diff mbox series

vfio/pci: Remove vfio_detach_device from vfio_realize error path

Message ID 20231011200934.549735-1-eric.auger@redhat.com (mailing list archive)
State New, archived
Headers show
Series vfio/pci: Remove vfio_detach_device from vfio_realize error path | expand

Commit Message

Eric Auger Oct. 11, 2023, 8:09 p.m. UTC
In vfio_realize, on the error path, we currently call
vfio_detach_device() after a successful vfio_attach_device.
While this looks natural, vfio_instance_finalize also induces
a vfio_detach_device(), and it seems to be the right place
instead as other resources are released there which happen
to be a prerequisite to a successful UNSET_CONTAINER.

So let's rely on the finalize vfio_detach_device call to free
all the relevant resources.

Fixes: a28e06621170 ("vfio/pci: Introduce vfio_[attach/detach]_device")
Reported-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

This applies on top of vfio-next

Note I am not sure the SHA1 of
vfio/pci: Introduce vfio_[attach/detach]_device
is stable.
---
 hw/vfio/pci.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

Comments

Duan, Zhenzhong Oct. 12, 2023, 2:34 a.m. UTC | #1
>-----Original Message-----
>From: Eric Auger <eric.auger@redhat.com>
>Sent: Thursday, October 12, 2023 4:10 AM
>To: eric.auger.pro@gmail.com; eric.auger@redhat.com; qemu-
>devel@nongnu.org; alex.williamson@redhat.com; clg@redhat.com; Duan,
>Zhenzhong <zhenzhong.duan@intel.com>; Liu, Yi L <yi.l.liu@intel.com>;
>yanghliu@redhat.com
>Subject: [PATCH] vfio/pci: Remove vfio_detach_device from vfio_realize error
>path
>
>In vfio_realize, on the error path, we currently call
>vfio_detach_device() after a successful vfio_attach_device.
>While this looks natural, vfio_instance_finalize also induces
>a vfio_detach_device(), and it seems to be the right place
>instead as other resources are released there which happen
>to be a prerequisite to a successful UNSET_CONTAINER.
>
>So let's rely on the finalize vfio_detach_device call to free
>all the relevant resources.
>
>Fixes: a28e06621170 ("vfio/pci: Introduce vfio_[attach/detach]_device")
>Reported-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>Signed-off-by: Eric Auger <eric.auger@redhat.com>

Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

Thanks
Zhenzhong
Eric Auger Oct. 12, 2023, 6:37 a.m. UTC | #2
Hi Zhenzhong,

On 10/12/23 04:34, Duan, Zhenzhong wrote:
>
>> -----Original Message-----
>> From: Eric Auger <eric.auger@redhat.com>
>> Sent: Thursday, October 12, 2023 4:10 AM
>> To: eric.auger.pro@gmail.com; eric.auger@redhat.com; qemu-
>> devel@nongnu.org; alex.williamson@redhat.com; clg@redhat.com; Duan,
>> Zhenzhong <zhenzhong.duan@intel.com>; Liu, Yi L <yi.l.liu@intel.com>;
>> yanghliu@redhat.com
>> Subject: [PATCH] vfio/pci: Remove vfio_detach_device from vfio_realize error
>> path
>>
>> In vfio_realize, on the error path, we currently call
>> vfio_detach_device() after a successful vfio_attach_device.
>> While this looks natural, vfio_instance_finalize also induces
>> a vfio_detach_device(), and it seems to be the right place
>> instead as other resources are released there which happen
>> to be a prerequisite to a successful UNSET_CONTAINER.
>>
>> So let's rely on the finalize vfio_detach_device call to free
>> all the relevant resources.
>>
>> Fixes: a28e06621170 ("vfio/pci: Introduce vfio_[attach/detach]_device")
>> Reported-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Thanks!

Eric
>
> Thanks
> Zhenzhong
>
Cédric Le Goater Oct. 12, 2023, 6:48 a.m. UTC | #3
On 10/11/23 22:09, Eric Auger wrote:
> In vfio_realize, on the error path, we currently call
> vfio_detach_device() after a successful vfio_attach_device.
> While this looks natural, vfio_instance_finalize also induces
> a vfio_detach_device(), and it seems to be the right place
> instead as other resources are released there which happen
> to be a prerequisite to a successful UNSET_CONTAINER.
> 
> So let's rely on the finalize vfio_detach_device call to free
> all the relevant resources.
> 
> Fixes: a28e06621170 ("vfio/pci: Introduce vfio_[attach/detach]_device")
> Reported-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> ---
> 
> This applies on top of vfio-next

Applied to vfio-next.

> Note I am not sure the SHA1 of
> vfio/pci: Introduce vfio_[attach/detach]_device
> is stable.

It should if I only rebase on master. If I need to re-apply, I will drop
the Fixes tag.

Thanks,

C.



> ---
>   hw/vfio/pci.c | 16 +++++++---------
>   1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 40ae46266e..6e3f6aba28 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -3115,7 +3115,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       vfio_populate_device(vdev, &err);
>       if (err) {
>           error_propagate(errp, err);
> -        goto out_detach;
> +        goto error;
>       }
>   
>       /* Get a copy of config space */
> @@ -3125,7 +3125,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       if (ret < (int)MIN(pci_config_size(&vdev->pdev), vdev->config_size)) {
>           ret = ret < 0 ? -errno : -EFAULT;
>           error_setg_errno(errp, -ret, "failed to read device config space");
> -        goto out_detach;
> +        goto error;
>       }
>   
>       /* vfio emulates a lot for us, but some bits need extra love */
> @@ -3144,7 +3144,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       if (vdev->vendor_id != PCI_ANY_ID) {
>           if (vdev->vendor_id >= 0xffff) {
>               error_setg(errp, "invalid PCI vendor ID provided");
> -            goto out_detach;
> +            goto error;
>           }
>           vfio_add_emulated_word(vdev, PCI_VENDOR_ID, vdev->vendor_id, ~0);
>           trace_vfio_pci_emulated_vendor_id(vbasedev->name, vdev->vendor_id);
> @@ -3155,7 +3155,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       if (vdev->device_id != PCI_ANY_ID) {
>           if (vdev->device_id > 0xffff) {
>               error_setg(errp, "invalid PCI device ID provided");
> -            goto out_detach;
> +            goto error;
>           }
>           vfio_add_emulated_word(vdev, PCI_DEVICE_ID, vdev->device_id, ~0);
>           trace_vfio_pci_emulated_device_id(vbasedev->name, vdev->device_id);
> @@ -3166,7 +3166,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       if (vdev->sub_vendor_id != PCI_ANY_ID) {
>           if (vdev->sub_vendor_id > 0xffff) {
>               error_setg(errp, "invalid PCI subsystem vendor ID provided");
> -            goto out_detach;
> +            goto error;
>           }
>           vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_VENDOR_ID,
>                                  vdev->sub_vendor_id, ~0);
> @@ -3177,7 +3177,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       if (vdev->sub_device_id != PCI_ANY_ID) {
>           if (vdev->sub_device_id > 0xffff) {
>               error_setg(errp, "invalid PCI subsystem device ID provided");
> -            goto out_detach;
> +            goto error;
>           }
>           vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_ID, vdev->sub_device_id, ~0);
>           trace_vfio_pci_emulated_sub_device_id(vbasedev->name,
> @@ -3210,7 +3210,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       vfio_msix_early_setup(vdev, &err);
>       if (err) {
>           error_propagate(errp, err);
> -        goto out_detach;
> +        goto error;
>       }
>   
>       vfio_bars_register(vdev);
> @@ -3326,8 +3326,6 @@ out_deregister:
>   out_teardown:
>       vfio_teardown_msi(vdev);
>       vfio_bars_exit(vdev);
> -out_detach:
> -    vfio_detach_device(vbasedev);
>   error:
>       error_prepend(errp, VFIO_MSG_PREFIX, vbasedev->name);
>   }
diff mbox series

Patch

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 40ae46266e..6e3f6aba28 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3115,7 +3115,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     vfio_populate_device(vdev, &err);
     if (err) {
         error_propagate(errp, err);
-        goto out_detach;
+        goto error;
     }
 
     /* Get a copy of config space */
@@ -3125,7 +3125,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     if (ret < (int)MIN(pci_config_size(&vdev->pdev), vdev->config_size)) {
         ret = ret < 0 ? -errno : -EFAULT;
         error_setg_errno(errp, -ret, "failed to read device config space");
-        goto out_detach;
+        goto error;
     }
 
     /* vfio emulates a lot for us, but some bits need extra love */
@@ -3144,7 +3144,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     if (vdev->vendor_id != PCI_ANY_ID) {
         if (vdev->vendor_id >= 0xffff) {
             error_setg(errp, "invalid PCI vendor ID provided");
-            goto out_detach;
+            goto error;
         }
         vfio_add_emulated_word(vdev, PCI_VENDOR_ID, vdev->vendor_id, ~0);
         trace_vfio_pci_emulated_vendor_id(vbasedev->name, vdev->vendor_id);
@@ -3155,7 +3155,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     if (vdev->device_id != PCI_ANY_ID) {
         if (vdev->device_id > 0xffff) {
             error_setg(errp, "invalid PCI device ID provided");
-            goto out_detach;
+            goto error;
         }
         vfio_add_emulated_word(vdev, PCI_DEVICE_ID, vdev->device_id, ~0);
         trace_vfio_pci_emulated_device_id(vbasedev->name, vdev->device_id);
@@ -3166,7 +3166,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     if (vdev->sub_vendor_id != PCI_ANY_ID) {
         if (vdev->sub_vendor_id > 0xffff) {
             error_setg(errp, "invalid PCI subsystem vendor ID provided");
-            goto out_detach;
+            goto error;
         }
         vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_VENDOR_ID,
                                vdev->sub_vendor_id, ~0);
@@ -3177,7 +3177,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     if (vdev->sub_device_id != PCI_ANY_ID) {
         if (vdev->sub_device_id > 0xffff) {
             error_setg(errp, "invalid PCI subsystem device ID provided");
-            goto out_detach;
+            goto error;
         }
         vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_ID, vdev->sub_device_id, ~0);
         trace_vfio_pci_emulated_sub_device_id(vbasedev->name,
@@ -3210,7 +3210,7 @@  static void vfio_realize(PCIDevice *pdev, Error **errp)
     vfio_msix_early_setup(vdev, &err);
     if (err) {
         error_propagate(errp, err);
-        goto out_detach;
+        goto error;
     }
 
     vfio_bars_register(vdev);
@@ -3326,8 +3326,6 @@  out_deregister:
 out_teardown:
     vfio_teardown_msi(vdev);
     vfio_bars_exit(vdev);
-out_detach:
-    vfio_detach_device(vbasedev);
 error:
     error_prepend(errp, VFIO_MSG_PREFIX, vbasedev->name);
 }