On 1/29/2025 5:58 PM, Adrian Hunter wrote:
+#define TDX_REGS_UNSUPPORTED_SET (BIT(VCPU_EXREG_RFLAGS) | \
+ BIT(VCPU_EXREG_SEGMENTS))
+
+fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit)
+{
+ /*
+ * force_immediate_exit requires vCPU entering for events injection with
+ * an immediately exit followed. But The TDX module doesn't guarantee
+ * entry, it's already possible for KVM to_think_ it completely entry
+ * to the guest without actually having done so.
+ * Since KVM never needs to force an immediate exit for TDX, and can't
+ * do direct injection, just warn on force_immediate_exit.
+ */
+ WARN_ON_ONCE(force_immediate_exit);
+
+ trace_kvm_entry(vcpu, force_immediate_exit);
+
+ tdx_vcpu_enter_exit(vcpu);
+
+ vcpu->arch.regs_avail &= ~TDX_REGS_UNSUPPORTED_SET;
I don't understand this. Why only clear RFLAGS and SEGMENTS?
When creating the vcpu, vcpu->arch.regs_avail = ~0 in
kvm_arch_vcpu_create().
now it only clears RFLAGS and SEGMENTS for TDX vcpu, which leaves other
bits set. But I don't see any code that syncs the guest value of into
vcpu->arch.regs[reg].
+ trace_kvm_exit(vcpu, KVM_ISA_VMX);
+
+ return EXIT_FASTPATH_NONE;
+}
