RE: [PATCH] intel-iommu: Add device info into list before doing context mapping

["Hao, Xudong" <xudong.hao@intel.com>]

Yes, Chris, thanks your comments.
How about this one?

---
 drivers/iommu/intel-iommu.c |   16 ++++++++++------
 1 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a004c39..0fc5efd 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2264,12 +2264,6 @@ static int domain_add_dev_info(struct dmar_domain *domain,
    if (!info)
        return -ENOMEM;

-   ret = domain_context_mapping(domain, pdev, translation);
-   if (ret) {
-       free_devinfo_mem(info);
-       return ret;
-   }
-
    info->segment = pci_domain_nr(pdev->bus);
    info->bus = pdev->bus->number;
    info->devfn = pdev->devfn;
@@ -2282,6 +2276,16 @@ static int domain_add_dev_info(struct dmar_domain *domain,
    pdev->dev.archdata.iommu = info;
    spin_unlock_irqrestore(&device_domain_lock, flags);

+   ret = domain_context_mapping(domain, pdev, translation);
+   if (ret) {
+       spin_lock_irqsave(&device_domain_lock, flags);
+       list_del(&info->link);
+       list_del(&info->global);
+       spin_unlock_irqrestore(&device_domain_lock, flags);
+       free_devinfo_mem(info);
+       return ret;
+   }
+
    return 0;
 }

> -----Original Message-----
> From: Chris Wright [mailto:chrisw@sous-sol.org]
> Sent: Wednesday, December 21, 2011 12:08 AM
> To: Hao, Xudong
> Cc: iommu@lists.linux-foundation.org; dwmw2@infradead.org; Zhang, Xiantao;
> linux-kernel@vger.kernel.org; kvm@vger.kernel.org
> Subject: Re: [PATCH] intel-iommu: Add device info into list before doing context
> mapping
> 
> * Hao, Xudong (xudong.hao@intel.com) wrote:
> > @@ -2282,6 +2276,14 @@ static int domain_add_dev_info(struct
> dmar_domain *domain,
> >  	pdev->dev.archdata.iommu = info;
> >  	spin_unlock_irqrestore(&device_domain_lock, flags);
> >
> > +	ret = domain_context_mapping(domain, pdev, translation);
> > +	if (ret) {
> > +		list_del(&info->link);
> > +		list_del(&info->global);
> 
> At the very least, this is not correct locking.
> 
> > +		free_devinfo_mem(info);
> > +		return ret;
> > +	}
> > +