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From: David Vrabel <david.vrabel@citrix.com>
To: Jan Beulich <JBeulich@suse.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Xen/PCI: correct notifier used for device removal
Date: Mon, 1 Feb 2016 12:01:21 +0000	[thread overview]
Message-ID: <56AF4911.8030208@citrix.com> (raw)
In-Reply-To: <56AF566002000078000CCE71@prv-mh.provo.novell.com>

On 01/02/16 11:58, Jan Beulich wrote:
> Commit 599bad38cf added BUS_NOTIFY_REMOVED_DEVICE in order to allow
> avoiding removal of IOMMU mappings before the driver actually got
> unbound from the device. Naturally we should be using this too.

Because otherwise...?  What happens if we don't make this change?

Removing IOMMU mappings for a device when the driver is still bound to
the device looks wrong to me. Surely the device is still active and may
still be performing DMA at this point?

David

> --- 4.5-rc2/drivers/xen/pci.c
> +++ 4.5-rc2-xen-PCI-remove-notifier/drivers/xen/pci.c
> @@ -185,7 +185,7 @@ static int xen_pci_notifier(struct notif
>  	case BUS_NOTIFY_ADD_DEVICE:
>  		r = xen_add_device(dev);
>  		break;
> -	case BUS_NOTIFY_DEL_DEVICE:
> +	case BUS_NOTIFY_REMOVED_DEVICE:
>  		r = xen_remove_device(dev);
>  		break;
>  	default:
> 
> 
> 

  reply	other threads:[~2016-02-01 12:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-01 11:58 [PATCH] Xen/PCI: correct notifier used for device removal Jan Beulich
2016-02-01 12:01 ` David Vrabel [this message]
2016-02-01 12:16   ` Jan Beulich
2016-02-01 13:03     ` David Vrabel
2016-02-01 13:08       ` Jan Beulich

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