[Qemu-devel] [PATCH v3 3/4] arm: Add PCIe host bridge in virt machine

[Alexander Graf]

Now that we have a working "generic" PCIe host bridge driver, we can plug
it into ARM's virt machine to always have PCIe available to normal ARM VMs.

I've successfully managed to expose a Bochs VGA device, XHCI and an e1000
into an AArch64 VM with this and they all lived happily ever after.

Signed-off-by: Alexander Graf <address@hidden>
Tested-by: Claudio Fontana <address@hidden>

---

Linux 3.19 only supports the generic PCIe host bridge driver for 32bit ARM
systems. If you want to use it with AArch64 guests, please apply the following
patch or wait until upstream cleaned up the code properly:

  http://csgraf.de/agraf/pci/pci-3.19.patch

v1 -> v2:

  - Add define for pci range types
  - Remove mmio_window_size
  - Use 4 PCI INTX IRQ lines

v2 -> v3:

  - Coding style fixes
  - Map ECAM space via alias to limit its size
  - Increase ECAM size to 16 buses
  - Use GPEX IRQ number define
  - Align ECAM region, Document region allocation better
  - Move interrupt-map into irq map function
  - s/FDT_PCI_RANGE_TYPE/FDT_PCI_RANGE_TYPE_MASK/
---
 default-configs/arm-softmmu.mak |   2 +
 hw/arm/virt.c                   | 140 ++++++++++++++++++++++++++++++++++++++--
 include/sysemu/device_tree.h    |   9 +++
 3 files changed, 146 insertions(+), 5 deletions(-)

diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
index f3513fa..7671ee2 100644
--- a/default-configs/arm-softmmu.mak
+++ b/default-configs/arm-softmmu.mak
@@ -82,6 +82,8 @@ CONFIG_ZYNQ=y
 CONFIG_VERSATILE_PCI=y
 CONFIG_VERSATILE_I2C=y
 
+CONFIG_PCI_GENERIC=y
+
 CONFIG_SDHCI=y
 CONFIG_INTEGRATOR_DEBUG=y
 
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 2353440..5bbc7cb 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -42,6 +42,7 @@
 #include "exec/address-spaces.h"
 #include "qemu/bitops.h"
 #include "qemu/error-report.h"
+#include "hw/pci-host/gpex.h"
 
 #define NUM_VIRTIO_TRANSPORTS 32
 
@@ -69,6 +70,7 @@ enum {
     VIRT_MMIO,
     VIRT_RTC,
     VIRT_FW_CFG,
+    VIRT_PCIE,
 };
 
 typedef struct MemMapEntry {
@@ -129,13 +131,15 @@ static const MemMapEntry a15memmap[] = {
     [VIRT_FW_CFG] =     { 0x09020000, 0x0000000a },
     [VIRT_MMIO] =       { 0x0a000000, 0x00000200 },
     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
-    /* 0x10000000 .. 0x40000000 reserved for PCI */
+    /* PCIe region layout: [ MMIO | PIO | ECAM ] */
+    [VIRT_PCIE] =       { 0x10000000, 0x30000000 },
     [VIRT_MEM] =        { 0x40000000, 30ULL * 1024 * 1024 * 1024 },
 };
 
 static const int a15irqmap[] = {
     [VIRT_UART] = 1,
     [VIRT_RTC] = 2,
+    [VIRT_PCIE] = 3, /* ... to 6 */
     [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */
 };
 
@@ -312,7 +316,7 @@ static void fdt_add_cpu_nodes(const VirtBoardInfo *vbi)
     }
 }
 
-static void fdt_add_gic_node(const VirtBoardInfo *vbi)
+static uint32_t fdt_add_gic_node(const VirtBoardInfo *vbi)
 {
     uint32_t gic_phandle;
 
@@ -331,9 +335,11 @@ static void fdt_add_gic_node(const VirtBoardInfo *vbi)
                                      2, vbi->memmap[VIRT_GIC_CPU].base,
                                      2, vbi->memmap[VIRT_GIC_CPU].size);
     qemu_fdt_setprop_cell(vbi->fdt, "/intc", "phandle", gic_phandle);
+
+    return gic_phandle;
 }
 
-static void create_gic(const VirtBoardInfo *vbi, qemu_irq *pic)
+static uint32_t create_gic(const VirtBoardInfo *vbi, qemu_irq *pic)
 {
     /* We create a standalone GIC v2 */
     DeviceState *gicdev;
@@ -380,7 +386,7 @@ static void create_gic(const VirtBoardInfo *vbi, qemu_irq 
*pic)
         pic[i] = qdev_get_gpio_in(gicdev, i);
     }
 
-    fdt_add_gic_node(vbi);
+    return fdt_add_gic_node(vbi);
 }
 
 static void create_uart(const VirtBoardInfo *vbi, qemu_irq *pic)
@@ -556,6 +562,127 @@ static void create_fw_cfg(const VirtBoardInfo *vbi)
     g_free(nodename);
 }
 
+static void create_pcie_irq_map(const VirtBoardInfo *vbi, uint32_t gic_phandle,
+                                int first_irq, const char *nodename)
+{
+    int devfn, pin;
+    uint32_t full_irq_map[4 * 4 * 8] = { 0 };
+    uint32_t *irq_map = full_irq_map;
+
+    for (devfn = 0; devfn <= 0x18; devfn += 0x8) {
+        for (pin = 0; pin < 4; pin++) {
+            int irq_type = GIC_FDT_IRQ_TYPE_SPI;
+            int irq_nr = first_irq + ((pin + PCI_SLOT(devfn)) % PCI_NUM_PINS);
+            int irq_level = GIC_FDT_IRQ_FLAGS_LEVEL_HI;
+            int i;
+
+            uint32_t map[] = {
+                devfn << 8, 0, 0,                           /* devfn */
+                pin + 1,                                    /* PCI pin */
+                gic_phandle, irq_type, irq_nr, irq_level }; /* GIC irq */
+
+            /* Convert map to big endian */
+            for (i = 0; i < 8; i++) {
+                irq_map[i] = cpu_to_be32(map[i]);
+            }
+            irq_map += 8;
+        }
+    }
+
+    qemu_fdt_setprop(vbi->fdt, nodename, "interrupt-map",
+                     full_irq_map, sizeof(full_irq_map));
+
+    qemu_fdt_setprop_cells(vbi->fdt, nodename, "interrupt-map-mask",
+                           0x1800, 0, 0, /* devfn (PCI_SLOT(3)) */
+                           0x7           /* PCI irq */);
+}
+
+static void create_pcie(const VirtBoardInfo *vbi, qemu_irq *pic,
+                        uint32_t gic_phandle)
+{
+    hwaddr base = vbi->memmap[VIRT_PCIE].base;
+    hwaddr size = vbi->memmap[VIRT_PCIE].size;
+    hwaddr end = base + size;
+    hwaddr size_mmio;
+    hwaddr size_ioport = 64 * 1024;
+    hwaddr size_ecam = PCIE_MMCFG_SIZE_MIN * 16; /* 16 PCIe buses */
+    hwaddr base_mmio = base;
+    hwaddr base_ioport;
+    hwaddr base_ecam;
+    int irq = vbi->irqmap[VIRT_PCIE];
+    MemoryRegion *mmio_alias;
+    MemoryRegion *mmio_reg;
+    MemoryRegion *ecam_alias;
+    MemoryRegion *ecam_reg;
+    DeviceState *dev;
+    char *nodename;
+    int i;
+
+    /*
+     * Align all the regions to their respective positions. Eventually
+     * we want to have:
+     *
+     *  < MMIO space >
+     *  < IO Port space >
+     *  < ECAM space >
+     *
+     * all naturally aligned after each other. The MMIO region always starts
+     * at 0 and shrinks depending on the size of the other 2 regions.
+     */
+    base_ecam = QEMU_ALIGN_DOWN(end - size_ecam, size_ecam);
+    size_ecam = end - base_ecam;
+    base_ioport = QEMU_ALIGN_DOWN(end - size_ecam - size_ioport, size_ioport);
+    size_ioport = base_ecam - base_ioport;
+    size_mmio = base_ioport - base;
+
+    dev = qdev_create(NULL, TYPE_GPEX_HOST);
+    qdev_init_nofail(dev);
+
+    /* 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, size_ecam);
+    memory_region_add_subregion(get_system_memory(), base_ecam, ecam_alias);
+
+    /* Map the MMIO window at the same spot in bus and cpu layouts */
+    mmio_alias = g_new0(MemoryRegion, 1);
+    mmio_reg = sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 1);
+    memory_region_init_alias(mmio_alias, OBJECT(dev), "pcie-mmio",
+                             mmio_reg, base_mmio, size_mmio);
+    memory_region_add_subregion(get_system_memory(), base_mmio, mmio_alias);
+
+    /* Map IO port space */
+    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 2, base_ioport);
+
+    for (i = 0; i < GPEX_NUM_IRQS; i++) {
+        sysbus_connect_irq(SYS_BUS_DEVICE(dev), i, pic[irq + i]);
+    }
+
+    nodename = g_strdup_printf("/address@hidden" PRIx64, base);
+    qemu_fdt_add_subnode(vbi->fdt, nodename);
+    qemu_fdt_setprop_string(vbi->fdt, nodename,
+                            "compatible", "pci-host-ecam-generic");
+    qemu_fdt_setprop_string(vbi->fdt, nodename, "device_type", "pci");
+    qemu_fdt_setprop_cell(vbi->fdt, nodename, "#address-cells", 3);
+    qemu_fdt_setprop_cell(vbi->fdt, nodename, "#size-cells", 2);
+    qemu_fdt_setprop_cells(vbi->fdt, nodename, "bus-range", 0, 1);
+
+    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_ioport, 2, size_ioport,
+
+                                 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, gic_phandle, irq, nodename);
+
+    g_free(nodename);
+}
+
 static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
 {
     const VirtBoardInfo *board = (const VirtBoardInfo *)binfo;
@@ -573,6 +700,7 @@ static void machvirt_init(MachineState *machine)
     MemoryRegion *ram = g_new(MemoryRegion, 1);
     const char *cpu_model = machine->cpu_model;
     VirtBoardInfo *vbi;
+    uint32_t gic_phandle;
 
     if (!cpu_model) {
         cpu_model = "cortex-a15";
@@ -634,12 +762,14 @@ static void machvirt_init(MachineState *machine)
 
     create_flash(vbi);
 
-    create_gic(vbi, pic);
+    gic_phandle = create_gic(vbi, pic);
 
     create_uart(vbi, pic);
 
     create_rtc(vbi, pic);
 
+    create_pcie(vbi, pic, gic_phandle);
+
     /* Create mmio transports, so the user can create virtio backends
      * (which will be automatically plugged in to the transports). If
      * no backend is created the transport will just sit harmlessly idle.
diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h
index 899f05c..359e143 100644
--- a/include/sysemu/device_tree.h
+++ b/include/sysemu/device_tree.h
@@ -110,4 +110,13 @@ int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
                                                 qdt_tmp);                 \
     })
 
+#define FDT_PCI_RANGE_RELOCATABLE          0x80000000
+#define FDT_PCI_RANGE_PREFETCHABLE         0x40000000
+#define FDT_PCI_RANGE_ALIASED              0x20000000
+#define FDT_PCI_RANGE_TYPE_MASK            0x03000000
+#define FDT_PCI_RANGE_MMIO_64BIT           0x03000000
+#define FDT_PCI_RANGE_MMIO                 0x02000000
+#define FDT_PCI_RANGE_IOPORT               0x01000000
+#define FDT_PCI_RANGE_CONFIG               0x00000000
+
 #endif /* __DEVICE_TREE_H__ */
-- 
1.7.12.4