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

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 14/06/12 14:56, Alex Williamson wrote:
> 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,


I am missing the point. What is that MSIMessage?
It is just an address and data, making a struct from this is a bit too much :)
I am totally unfamiliar with kvm_irqchip_add_msi_route to see the bigger picture, sorry.


> 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
> 
> 
> 


-- 
Alexey