[RFC PATCH 4/5] hw/i386/acpi-build: Turn off support of PCIe native hot-plug and SHPC in _OSC

[Julia Suvorova]

Other methods may be used if the system is capable of this and the _OSC bit
is set. Disable them explicitly to force ACPI PCI hot-plug use. The older
versions will still use PCIe native.

Signed-off-by: Julia Suvorova <jusual@redhat.com>
---
 hw/i386/acpi-build.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 5c5ad88ad6..0e2891c3ea 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1599,6 +1599,7 @@ static Aml *build_q35_osc_method(AcpiPmInfo *pm)
     Aml *method;
     Aml *a_cwd1 = aml_name("CDW1");
     Aml *a_ctrl = aml_local(0);
+    unsigned osc_ctrl;
 
     method = aml_method("_OSC", 4, AML_NOTSERIALIZED);
     aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1"));
@@ -1612,9 +1613,12 @@ static Aml *build_q35_osc_method(AcpiPmInfo *pm)
 
     /*
      * Always allow native PME, AER (no dependencies)
-     * Allow SHPC (PCI bridges can have SHPC controller)
+     * Need to disable native and SHPC hot-plug to use acpihp
+     *
+     * PCI Firmware Specification, Revision 3.2
      */
-    aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1F), a_ctrl));
+    osc_ctrl = pm->pcihp_bridge_en ? 0x1C : 0x1F;
+    aml_append(if_ctx, aml_and(a_ctrl, aml_int(osc_ctrl), a_ctrl));
 
     if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1))));
     /* Unknown revision */
@@ -1696,7 +1700,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
         aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
         aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
         aml_append(dev, aml_name_decl("_UID", aml_int(1)));
-        aml_append(dev, build_q35_osc_method());
+        aml_append(dev, build_q35_osc_method(pm));
         aml_append(sb_scope, dev);
         aml_append(dsdt, sb_scope);
 
@@ -1771,7 +1775,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
             if (pci_bus_is_express(bus)) {
                 aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08")));
                 aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
-                aml_append(dev, build_q35_osc_method());
+                aml_append(dev, build_q35_osc_method(pm));
             } else {
                 aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
             }
-- 
2.25.4