Re: [Qemu-devel] [QEMU][RFC V2 06/10] xen-pci: register PCI device in Xen and handle IOREQ_TYPE_PCI_CONFIG

[Stefano Stabellini]

On Wed, 22 Aug 2012, Julien Grall wrote:
> With QEMU disaggregation QEMU needs to specify which PCI device it's able to
> handle. It will use the device place in the topology (domain, bus, device,
> function).
> When Xen will trap an access for the config space, it will forge a new
> ioreq and forward it to the right QEMU.
> 
> Signed-off-by: Julien Grall <address@hidden>
> ---
>  hw/pci.c   |    6 ++++++
>  hw/xen.h   |    1 +
>  xen-all.c  |   38 ++++++++++++++++++++++++++++++++++++++
>  xen-stub.c |    5 +++++
>  4 files changed, 50 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index 4d95984..0112edf 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -33,6 +33,7 @@
>  #include "qmp-commands.h"
>  #include "msi.h"
>  #include "msix.h"
> +#include "xen.h"
>  
>  //#define DEBUG_PCI
>  #ifdef DEBUG_PCI
> @@ -781,6 +782,11 @@ static PCIDevice *do_pci_register_device(PCIDevice 
> *pci_dev, PCIBus *bus,
>      pci_dev->devfn = devfn;
>      pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
>      pci_dev->irq_state = 0;
> +
> +    if (xen_enabled() && xen_register_pcidev(pci_dev)) {
> +        return NULL;

Is this an error condition? If so we should print an error message,
right?


> +    }
> +
>      pci_config_alloc(pci_dev);
>  
>      pci_config_set_vendor_id(pci_dev->config, pc->vendor_id);
> diff --git a/hw/xen.h b/hw/xen.h
> index e5926b7..663731a 100644
> --- a/hw/xen.h
> +++ b/hw/xen.h
> @@ -35,6 +35,7 @@ int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num);
>  void xen_piix3_set_irq(void *opaque, int irq_num, int level);
>  void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int 
> len);
>  void xen_hvm_inject_msi(uint64_t addr, uint32_t data);
> +int xen_register_pcidev(PCIDevice *pci_dev);
>  void xen_cmos_set_s3_resume(void *opaque, int irq, int level);
>  
>  qemu_irq *xen_interrupt_controller_init(void);
> diff --git a/xen-all.c b/xen-all.c
> index 14e5d3d..485c312 100644
> --- a/xen-all.c
> +++ b/xen-all.c
> @@ -174,6 +174,16 @@ void xen_piix3_set_irq(void *opaque, int irq_num, int 
> level)
>                                irq_num & 3, level);
>  }
>  
> +int xen_register_pcidev(PCIDevice *pci_dev)
> +{
> +    DPRINTF("register pci %x:%x.%x %s\n", 0, (pci_dev->devfn >> 3) & 0x1f,
> +            pci_dev->devfn & 0x7, pci_dev->name);
> +
> +    return xen_xc_hvm_register_pcidev(xen_xc, xen_domid, serverid,
> +                                      0, 0, pci_dev->devfn >> 3,
> +                                      pci_dev->devfn & 0x7);
> +}
> +
>  void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int 
> len)
>  {
>      int i;
> @@ -943,6 +953,29 @@ static void cpu_ioreq_move(ioreq_t *req)
>      }
>  }
>  
> +#if __XEN_LATEST_INTERFACE_VERSION__ >= 0x00040300
> +static void cpu_ioreq_config_space(ioreq_t *req)
> +{
> +    uint64_t cf8 = req->addr;
> +    uint32_t tmp = req->size;
> +    uint16_t size = req->size & 0xff;
> +    uint16_t off = req->size >> 16;
> +
> +    if ((size + off + 0xcfc) > 0xd00) {
> +        hw_error("Invalid ioreq config space size = %u off = %u\n",
> +                 size, off);
> +    }
> +
> +    req->addr = 0xcfc + off;
> +    req->size = size;
> +
> +    do_outp(0xcf8, 4, cf8);
> +    cpu_ioreq_pio(req);
> +    req->addr = cf8;
> +    req->size = tmp;
> +}
> +#endif
> +
>  static void handle_ioreq(ioreq_t *req)
>  {
>      if (!req->data_is_ptr && (req->dir == IOREQ_WRITE) &&
> @@ -962,6 +995,11 @@ static void handle_ioreq(ioreq_t *req)
>          case IOREQ_TYPE_INVALIDATE:
>              xen_invalidate_map_cache();
>              break;
> +#if __XEN_LATEST_INTERFACE_VERSION__ >= 0x00040300
> +        case IOREQ_TYPE_PCI_CONFIG:
> +            cpu_ioreq_config_space(req);
> +            break;
> +#endif
>          default:
>              hw_error("Invalid ioreq type 0x%x\n", req->type);
>      }
> diff --git a/xen-stub.c b/xen-stub.c
> index 8ff2b79..0128965 100644
> --- a/xen-stub.c
> +++ b/xen-stub.c
> @@ -25,6 +25,11 @@ void xen_piix3_set_irq(void *opaque, int irq_num, int 
> level)
>  {
>  }
>  
> +int xen_register_pcidev(PCIDevice *pci_dev)
> +{
> +    return 1;
> +}
> +
>  void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int 
> len)
>  {
>  }
> -- 
> Julien Grall
>