[PATCH] x86/viridian: use hv_timer_message_payload struct

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

Instead of open-coding the struct type in
viridian_synic_deliver_timer_msg().  Additionally expand the union field
in hv_message struct to contain the timer payload, this way the memcpy in
viridian_synic_deliver_timer_msg() can be replaced with a struct assign.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/hvm/viridian/synic.c            | 17 ++++++----------
 xen/arch/x86/include/asm/guest/hyperv-tlfs.h | 21 ++++++++++----------
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/xen/arch/x86/hvm/viridian/synic.c 
b/xen/arch/x86/hvm/viridian/synic.c
index e6cba7548f1b..6d7b6bd0eda2 100644
--- a/xen/arch/x86/hvm/viridian/synic.c
+++ b/xen/arch/x86/hvm/viridian/synic.c
@@ -327,15 +327,10 @@ bool viridian_synic_deliver_timer_msg(struct vcpu *v, 
unsigned int sintx,
     struct viridian_vcpu *vv = v->arch.hvm.viridian;
     const union hv_synic_sint *vs = &vv->sint[sintx];
     struct hv_message *msg = vv->simp.ptr;
-    struct {
-        uint32_t TimerIndex;
-        uint32_t Reserved;
-        uint64_t ExpirationTime;
-        uint64_t DeliveryTime;
-    } payload = {
-        .TimerIndex = index,
-        .ExpirationTime = expiration,
-        .DeliveryTime = delivery,
+    const struct hv_timer_message_payload payload = {
+        .timer_index = index,
+        .expiration_time = expiration,
+        .delivery_time = delivery,
     };
 
     /* Don't assume SIM page to be mapped. */
@@ -359,8 +354,8 @@ bool viridian_synic_deliver_timer_msg(struct vcpu *v, 
unsigned int sintx,
     msg->header.message_flags.msg_pending = 0;
     msg->header.payload_size = sizeof(payload);
 
-    BUILD_BUG_ON(sizeof(payload) > sizeof(msg->u.payload));
-    memcpy(msg->u.payload, &payload, sizeof(payload));
+    BUILD_BUG_ON(sizeof(msg->payload.timer) > sizeof(msg->payload.raw));
+    msg->payload.timer = payload;
 
     if ( !vs->masked && vlapic_enabled(vcpu_vlapic(v)) )
         vlapic_set_irq(vcpu_vlapic(v), vs->vector, 0);
diff --git a/xen/arch/x86/include/asm/guest/hyperv-tlfs.h 
b/xen/arch/x86/include/asm/guest/hyperv-tlfs.h
index 79cfc90dd8ec..18da73c74e03 100644
--- a/xen/arch/x86/include/asm/guest/hyperv-tlfs.h
+++ b/xen/arch/x86/include/asm/guest/hyperv-tlfs.h
@@ -527,12 +527,21 @@ struct hv_message_header {
        };
 };
 
+/* Define timer message payload structure. */
+struct hv_timer_message_payload {
+       uint32_t timer_index;
+       uint32_t reserved;
+       uint64_t expiration_time; /* When the timer expired */
+       uint64_t delivery_time;   /* When the message was delivered */
+};
+
 /* Define synthetic interrupt controller message format. */
 struct hv_message {
        struct hv_message_header header;
        union {
-               uint64_t payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
-       } u;
+               struct hv_timer_message_payload timer;
+               uint64_t raw[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
+       } payload;
 };
 
 /* Define the synthetic interrupt message page layout. */
@@ -540,14 +549,6 @@ struct hv_message_page {
        struct hv_message sint_message[HV_SYNIC_SINT_COUNT];
 };
 
-/* Define timer message payload structure. */
-struct hv_timer_message_payload {
-       uint32_t timer_index;
-       uint32_t reserved;
-       uint64_t expiration_time; /* When the timer expired */
-       uint64_t delivery_time;   /* When the message was delivered */
-};
-
 struct hv_nested_enlightenments_control {
        struct {
                uint32_t directhypercall:1;
-- 
2.51.0