tree 0dd6f60a073e1a5b806e545795065104deda6f73
parent 669f2cf7e02b78fc11caae036cc3994cfa51d0c3
author Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> 1605936279 +0000
committer Jianxiong Gao <jxgao@google.com> 1684364711 +0000

x86/tdx: Add TDX Guest event notify interrupt support

Host-guest event notification via configured interrupt vector is useful
in cases where a guest makes an asynchronous request and needs a
callback from the host to indicate the completion or to let the host
notify the guest about events like device removal. One usage example is,
callback requirement of GetQuote asynchronous hypercall.

In TDX guest, SetupEventNotifyInterrupt hypercall can be used by the
guest to specify which interrupt vector to use as an event-notify
vector from the VMM. Details about the SetupEventNotifyInterrupt
hypercall can be found in TDX Guest-Host Communication Interface
(GHCI) Specification, section "VP.VMCALL<SetupEventNotifyInterrupt>".

As per design, VMM will post the event completion IRQ using the same
CPU on which SetupEventNotifyInterrupt hypercall request is received.
So allocate an IRQ vector from "x86_vector_domain", and set the CPU
affinity of the IRQ vector to the CPU on which
SetupEventNotifyInterrupt hypercall is made.

Add tdx_register_event_irq_cb()/tdx_unregister_event_irq_cb()
interfaces to allow drivers to register/unregister event notification
handlers.

Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Erdem Aktas <erdemaktas@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>