On 02/03/2025 23:36, Gavin Shan wrote: > On 2/14/25 2:13 AM, Steven Price wrote: >> From: Sean Christopherson <seanjc@xxxxxxxxxx> >> >> Add flags to "struct kvm_gfn_range" to let notifier events target only >> shared and only private mappings, and write up the existing mmu_notifier >> events to be shared-only (private memory is never associated with a >> userspace virtual address, i.e. can't be reached via mmu_notifiers). >> >> Add two flags so that KVM can handle the three possibilities (shared, >> private, and shared+private) without needing something like a tri-state >> enum. >> >> Link: https://lore.kernel.org/all/ZJX0hk+KpQP0KUyB@xxxxxxxxxx >> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> >> Signed-off-by: Steven Price <steven.price@xxxxxxx> >> --- >> include/linux/kvm_host.h | 2 ++ >> virt/kvm/kvm_main.c | 7 +++++++ >> 2 files changed, 9 insertions(+) >> >> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h >> index 3cb9a32a6330..0de1e485452c 100644 >> --- a/include/linux/kvm_host.h >> +++ b/include/linux/kvm_host.h >> @@ -266,6 +266,8 @@ struct kvm_gfn_range { >> gfn_t end; >> union kvm_mmu_notifier_arg arg; >> enum kvm_gfn_range_filter attr_filter; >> + bool only_private; >> + bool only_shared; >> bool may_block; >> }; > > The added members (only_private and only_shared) looks duplicated to the > member of attr_filter, which can be set to KVM_FILTER_SHARED, > KVM_FILTER_PRIVATE, > or both of them. More details can be found from the following commit where > attr_filter was by dca6c88532322 ("KVM: Add member to struct kvm_gfn_range > to indicate private/shared"). > > I'm guessing Sean's suggestion was given before dca6c88532322 showed up. Thanks for pointing this out - you are absolutely right. I need to switch the code in the following patches over to use attr_filter instead. I hadn't realised when rebasing that attr_filter is the replacement. Thanks, Steve >> bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range); >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c >> index faf10671eed2..4f0136094fac 100644 >> --- a/virt/kvm/kvm_main.c >> +++ b/virt/kvm/kvm_main.c >> @@ -593,6 +593,13 @@ static __always_inline kvm_mn_ret_t >> __kvm_handle_hva_range(struct kvm *kvm, >> * the second or later invocation of the handler). >> */ >> gfn_range.arg = range->arg; >> + >> + /* >> + * HVA-based notifications aren't relevant to private >> + * mappings as they don't have a userspace mapping. >> + */ >> + gfn_range.only_private = false; >> + gfn_range.only_shared = true; >> gfn_range.may_block = range->may_block; >> /* >> * HVA-based notifications aren't relevant to private > > Thanks, > Gavin >
