[PATCH V2 20/23] xen/ioreq: Make x86's send_invalidate_req() common

[Oleksandr Tyshchenko <olekstysh@gmail.com>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

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 send_invalidate_ioreq).
This patch also moves per-domain qemu_mapcache_invalidate
variable out of the arch sub-struct.

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>

---
Please note, this is a split/cleanup/hardening of Julien's PoC:
"Add support for Guest IO forwarding to a device emulator"

***
Please note, this patch depends on the following which is
on review:
https://patchwork.kernel.org/patch/11803383/
***

Changes RFC -> V1:
   - move send_invalidate_req() to the common code
   - update patch subject/description
   - move qemu_mapcache_invalidate out of the arch sub-struct,
     update checks
   - remove #if defined(CONFIG_ARM64) from the common code

Changes V1 -> V2:
   - was split into:
     - xen/ioreq: Make x86's send_invalidate_req() common
     - xen/arm: Add mapcache invalidation handling
   - update patch description/subject
   - move Arm bits to a separate patch
   - don't alter the common code, the flag is set by arch code
   - rename send_invalidate_req() to send_invalidate_ioreq()
   - guard qemu_mapcache_invalidate with CONFIG_IOREQ_SERVER
   - use bool instead of bool_t
   - remove blank line blank line between head comment and #include-s
---
 xen/arch/x86/hvm/hypercall.c     |  9 +++++----
 xen/arch/x86/hvm/io.c            | 14 --------------
 xen/common/ioreq.c               | 14 ++++++++++++++
 xen/include/asm-x86/hvm/domain.h |  1 -
 xen/include/asm-x86/hvm/io.h     |  1 -
 xen/include/xen/ioreq.h          |  1 +
 xen/include/xen/sched.h          |  2 ++
 7 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
index b6ccaf4..324ff97 100644
--- a/xen/arch/x86/hvm/hypercall.c
+++ b/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->qemu_mapcache_invalidate = true;
 
     return rc;
 }
@@ -329,9 +330,9 @@ int hvm_hypercall(struct cpu_user_regs *regs)
     if ( curr->hcall_preempted )
         return HVM_HCALL_preempted;
 
-    if ( unlikely(currd->arch.hvm.qemu_mapcache_invalidate) &&
-         test_and_clear_bool(currd->arch.hvm.qemu_mapcache_invalidate) )
-        send_invalidate_req();
+    if ( unlikely(currd->qemu_mapcache_invalidate) &&
+         test_and_clear_bool(currd->qemu_mapcache_invalidate) )
+        send_invalidate_ioreq();
 
     return HVM_HCALL_completed;
 }
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 2d03ffe..e51304c 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/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 ( broadcast_ioreq(&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;
diff --git a/xen/common/ioreq.c b/xen/common/ioreq.c
index a72bc0e..2203cf0 100644
--- a/xen/common/ioreq.c
+++ b/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 send_invalidate_ioreq(void)
+{
+    ioreq_t p = {
+        .type = IOREQ_TYPE_INVALIDATE,
+        .size = 4,
+        .dir = IOREQ_WRITE,
+        .data = ~0UL, /* flush all */
+    };
+
+    if ( broadcast_ioreq(&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)
 {
diff --git a/xen/include/asm-x86/hvm/domain.h b/xen/include/asm-x86/hvm/domain.h
index c3af339..caab3a9 100644
--- a/xen/include/asm-x86/hvm/domain.h
+++ b/xen/include/asm-x86/hvm/domain.h
@@ -117,7 +117,6 @@ struct hvm_domain {
 
     struct viridian_domain *viridian;
 
-    bool_t                 qemu_mapcache_invalidate;
     bool_t                 is_s3_suspended;
 
     /*
diff --git a/xen/include/asm-x86/hvm/io.h b/xen/include/asm-x86/hvm/io.h
index fb64294..3da0136 100644
--- a/xen/include/asm-x86/hvm/io.h
+++ b/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);
diff --git a/xen/include/xen/ioreq.h b/xen/include/xen/ioreq.h
index 0679fef..aad682f 100644
--- a/xen/include/xen/ioreq.h
+++ b/xen/include/xen/ioreq.h
@@ -126,6 +126,7 @@ struct ioreq_server *select_ioreq_server(struct domain *d,
 int send_ioreq(struct ioreq_server *s, ioreq_t *proto_p,
                bool buffered);
 unsigned int broadcast_ioreq(ioreq_t *p, bool buffered);
+void send_invalidate_ioreq(void);
 
 void ioreq_init(struct domain *d);
 
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 290cddb..1b8c6eb 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -555,6 +555,8 @@ struct domain
         struct ioreq_server     *server[MAX_NR_IOREQ_SERVERS];
         unsigned int            nr_servers;
     } ioreq_server;
+
+    bool qemu_mapcache_invalidate;
 #endif
 };
 
-- 
2.7.4