On 3/19/20 5:14 PM, Jason Gunthorpe wrote:
On Tue, Mar 17, 2020 at 04:14:31PM -0700, Ralph Campbell wrote:+static int dmirror_fault(struct dmirror *dmirror, unsigned long start, + unsigned long end, bool write) +{ + struct mm_struct *mm = dmirror->mm; + unsigned long addr; + uint64_t pfns[64]; + struct hmm_range range = { + .notifier = &dmirror->notifier, + .pfns = pfns, + .flags = dmirror_hmm_flags, + .values = dmirror_hmm_values, + .pfn_shift = DPT_SHIFT, + .pfn_flags_mask = ~(dmirror_hmm_flags[HMM_PFN_VALID] | + dmirror_hmm_flags[HMM_PFN_WRITE]),Since pfns is not initialized pfn_flags_mask should be 0.
Good point.
+ .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. In hmm_pte_need_fault(), HMM_FAULT_SNAPSHOT is checked and returns early before checking pfn_flags_mask and default_flags since no faults are being requested.
