive=disk,bus=legacyide.0 \
     -drive file=xp_sp3.iso,if=none,id=cdrom -device ide-cd,drive=cdrom,bus=legacyide.1 

Please note that you have to use the piix3-ide because Win2003 (and probably XP)
does not have Q35 AHCI drivers inbox.

Thanks,
Marcel

 hw/i386/acpi-build.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 52c9470..4c66568 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1509,6 +1509,9 @@ static Aml *build_gsi_link_dev(const char *name, uint8_t uid, uint8_t gsi)
 
     aml_append(dev, aml_name_decl("_CRS", crs));
 
+    method = aml_method("_DIS", 0, AML_NOTSERIALIZED);
+    aml_append(dev, method);
+
     method = aml_method("_SRS", 1, AML_NOTSERIALIZED);
     aml_append(dev, method);
 
-- 
2.4.3