Re: [Qemu-devel] [PATCH 1/3] msi/msix: added functions to API to set up message address and data

[Alex Williamson <alex.williamson@redhat.com>]

On Thu, 2012-06-14 at 14:31 +1000, Alexey Kardashevskiy wrote:
> Normally QEMU expects the guest to initialize MSI/MSIX vectors.
> However on POWER the guest uses RTAS subsystem to configure MSI/MSIX and
> does not write these vectors to device's config space or MSIX BAR.
> 
> On the other hand, msi_notify()/msix_notify() write to these vectors to
> signal the guest about an interrupt so we have to write correct vectors
> to the devices in order not to change every user of MSI/MSIX.
> 
> The first aim is to support MSIX for virtio-pci on POWER. There is
> another patch for POWER coming which introduces a special memory region
> where MSI/MSIX vectors point to.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>  hw/msi.c  |   14 ++++++++++++++
>  hw/msi.h  |    1 +
>  hw/msix.c |   10 ++++++++++
>  hw/msix.h |    3 +++
>  4 files changed, 28 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/msi.c b/hw/msi.c
> index 5d6ceb6..124878a 100644
> --- a/hw/msi.c
> +++ b/hw/msi.c
> @@ -358,3 +358,17 @@ unsigned int msi_nr_vectors_allocated(const PCIDevice *dev)
>      uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
>      return msi_nr_vectors(flags);
>  }
> +
> +void msi_set_address_data(PCIDevice *dev, uint64_t address, uint16_t data)
> +{
> +    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), address);
> +    } else {
> +        pci_set_long(dev->config + msi_address_lo_off(dev), address);
> +    }
> +    pci_set_word(dev->config + msi_data_off(dev, msi64bit), data);
> +}

Why not make it msi_set_message() and pass MSIMessage?  I'd be great if
you tossed in a msi_get_message() as well, I think we need it to be able
to do a kvm_irqchip_add_msi_route() with MSI.  Thanks,

Alex

> +
> diff --git a/hw/msi.h b/hw/msi.h
> index 3040bb0..0acf434 100644
> --- a/hw/msi.h
> +++ b/hw/msi.h
> @@ -34,6 +34,7 @@ void msi_reset(PCIDevice *dev);
>  void msi_notify(PCIDevice *dev, unsigned int vector);
>  void msi_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len);
>  unsigned int msi_nr_vectors_allocated(const PCIDevice *dev);
> +void msi_set_address_data(PCIDevice *dev, uint64_t address, uint16_t data);
> 
>  static inline bool msi_present(const PCIDevice *dev)
>  {
> diff --git a/hw/msix.c b/hw/msix.c
> index 3835eaa..c57c299 100644
> --- a/hw/msix.c
> +++ b/hw/msix.c
> @@ -414,3 +414,13 @@ void msix_unuse_all_vectors(PCIDevice *dev)
>          return;
>      msix_free_irq_entries(dev);
>  }
> +
> +void msix_set_address_data(PCIDevice *dev, int vector,
> +                           uint64_t address, uint32_t data)
> +{
> +    uint8_t *table_entry = dev->msix_table_page + vector * PCI_MSIX_ENTRY_SIZE;
> +    pci_set_quad(table_entry + PCI_MSIX_ENTRY_LOWER_ADDR, address);
> +    pci_set_long(table_entry + PCI_MSIX_ENTRY_DATA, data);
> +    table_entry[PCI_MSIX_ENTRY_VECTOR_CTRL] &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
> +}
> +
> diff --git a/hw/msix.h b/hw/msix.h
> index 5aba22b..e6bb696 100644
> --- a/hw/msix.h
> +++ b/hw/msix.h
> @@ -29,4 +29,7 @@ void msix_notify(PCIDevice *dev, unsigned vector);
> 
>  void msix_reset(PCIDevice *dev);
> 
> +void msix_set_address_data(PCIDevice *dev, int vector,
> +                           uint64_t address, uint32_t data);
> +
>  #endif