Re: [Qemu-devel] [PATCH v4 2/3] hw/pci: Introduce pci_requester_id()

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Oct 14, 2015 at 06:06:37PM +0300, Pavel Fedin wrote:
> For GICv3 ITS implementation we are going to use requester IDs in KVM IRQ
> routing code. This patch introduces reusable convenient way to obtain this
> ID from the device pointer.
> 
> Since requester ID is an architecture-specific thing, the function can be
> overridden on per-architecture basis. Default stub just returns 0.
> 
> MemTxAttrs.stream_id also renamed to requester_id in order to better
> reflect semantics of the field.
> 
> Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
> ---
>  hw/pci/msi.c             |  2 +-
>  include/exec/memattrs.h  |  4 ++--
>  include/hw/pci/pci.h     |  1 +
>  stubs/Makefile.objs      |  1 +
>  stubs/pci.c              | 16 ++++++++++++++++
>  target-arm/Makefile.objs |  1 +
>  target-arm/pci.c         | 16 ++++++++++++++++
>  7 files changed, 38 insertions(+), 3 deletions(-)
>  create mode 100644 stubs/pci.c
>  create mode 100644 target-arm/pci.c
> 
> diff --git a/hw/pci/msi.c b/hw/pci/msi.c
> index f9c0484..c1dd531 100644
> --- a/hw/pci/msi.c
> +++ b/hw/pci/msi.c
> @@ -294,7 +294,7 @@ void msi_send_message(PCIDevice *dev, MSIMessage msg)
>  {
>      MemTxAttrs attrs = {};
>  
> -    attrs.stream_id = (pci_bus_num(dev->bus) << 8) | dev->devfn;
> +    attrs.requester_id = pci_requester_id(dev);
>      address_space_stl_le(&dev->bus_master_as, msg.address, msg.data,
>                           attrs, NULL);
>  }
> diff --git a/include/exec/memattrs.h b/include/exec/memattrs.h
> index f8537a8..e601061 100644
> --- a/include/exec/memattrs.h
> +++ b/include/exec/memattrs.h
> @@ -35,8 +35,8 @@ typedef struct MemTxAttrs {
>      unsigned int secure:1;
>      /* Memory access is usermode (unprivileged) */
>      unsigned int user:1;
> -    /* Stream ID (for MSI for example) */
> -    unsigned int stream_id:16;
> +    /* Requester ID (for MSI for example) */
> +    unsigned int requester_id:16;
>  } MemTxAttrs;
>  
>  /* Bus masters which don't specify any attributes will get this,
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 551cb3d..708dc3a 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -381,6 +381,7 @@ void pci_bus_fire_intx_routing_notifier(PCIBus *bus);
>  void pci_device_set_intx_routing_notifier(PCIDevice *dev,
>                                            PCIINTxRoutingNotifier notifier);
>  void pci_device_reset(PCIDevice *dev);
> +uint16_t pci_requester_id(PCIDevice *dev);
>  
>  PCIDevice *pci_nic_init_nofail(NICInfo *nd, PCIBus *rootbus,
>                                 const char *default_model,
> diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
> index 85e4e81..dbd69a9 100644
> --- a/stubs/Makefile.objs
> +++ b/stubs/Makefile.objs
> @@ -22,6 +22,7 @@ stub-obj-y += migr-blocker.o
>  stub-obj-y += mon-is-qmp.o
>  stub-obj-y += mon-printf.o
>  stub-obj-y += monitor-init.o
> +stub-obj-$(CONFIG_PCI) += pci.o
>  stub-obj-y += notify-event.o
>  stub-obj-$(CONFIG_SPICE) += qemu-chr-open-spice.o
>  stub-obj-y += qtest.o
> diff --git a/stubs/pci.c b/stubs/pci.c
> new file mode 100644
> index 0000000..3b13000
> --- /dev/null
> +++ b/stubs/pci.c
> @@ -0,0 +1,16 @@
> +/*
> + * QEMU architecture-specific PCI functions
> + *
> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
> + * Written by Pavel Fedin
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +#include "hw/pci/pci.h"
> +
> +uint16_t pci_requester_id(PCIDevice *dev)
> +{
> +    return 0;
> +}

OK this is now wrong. You should move the logic back here
from target-arm.

> diff --git a/target-arm/Makefile.objs b/target-arm/Makefile.objs
> index 9460b40..7b47434 100644
> --- a/target-arm/Makefile.objs
> +++ b/target-arm/Makefile.objs
> @@ -1,5 +1,6 @@
>  obj-y += arm-semi.o
>  obj-$(CONFIG_SOFTMMU) += machine.o
> +obj-$(CONFIG_PCI) += pci.o
>  obj-$(CONFIG_KVM) += kvm.o
>  obj-$(call land,$(CONFIG_KVM),$(call lnot,$(TARGET_AARCH64))) += kvm32.o
>  obj-$(call land,$(CONFIG_KVM),$(TARGET_AARCH64)) += kvm64.o
> diff --git a/target-arm/pci.c b/target-arm/pci.c
> new file mode 100644
> index 0000000..9bd5964
> --- /dev/null
> +++ b/target-arm/pci.c
> @@ -0,0 +1,16 @@
> +/*
> + * QEMU ARM specific PCI functions
> + *
> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
> + * Written by Pavel Fedin
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +#include "hw/pci/pci.h"
> +
> +uint16_t pci_requester_id(PCIDevice *dev)
> +{
> +    return (pci_bus_num(dev->bus) << 8) | dev->devfn;
> +}
> -- 
> 2.4.4