[PATCH v7 086/102] KVM: TDX: handle EXCEPTION_NMI and EXTERNAL_INTERRUPT

isaku.yamahata
2022-06-27T22:01:22Z

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

Because guest TD state is protected, exceptions in guest TDs can't be
intercepted. TDX VMM doesn't need to handle exceptions.
tdx_handle_exit_irqoff() handles NMI and machine check. Ignore NMI and
machine check and continue guest TD execution.

For external interrupt, increment stats same to the VMX case.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx/tdx.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 14f65d7b3824..6e8a7e4b4da2 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -852,6 +852,25 @@ void tdx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
tdexit_intr_info(vcpu));
}

+static int tdx_handle_exception(struct kvm_vcpu *vcpu)
+{
+ u32 intr_info = tdexit_intr_info(vcpu);
+
+ if (is_nmi(intr_info) || is_machine_check(intr_info))
+ return 1;
+
+ kvm_pr_unimpl("unexpected exception 0x%x(exit_reason 0x%llx qual 0x%lx)\n",
+ intr_info,
+ to_tdx(vcpu)->exit_reason.full, tdexit_exit_qual(vcpu));
+ return -EFAULT;
+}
+
+static int tdx_handle_external_interrupt(struct kvm_vcpu *vcpu)
+{
+ ++vcpu->stat.irq_exits;
+ return 1;
+}
+
static int tdx_handle_triple_fault(struct kvm_vcpu *vcpu)
{
vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
@@ -1251,6 +1270,10 @@ int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
WARN_ON_ONCE(fastpath != EXIT_FASTPATH_NONE);

switch (exit_reason.basic) {
+ case EXIT_REASON_EXCEPTION_NMI:
+ return tdx_handle_exception(vcpu);
+ case EXIT_REASON_EXTERNAL_INTERRUPT:
+ return tdx_handle_external_interrupt(vcpu);
case EXIT_REASON_EPT_VIOLATION:
return tdx_handle_ept_violation(vcpu);
case EXIT_REASON_EPT_MISCONFIG:
--
2.25.1