microvm: add pcie support

Uses the existing gpex device which is also used as pcie host bridge on
arm/aarch64.  For now only a 32bit mmio window and no ioport support.

It is disabled by default, use "-machine microvm,pcie=on" to enable.
ACPI support must be enabled too because the bus is declared in the
DSDT table.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20200928104256.9241-6-kraxel@redhat.com

3 files changed, 97 insertions, 0 deletions

diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
index d0bd8b537d..32aa15533b 100644
--- a/hw/i386/Kconfig
+++ b/hw/i386/Kconfig
@@ -104,6 +104,7 @@ config MICROVM
     select MC146818RTC
     select VIRTIO_MMIO
     select ACPI_HW_REDUCED
+    select PCI_EXPRESS_GENERIC_BRIDGE
 
 config X86_IOMMU
     bool
diff --git a/hw/i386/acpi-microvm.c b/hw/i386/acpi-microvm.c
index df39c5d3bd..f16f231195 100644
--- a/hw/i386/acpi-microvm.c
+++ b/hw/i386/acpi-microvm.c
@@ -33,6 +33,8 @@
 #include "hw/boards.h"
 #include "hw/i386/fw_cfg.h"
 #include "hw/i386/microvm.h"
+#include "hw/pci/pci.h"
+#include "hw/pci/pcie_host.h"
 #include "hw/virtio/virtio-mmio.h"
 
 #include "acpi-common.h"
@@ -87,6 +89,15 @@ static void acpi_dsdt_add_virtio(Aml *scope,
     }
 }
 
+static void acpi_dsdt_add_pci(Aml *scope, MicrovmMachineState *mms)
+{
+    if (mms->pcie != ON_OFF_AUTO_ON) {
+        return;
+    }
+
+    acpi_dsdt_add_gpex(scope, &mms->gpex);
+}
+
 static void
 build_dsdt_microvm(GArray *table_data, BIOSLinker *linker,
                    MicrovmMachineState *mms)
@@ -112,6 +123,7 @@ build_dsdt_microvm(GArray *table_data, BIOSLinker *linker,
                   GED_MMIO_IRQ, AML_SYSTEM_MEMORY, GED_MMIO_BASE);
     acpi_dsdt_add_power_button(sb_scope);
     acpi_dsdt_add_virtio(sb_scope, mms);
+    acpi_dsdt_add_pci(sb_scope, mms);
     aml_append(dsdt, sb_scope);
 
     /* ACPI 5.0: Table 7-209 System State Package */
diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 60d3272230..273abe28c9 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -46,6 +46,7 @@
 #include "hw/virtio/virtio-mmio.h"
 #include "hw/acpi/acpi.h"
 #include "hw/acpi/generic_event_device.h"
+#include "hw/pci-host/gpex.h"
 
 #include "cpu.h"
 #include "elf.h"
@@ -101,6 +102,55 @@ static void microvm_gsi_handler(void *opaque, int n, int level)
     qemu_set_irq(s->ioapic_irq[n], level);
 }
 
+static void create_gpex(MicrovmMachineState *mms)
+{
+    X86MachineState *x86ms = X86_MACHINE(mms);
+    MemoryRegion *mmio32_alias;
+    MemoryRegion *mmio64_alias;
+    MemoryRegion *mmio_reg;
+    MemoryRegion *ecam_alias;
+    MemoryRegion *ecam_reg;
+    DeviceState *dev;
+    int i;
+
+    dev = qdev_new(TYPE_GPEX_HOST);
+    sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
+
+    /* Map only the first size_ecam bytes of ECAM space */
+    ecam_alias = g_new0(MemoryRegion, 1);
+    ecam_reg = sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0);
+    memory_region_init_alias(ecam_alias, OBJECT(dev), "pcie-ecam",
+                             ecam_reg, 0, mms->gpex.ecam.size);
+    memory_region_add_subregion(get_system_memory(),
+                                mms->gpex.ecam.base, ecam_alias);
+
+    /* Map the MMIO window into system address space so as to expose
+     * the section of PCI MMIO space which starts at the same base address
+     * (ie 1:1 mapping for that part of PCI MMIO space visible through
+     * the window).
+     */
+    mmio_reg = sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 1);
+    if (mms->gpex.mmio32.size) {
+        mmio32_alias = g_new0(MemoryRegion, 1);
+        memory_region_init_alias(mmio32_alias, OBJECT(dev), "pcie-mmio32", mmio_reg,
+                                 mms->gpex.mmio32.base, mms->gpex.mmio32.size);
+        memory_region_add_subregion(get_system_memory(),
+                                    mms->gpex.mmio32.base, mmio32_alias);
+    }
+    if (mms->gpex.mmio64.size) {
+        mmio64_alias = g_new0(MemoryRegion, 1);
+        memory_region_init_alias(mmio64_alias, OBJECT(dev), "pcie-mmio64", mmio_reg,
+                                 mms->gpex.mmio64.base, mms->gpex.mmio64.size);
+        memory_region_add_subregion(get_system_memory(),
+                                    mms->gpex.mmio64.base, mmio64_alias);
+    }
+
+    for (i = 0; i < GPEX_NUM_IRQS; i++) {
+        sysbus_connect_irq(SYS_BUS_DEVICE(dev), i,
+                           x86ms->gsi[mms->gpex.irq + i]);
+    }
+}
+
 static void microvm_devices_init(MicrovmMachineState *mms)
 {
     X86MachineState *x86ms = X86_MACHINE(mms);
@@ -147,6 +197,15 @@ static void microvm_devices_init(MicrovmMachineState *mms)
         x86ms->acpi_dev = HOTPLUG_HANDLER(dev);
     }
 
+    if (x86_machine_is_acpi_enabled(x86ms) && mms->pcie == ON_OFF_AUTO_ON) {
+        mms->gpex.mmio32.base = PCIE_MMIO_BASE;
+        mms->gpex.mmio32.size = PCIE_MMIO_SIZE;
+        mms->gpex.ecam.base   = PCIE_ECAM_BASE;
+        mms->gpex.ecam.size   = PCIE_ECAM_SIZE;
+        mms->gpex.irq         = PCIE_IRQ_BASE;
+        create_gpex(mms);
+    }
+
     if (mms->pic == ON_OFF_AUTO_ON || mms->pic == ON_OFF_AUTO_AUTO) {
         qemu_irq *i8259;
 
@@ -446,6 +505,23 @@ static void microvm_machine_set_rtc(Object *obj, Visitor *v, const char *name,
     visit_type_OnOffAuto(v, name, &mms->rtc, errp);
 }
 
+static void microvm_machine_get_pcie(Object *obj, Visitor *v, const char *name,
+                                     void *opaque, Error **errp)
+{
+    MicrovmMachineState *mms = MICROVM_MACHINE(obj);
+    OnOffAuto pcie = mms->pcie;
+
+    visit_type_OnOffAuto(v, name, &pcie, errp);
+}
+
+static void microvm_machine_set_pcie(Object *obj, Visitor *v, const char *name,
+                                     void *opaque, Error **errp)
+{
+    MicrovmMachineState *mms = MICROVM_MACHINE(obj);
+
+    visit_type_OnOffAuto(v, name, &mms->pcie, errp);
+}
+
 static bool microvm_machine_get_isa_serial(Object *obj, Error **errp)
 {
     MicrovmMachineState *mms = MICROVM_MACHINE(obj);
@@ -521,6 +597,7 @@ static void microvm_machine_initfn(Object *obj)
     mms->pic = ON_OFF_AUTO_AUTO;
     mms->pit = ON_OFF_AUTO_AUTO;
     mms->rtc = ON_OFF_AUTO_AUTO;
+    mms->pcie = ON_OFF_AUTO_AUTO;
     mms->isa_serial = true;
     mms->option_roms = true;
     mms->auto_kernel_cmdline = true;
@@ -587,6 +664,13 @@ static void microvm_class_init(ObjectClass *oc, void *data)
     object_class_property_set_description(oc, MICROVM_MACHINE_RTC,
         "Enable MC146818 RTC");
 
+    object_class_property_add(oc, MICROVM_MACHINE_PCIE, "OnOffAuto",
+                              microvm_machine_get_pcie,
+                              microvm_machine_set_pcie,
+                              NULL, NULL);
+    object_class_property_set_description(oc, MICROVM_MACHINE_PCIE,
+        "Enable PCIe");
+
     object_class_property_add_bool(oc, MICROVM_MACHINE_ISA_SERIAL,
                                    microvm_machine_get_isa_serial,
                                    microvm_machine_set_isa_serial);