Re: [Qemu-devel] [PATCH v2 3/4] arm: Add PCIe host bridge in virt machine

[Alexander Graf]

On 22.01.15 16:28, Claudio Fontana wrote:
> Hi Alexander,
> 
> thank you for the respin. I retested with the new mappings on OSv for AArch64,
> and they show up ok in the guest.
> 
> Just a couple minor comments below, otherwise I think this is good.
> 
> On 21.01.2015 17:18, Alexander Graf wrote:
>> Now that we have a working "generic" PCIe host bridge driver, we can plug
>> it into ARMs 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
>> ---
>>  default-configs/arm-softmmu.mak |   2 +
>>  hw/arm/virt.c                   | 112 
>> ++++++++++++++++++++++++++++++++++++++--
>>  include/sysemu/device_tree.h    |   9 ++++
>>  3 files changed, 118 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..a727b4e 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 +131,14 @@ 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 */
>> +    [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 +315,7 @@ 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 +334,11 @@ 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 +385,7 @@ 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 +561,100 @@ 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) {
> 
> devfn += 0x8 (spaces)

Yeah, I had it like that and it looked uglier. I guess it's a matter of
personal preference?

> 
>> +        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));
>> +}
> 
> I raise again (? or maybe for the first time) the suggestion to add a comment 
> like:
> 
> /* see the openfirmware specs at 
>  * http://www.firmware.org/1275/practice/imap/imap0_9d.pdf
>  */
> 
> and optionally also a reference to the linux host-generic-pci bindings:
> 
> /* see the linux Documentation about device tree bindings at:
>  * 
> https://www.kernel.org/doc/Documentation/devicetree/bindings/pci/host-generic-pci.txt
>  */

I added those links to the big description comment at the top of this file.


Alex