On 1/7/2018 10:28 AM, Borislav Petkov wrote:
> On Thu, Dec 21, 2017 at 04:03:12PM -0600, Tom Lendacky wrote:
>> In preparation for encrypting more than just the kernel during early
>> boot processing, centralize the use of the PMD flag settings based
>> on the type of mapping desired.  When 4KB aligned encryption is added,
>> this will allow either PTE flags or large page PMD flags to be used
>> without requiring the caller to adjust.
>>
>> Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
>> ---
>>  arch/x86/mm/mem_encrypt.c |  131 
>> ++++++++++++++++++++++++++-------------------
>>  1 file changed, 77 insertions(+), 54 deletions(-)
>>
>> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
>> index 5a20696..9b180f8 100644
>> --- a/arch/x86/mm/mem_encrypt.c
>> +++ b/arch/x86/mm/mem_encrypt.c
>> @@ -468,31 +468,40 @@ struct sme_populate_pgd_data {
>>      void    *pgtable_area;
>>      pgd_t   *pgd;
>>  
>> -    pmdval_t pmd_val;
>> +    pmdval_t pmd_flags;
>> +    unsigned long paddr;
>> +
>>      unsigned long vaddr;
>> +    unsigned long vaddr_end;
>>  };
>>  
>> -static void __init sme_clear_pgd(pgd_t *pgd_base, unsigned long start,
>> -                             unsigned long end)
>> +static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
>>  {
>>      unsigned long pgd_start, pgd_end, pgd_size;
>>      pgd_t *pgd_p;
>>  
>> -    pgd_start = start & PGDIR_MASK;
>> -    pgd_end = end & PGDIR_MASK;
>> +    pgd_start = ppd->vaddr & PGDIR_MASK;
>> +    pgd_end = ppd->vaddr_end & PGDIR_MASK;
>>  
>>      pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1);
>>      pgd_size *= sizeof(pgd_t);
> 
> This is a strange way of writing this. I'd expect:
> 
>       pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);

Yup, clearer as one line.  I can fix that up.

> 
>>  
>> -    pgd_p = pgd_base + pgd_index(start);
>> +    pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
>>  
>>      memset(pgd_p, 0, pgd_size);
>>  }
>>  
>> -#define PGD_FLAGS   _KERNPG_TABLE_NOENC
>> -#define P4D_FLAGS   _KERNPG_TABLE_NOENC
>> -#define PUD_FLAGS   _KERNPG_TABLE_NOENC
>> -#define PMD_FLAGS   (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
>> +#define PGD_FLAGS           _KERNPG_TABLE_NOENC
>> +#define P4D_FLAGS           _KERNPG_TABLE_NOENC
>> +#define PUD_FLAGS           _KERNPG_TABLE_NOENC
>> +
>> +#define PMD_FLAGS_LARGE             (__PAGE_KERNEL_LARGE_EXEC & 
>> ~_PAGE_GLOBAL)
>> +
>> +#define PMD_FLAGS_DEC               PMD_FLAGS_LARGE
>> +#define PMD_FLAGS_DEC_WP    ((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
>> +                             (_PAGE_PAT | _PAGE_PWT))
>> +
>> +#define PMD_FLAGS_ENC               (PMD_FLAGS_LARGE | _PAGE_ENC)
>>  
>>  static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
>>  {
>> @@ -561,7 +570,36 @@ static void __init sme_populate_pgd_large(struct 
>> sme_populate_pgd_data *ppd)
>>  
>>      pmd_p += pmd_index(ppd->vaddr);
>>      if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
>> -            native_set_pmd(pmd_p, native_make_pmd(ppd->pmd_val));
>> +            native_set_pmd(pmd_p,
>> +                           native_make_pmd(ppd->paddr | ppd->pmd_flags));
> 
> Never do those ugly line breaks. Just let it stick out.

Will do.

Thanks,
Tom

> 
> Otherwise, sme_encrypt_kernel() is starting to look quite readable :)
> 

Reply via email to