lkml.org 
[lkml]   [2019]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 5/6] iommu/vt-d: Cleanup after delegating DMA domain to generic iommu
From
Date
On Mon, 2019-06-10 at 11:45 -0700, Mehta, Sohil wrote:
> On Sun, 2019-06-09 at 10:38 +0800, Lu Baolu wrote:
> > static int __init si_domain_init(int hw)
> > @@ -3306,14 +3252,13 @@ static int __init init_dmars(void)
> > if (pasid_supported(iommu))
> > intel_svm_init(iommu);
> > #endif
> > - }
> >
> > - /*
> > - * Now that qi is enabled on all iommus, set the root entry
> > and flush
> > - * caches. This is required on some Intel X58 chipsets,
> > otherwise the
> > - * flush_context function will loop forever and the boot
> > hangs.
> > - */
> > - for_each_active_iommu(iommu, drhd) {
> > + /*
> > + * Now that qi is enabled on all iommus, set the root
> > entry and
> > + * flush caches. This is required on some Intel X58
> > chipsets,
> > + * otherwise the flush_context function will loop
> > forever and
> > + * the boot hangs.
> > + */
> > iommu_flush_write_buffer(iommu);
> > iommu_set_root_entry(iommu);
> > iommu->flush.flush_context(iommu, 0, 0, 0,
> > DMA_CCMD_GLOBAL_INVL);
>
> This changes the intent of the original code. As the comment says
> enable QI on all IOMMUs, then flush the caches and set the root entry.
> The order of setting the root entries has changed now.
>
> Refer:
> Commit a4c34ff1c029 ('iommu/vt-d: Enable QI on all IOMMUs before
> setting root entry')

Thanks Sohil! for catching the bug.
Will send a V2 to Lu Baolu fixing this.

Regards,
Sai

\
 
 \ /
  Last update: 2019-06-10 21:28    [W:0.063 / U:0.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site