On Wed, Jun 28, 2023 at 02:41:56PM +0800, Yuan Yao <yuan.yao@xxxxxxxxxxxxxxx> wrote: > On Thu, Jun 22, 2023 at 04:16:29PM -0700, isaku.yamahata@xxxxxxxxx wrote: > > From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> > > > > Add flags to strut kvm_gfn_range to indicate who triggered the callback > > and new memory attributes. > > > > TDX needs to know the reason for a callback by kvm_unmap_gfn_range(). mmu > > notifier, set memory attributes ioctl or KVM gmem callback. With TDX, > > zapping a private page from the encrypted page table and adding the page > > back to the same private GPA results in zeroing the page, and the guest has > > to accept the page again. On the change of memory attribute from private > > Is this part used to explains why on MMU notifier only shared pages should > be zapped ? Right for TDX. > > to shared, zapping the GPA range irrespective to private-or-shared and > > expecting the fault doesn't work for TDX. Instead, zap shared pages only > > and keep the private pages. Concretely > > Do you mean: > > On the change of memory attribute, zapping the GPA range irrespective to > private-or-shared and expecting that the EPT mapping for attribute converts > to doesn't exist at the time of changing the attribute, zap the "from" > attribute range only and ignore the "to" attribute. That's what I meant. The requirement seems specific to TDX. I'll update this patch following the suggestion by Sean. [1] [1] https://lore.kernel.org/all/ZJX0hk+KpQP0KUyB@xxxxxxxxxx/ -- Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
