diff mbox series

[v6,09/19] vfio-user: find and init PCI device

Message ID fcc3548397af6c548d46fdeb1ddeedc1c71f28e2.1645079934.git.jag.raman@oracle.com (mailing list archive)
State New, archived
Headers show
Series vfio-user server in QEMU | expand

Commit Message

Jag Raman Feb. 17, 2022, 7:48 a.m. UTC 
Find the PCI device with specified id. Initialize the device context
with the QEMU PCI device

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/remote/vfio-user-obj.c | 59 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

Comments

Stefan Hajnoczi Feb. 21, 2022, 3:57 p.m. UTC | #1 
On Thu, Feb 17, 2022 at 02:48:56AM -0500, Jagannathan Raman wrote:
> @@ -221,6 +272,14 @@ static void vfu_object_finalize(Object *obj)
>  
>      o->device = NULL;
>  
> +    if (o->unplug_blocker && o->pci_dev) {
> +        qdev_del_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
> +        error_free(o->unplug_blocker);
> +        o->unplug_blocker = NULL;
> +    }
> +
> +    o->pci_dev = NULL;

Since we don't hold a reference to o->pci_dev there is an assumption
about the order of --object vs --device ->finalize() here. I think it
will work because softmmu/runstate.c:qemu_cleanup() doesn't unref
main_system_bus and only --object ->finalize() is called, but this seems
fragile. We should probably hold a reference to pci_dev and call
object_unref() on it.
Jag Raman Feb. 28, 2022, 7:17 p.m. UTC | #2 
> On Feb 21, 2022, at 10:57 AM, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> 
> On Thu, Feb 17, 2022 at 02:48:56AM -0500, Jagannathan Raman wrote:
>> @@ -221,6 +272,14 @@ static void vfu_object_finalize(Object *obj)
>> 
>>     o->device = NULL;
>> 
>> +    if (o->unplug_blocker && o->pci_dev) {
>> +        qdev_del_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
>> +        error_free(o->unplug_blocker);
>> +        o->unplug_blocker = NULL;
>> +    }
>> +
>> +    o->pci_dev = NULL;
> 
> Since we don't hold a reference to o->pci_dev there is an assumption
> about the order of --object vs --device ->finalize() here. I think it
> will work because softmmu/runstate.c:qemu_cleanup() doesn't unref
> main_system_bus and only --object ->finalize() is called, but this seems
> fragile. We should probably hold a reference to pci_dev and call
> object_unref() on it.

OK, will do.

Thank you!
--
Jag
diff mbox series

Patch

diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
index 496e6c8038..9c76913545 100644
--- a/hw/remote/vfio-user-obj.c
+++ b/hw/remote/vfio-user-obj.c
@@ -44,6 +44,8 @@ 
 #include "qemu/notify.h"
 #include "sysemu/sysemu.h"
 #include "libvfio-user.h"
+#include "hw/qdev-core.h"
+#include "hw/pci/pci.h"
 
 #define TYPE_VFU_OBJECT "x-vfio-user-server"
 OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT)
@@ -89,6 +91,10 @@  struct VfuObject {
     Notifier machine_done;
 
     vfu_ctx_t *vfu_ctx;
+
+    PCIDevice *pci_dev;
+
+    Error *unplug_blocker;
 };
 
 static void vfu_object_init_ctx(VfuObject *o, Error **errp);
@@ -163,6 +169,9 @@  static void vfu_object_machine_done(Notifier *notifier, void *data)
 static void vfu_object_init_ctx(VfuObject *o, Error **errp)
 {
     ERRP_GUARD();
+    DeviceState *dev = NULL;
+    vfu_pci_type_t pci_type = VFU_PCI_TYPE_CONVENTIONAL;
+    int ret;
 
     if (o->vfu_ctx || !o->socket || !o->device ||
             !phase_check(PHASE_MACHINE_READY)) {
@@ -181,6 +190,48 @@  static void vfu_object_init_ctx(VfuObject *o, Error **errp)
         error_setg(errp, "vfu: Failed to create context - %s", strerror(errno));
         return;
     }
+
+    dev = qdev_find_recursive(sysbus_get_default(), o->device);
+    if (dev == NULL) {
+        error_setg(errp, "vfu: Device %s not found", o->device);
+        goto fail;
+    }
+
+    if (!object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+        error_setg(errp, "vfu: %s not a PCI device", o->device);
+        goto fail;
+    }
+
+    o->pci_dev = PCI_DEVICE(dev);
+
+    if (pci_is_express(o->pci_dev)) {
+        pci_type = VFU_PCI_TYPE_EXPRESS;
+    }
+
+    ret = vfu_pci_init(o->vfu_ctx, pci_type, PCI_HEADER_TYPE_NORMAL, 0);
+    if (ret < 0) {
+        error_setg(errp,
+                   "vfu: Failed to attach PCI device %s to context - %s",
+                   o->device, strerror(errno));
+        goto fail;
+    }
+
+    error_setg(&o->unplug_blocker,
+               "vfu: %s for %s must be deleted before unplugging",
+               TYPE_VFU_OBJECT, o->device);
+    qdev_add_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
+
+    return;
+
+fail:
+    vfu_destroy_ctx(o->vfu_ctx);
+    if (o->unplug_blocker && o->pci_dev) {
+        qdev_del_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
+        error_free(o->unplug_blocker);
+        o->unplug_blocker = NULL;
+    }
+    o->vfu_ctx = NULL;
+    o->pci_dev = NULL;
 }
 
 static void vfu_object_init(Object *obj)
@@ -221,6 +272,14 @@  static void vfu_object_finalize(Object *obj)
 
     o->device = NULL;
 
+    if (o->unplug_blocker && o->pci_dev) {
+        qdev_del_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
+        error_free(o->unplug_blocker);
+        o->unplug_blocker = NULL;
+    }
+
+    o->pci_dev = NULL;
+
     if (!k->nr_devs && k->auto_shutdown) {
         qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
     }