xen/ioreq: Make x86's send_invalidate_req() common

As the IOREQ is a common feature now and we also need to
invalidate qemu/demu mapcache on Arm when the required condition
occurs this patch moves this function to the common code
(and remames it to ioreq_signal_mapcache_invalidate).
This patch also moves per-domain qemu_mapcache_invalidate
variable out of the arch sub-struct (and drops "qemu" prefix).

We don't put this variable inside the #ifdef CONFIG_IOREQ_SERVER
at the end of struct domain, but in the hole next to the group
of 5 bools further up which is more efficient.

The subsequent patch will add mapcache invalidation handling on Arm.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
CC: Julien Grall <julien.grall@arm.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
[On Arm only]
Tested-by: Wei Chen <Wei.Chen@arm.com>

xen/arch/x86/hvm/hypercall.c

@@ -20,6 +20,7 @@
  */
 #include <xen/lib.h>
 #include <xen/hypercall.h>
+#include <xen/ioreq.h>
 #include <xen/nospec.h>
 
 #include <asm/hvm/emulate.h>
@@ -47,7 +48,7 @@ static long hvm_memory_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         rc = compat_memory_op(cmd, arg);
 
     if ( (cmd & MEMOP_CMD_MASK) == XENMEM_decrease_reservation )
-        curr->domain->arch.hvm.qemu_mapcache_invalidate = true;
+        curr->domain->mapcache_invalidate = true;
 
     return rc;
 }
@@ -326,9 +327,9 @@ int hvm_hypercall(struct cpu_user_regs *regs)
 
     HVM_DBG_LOG(DBG_LEVEL_HCALL, "hcall%lu -> %lx", eax, regs->rax);
 
-    if ( unlikely(currd->arch.hvm.qemu_mapcache_invalidate) &&
-         test_and_clear_bool(currd->arch.hvm.qemu_mapcache_invalidate) )
-        send_invalidate_req();
+    if ( unlikely(currd->mapcache_invalidate) &&
+         test_and_clear_bool(currd->mapcache_invalidate) )
+        ioreq_signal_mapcache_invalidate();
 
     return curr->hcall_preempted ? HVM_HCALL_preempted : HVM_HCALL_completed;
 }

xen/arch/x86/hvm/io.c

@@ -64,20 +64,6 @@ void send_timeoffset_req(unsigned long timeoff)
         gprintk(XENLOG_ERR, "Unsuccessful timeoffset update\n");
 }
 
-/* Ask ioemu mapcache to invalidate mappings. */
-void send_invalidate_req(void)
-{
-    ioreq_t p = {
-        .type = IOREQ_TYPE_INVALIDATE,
-        .size = 4,
-        .dir = IOREQ_WRITE,
-        .data = ~0UL, /* flush all */
-    };
-
-    if ( ioreq_broadcast(&p, false) != 0 )
-        gprintk(XENLOG_ERR, "Unsuccessful map-cache invalidate\n");
-}
-
 bool hvm_emulate_one_insn(hvm_emulate_validate_t *validate, const char *descr)
 {
     struct hvm_emulate_ctxt ctxt;

xen/common/ioreq.c

@@ -35,6 +35,20 @@
 #include <public/hvm/ioreq.h>
 #include <public/hvm/params.h>
 
+/* Ask ioemu mapcache to invalidate mappings. */
+void ioreq_signal_mapcache_invalidate(void)
+{
+    ioreq_t p = {
+        .type = IOREQ_TYPE_INVALIDATE,
+        .size = 4,
+        .dir = IOREQ_WRITE,
+        .data = ~0UL, /* flush all */
+    };
+
+    if ( ioreq_broadcast(&p, false) != 0 )
+        gprintk(XENLOG_ERR, "Unsuccessful map-cache invalidate\n");
+}
+
 static void set_ioreq_server(struct domain *d, unsigned int id,
                              struct ioreq_server *s)
 {

xen/include/asm-x86/hvm/domain.h

@@ -120,7 +120,6 @@ struct hvm_domain {
 
     struct viridian_domain *viridian;
 
-    bool_t                 qemu_mapcache_invalidate;
     bool_t                 is_s3_suspended;
 
     /*

xen/include/asm-x86/hvm/io.h

@@ -97,7 +97,6 @@ bool relocate_portio_handler(
     unsigned int size);
 
 void send_timeoffset_req(unsigned long timeoff);
-void send_invalidate_req(void);
 bool handle_mmio_with_translation(unsigned long gla, unsigned long gpfn,
                                   struct npfec);
 bool handle_pio(uint16_t port, unsigned int size, int dir);

xen/include/xen/ioreq.h

@@ -103,6 +103,7 @@ struct ioreq_server *ioreq_server_select(struct domain *d,
 int ioreq_send(struct ioreq_server *s, ioreq_t *proto_p,
                bool buffered);
 unsigned int ioreq_broadcast(ioreq_t *p, bool buffered);
+void ioreq_signal_mapcache_invalidate(void);
 
 void ioreq_domain_init(struct domain *d);
 

xen/include/xen/sched.h

@@ -444,6 +444,11 @@ struct domain
      * unpaused for the first time by the systemcontroller.
      */
     bool             creation_finished;
+    /*
+     * Indicates that mapcache invalidation request should be sent to
+     * the device emulator.
+     */
+    bool             mapcache_invalidate;
 
     /* Which guest this guest has privileges on */
     struct domain   *target;