Re: [Qemu-devel] [PATCH] msi/msix: added API to set MSI message address and data

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

On Thu, Jul 19, 2012 at 10:35:07AM +1000, Alexey Kardashevskiy wrote:
> Added (msi|msix)_set_message() function for whoever might
> want to use them.
> 
> Currently msi_notify()/msix_notify() write to these vectors to
> signal the guest about an interrupt so the correct values have to
> written there by the guest or QEMU.
> 
> For example, POWER guest never initializes MSI/MSIX vectors, instead
> it uses RTAS hypercalls. So in order to support MSIX for virtio-pci on
> POWER we have to initialize MSI/MSIX message from QEMU.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Thanks, applied.

> ---
>  hw/msi.c  |   17 +++++++++++++++++
>  hw/msi.h  |    1 +
>  hw/msix.c |   13 +++++++++++++
>  hw/msix.h |    1 +
>  4 files changed, 32 insertions(+)
> 
> diff --git a/hw/msi.c b/hw/msi.c
> index 5233204..e2273a0 100644
> --- a/hw/msi.c
> +++ b/hw/msi.c
> @@ -105,6 +105,23 @@ static inline uint8_t msi_pending_off(const PCIDevice* dev, bool msi64bit)
>      return dev->msi_cap + (msi64bit ? PCI_MSI_PENDING_64 : PCI_MSI_PENDING_32);
>  }
>  
> +/*
> + * Special API for POWER to configure the vectors through
> + * a side channel. Should never be used by devices.
> + */
> +void msi_set_message(PCIDevice *dev, MSIMessage msg)
> +{
> +    uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
> +    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
> +
> +    if (msi64bit) {
> +        pci_set_quad(dev->config + msi_address_lo_off(dev), msg.address);
> +    } else {
> +        pci_set_long(dev->config + msi_address_lo_off(dev), msg.address);
> +    }
> +    pci_set_word(dev->config + msi_data_off(dev, msi64bit), msg.data);
> +}
> +
>  bool msi_enabled(const PCIDevice *dev)
>  {
>      return msi_present(dev) &&
> diff --git a/hw/msi.h b/hw/msi.h
> index 75747ab..6ec1f99 100644
> --- a/hw/msi.h
> +++ b/hw/msi.h
> @@ -31,6 +31,7 @@ struct MSIMessage {
>  
>  extern bool msi_supported;
>  
> +void msi_set_message(PCIDevice *dev, MSIMessage msg);
>  bool msi_enabled(const PCIDevice *dev);
>  int msi_init(struct PCIDevice *dev, uint8_t offset,
>               unsigned int nr_vectors, bool msi64bit, bool msi_per_vector_mask);
> diff --git a/hw/msix.c b/hw/msix.c
> index fd9ea95..800fc32 100644
> --- a/hw/msix.c
> +++ b/hw/msix.c
> @@ -37,6 +37,19 @@ static MSIMessage msix_get_message(PCIDevice *dev, unsigned vector)
>      return msg;
>  }
>  
> +/*
> + * Special API for POWER to configure the vectors through
> + * a side channel. Should never be used by devices.
> + */
> +void msix_set_message(PCIDevice *dev, int vector, struct MSIMessage msg)
> +{
> +    uint8_t *table_entry = dev->msix_table + vector * PCI_MSIX_ENTRY_SIZE;
> +
> +    pci_set_quad(table_entry + PCI_MSIX_ENTRY_LOWER_ADDR, msg.address);
> +    pci_set_long(table_entry + PCI_MSIX_ENTRY_DATA, msg.data);
> +    table_entry[PCI_MSIX_ENTRY_VECTOR_CTRL] &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
> +}
> +
>  static uint8_t msix_pending_mask(int vector)
>  {
>      return 1 << (vector % 8);
> diff --git a/hw/msix.h b/hw/msix.h
> index 1786e27..15211cb 100644
> --- a/hw/msix.h
> +++ b/hw/msix.h
> @@ -4,6 +4,7 @@
>  #include "qemu-common.h"
>  #include "pci.h"
>  
> +void msix_set_message(PCIDevice *dev, int vector, MSIMessage msg);
>  int msix_init(PCIDevice *dev, unsigned short nentries,
>                MemoryRegion *table_bar, uint8_t table_bar_nr,
>                unsigned table_offset, MemoryRegion *pba_bar,
> -- 
> 1.7.10.4