KVM: TDX: Implement non-NMI interrupt injection

Implement non-NMI interrupt injection for TDX via posted interrupt.

As CPU state is protected and APICv is enabled for the TDX guest, TDX
supports non-NMI interrupt injection only by posted interrupt. Posted
interrupt descriptors (PIDs) are allocated in shared memory, KVM can
update them directly.  If target vCPU is in non-root mode, send posted
interrupt notification to the vCPU and hardware will sync PIR to vIRR
atomically.  Otherwise, kick it to pick up the interrupt from PID. To
post pending interrupts in the PID, KVM can generate a self-IPI with
notification vector prior to TD entry.

Since the guest status of TD vCPU is protected, assume interrupt is
always allowed.  Ignore the code path for event injection mechanism or
LAPIC emulation for TDX.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Binbin Wu <binbin.wu@linux.intel.com>
Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20250222014757.897978-5-binbin.wu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

0 files changed, 0 insertions, 0 deletions