Re: [PATCH v8 RESEND 27/38] iommu/amd: Allow the AMD IOMMU to work with memory encryption

Tom Lendacky
2017-06-28T14:05:53Z

On 6/28/2017 4:36 AM, Joerg Roedel wrote:
> Hi Tom,

Hi Joerg,

>
> On Tue, Jun 27, 2017 at 10:12:30AM -0500, Tom Lendacky wrote:
>> ---
>> drivers/iommu/amd_iommu.c | 30 ++++++++++++++++--------------
>> drivers/iommu/amd_iommu_init.c | 34 ++++++++++++++++++++++++++++------
>> drivers/iommu/amd_iommu_proto.h | 10 ++++++++++
>> drivers/iommu/amd_iommu_types.h | 2 +-
>> 4 files changed, 55 insertions(+), 21 deletions(-)
>
> Looks like a straightforward change. Just one nit below.
>
>> +static bool amd_iommu_supports_sme(void)
>> +{
>> + if (!sme_active() || (boot_cpu_data.x86 != 0x17))
>> + return true;
>> +
>> + /* For Fam17h, a specific level of support is required */
>> + if (boot_cpu_data.microcode >= 0x08001205)
>> + return true;
>> +
>> + if ((boot_cpu_data.microcode >= 0x08001126) &&
>> + (boot_cpu_data.microcode <= 0x080011ff))
>> + return true;
>> +
>> + pr_notice("AMD-Vi: IOMMU not currently supported when SME is active\n");
>> +
>> + return false;
>> +}
>
> The name of the function is misleading. It checks whether the IOMMU can
> be enabled when SME is active. But the name suggests that it checks
> whether the iommu hardware supports SME.
>
> How about renaming it to amd_iommu_sme_check()?

Can do.

Thanks,
Tom

>
> With that change the patch is:
>
> Acked-by: Joerg Roedel <jroedel@suse.de>
>