[Qemu-devel] [PATCH v8] hw/arm/virt: Add high MMIO PCI region, 512G in size

[Pavel Fedin <p.fedin@samsung.com>]

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>
---
v7 => v8:
- Split up between region and FDT creation
- Renamed alias variable to high_mmio_alias
v6 => v7:
- Renamed alias variable to mmio64_alias
v5 => v6:
- Specify correct FDT_PCI_RANGE_MMIO_64BIT type for the region, the bug
  was discovered by running UEFI
v4 => v5:
- Removed machine-dependent "highmem" default, now always ON
v3 => v4:
- Added "highmem" option which controls presence of this region. Default
  value is on for 64-bit CPUs and off for 32-bit CPUs.
- Supply correct min and max address to aml_qword_memory()
v2 => v3:
- Region size increased to 512G
- Added ACPI description
v1 => v2:
- Region address changed to 512G, leaving more space for RAM
---
 hw/arm/virt-acpi-build.c         | 17 +++++++++--
 hw/arm/virt.c                    | 65 +++++++++++++++++++++++++++++++++++-----
 include/hw/arm/virt-acpi-build.h |  1 +
 include/hw/arm/virt.h            |  1 +
 4 files changed, 75 insertions(+), 9 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index f365140..9088248 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 d5a8417..003a47c 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -79,6 +79,7 @@ typedef struct {
 typedef struct {
     MachineState parent;
     bool secure;
+    bool highmem;
 } VirtMachineState;
 
 #define TYPE_VIRT_MACHINE   "virt"
@@ -119,6 +120,7 @@ static const MemMapEntry a15memmap[] = {
     [VIRT_PCIE_PIO] =           { 0x3eff0000, 0x00010000 },
     [VIRT_PCIE_ECAM] =          { 0x3f000000, 0x01000000 },
     [VIRT_MEM] =                { 0x40000000, 30ULL * 1024 * 1024 * 1024 },
+    [VIRT_PCIE_MMIO_HIGH] =   { 0x8000000000, 0x8000000000 },
 };
 
 static const int a15irqmap[] = {
@@ -666,10 +668,13 @@ 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;
@@ -706,6 +711,16 @@ 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);
 
@@ -727,11 +742,23 @@ 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);
@@ -889,7 +916,7 @@ 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
@@ -904,6 +931,7 @@ 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);
 
@@ -941,6 +969,20 @@ 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);
@@ -953,6 +995,15 @@ 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)
diff --git a/include/hw/arm/virt-acpi-build.h b/include/hw/arm/virt-acpi-build.h
index 04f174d..19b68a4 100644
--- a/include/hw/arm/virt-acpi-build.h
+++ b/include/hw/arm/virt-acpi-build.h
@@ -31,6 +31,7 @@ typedef struct VirtGuestInfo {
     FWCfgState *fw_cfg;
     const MemMapEntry *memmap;
     const int *irqmap;
+    bool use_highmem;
 } VirtGuestInfo;
 
 
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index d22fd8e..808753f 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -56,6 +56,7 @@ enum {
     VIRT_PCIE_ECAM,
     VIRT_GIC_V2M,
     VIRT_PLATFORM_BUS,
+    VIRT_PCIE_MMIO_HIGH,
 };
 
 typedef struct MemMapEntry {
-- 
1.9.5.msysgit.0