The start info structure that is defined as part of the x86/HVM direct boot
ABI and used for starting Xen PVH guests would be more versatile if it also
included a way to pass information about the memory map to the guest. This
would allow KVM guests to share the same entry point.
Signed-off-by: Maran Wilson <maran.wilson@xxxxxxxxxx>
---
include/xen/interface/hvm/start_info.h | 50 +++++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/include/xen/interface/hvm/start_info.h b/include/xen/interface/hvm/start_info.h
index 648415976ead..80cfbd35c1af 100644
--- a/include/xen/interface/hvm/start_info.h
+++ b/include/xen/interface/hvm/start_info.h
@@ -33,7 +33,7 @@
* | magic | Contains the magic value XEN_HVM_START_MAGIC_VALUE
* | | ("xEn3" with the 0x80 bit of the "E" set).
* 4 +----------------+
- * | version | Version of this structure. Current version is 0. New
+ * | version | Version of this structure. Current version is 1. New
* | | versions are guaranteed to be backwards-compatible.
* 8 +----------------+
* | flags | SIF_xxx flags.
@@ -48,6 +48,15 @@
* 32 +----------------+
* | rsdp_paddr | Physical address of the RSDP ACPI data structure.
* 40 +----------------+
+ * | memmap_paddr | Physical address of the (optional) memory map. Only
+ * | | present in version 1 and newer of the structure.
+ * 48 +----------------+
+ * | memmap_entries | Number of entries in the memory map table. Only
+ * | | present in version 1 and newer of the structure.
+ * | | Zero if there is no memory map being provided.
+ * 52 +----------------+
+ * | reserved | Version 1 and newer only.
+ * 56 +----------------+
*
* The layout of each entry in the module structure is the following:
*
@@ -62,10 +71,34 @@
* | reserved |
* 32 +----------------+
*
+ * The layout of each entry in the memory map table is as follows:
+ *
+ * 0 +----------------+
+ * | addr | Base address
+ * 8 +----------------+
+ * | size | Size of mapping in bytes
+ * 16 +----------------+
+ * | type | Type of mapping as defined between the hypervisor
+ * | | and guest it's starting. E820_TYPE_xxx, for example.
+ * 20 +----------------|
+ * | reserved |
+ * 24 +----------------+
+ *
* The address and sizes are always a 64bit little endian unsigned integer.
*
* NB: Xen on x86 will always try to place all the data below the 4GiB
* boundary.
+ *
+ * Version numbers of the hvm_start_info structure have evolved like this:
+ *
+ * Version 0:
+ *
+ * Version 1: Added the memmap_paddr/memmap_entries fields (plus 4 bytes of
+ * padding) to the end of the hvm_start_info struct. These new
+ * fields can be used to pass a memory map to the guest. The
+ * memory map is optional and so guests that understand version 1
+ * of the structure must check that memmap_entries is non-zero
+ * before trying to read the memory map.
*/
#define XEN_HVM_START_MAGIC_VALUE 0x336ec578
@@ -86,6 +119,14 @@ struct hvm_start_info {
uint64_t cmdline_paddr; /* Physical address of the command line. */
uint64_t rsdp_paddr; /* Physical address of the RSDP ACPI data */
/* structure. */
+ uint64_t memmap_paddr; /* Physical address of an array of */
+ /* hvm_memmap_table_entry. Only present in */
+ /* version 1 and newer of the structure */
+ uint32_t memmap_entries; /* Number of entries in the memmap table. */
+ /* Only present in version 1 and newer of */
+ /* the structure. Value will be zero if */
+ /* there is no memory map being provided. */
+ uint32_t reserved;
};
struct hvm_modlist_entry {
@@ -95,4 +136,11 @@ struct hvm_modlist_entry {
uint64_t reserved;
};
+struct hvm_memmap_table_entry {
+ uint64_t addr; /* Base address of the memory region */
+ uint64_t size; /* Size of the memory region in bytes */
+ uint32_t type; /* Mapping type */
+ uint32_t reserved;
+};
+
#endif /* __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__ */
--
2.16.1
