[Qemu-devel] [PATCH v2] Add stream ID to MSI write

[Qemu-devel] [PATCH v2] Add stream ID to MSI write

[Pavel Fedin]

GICv3 ITS distinguishes between devices by using hardwired device IDs passed on the bus.
This patch implements passing these IDs in qemu.
SMMU is also known to use stream IDs, therefore this addition can also be useful for
implementing platforms with SMMU.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

 Changes from v1:
- Added bus number to the stream ID
- Added stream ID not only to MSI-X, but also to plain MSI. Some common code was made into
msi_send_message() function.

---
 hw/pci/msi.c            | 10 +++++++++-
 hw/pci/msix.c           |  3 +--
 include/exec/memattrs.h |  2 ++
 include/hw/pci/msi.h    |  1 +
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/hw/pci/msi.c b/hw/pci/msi.c
index 2949938..c111dba 100644
--- a/hw/pci/msi.c
+++ b/hw/pci/msi.c
@@ -291,8 +291,16 @@ void msi_notify(PCIDevice *dev, unsigned int vector)
                    "notify vector 0x%x"
                    " address: 0x%"PRIx64" data: 0x%"PRIx32"\n",
                    vector, msg.address, msg.data);
+    msi_send_message(dev, msg);
+}
+
+void msi_send_message(PCIDevice *dev, MSIMessage msg)
+{
+    MemTxAttrs attrs = {};
+
+    attrs.stream_id = (pci_bus_num(dev->bus) << 8) | dev->devfn;
     address_space_stl_le(&dev->bus_master_as, msg.address, msg.data,
-                         MEMTXATTRS_UNSPECIFIED, NULL);
+                         attrs, NULL);
 }
 
 /* Normally called by pci_default_write_config(). */
diff --git a/hw/pci/msix.c b/hw/pci/msix.c
index 9935f98..7716bf3 100644
--- a/hw/pci/msix.c
+++ b/hw/pci/msix.c
@@ -443,8 +443,7 @@ void msix_notify(PCIDevice *dev, unsigned vector)
 
     msg = msix_get_message(dev, vector);
 
-    address_space_stl_le(&dev->bus_master_as, msg.address, msg.data,
-                         MEMTXATTRS_UNSPECIFIED, NULL);
+    msi_send_message(dev, msg);
 }
 
 void msix_reset(PCIDevice *dev)
diff --git a/include/exec/memattrs.h b/include/exec/memattrs.h
index 1389b4b..96dc440 100644
--- a/include/exec/memattrs.h
+++ b/include/exec/memattrs.h
@@ -33,6 +33,8 @@ typedef struct MemTxAttrs {
     unsigned int secure:1;
     /* Memory access is usermode (unprivileged) */
     unsigned int user:1;
+    /* Stream ID (for MSI for example) */
+    unsigned int stream_id:16;
 } MemTxAttrs;
 
 /* Bus masters which don't specify any attributes will get this,
diff --git a/include/hw/pci/msi.h b/include/hw/pci/msi.h
index 81a3848..50e452b 100644
--- a/include/hw/pci/msi.h
+++ b/include/hw/pci/msi.h
@@ -39,6 +39,7 @@ int msi_init(struct PCIDevice *dev, uint8_t offset,
 void msi_uninit(struct PCIDevice *dev);
 void msi_reset(PCIDevice *dev);
 void msi_notify(PCIDevice *dev, unsigned int vector);
+void msi_send_message(PCIDevice *dev, MSIMessage msg);
 void msi_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len);
 unsigned int msi_nr_vectors_allocated(const PCIDevice *dev);
 
-- 
1.9.5.msysgit.0