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>
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 5d32afe..461bd85 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -37,6 +37,7 @@
/* TDX hypercall Leaf IDs */
#define TDVMCALL_MAP_GPA 0x10001
#define TDVMCALL_REPORT_FATAL_ERROR 0x10003
+#define TDVMCALL_SETUP_NOTIFY_INTR 0x10004
/* MMIO direction */
#define EPT_READ 0
@@ -80,6 +81,16 @@ static int tdx_event_irq __ro_after_init;
static LIST_HEAD(event_irq_cb_list);
static DEFINE_SPINLOCK(event_irq_cb_lock);
+struct event_irq_entry {
+ tdx_event_irq_cb_t handler;
+ void *data;
+ struct list_head head;
+};
+
+static int tdx_event_irq __ro_after_init;
+static LIST_HEAD(event_irq_cb_list);
+static DEFINE_SPINLOCK(event_irq_cb_lock);
+
/*
* Wrapper for standard use of __tdx_hypercall with no output aside from
* return code.
diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index acb7681..93c47c1 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -80,8 +80,6 @@ int tdx_register_event_irq_cb(tdx_event_irq_cb_t handler, void *data);
int tdx_unregister_event_irq_cb(tdx_event_irq_cb_t handler, void *data);
-int tdx_hcall_get_quote(u8 *buf, size_t size);
-
#else
static inline void tdx_early_init(void) { };
