[RFC,server,04/11] vfio-user: find and init PCI device

Commit Message

Jag Raman July 19, 2021, 8 p.m. UTC

Find the PCI device with specified id. Initialize the device context
with the QEMU PCI device

Signed-off-by: Elena Ufimtseva <[e-mail]>
Signed-off-by: John G Johnson <[e-mail]>
Signed-off-by: Jagannathan Raman <[e-mail]>
---
 hw/remote/vfio-user-obj.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

Comments

John Levon July 26, 2021, 3:05 p.m. UTC | #1

On Mon, Jul 19, 2021 at 04:00:06PM -0400, Jagannathan Raman wrote:

> +    vfu_pci_set_id(o->vfu_ctx,
> +                   pci_get_word(o->pci_dev->config + PCI_VENDOR_ID),
> +                   pci_get_word(o->pci_dev->config + PCI_DEVICE_ID),
> +                   pci_get_word(o->pci_dev->config + PCI_SUBSYSTEM_VENDOR_ID),
> +                   pci_get_word(o->pci_dev->config + PCI_SUBSYSTEM_ID));

Since you handle all config space accesses yourselves, is there even any need
for this?

regards
john

Jag Raman July 28, 2021, 5:08 p.m. UTC | #2

> On Jul 26, 2021, at 11:05 AM, John Levon <[e-mail]> wrote:
> 
> On Mon, Jul 19, 2021 at 04:00:06PM -0400, Jagannathan Raman wrote:
> 
>> +    vfu_pci_set_id(o->vfu_ctx,
>> +                   pci_get_word(o->pci_dev->config + PCI_VENDOR_ID),
>> +                   pci_get_word(o->pci_dev->config + PCI_DEVICE_ID),
>> +                   pci_get_word(o->pci_dev->config + PCI_SUBSYSTEM_VENDOR_ID),
>> +                   pci_get_word(o->pci_dev->config + PCI_SUBSYSTEM_ID));
> 
> Since you handle all config space accesses yourselves, is there even any need
> for this?

I think that makes sense. Since the QEMU server handles all the config space
accesses, it’s not necessary to register the device’s vendor/device ID with the library.

Thank you!
--
Jag

> 
> regards
> john

Patch

diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
index adb3193..e362709 100644
--- a/hw/remote/vfio-user-obj.c
+++ b/hw/remote/vfio-user-obj.c
@@ -37,6 +37,8 @@ 
 #include "qemu/notify.h"
 #include "qapi/error.h"
 #include "sysemu/sysemu.h"
+#include "hw/qdev-core.h"
+#include "hw/pci/pci.h"
 
 #include "libvfio-user/include/libvfio-user.h"
 
@@ -62,6 +64,8 @@  struct VfuObject {
     Notifier machine_done;
 
     vfu_ctx_t *vfu_ctx;
+
+    PCIDevice *pci_dev;
 };
 
 static void vfu_object_set_socket(Object *obj, const char *str, Error **errp)
@@ -89,6 +93,8 @@  static void vfu_object_set_devid(Object *obj, const char *str, Error **errp)
 static void vfu_object_machine_done(Notifier *notifier, void *data)
 {
     VfuObject *o = container_of(notifier, VfuObject, machine_done);
+    DeviceState *dev = NULL;
+    int ret;
 
     o->vfu_ctx = vfu_create_ctx(VFU_TRANS_SOCK, o->socket, 0,
                                 o, VFU_DEV_TYPE_PCI);
@@ -97,6 +103,28 @@  static void vfu_object_machine_done(Notifier *notifier, void *data)
                    strerror(errno));
         return;
     }
+
+    dev = qdev_find_recursive(sysbus_get_default(), o->devid);
+    if (dev == NULL) {
+        error_setg(&error_abort, "vfu: Device %s not found", o->devid);
+        return;
+    }
+    o->pci_dev = PCI_DEVICE(dev);
+
+    ret = vfu_pci_init(o->vfu_ctx, VFU_PCI_TYPE_CONVENTIONAL,
+                       PCI_HEADER_TYPE_NORMAL, 0);
+    if (ret < 0) {
+        error_setg(&error_abort,
+                   "vfu: Failed to attach PCI device %s to context - %s",
+                   o->devid, strerror(errno));
+        return;
+    }
+
+    vfu_pci_set_id(o->vfu_ctx,
+                   pci_get_word(o->pci_dev->config + PCI_VENDOR_ID),
+                   pci_get_word(o->pci_dev->config + PCI_DEVICE_ID),
+                   pci_get_word(o->pci_dev->config + PCI_SUBSYSTEM_VENDOR_ID),
+                   pci_get_word(o->pci_dev->config + PCI_SUBSYSTEM_ID));
 }
 
 static void vfu_object_init(Object *obj)