Re: [PATCH v2 1/4] iommu/vt-d: Enable write protect for supervisor SVM

[Guenter Roeck]

On Tue, Mar 02, 2021 at 02:13:57AM -0800, Jacob Pan wrote:
> Write protect bit, when set, inhibits supervisor writes to the read-only
> pages. In supervisor shared virtual addressing (SVA), where page tables
> are shared between CPU and DMA, IOMMU PASID entry WPE bit should match
> CR0.WP bit in the CPU.
> This patch sets WPE bit for supervisor PASIDs if CR0.WP is set.
> 
> Signed-off-by: Sanjay Kumar <sanjay.k.kumar@xxxxxxxxx>
> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> ---

ia64:defconfig:

drivers/iommu/intel/pasid.c: In function 'pasid_enable_wpe':
drivers/iommu/intel/pasid.c:536:22: error: implicit declaration of function 'read_cr0'
drivers/iommu/intel/pasid.c:539:23: error: 'X86_CR0_WP' undeclared

Maybe it _is_ time to retire ia64 ?

Guenter