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From: Alexey Kardashevskiy <aik@ozlabs.ru>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	"kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>
Subject: [Qemu-devel] [PATCH] msi/msix: added API to set MSI message address and data
Date: Thu, 21 Jun 2012 21:39:10 +1000	[thread overview]
Message-ID: <4FE307DE.5070002@ozlabs.ru> (raw)
In-Reply-To: <4FE2FDE1.1090401@siemens.com>

Added (msi|msix)_set_message() functions.

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>
---
 hw/msi.c  |   13 +++++++++++++
 hw/msi.h  |    1 +
 hw/msix.c |    9 +++++++++
 hw/msix.h |    2 ++
 4 files changed, 25 insertions(+)

diff --git a/hw/msi.c b/hw/msi.c
index 5233204..cc6102f 100644
--- a/hw/msi.c
+++ b/hw/msi.c
@@ -105,6 +105,19 @@ 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);
 }
 
+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 ded3c55..5f7d6d3 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -45,6 +45,15 @@ static MSIMessage msix_get_message(PCIDevice *dev, unsigned vector)
     return msg;
 }
 
+void msix_set_message(PCIDevice *dev, int vector, struct MSIMessage msg)
+{
+    uint8_t *table_entry = dev->msix_table_page + 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;
+}
+
 /* Add MSI-X capability to the config space for the device. */
 /* Given a bar and its size, add MSI-X table on top of it
  * and fill MSI-X capability in the config space.
diff --git a/hw/msix.h b/hw/msix.h
index 50aee82..26a437e 100644
--- a/hw/msix.h
+++ b/hw/msix.h
@@ -4,6 +4,8 @@
 #include "qemu-common.h"
 #include "pci.h"
 
+void msix_set_message(PCIDevice *dev, int vector, MSIMessage msg);
+
 int msix_init(PCIDevice *pdev, unsigned short nentries,
               MemoryRegion *bar,
               unsigned bar_nr, unsigned bar_size);
-- 
1.7.10

ps. double '-' and git version is an end-of-patch scissor as I read somewhere, cannot recall where exactly :)






On 21/06/12 20:56, Jan Kiszka wrote:
> On 2012-06-21 12:50, Alexey Kardashevskiy wrote:
>> On 21/06/12 20:38, Jan Kiszka wrote:
>>> On 2012-06-21 12:28, Alexey Kardashevskiy wrote:
>>>> On 21/06/12 17:39, Jan Kiszka wrote:
>>>>> On 2012-06-21 09:18, Alexey Kardashevskiy wrote:
>>>>>>
>>>>>> agrhhh. sha1 of the patch changed after rebasing :)
>>>>>>
>>>>>>
>>>>>>
>>>>>> Added (msi|msix)_(set|get)_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.
>>>>>>
>>>>>> As only set* function are required by now, the "get" functions were added
>>>>>> or made public for a symmetry.
>>>>>>
>>>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>>>>> ---
>>>>>>  hw/msi.c  |   29 +++++++++++++++++++++++++++++
>>>>>>  hw/msi.h  |    2 ++
>>>>>>  hw/msix.c |   11 ++++++++++-
>>>>>>  hw/msix.h |    3 +++
>>>>>>  4 files changed, 44 insertions(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/hw/msi.c b/hw/msi.c
>>>>>> index 5233204..9ad84a4 100644
>>>>>> --- a/hw/msi.c
>>>>>> +++ b/hw/msi.c
>>>>>> @@ -105,6 +105,35 @@ 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);
>>>>>>  }
>>>>>>  
>>>>>> +MSIMessage msi_get_message(PCIDevice *dev)
>>>>>
>>>>> MSIMessage msi_get_message(PCIDevice *dev, unsigned vector)
>>>>
>>>>
>>>> Who/how/why is going to calculate the vector here?
>>>>
>>>>>
>>>>>> +{
>>>>>> +    uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
>>>>>> +    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
>>>>>> +    MSIMessage msg;
>>>>>> +
>>>>>> +    if (msi64bit) {
>>>>>> +        msg.address = pci_get_quad(dev->config + msi_address_lo_off(dev));
>>>>>> +    } else {
>>>>>> +        msg.address = pci_get_long(dev->config + msi_address_lo_off(dev));
>>>>>> +    }
>>>>>> +    msg.data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));
>>>>>
>>>>> And I have this here in addition:
>>>>>
>>>>>     unsigned int nr_vectors = msi_nr_vectors(flags);
>>>>>     ...
>>>>>
>>>>>     if (nr_vectors > 1) {
>>>>>         msg.data &= ~(nr_vectors - 1);
>>>>>         msg.data |= vector;
>>>>>     }
>>>>>
>>>>> See PCI spec and existing code.
>>>>
>>>>
>>>> What for? I really do not get it why someone might want to read something but not real value.
>>>> What PCI code should I look?
>>>
>>> I'm not sure what your use case for reading the message is. For KVM
>>> device assignment it is preparing an alternative message delivery path
>>> for MSI vectors. And for this we will need vector notifier support for
>>> MSI as well. You can check the MSI-X code for corresponding use cases of
>>> msix_get_message.
>>
>>> And when we already have msi_get_message, another logical use case is
>>> msi_notify. See msix.c again.
>>
>> Aaaa.
>>
>> I have no case for reading the message. All I need is writing. And I want it public as I want to use
>> it from hw/spapr_pci.c. You suggested to add reading, I added "get" to be _symmetric_ to "set"
>> ("get" returns what "set" wrote). You want a different thing which I can do but it is not
>> msi_get_message(), it is something like msi_prepare_message(MSImessage msg) or
>> msi_set_vector(uint16_t data) or simply internal kitchen of msi_notify().
>>
>> Still can do what you suggested, it just does not seem right.
> 
> It is right - when looking at it from a different angle. ;)
> 
> I don't mind if you add msi_get_message now or leave this to me. Likely
> the latter is better as you have no use case for msi_get_message (and
> also msix_get_message!) outside of their modules, thus we should not
> export those functions anyway.
> 
> Jan
> 


-- 
Alexey

  reply	other threads:[~2012-06-21 11:39 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-14  4:29 [Qemu-devel] [PATCH 0/3] adding MSI/MSIX for PCI on POWER Alexey Kardashevskiy
2012-06-14  4:31 ` [Qemu-devel] [PATCH 1/3] msi/msix: added functions to API to set up message address and data Alexey Kardashevskiy
2012-06-14  4:56   ` Alex Williamson
2012-06-14  5:17     ` Alexey Kardashevskiy
2012-06-14  5:38       ` Alex Williamson
2012-06-14  5:44         ` Alexey Kardashevskiy
2012-06-14 18:37           ` Alex Williamson
2012-06-14  5:45       ` Jan Kiszka
2012-06-21  6:46         ` [Qemu-devel] [PATCH] msi/msix: added functions to API to set up message address, " Alexey Kardashevskiy
2012-06-21  6:53           ` Jan Kiszka
2012-06-21  7:18             ` [Qemu-devel] [PATCH] msi/msix: added public API to set/get MSI " Alexey Kardashevskiy
2012-06-21  7:39               ` Jan Kiszka
2012-06-21 10:28                 ` Alexey Kardashevskiy
2012-06-21 10:38                   ` Jan Kiszka
2012-06-21 10:50                     ` Alexey Kardashevskiy
2012-06-21 10:56                       ` Jan Kiszka
2012-06-21 11:39                         ` Alexey Kardashevskiy [this message]
2012-06-21 11:49                           ` [Qemu-devel] [PATCH] msi/msix: added API to set MSI message address " Jan Kiszka
2012-06-22  1:03                             ` Alexey Kardashevskiy
2012-06-22  1:15                               ` Alexey Kardashevskiy
2012-07-02  4:28                                 ` Alexey Kardashevskiy
2012-07-02  7:24                                   ` Jan Kiszka
2012-07-06 15:36                                     ` Alexander Graf
2012-07-06 15:58                                       ` Jan Kiszka
2012-07-11 18:22                                         ` Alexander Graf
2012-07-18 12:43                           ` Michael S. Tsirkin
2012-07-18 13:17                             ` Alexey Kardashevskiy
2012-07-18 15:23                               ` Michael S. Tsirkin
2012-07-19  0:32                                 ` Alexey Kardashevskiy
2012-07-19  9:27                                   ` Michael S. Tsirkin
2012-07-19 14:24                                     ` Alexey Kardashevskiy
2012-07-19 14:43                                       ` Michael S. Tsirkin
2012-07-19 14:50                                         ` Alexey Kardashevskiy
2012-07-19 14:56                                           ` Michael S. Tsirkin
2012-07-19  0:35                                 ` Alexey Kardashevskiy
2012-07-19  9:27                                   ` Michael S. Tsirkin
2012-06-21 15:44                         ` [Qemu-devel] [PATCH] msi/msix: added public API to set/get MSI message address, " Alex Williamson
2012-06-14  4:33 ` [Qemu-devel] [PATCH 2/3] pseries: added allocator for a block of IRQs Alexey Kardashevskiy
2012-06-14  4:34 ` [Qemu-devel] [PATCH 3/3] pseries pci: added MSI/MSIX support Alexey Kardashevskiy
2012-06-14  4:42 ` [Qemu-devel] [PATCH 0/3] adding MSI/MSIX for PCI on POWER Alexey Kardashevskiy

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