msi/msix: added API to set MSI message address and data

Added (msi|msix)_set_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.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/msi.c b/hw/msi.c
index 52332041e7314f26aa93ee86b53521cfd9b42e6b..e2273a09ae1f84fb17a43b231fafbca927297937 100644 (file)
--- a/hw/msi.c
+++ b/hw/msi.c
@@ -105,6 +105,23 @@ 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);
 }
 
+/*
+ * Special API for POWER to configure the vectors through
+ * a side channel. Should never be used by devices.
+ */
+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 75747abc25d9256712446b2fca0892b021357024..6ec1f99f809ff040048db71d733b1cdb33e5d7a7 100644 (file)
--- 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 fd9ea95da1176ce5a2ba7ead364e7f36f7115276..800fc32f0b0e54a05637a8b51510aed7c1a9b236 100644 (file)
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -37,6 +37,19 @@ static MSIMessage msix_get_message(PCIDevice *dev, unsigned vector)
     return msg;
 }
 
+/*
+ * Special API for POWER to configure the vectors through
+ * a side channel. Should never be used by devices.
+ */
+void msix_set_message(PCIDevice *dev, int vector, struct MSIMessage msg)
+{
+    uint8_t *table_entry = dev->msix_table + 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;
+}
+
 static uint8_t msix_pending_mask(int vector)
 {
     return 1 << (vector % 8);

diff --git a/hw/msix.h b/hw/msix.h
index 1786e2766bd84ed343ecf7c13f0b07a25081045f..15211cb592740cf4ed8595631310632502428705 100644 (file)
--- a/hw/msix.h
+++ b/hw/msix.h
@@ -4,6 +4,7 @@
 #include "qemu-common.h"
 #include "pci.h"
 
+void msix_set_message(PCIDevice *dev, int vector, MSIMessage msg);
 int msix_init(PCIDevice *dev, unsigned short nentries,
               MemoryRegion *table_bar, uint8_t table_bar_nr,
               unsigned table_offset, MemoryRegion *pba_bar,