Re: [PATCH 3/4] mm: simplify device private page handling in hmm_range_fault

On Thu, Mar 19, 2020 at 06:33:04PM -0700, Ralph Campbell wrote:

...

...

• .default_flags = dmirror_hmm_flags[HMM_PFN_VALID] |
  

• 		(write ? dmirror_hmm_flags[HMM_PFN_WRITE] : 0),
  

• .dev_private_owner = dmirror->mdevice,
  

• };
• int ret = 0;

...

+static int dmirror_snapshot(struct dmirror *dmirror,

• 	    struct hmm_dmirror_cmd *cmd)
  

+{

• struct mm_struct *mm = dmirror->mm;
• unsigned long start, end;
• unsigned long size = cmd->npages << PAGE_SHIFT;
• unsigned long addr;
• unsigned long next;
• uint64_t pfns[64];
• unsigned char perm[64];
• char __user *uptr;
• struct hmm_range range = {

• .pfns = pfns,
  

• .flags = dmirror_hmm_flags,
  

• .values = dmirror_hmm_values,
  

• .pfn_shift = DPT_SHIFT,
  

• .pfn_flags_mask = ~0ULL,
  

Same here, especially since this is snapshot

Jason

Actually, snapshot ignores pfn_flags_mask and default_flags.

Yes, so no reason to set them to not 0..

Jason