| Message ID | 9f64fe39a205b769bf08f2996efb0b5afc6c1900.1705965635.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM TDX basic feature support | expand |
On 1/23/2024 7:53 AM, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata <isaku.yamahata@intel.com> > > The private GPAs that typically guest memfd backs aren't subject to MMU > notifier because it isn't mapped into virtual address of user process. > kvm_tdp_mmu_handle_gfn() handles the callback of the MMU notifier, > clear_flush_young(), clear_young(), test_gfn() and change_pte(). Make Nit: test_gfn() -> test_young(), and a same typo in the comment below. Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> > kvm_tdp_mmu_handle_gfn() aware of private mapping and skip private mapping. > > Even with AS_UNMOVABLE set, those mmu notifier are called. For example, > ksmd triggers change_pte(). > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > v18: > - newly added > --- > arch/x86/kvm/mmu/tdp_mmu.c | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index e7514a807134..fdc6e2221c33 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -1157,9 +1157,29 @@ static __always_inline bool kvm_tdp_mmu_handle_gfn(struct kvm *kvm, > * into this helper allow blocking; it'd be dead, wasteful code. > */ > for_each_tdp_mmu_root(kvm, root, range->slot->as_id) { > + gfn_t start, end; > + > + /* > + * This function is called on behalf of mmu_notifier of > + * clear_flush_young(), clear_young(), test_gfn(), and test_gfn() should be test_young() > + * change_pte(). They apply to only shared GPAs. > + */ > + WARN_ON_ONCE(range->only_private); > + WARN_ON_ONCE(!range->only_shared); > + if (is_private_sp(root)) > + continue; > + > + /* > + * For TDX shared mapping, set GFN shared bit to the range, > + * so the handler() doesn't need to set it, to avoid duplicated > + * code in multiple handler()s. > + */ > + start = kvm_gfn_to_shared(kvm, range->start); > + end = kvm_gfn_to_shared(kvm, range->end); > + > rcu_read_lock(); > > - tdp_root_for_each_leaf_pte(iter, root, range->start, range->end) > + tdp_root_for_each_leaf_pte(iter, root, start, end) > ret |= handler(kvm, &iter, range); > > rcu_read_unlock();
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index e7514a807134..fdc6e2221c33 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1157,9 +1157,29 @@ static __always_inline bool kvm_tdp_mmu_handle_gfn(struct kvm *kvm, * into this helper allow blocking; it'd be dead, wasteful code. */ for_each_tdp_mmu_root(kvm, root, range->slot->as_id) { + gfn_t start, end; + + /* + * This function is called on behalf of mmu_notifier of + * clear_flush_young(), clear_young(), test_gfn(), and + * change_pte(). They apply to only shared GPAs. + */ + WARN_ON_ONCE(range->only_private); + WARN_ON_ONCE(!range->only_shared); + if (is_private_sp(root)) + continue; + + /* + * For TDX shared mapping, set GFN shared bit to the range, + * so the handler() doesn't need to set it, to avoid duplicated + * code in multiple handler()s. + */ + start = kvm_gfn_to_shared(kvm, range->start); + end = kvm_gfn_to_shared(kvm, range->end); + rcu_read_lock(); - tdp_root_for_each_leaf_pte(iter, root, range->start, range->end) + tdp_root_for_each_leaf_pte(iter, root, start, end) ret |= handler(kvm, &iter, range); rcu_read_unlock();