Re: [Qemu-devel] [PATCH v2 13/22] hw/pvrdma: Make sure PCI function 0 is vmxnet3

[Marcel Apfelbaum]

On 11/11/18 9:45 AM, Yuval Shaia wrote:
On Sat, Nov 10, 2018 at 08:27:44PM +0200, Marcel Apfelbaum wrote:

On 11/8/18 6:08 PM, Yuval Shaia wrote:
Guest driver enforces it, we should also.

Signed-off-by: Yuval Shaia <yuval.sh...@oracle.com>
---
   hw/rdma/vmw/pvrdma.h      | 2 ++
   hw/rdma/vmw/pvrdma_main.c | 3 +++
   2 files changed, 5 insertions(+)

diff --git a/hw/rdma/vmw/pvrdma.h b/hw/rdma/vmw/pvrdma.h
index b019cb843a..10a3c4fb7c 100644
--- a/hw/rdma/vmw/pvrdma.h
+++ b/hw/rdma/vmw/pvrdma.h
@@ -20,6 +20,7 @@
   #include "hw/pci/pci.h"
   #include "hw/pci/msix.h"
   #include "chardev/char-fe.h"
+#include "hw/net/vmxnet3_defs.h"
   #include "../rdma_backend_defs.h"
   #include "../rdma_rm_defs.h"
@@ -85,6 +86,7 @@ typedef struct PVRDMADev {
       RdmaBackendDev backend_dev;
       RdmaDeviceResources rdma_dev_res;
       CharBackend mad_chr;
+    VMXNET3State *func0;
   } PVRDMADev;
   #define PVRDMA_DEV(dev) OBJECT_CHECK(PVRDMADev, (dev), PVRDMA_HW_NAME)
diff --git a/hw/rdma/vmw/pvrdma_main.c b/hw/rdma/vmw/pvrdma_main.c
index ac8c092db0..fa6468d221 100644
--- a/hw/rdma/vmw/pvrdma_main.c
+++ b/hw/rdma/vmw/pvrdma_main.c
@@ -576,6 +576,9 @@ static void pvrdma_realize(PCIDevice *pdev, Error **errp)
           return;
       }
+    /* Break if not vmxnet3 device in slot 0 */
+    dev->func0 = VMXNET3(pci_get_function_0(pdev));
+
I don't see the error code flow in case VMXNET3 is not func 0.
Am I missing something?
Yes, this is a dynamic cast that will break the process when fail to cast.

This is the error message that you will get in case that device on function
0 is not vmxnet3:

pvrdma_main.c:589:pvrdma_realize: Object 0x557b959841a0 is not an instance of 
type vmxnet3

I am not sure we will see this error if QEMU is compiled in Release mode.
I think object_dynamic_cast_assert throws this error only if 
CONFIG_QOM_CAST_DEBUG
is set, and is possible the mentioned flag is not set in Release.

Thanks,
Marcel



Thanks,
Marcel

       memdev_root = object_resolve_path("/objects", NULL);
       if (memdev_root) {
           object_child_foreach(memdev_root, pvrdma_check_ram_shared, 
&ram_shared);