On Sat, May 17, 2025, Paolo Bonzini wrote: > On 5/16/25 23:54, Sean Christopherson wrote: > > + /* > > + * Write mmu_page_hash exactly once as there may be concurrent readers, > > + * e.g. to check for shadowed PTEs in mmu_try_to_unsync_pages(). Note, > > + * mmu_lock must be held for write to add (or remove) shadow pages, and > > + * so readers are guaranteed to see an empty list for their current > > + * mmu_lock critical section. > > + */ > > + WRITE_ONCE(kvm->arch.mmu_page_hash, h); > > Use smp_store_release here (unlike READ_ONCE(), it's technically incorrect > to use WRITE_ONCE() here!), Can you elaborate why? Due to my x86-centric life, my memory ordering knowledge is woefully inadequate. > with a remark that it pairs with kvm_get_mmu_page_hash(). That's both more > accurate and leads to a better comment than "write exactly once".
