[Qemu-devel] [PATCH v2 1/5] vmxnet3: Change offsets of msi/msix pci capabilities

[Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>]

Place device reported PCI capabilities at the same offsets as placed by
the VMware virtual hardware: MSI at [84], MSI-X at [9c].

For compatability, preserve old offsets using 'x-old-msi-offsets' toggle.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
---
 hw/net/vmxnet3.c    | 20 +++++++++++++++++---
 include/hw/compat.h |  4 ++++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index 5e3a233..1985dcf 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -36,6 +36,16 @@
 #define VMXNET3_MSIX_BAR_SIZE 0x2000
 #define MIN_BUF_SIZE 60
 
+/* Compatability flags for migration */
+#define VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS_BIT 0
+#define VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS \
+    (1 << VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS_BIT)
+
+#define VMXNET3_MSI_OFFSET(s) \
+    ((s)->compat_flags & VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS ? 0x50 : 0x84)
+#define VMXNET3_MSIX_OFFSET(s) \
+    ((s)->compat_flags & VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS ? 0 : 0x9c)
+
 #define VMXNET3_BAR0_IDX      (0)
 #define VMXNET3_BAR1_IDX      (1)
 #define VMXNET3_MSIX_BAR_IDX  (2)
@@ -313,6 +323,9 @@ typedef struct {
         MACAddr *mcast_list;
         uint32_t mcast_list_len;
         uint32_t mcast_list_buff_size; /* needed for live migration. */
+
+        /* Compatability flags for migration */
+        uint32_t compat_flags;
 } VMXNET3State;
 
 /* Interrupt management */
@@ -2103,7 +2116,7 @@ vmxnet3_init_msix(VMXNET3State *s)
                         VMXNET3_MSIX_BAR_IDX, VMXNET3_OFF_MSIX_TABLE,
                         &s->msix_bar,
                         VMXNET3_MSIX_BAR_IDX, VMXNET3_OFF_MSIX_PBA,
-                        0);
+                        VMXNET3_MSIX_OFFSET(s));
 
     if (0 > res) {
         VMW_WRPRN("Failed to initialize MSI-X, error %d", res);
@@ -2131,7 +2144,6 @@ vmxnet3_cleanup_msix(VMXNET3State *s)
     }
 }
 
-#define VMXNET3_MSI_OFFSET        (0x50)
 #define VMXNET3_USE_64BIT         (true)
 #define VMXNET3_PER_VECTOR_MASK   (false)
 
@@ -2141,7 +2153,7 @@ vmxnet3_init_msi(VMXNET3State *s)
     PCIDevice *d = PCI_DEVICE(s);
     int res;
 
-    res = msi_init(d, VMXNET3_MSI_OFFSET, VMXNET3_MAX_NMSIX_INTRS,
+    res = msi_init(d, VMXNET3_MSI_OFFSET(s), VMXNET3_MAX_NMSIX_INTRS,
                    VMXNET3_USE_64BIT, VMXNET3_PER_VECTOR_MASK);
     if (0 > res) {
         VMW_WRPRN("Failed to initialize MSI, error %d", res);
@@ -2552,6 +2564,8 @@ static const VMStateDescription vmstate_vmxnet3 = {
 
 static Property vmxnet3_properties[] = {
     DEFINE_NIC_PROPERTIES(VMXNET3State, conf),
+    DEFINE_PROP_BIT("x-old-msi-offsets", VMXNET3State, compat_flags,
+                    VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS_BIT, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/compat.h b/include/hw/compat.h
index d0b1c4f..01e326d 100644
--- a/include/hw/compat.h
+++ b/include/hw/compat.h
@@ -18,6 +18,10 @@
             .driver   = "virtio-pci",\
             .property = "migrate-extra",\
             .value    = "off",\
+        },{\
+            .driver   = "vmxnet3",\
+            .property = "x-old-msi-offsets",\
+            .value    = "on",\
         },
 
 #define HW_COMPAT_2_3 \
-- 
1.9.1