[Qemu-devel] [PATCH 1/2] acpi: tpm: Fix TPM ACPI description (BZ 1281413)

[Stefan Berger]

This patch addresses BZ 1281413.

https://bugzilla.redhat.com/show_bug.cgi?id=1281413

Fix the APCI description to make it work on operating systems that are
more strict about the contents of the TPM's ACPI description than Linux
is. The ACPI description was broken in commit 9e472263.

We roll back the ACPI description to where it was in QEMU 2.3.1 and
deactivate the interrupt, modify the scope to \_SB, and change the
name of the device back to 'TPM' from 'ISA.TPM'. Here's the ACPI
description from QEMU 2.3.1:

    Scope(\_SB) {
        /* TPM with emulated TPM TIS interface */
        Device (TPM) {
            Name (_HID, EisaID ("PNP0C31"))
            Name (_CRS, ResourceTemplate ()
            {
                Memory32Fixed (ReadWrite, TPM_TIS_ADDR_BASE, TPM_TIS_ADDR_SIZE)
                // older Linux tpm_tis drivers do not work with IRQ
                //IRQNoFlags () {TPM_TIS_IRQ}
            })
            Method (_STA, 0, NotSerialized) {
                Return (0x0F)
            }
        }
    }

Signed-off-by: Stefan Berger <address@hidden>
---
 hw/i386/acpi-build.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 35180ef..e11c721 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -2335,22 +2335,20 @@ build_dsdt(GArray *table_data, GArray *linker,
                 Aml *scope = aml_scope("PCI0");
                 /* Scan all PCI buses. Generate tables to support hotplug. */
                 build_append_pci_bus_devices(scope, bus, pm->pcihp_bridge_en);
-
-                if (misc->tpm_version != TPM_VERSION_UNSPEC) {
-                    dev = aml_device("ISA.TPM");
-                    aml_append(dev, aml_name_decl("_HID", 
aml_eisaid("PNP0C31")));
-                    aml_append(dev, aml_name_decl("_STA", aml_int(0xF)));
-                    crs = aml_resource_template();
-                    aml_append(crs, aml_memory32_fixed(TPM_TIS_ADDR_BASE,
-                               TPM_TIS_ADDR_SIZE, AML_READ_WRITE));
-                    aml_append(crs, aml_irq_no_flags(TPM_TIS_IRQ));
-                    aml_append(dev, aml_name_decl("_CRS", crs));
-                    aml_append(scope, dev);
-                }
-
-                aml_append(sb_scope, scope);
             }
         }
+
+        if (misc->tpm_version != TPM_VERSION_UNSPEC) {
+            dev = aml_device("TPM");
+            aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0C31")));
+            aml_append(dev, aml_name_decl("_STA", aml_int(0xF)));
+            crs = aml_resource_template();
+            aml_append(crs, aml_memory32_fixed(TPM_TIS_ADDR_BASE,
+                       TPM_TIS_ADDR_SIZE, AML_READ_WRITE));
+            //aml_append(crs, aml_irq_no_flags(TPM_TIS_IRQ));
+            aml_append(dev, aml_name_decl("_CRS", crs));
+            aml_append(sb_scope, dev);
+        }
         aml_append(dsdt, sb_scope);
     }
 
-- 
2.5.5