[PATCH v10 043/108] KVM: x86/mmu: Require TDP MMU for TDX

isaku.yamahata
2022-10-30T06:27:12Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

Require the TDP MMU for guest TDs, the so called "shadow" MMU does not
support mapping guest private memory, i.e. does not support Secure-EPT.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/mmu/tdp_mmu.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index c6be76f9849c..1bf58288ea79 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -18,8 +18,12 @@ int kvm_mmu_init_tdp_mmu(struct kvm *kvm)
{
struct workqueue_struct *wq;

+ /*
+ * Because only the TDP MMU supports TDX, require the TDP MMU for guest
+ * TDs.
+ */
if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled))
- return 0;
+ return kvm->arch.vm_type == KVM_X86_TDX_VM ? -EOPNOTSUPP : 0;

wq = alloc_workqueue("kvm", WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 0);
if (!wq)
--
2.25.1