[PATCH 3/8] hvmloader: add helper functions to get/set HVM params

[David Vrabel <david.vrabel@citrix.com>]

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
 tools/firmware/hvmloader/Makefile    |    1 +
 tools/firmware/hvmloader/hvm_param.c |   36 ++++++++++++++++++++++++++++++++++
 tools/firmware/hvmloader/hvmloader.c |   14 ++-----------
 tools/firmware/hvmloader/util.h      |    9 +++++++++
 tools/firmware/hvmloader/xenbus.c    |   14 +++++--------
 5 files changed, 53 insertions(+), 21 deletions(-)
 create mode 100644 tools/firmware/hvmloader/hvm_param.c

diff --git a/tools/firmware/hvmloader/Makefile b/tools/firmware/hvmloader/Makefile
index 00ee952..46a79c5 100644
--- a/tools/firmware/hvmloader/Makefile
+++ b/tools/firmware/hvmloader/Makefile
@@ -31,6 +31,7 @@ CFLAGS += $(CFLAGS_xeninclude)
 OBJS  = hvmloader.o mp_tables.o util.o smbios.o 
 OBJS += smp.o cacheattr.o xenbus.o
 OBJS += e820.o pci.o pir.o ctype.o
+OBJS += hvm_param.o
 ifeq ($(debug),y)
 OBJS += tests.o
 endif
diff --git a/tools/firmware/hvmloader/hvm_param.c b/tools/firmware/hvmloader/hvm_param.c
new file mode 100644
index 0000000..f7d8720
--- /dev/null
+++ b/tools/firmware/hvmloader/hvm_param.c
@@ -0,0 +1,36 @@
+/*
+ * hvm_param.c: get/set HVM params.
+ *
+ * Copyright (C) 2014 Citrix Systems R&D Ltd.
+ */
+#include "util.h"
+#include "config.h"
+#include "hypercall.h"
+
+#include <xen/hvm/params.h>
+
+int hvm_param_get(uint32_t index, uint64_t *value)
+{
+    struct xen_hvm_param p;
+    int ret;
+
+    p.domid = DOMID_SELF;
+    p.index = index;
+
+    ret = hypercall_hvm_op(HVMOP_get_param, &p);
+    if (ret == 0)
+        *value = p.value;
+
+    return ret;
+}
+
+int hvm_param_set(uint32_t index, uint64_t value)
+{
+    struct xen_hvm_param p;
+
+    p.domid = DOMID_SELF;
+    p.index = index;
+    p.value = value;
+
+    return hypercall_hvm_op(HVMOP_set_param, &p);
+}
diff --git a/tools/firmware/hvmloader/hvmloader.c b/tools/firmware/hvmloader/hvmloader.c
index 1cc8cf2..7b0da38 100644
--- a/tools/firmware/hvmloader/hvmloader.c
+++ b/tools/firmware/hvmloader/hvmloader.c
@@ -176,14 +176,10 @@ static void cmos_write_memory_size(void)
 static void init_vm86_tss(void)
 {
     void *tss;
-    struct xen_hvm_param p;
 
     tss = mem_alloc(128, 128);
     memset(tss, 0, 128);
-    p.domid = DOMID_SELF;
-    p.index = HVM_PARAM_VM86_TSS;
-    p.value = virt_to_phys(tss);
-    hypercall_hvm_op(HVMOP_set_param, &p);
+    hvm_param_set(HVM_PARAM_VM86_TSS, virt_to_phys(tss));
     printf("vm86 TSS at %08lx\n", virt_to_phys(tss));
 }
 
@@ -314,12 +310,6 @@ int main(void)
 
     if ( acpi_enabled )
     {
-        struct xen_hvm_param p = {
-            .domid = DOMID_SELF,
-            .index = HVM_PARAM_ACPI_IOPORTS_LOCATION,
-            .value = 1,
-        };
-
         if ( bios->acpi_build_tables )
         {
             printf("Loading ACPI ...\n");
@@ -328,7 +318,7 @@ int main(void)
 
         acpi_enable_sci();
 
-        hypercall_hvm_op(HVMOP_set_param, &p);
+        hvm_param_set(HVM_PARAM_ACPI_IOPORTS_LOCATION, 1);
     }
 
     init_vm86_tss();
diff --git a/tools/firmware/hvmloader/util.h b/tools/firmware/hvmloader/util.h
index 9ccb905..e4b6be4 100644
--- a/tools/firmware/hvmloader/util.h
+++ b/tools/firmware/hvmloader/util.h
@@ -210,6 +210,15 @@ const char *xenstore_read(const char *path, const char *default_resp);
  */
 int xenstore_write(const char *path, const char *value);
 
+
+/* Get a HVM param.
+ */
+int hvm_param_get(uint32_t index, uint64_t *value);
+
+/* Set a HVM param.
+ */
+int hvm_param_set(uint32_t index, uint64_t value);
+
 /* Setup PCI bus */
 void pci_setup(void);
 
diff --git a/tools/firmware/hvmloader/xenbus.c b/tools/firmware/hvmloader/xenbus.c
index fe72e97..64c2176 100644
--- a/tools/firmware/hvmloader/xenbus.c
+++ b/tools/firmware/hvmloader/xenbus.c
@@ -41,21 +41,17 @@ static char payload[XENSTORE_PAYLOAD_MAX + 1];  /* Unmarshalling area */
  * Call once, before any other xenbus actions. */
 void xenbus_setup(void)
 {
-    xen_hvm_param_t param;
+    uint64_t val;
 
     /* Ask Xen where the xenbus shared page is. */
-    param.domid = DOMID_SELF;
-    param.index = HVM_PARAM_STORE_PFN;
-    if ( hypercall_hvm_op(HVMOP_get_param, &param) )
+    if ( hvm_param_get(HVM_PARAM_STORE_PFN, &val) )
         BUG();
-    rings = (void *) (unsigned long) (param.value << PAGE_SHIFT);
+    rings = (void *) (unsigned long) (val << PAGE_SHIFT);
 
     /* Ask Xen where the xenbus event channel is. */
-    param.domid = DOMID_SELF;
-    param.index = HVM_PARAM_STORE_EVTCHN;
-    if ( hypercall_hvm_op(HVMOP_get_param, &param) )
+    if ( hvm_param_get(HVM_PARAM_STORE_EVTCHN, &val) )
         BUG();
-    event = param.value;
+    event = val;
 
     printf("Xenbus rings @0x%lx, event channel %lu\n",
            (unsigned long) rings, (unsigned long) event);
-- 
1.7.10.4