On Fri, 2022-03-04 at 11:49 -0800, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata <isaku.yamahata@intel.com> > > At this point, TDX supports TDP MMU and doesn't support legacy MMU. > Forcibly use TDP MMU for TDX irrelevant of kernel parameter to disable > TDP MMU. > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/kvm/mmu/tdp_mmu.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index b33ace3d4456..9df6aa4da202 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -16,7 +16,12 @@ module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0644); > /* Initializes the TDP MMU for the VM, if enabled. */ > bool kvm_mmu_init_tdp_mmu(struct kvm *kvm) > { > - if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled)) > + /* > + * Because TDX supports only TDP MMU, forcibly use TDP MMU in the case > + * of TDX. > + */ > + if (kvm->arch.vm_type != KVM_X86_TDX_VM && > + (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled))) > return false; > > /* This should not be changed for the lifetime of the VM. */ Please move this patch forward before introducing any private/shared mapping support, otherwise nothing prevents you from creating a TD against legacy MMU, which is broken (especially you have allowed userspace to create TD in patch 10 "KVM: TDX: Make TDX VM type supported").
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index b33ace3d4456..9df6aa4da202 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -16,7 +16,12 @@ module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0644); /* Initializes the TDP MMU for the VM, if enabled. */ bool kvm_mmu_init_tdp_mmu(struct kvm *kvm) { - if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled)) + /* + * Because TDX supports only TDP MMU, forcibly use TDP MMU in the case + * of TDX. + */ + if (kvm->arch.vm_type != KVM_X86_TDX_VM && + (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled))) return false; /* This should not be changed for the lifetime of the VM. */