[RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used

[Julia Suvorova <jusual@redhat.com>]

Instead of changing the hot-plug type in _OSC register, do not
initialize the slot capability or set the 'Slot Implemented' flag.
This way guest will choose ACPI hot-plug if it is preferred and leave
the option to use SHPC with pcie-pci-bridge.

Signed-off-by: Julia Suvorova <jusual@redhat.com>
---
 hw/i386/acpi-build.h |  2 ++
 hw/i386/acpi-build.c |  2 +-
 hw/pci/pcie.c        | 16 ++++++++++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
index 487ec7710f..4c5bfb3d0b 100644
--- a/hw/i386/acpi-build.h
+++ b/hw/i386/acpi-build.h
@@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
 
 void acpi_setup(void);
 
+Object *object_resolve_type_unambiguous(const char *typename);
+
 #endif
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index cf503b16af..b7811a8912 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
     *data = fadt;
 }
 
-static Object *object_resolve_type_unambiguous(const char *typename)
+Object *object_resolve_type_unambiguous(const char *typename)
 {
     bool ambig;
     Object *o = object_resolve_path_type("", typename, &ambig);
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 5b48bae0f6..c1a082e8b9 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -27,6 +27,8 @@
 #include "hw/pci/pci_bus.h"
 #include "hw/pci/pcie_regs.h"
 #include "hw/pci/pcie_port.h"
+#include "hw/i386/ich9.h"
+#include "hw/i386/acpi-build.h"
 #include "qemu/range.h"
 
 //#define DEBUG_PCIE
@@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
     pcie_cap_slot_push_attention_button(hotplug_pdev);
 }
 
+static bool acpi_pcihp_enabled(void)
+{
+    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
+
+    return lpc &&
+           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
+                                    NULL);
+
+}
+
 /* pci express slot for pci express root/downstream port
    PCI express capability slot registers */
 void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
 {
     uint32_t pos = dev->exp.exp_cap;
 
+    if (acpi_pcihp_enabled()) {
+        return;
+    }
+
     pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
                                PCI_EXP_FLAGS_SLOT);
 
-- 
2.25.4