From 1d7a2ccf82fe3e51e369fdabed38b3a01ac7a725 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Thu, 24 Oct 2019 19:46:09 +1100
Subject: [PATCH] [c-host] windows: update ivshmem driver header and usage

---
 VERSION                                |  2 +-
 c-host/platform/Windows/src/platform.c |  7 ++++++-
 vendor/ivshmem/ivshmem.h               | 13 +++++++++++++
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/VERSION b/VERSION
index 05aa7aac..0ad3e648 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-B1-12-g9377fdfc37+1
\ No newline at end of file
+B1-13-ge1bfb1234b+1
\ No newline at end of file
diff --git a/c-host/platform/Windows/src/platform.c b/c-host/platform/Windows/src/platform.c
index 51768527..0a0e20fc 100644
--- a/c-host/platform/Windows/src/platform.c
+++ b/c-host/platform/Windows/src/platform.c
@@ -368,11 +368,16 @@ bool os_shmemMmap(void **ptr)
     return true;
   }
 
+  IVSHMEM_MMAP_CONFIG config =
+  {
+    .cacheMode = IVSHMEM_CACHE_WRITECOMBINED
+  };
+
   memset(&app.shmemMap, 0, sizeof(IVSHMEM_MMAP));
   if (!DeviceIoControl(
     app.shmemHandle,
     IOCTL_IVSHMEM_REQUEST_MMAP,
-    NULL, 0,
+    &config, sizeof(IVSHMEM_MMAP_CONFIG),
     &app.shmemMap, sizeof(IVSHMEM_MMAP),
     NULL, NULL))
   {
diff --git a/vendor/ivshmem/ivshmem.h b/vendor/ivshmem/ivshmem.h
index 20105ff5..3f98491e 100644
--- a/vendor/ivshmem/ivshmem.h
+++ b/vendor/ivshmem/ivshmem.h
@@ -7,6 +7,19 @@ DEFINE_GUID (GUID_DEVINTERFACE_IVSHMEM,
 typedef UINT16 IVSHMEM_PEERID;
 typedef UINT64 IVSHMEM_SIZE;
 
+#define IVSHMEM_CACHE_NONCACHED     0
+#define IVSHMEM_CACHE_CACHED        1
+#define IVSHMEM_CACHE_WRITECOMBINED 2
+
+/*
+    This structure is for use with the IOCTL_IVSHMEM_REQUEST_MMAP IOCTL
+*/
+typedef struct IVSHMEM_MMAP_CONFIG
+{
+    UINT8 cacheMode; // the caching mode of the mapping, see IVSHMEM_CACHE_* for options
+}
+IVSHMEM_MMAP_CONFIG, *PIVSHMEM_MMAP_CONFIG;
+
 /*
     This structure is for use with the IOCTL_IVSHMEM_REQUEST_MMAP IOCTL
 */