hvm, vt-d: Add memory cache-attribute pinning domctl for HVM

guests. Use this to pin virtual framebuffer VRAM as attribute WB, even
if guest tries to map with other attributes.
Signed-off-by: Disheng Su <disheng.su@intel.com>

3 files changed, 27 insertions, 0 deletions

diff --git a/tools/ioemu/hw/cirrus_vga.c b/tools/ioemu/hw/cirrus_vga.c
index 68ec0b392b..2fd1626362 100644
--- a/tools/ioemu/hw/cirrus_vga.c
+++ b/tools/ioemu/hw/cirrus_vga.c
@@ -2565,6 +2565,12 @@ static void *set_vram_mapping(unsigned long begin, unsigned long end)
         return NULL;
     }
 
+    (void)xc_domain_pin_memory_cacheattr(
+        xc_handle, domid,
+        begin >> TARGET_PAGE_BITS,
+        end >> TARGET_PAGE_BITS,
+        XEN_DOMCTL_MEM_CACHEATTR_WB);
+
     vram_pointer = xc_map_foreign_pages(xc_handle, domid,
                                         PROT_READ|PROT_WRITE,
                                         extent_start, nr_extents);
diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
index 3c3bb351f6..a67ec53947 100644
--- a/tools/libxc/xc_domain.c
+++ b/tools/libxc/xc_domain.c
@@ -376,6 +376,21 @@ int xc_domain_setmaxmem(int xc_handle,
     return do_domctl(xc_handle, &domctl);
 }
 
+int xc_domain_pin_memory_cacheattr(int xc_handle,
+                                   uint32_t domid,
+                                   unsigned long start,
+                                   unsigned long end,
+                                   unsigned int type)
+{
+    DECLARE_DOMCTL;
+    domctl.cmd = XEN_DOMCTL_pin_mem_cacheattr;
+    domctl.domain = (domid_t)domid;
+    domctl.u.pin_mem_cacheattr.start = start;
+    domctl.u.pin_mem_cacheattr.end = end;
+    domctl.u.pin_mem_cacheattr.type = type;
+    return do_domctl(xc_handle, &domctl);
+}
+
 #if defined(__i386__) || defined(__x86_64__)
 #include "xc_e820.h"
 int xc_domain_set_memmap_limit(int xc_handle,
diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index bf08942787..5c7f5a649c 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -614,6 +614,12 @@ int xc_domain_iomem_permission(int xc_handle,
                                unsigned long nr_mfns,
                                uint8_t allow_access);
 
+int xc_domain_pin_memory_cacheattr(int xc_handle,
+                                   uint32_t domid,
+                                   unsigned long start,
+                                   unsigned long end,
+                                   unsigned int type);
+
 unsigned long xc_make_page_below_4G(int xc_handle, uint32_t domid,
                                     unsigned long mfn);