hw/arm/virt: Add high MMIO PCI region, 512G in size

This large region is necessary for some devices like ivshmem and video cards
32-bit kernels can be built without LPAE support. In this case such a kernel
will not be able to use PCI controller which has windows in high addresses.
In order to work around the problem, "highmem" option is introduced. It
defaults to on on, but can be manually set to off in order to be able to run
those old 32-bit guests.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Shannon Zhao <shannon.zhao@linaro.org>
[PMM: Added missing ULL suffixes and a comment to the a15memmap[] entry]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 74 insertions, 9 deletions

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index f365140319..9088248c3a 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -159,7 +159,8 @@ static void acpi_dsdt_add_virtio(Aml *scope,
     }
 }
 
-static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap, int irq)
+static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap, int irq,
+                              bool use_highmem)
 {
     Aml *method, *crs, *ifctx, *UUID, *ifctx1, *elsectx, *buf;
     int i, bus_no;
@@ -234,6 +235,17 @@ static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap, int irq)
                      AML_ENTIRE_RANGE, 0x0000, 0x0000, size_pio - 1, base_pio,
                      size_pio));
 
+    if (use_highmem) {
+        hwaddr base_mmio_high = memmap[VIRT_PCIE_MMIO_HIGH].base;
+        hwaddr size_mmio_high = memmap[VIRT_PCIE_MMIO_HIGH].size;
+
+        aml_append(rbuf,
+            aml_qword_memory(AML_POS_DECODE, AML_MIN_FIXED, AML_MAX_FIXED,
+                             AML_NON_CACHEABLE, AML_READ_WRITE, 0x0000,
+                             base_mmio_high, base_mmio_high, 0x0000,
+                             size_mmio_high));
+    }
+
     aml_append(method, aml_name_decl("RBUF", rbuf));
     aml_append(method, aml_return(rbuf));
     aml_append(dev, method);
@@ -510,7 +522,8 @@ build_dsdt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info)
     acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]);
     acpi_dsdt_add_virtio(scope, &memmap[VIRT_MMIO],
                     (irqmap[VIRT_MMIO] + ARM_SPI_BASE), NUM_VIRTIO_TRANSPORTS);
-    acpi_dsdt_add_pci(scope, memmap, (irqmap[VIRT_PCIE] + ARM_SPI_BASE));
+    acpi_dsdt_add_pci(scope, memmap, (irqmap[VIRT_PCIE] + ARM_SPI_BASE),
+                      guest_info->use_highmem);
 
     aml_append(dsdt, scope);
 
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index bbd061b9b6..60736c2062 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -80,6 +80,7 @@ typedef struct {
 typedef struct {
     MachineState parent;
     bool secure;
+    bool highmem;
 } VirtMachineState;
 
 #define TYPE_VIRT_MACHINE   "virt"
@@ -120,6 +121,8 @@ static const MemMapEntry a15memmap[] = {
     [VIRT_PCIE_PIO] =           { 0x3eff0000, 0x00010000 },
     [VIRT_PCIE_ECAM] =          { 0x3f000000, 0x01000000 },
     [VIRT_MEM] =                { 0x40000000, 30ULL * 1024 * 1024 * 1024 },
+    /* Second PCIe window, 512GB wide at the 512GB boundary */
+    [VIRT_PCIE_MMIO_HIGH] =   { 0x8000000000ULL, 0x8000000000ULL },
 };
 
 static const int a15irqmap[] = {
@@ -667,10 +670,13 @@ static void create_pcie_irq_map(const VirtBoardInfo *vbi, uint32_t gic_phandle,
                            0x7           /* PCI irq */);
 }
 
-static void create_pcie(const VirtBoardInfo *vbi, qemu_irq *pic)
+static void create_pcie(const VirtBoardInfo *vbi, qemu_irq *pic,
+                        bool use_highmem)
 {
     hwaddr base_mmio = vbi->memmap[VIRT_PCIE_MMIO].base;
     hwaddr size_mmio = vbi->memmap[VIRT_PCIE_MMIO].size;
+    hwaddr base_mmio_high = vbi->memmap[VIRT_PCIE_MMIO_HIGH].base;
+    hwaddr size_mmio_high = vbi->memmap[VIRT_PCIE_MMIO_HIGH].size;
     hwaddr base_pio = vbi->memmap[VIRT_PCIE_PIO].base;
     hwaddr size_pio = vbi->memmap[VIRT_PCIE_PIO].size;
     hwaddr base_ecam = vbi->memmap[VIRT_PCIE_ECAM].base;
@@ -707,6 +713,16 @@ static void create_pcie(const VirtBoardInfo *vbi, qemu_irq *pic)
                              mmio_reg, base_mmio, size_mmio);
     memory_region_add_subregion(get_system_memory(), base_mmio, mmio_alias);
 
+    if (use_highmem) {
+        /* Map high MMIO space */
+        MemoryRegion *high_mmio_alias = g_new0(MemoryRegion, 1);
+
+        memory_region_init_alias(high_mmio_alias, OBJECT(dev), "pcie-mmio-high",
+                                 mmio_reg, base_mmio_high, size_mmio_high);
+        memory_region_add_subregion(get_system_memory(), base_mmio_high,
+                                    high_mmio_alias);
+    }
+
     /* Map IO port space */
     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 2, base_pio);
 
@@ -728,11 +744,23 @@ static void create_pcie(const VirtBoardInfo *vbi, qemu_irq *pic)
 
     qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg",
                                  2, base_ecam, 2, size_ecam);
-    qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "ranges",
-                                 1, FDT_PCI_RANGE_IOPORT, 2, 0,
-                                 2, base_pio, 2, size_pio,
-                                 1, FDT_PCI_RANGE_MMIO, 2, base_mmio,
-                                 2, base_mmio, 2, size_mmio);
+
+    if (use_highmem) {
+        qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "ranges",
+                                     1, FDT_PCI_RANGE_IOPORT, 2, 0,
+                                     2, base_pio, 2, size_pio,
+                                     1, FDT_PCI_RANGE_MMIO, 2, base_mmio,
+                                     2, base_mmio, 2, size_mmio,
+                                     1, FDT_PCI_RANGE_MMIO_64BIT,
+                                     2, base_mmio_high,
+                                     2, base_mmio_high, 2, size_mmio_high);
+    } else {
+        qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "ranges",
+                                     1, FDT_PCI_RANGE_IOPORT, 2, 0,
+                                     2, base_pio, 2, size_pio,
+                                     1, FDT_PCI_RANGE_MMIO, 2, base_mmio,
+                                     2, base_mmio, 2, size_mmio);
+    }
 
     qemu_fdt_setprop_cell(vbi->fdt, nodename, "#interrupt-cells", 1);
     create_pcie_irq_map(vbi, vbi->gic_phandle, irq, nodename);
@@ -915,7 +943,7 @@ static void machvirt_init(MachineState *machine)
 
     create_rtc(vbi, pic);
 
-    create_pcie(vbi, pic);
+    create_pcie(vbi, pic, vms->highmem);
 
     /* Create mmio transports, so the user can create virtio backends
      * (which will be automatically plugged in to the transports). If
@@ -930,6 +958,7 @@ static void machvirt_init(MachineState *machine)
     guest_info->fw_cfg = fw_cfg_find();
     guest_info->memmap = vbi->memmap;
     guest_info->irqmap = vbi->irqmap;
+    guest_info->use_highmem = vms->highmem;
     guest_info_state->machine_done.notify = virt_guest_info_machine_done;
     qemu_add_machine_init_done_notifier(&guest_info_state->machine_done);
 
@@ -967,6 +996,20 @@ static void virt_set_secure(Object *obj, bool value, Error **errp)
     vms->secure = value;
 }
 
+static bool virt_get_highmem(Object *obj, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+
+    return vms->highmem;
+}
+
+static void virt_set_highmem(Object *obj, bool value, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+
+    vms->highmem = value;
+}
+
 static void virt_instance_init(Object *obj)
 {
     VirtMachineState *vms = VIRT_MACHINE(obj);
@@ -979,6 +1022,15 @@ static void virt_instance_init(Object *obj)
                                     "Set on/off to enable/disable the ARM "
                                     "Security Extensions (TrustZone)",
                                     NULL);
+
+    /* High memory is enabled by default */
+    vms->highmem = true;
+    object_property_add_bool(obj, "highmem", virt_get_highmem,
+                             virt_set_highmem, NULL);
+    object_property_set_description(obj, "highmem",
+                                    "Set on/off to enable/disable using "
+                                    "physical address space above 32 bits",
+                                    NULL);
 }
 
 static void virt_class_init(ObjectClass *oc, void *data)