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

[Benjamin Herrenschmidt]

On Wed, 2012-06-13 at 13:39 +1000, Alexey Kardashevskiy wrote:
> On 13/06/12 13:22, Benjamin Herrenschmidt wrote:
> > On Wed, 2012-06-13 at 12:44 +1000, Alexey Kardashevskiy wrote:
> >> Ping?
> > 
> > FYI. The way it normally works on pseries is that RTAS, which is the
> > part of the firmware that lives inside the partition alongside the OS,
> > performs the accesses to configure the MSI/MSI-X.
> > 
> > With qemu "pseries" machine we don't have such an RTAS currently, it's
> > all implemented by qemu (or rather we have a tiny 5 instructions RTAS
> > which does a hypercall to qemu).
> > 
> > So we need to be able to do the configuration from within qemu.
> > 
> > Alexey: Can this be used for supporting MSI/MSI-X with emulated devices
> > and virtio as well ?
> 
> This is exactly to support MSIX on virtio-pci devices as there were no other 
> MSIX users on power :)
> VFIO came up later (and it does not require any change in spapr-msix code).

Then you should have mentioned that in the changeset comments :-)

> > Any chance you can do patches for that too ?
> 
> I am polishing descriptions now and post them a bit later.

Ok, thanks.

Cheers,
Ben.

> 
> 
> > Cheers,
> > Ben.
> > 
> >>
> >> On 12/05/12 16:48, Alexey Kardashevskiy wrote:
> >>> Added msi_set_address_data and msix_set_address_data in order to support
> >>> sPAPR-specific implementation of MSI/MSIX configuration mechanism.
> >>> POWER guest does not initialize these fields, it expects a supervisor to
> >>> get them initialized.
> >>>
> >>> Required for VFIO on POWER.
> >>>
> >>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> >>> ---
> >>>  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);
> >>> +}
> >>> +
> >>> 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
> 
> 
> 
>