[Qemu-devel] [RFC] hw/arm/virt: Add a "generic-ehci" USB controller to ARM virt model

[Jérémy Fanguède]

This patch enables the attachment of USB devices (emulated or
passthrough) on the ARM virt model, without the need of a PCI USB
controller, by adding a generic EHCI USB controller to the system bus.

Signed-off-by: Nikolay Nikolaev <address@hidden>
Signed-off-by: Jérémy Fanguède <address@hidden>
---

A new EHCI USB controller named "generic_ehci" is introduced
(hw/usb/hcd-ehci-sysbus.c). Then, in the virt model, this controller
is added to the system bus. For this purpose a new function,
create_usb, modeled on other create_* functions, is in charge to
create this device and dynamically add the node needed to the device
tree.

The Linux guest OS should include the EHCI platform driver
(CONFIG_USB_EHCI_HCD_PLATFORM).

This patch works fine with TCG on x86 and ARM machines, for both
emulated and host devices, with this kind of cmdline:
-usb \
-device usb-tablet \
-device usb-host,hostbus=1,hostaddr=5

Unfortunately, with KVM, only emulated devices works, for host devices
(passthrough), a random kernel panic occurred. Tests for KVM are
performed on a Samsung Chromebook, with upstream kernel and a USB
stick.
---
 hw/arm/virt.c            | 29 +++++++++++++++++++++++++++++
 hw/usb/hcd-ehci-sysbus.c | 16 ++++++++++++++++
 hw/usb/hcd-ehci.h        |  1 +
 3 files changed, 46 insertions(+)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 7d082e2..c362685 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -39,6 +39,7 @@
 #include "sysemu/kvm.h"
 #include "hw/boards.h"
 #include "hw/loader.h"
+#include "hw/usb/hcd-ehci.h"
 #include "exec/address-spaces.h"
 #include "qemu/bitops.h"
 #include "qemu/error-report.h"
@@ -71,6 +72,7 @@ enum {
     VIRT_RTC,
     VIRT_FW_CFG,
     VIRT_PCIE,
+    VIRT_USB,
 };
 
 typedef struct MemMapEntry {
@@ -129,6 +131,7 @@ static const MemMapEntry a15memmap[] = {
     [VIRT_UART] =       { 0x09000000, 0x00001000 },
     [VIRT_RTC] =        { 0x09010000, 0x00001000 },
     [VIRT_FW_CFG] =     { 0x09020000, 0x0000000a },
+    [VIRT_USB] =        { 0x09030000, 0x00001000 },
     [VIRT_MMIO] =       { 0x0a000000, 0x00000200 },
     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
     /*
@@ -146,6 +149,7 @@ static const int a15irqmap[] = {
     [VIRT_UART] = 1,
     [VIRT_RTC] = 2,
     [VIRT_PCIE] = 3, /* ... to 6 */
+    [VIRT_USB] = 7,
     [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */
 };
 
@@ -448,6 +452,27 @@ static void create_rtc(const VirtBoardInfo *vbi, qemu_irq 
*pic)
     g_free(nodename);
 }
 
+static void create_usb(const VirtBoardInfo *vbi, qemu_irq *pic)
+{
+    char *nodename;
+    hwaddr base = vbi->memmap[VIRT_USB].base;
+    hwaddr size = vbi->memmap[VIRT_USB].size;
+    int irq = vbi->irqmap[VIRT_USB];
+    const char compat[] = "generic-ehci";
+
+    sysbus_create_simple(TYPE_GENERIC_EHCI, base, pic[irq]);
+
+    nodename = g_strdup_printf("/address@hidden" PRIx64, base);
+    qemu_fdt_add_subnode(vbi->fdt, nodename);
+    qemu_fdt_setprop(vbi->fdt, nodename, "compatible", compat, sizeof(compat));
+    qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg",
+                                 2, base, 2, size);
+    qemu_fdt_setprop_cells(vbi->fdt, nodename, "interrupts",
+                           GIC_FDT_IRQ_TYPE_SPI, irq,
+                           GIC_FDT_IRQ_FLAGS_LEVEL_HI);
+    g_free(nodename);
+}
+
 static void create_virtio_devices(const VirtBoardInfo *vbi, qemu_irq *pic)
 {
     int i;
@@ -821,6 +846,10 @@ static void machvirt_init(MachineState *machine)
 
     create_pcie(vbi, pic, gic_phandle);
 
+    if (usb_enabled()) {
+        create_usb(vbi, pic);
+    }
+
     /* 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/hw/usb/hcd-ehci-sysbus.c b/hw/usb/hcd-ehci-sysbus.c
index cd1cc14..4cf8cc1 100644
--- a/hw/usb/hcd-ehci-sysbus.c
+++ b/hw/usb/hcd-ehci-sysbus.c
@@ -217,6 +217,21 @@ static const TypeInfo ehci_fusbh200_type_info = {
     .class_init    = fusbh200_ehci_class_init,
 };
 
+static void generic_ehci_class_init(ObjectClass *oc, void *data)
+{
+    SysBusEHCIClass *sec = SYS_BUS_EHCI_CLASS(oc);
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    sec->capsbase = 0x0;
+    sec->opregbase = 0x10;
+    set_bit(DEVICE_CATEGORY_USB, dc->categories);
+}
+
+static const TypeInfo ehci_generic_type_info = {
+    .name          = TYPE_GENERIC_EHCI,
+    .parent        = TYPE_SYS_BUS_EHCI,
+    .class_init    = generic_ehci_class_init,
+};
 static void ehci_sysbus_register_types(void)
 {
     type_register_static(&ehci_type_info);
@@ -224,6 +239,7 @@ static void ehci_sysbus_register_types(void)
     type_register_static(&ehci_exynos4210_type_info);
     type_register_static(&ehci_tegra2_type_info);
     type_register_static(&ehci_fusbh200_type_info);
+    type_register_static(&ehci_generic_type_info);
 }
 
 type_init(ehci_sysbus_register_types)
diff --git a/hw/usb/hcd-ehci.h b/hw/usb/hcd-ehci.h
index 87b240f..9f1d759 100644
--- a/hw/usb/hcd-ehci.h
+++ b/hw/usb/hcd-ehci.h
@@ -343,6 +343,7 @@ typedef struct EHCIPCIState {
 #define TYPE_EXYNOS4210_EHCI "exynos4210-ehci-usb"
 #define TYPE_TEGRA2_EHCI "tegra2-ehci-usb"
 #define TYPE_FUSBH200_EHCI "fusbh200-ehci-usb"
+#define TYPE_GENERIC_EHCI "generic-ehci-usb"
 
 #define SYS_BUS_EHCI(obj) \
     OBJECT_CHECK(EHCISysBusState, (obj), TYPE_SYS_BUS_EHCI)
-- 
1.9.1