[v3,1/6] ACPI: Add a function for building named qword entries

Commit Message

[e-mail] Jan. 23, 2017, 7:32 a.m. UTC

From: Ben Warren <[e-mail]>

This is initially used to patch a 64-bit address into the VM Generation ID SSDT

Signed-off-by: Ben Warren <[e-mail]>
---
 hw/acpi/aml-build.c         | 28 ++++++++++++++++++++++++++++
 include/hw/acpi/aml-build.h |  4 ++++
 2 files changed, 32 insertions(+)

Patch

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index b2a1e40..dc4edc2 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -285,6 +285,34 @@  build_append_named_dword(GArray *array, const char *name_format, ...)
     return offset;
 }
 
+/*
+ * Build NAME(XXXX, 0x00000000) where 0x00000000 is encoded as a qword,
+ * and return the offset to 0x00000000 for runtime patching.
+ *
+ * Warning: runtime patching is best avoided. Only use this as
+ * a replacement for DataTableRegion (for guests that don't
+ * support it).
+ */
+int
+build_append_named_qword(GArray *array, const char *name_format, ...)
+{
+    int offset;
+    va_list ap;
+
+    build_append_byte(array, 0x08); /* NameOp */
+    va_start(ap, name_format);
+    build_append_namestringv(array, name_format, ap);
+    va_end(ap);
+
+    build_append_byte(array, 0x0E); /* QWordPrefix */
+
+    offset = array->len;
+    build_append_int_noprefix(array, 0x00000000, 8);
+    assert(array->len == offset + 8);
+
+    return offset;
+}
+
 static GPtrArray *alloc_list;
 
 static Aml *aml_alloc(void)
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 559326c..dbf63cf 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -385,6 +385,10 @@  int
 build_append_named_dword(GArray *array, const char *name_format, ...)
 GCC_FMT_ATTR(2, 3);
 
+int
+build_append_named_qword(GArray *array, const char *name_format, ...)
+GCC_FMT_ATTR(2, 3);
+
 void build_srat_memory(AcpiSratMemoryAffinity *numamem, uint64_t base,
                        uint64_t len, int node, MemoryAffinityFlags flags);