[Patch v6 04/13] tools/libxc: C implementation of stream format

[Andrew Cooper <andrew.cooper3@citrix.com>]

Provide the C structures matching the binary (wire) format of the new
stream format.  All header/record fields are naturally aligned and
explicit padding fields are used to ensure the correct layout (i.e.,
there is no need for any non-standard structure packing pragma or
attribute).

Provide some helper functions for converting types to string for
diagnostic purposes.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
 tools/libxc/saverestore/common.c        |   87 ++++++++++++++++++
 tools/libxc/saverestore/common.h        |    8 ++
 tools/libxc/saverestore/stream_format.h |  151 +++++++++++++++++++++++++++++++
 3 files changed, 246 insertions(+)
 create mode 100644 tools/libxc/saverestore/common.c
 create mode 100644 tools/libxc/saverestore/stream_format.h

diff --git a/tools/libxc/saverestore/common.c b/tools/libxc/saverestore/common.c
new file mode 100644
index 0000000..7884175
--- /dev/null
+++ b/tools/libxc/saverestore/common.c
@@ -0,0 +1,87 @@
+#include "common.h"
+
+static const char *dhdr_types[] =
+{
+    [DHDR_TYPE_X86_PV]  = "x86 PV",
+    [DHDR_TYPE_X86_HVM] = "x86 HVM",
+    [DHDR_TYPE_X86_PVH] = "x86 PVH",
+    [DHDR_TYPE_ARM]     = "ARM",
+};
+
+const char *dhdr_type_to_str(uint32_t type)
+{
+    if ( type < ARRAY_SIZE(dhdr_types) && dhdr_types[type] )
+        return dhdr_types[type];
+
+    return "Reserved";
+}
+
+static const char *mandatory_rec_types[] =
+{
+    [REC_TYPE_END]                  = "End",
+    [REC_TYPE_PAGE_DATA]            = "Page data",
+    [REC_TYPE_X86_PV_INFO]          = "x86 PV info",
+    [REC_TYPE_X86_PV_P2M_FRAMES]    = "x86 PV P2M frames",
+    [REC_TYPE_X86_PV_VCPU_BASIC]    = "x86 PV vcpu basic",
+    [REC_TYPE_X86_PV_VCPU_EXTENDED] = "x86 PV vcpu extended",
+    [REC_TYPE_X86_PV_VCPU_XSAVE]    = "x86 PV vcpu xsave",
+    [REC_TYPE_SHARED_INFO]          = "Shared info",
+    [REC_TYPE_TSC_INFO]             = "TSC info",
+    [REC_TYPE_HVM_CONTEXT]          = "HVM context",
+    [REC_TYPE_HVM_PARAMS]           = "HVM params",
+    [REC_TYPE_TOOLSTACK]            = "Toolstack",
+    [REC_TYPE_X86_PV_VCPU_MSRS]     = "x86 PV vcpu msrs",
+    [REC_TYPE_VERIFY]               = "Verify",
+};
+
+
+static const char *optional_rec_types[] =
+{
+    [_REC_TYPE_SAVING_CPU] = "Saving CPU",
+};
+
+
+const char *rec_type_to_str(uint32_t type)
+{
+    if ( type & REC_TYPE_OPTIONAL )
+    {
+        uint32_t idx = type & ~REC_TYPE_OPTIONAL;
+
+        if ( (idx < ARRAY_SIZE(optional_rec_types)) &&
+             optional_rec_types[idx] )
+            return optional_rec_types[idx];
+    }
+    else
+    {
+        if ( (type < ARRAY_SIZE(mandatory_rec_types)) &&
+             (mandatory_rec_types[type]) )
+            return mandatory_rec_types[type];
+    }
+
+    return "Reserved";
+}
+
+static void __attribute__((unused)) build_assertions(void)
+{
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_ihdr) != 24);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_dhdr) != 16);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rhdr) != 8);
+
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rec_page_data_header)  != 8);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rec_x86_pv_info)       != 8);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rec_x86_pv_p2m_frames) != 8);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rec_x86_pv_vcpu_hdr)   != 8);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rec_tsc_info)          != 24);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rec_hvm_params_entry)  != 16);
+    XC_BUILD_BUG_ON(sizeof(struct xc_sr_rec_hvm_params)        != 8);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/tools/libxc/saverestore/common.h b/tools/libxc/saverestore/common.h
index f1aff44..cbecf0a 100644
--- a/tools/libxc/saverestore/common.h
+++ b/tools/libxc/saverestore/common.h
@@ -3,6 +3,14 @@
 
 #include "../xg_private.h"
 
+#include "stream_format.h"
+
+/* String representation of Domain Header types. */
+const char *dhdr_type_to_str(uint32_t type);
+
+/* String representation of Record types. */
+const char *rec_type_to_str(uint32_t type);
+
 #endif
 /*
  * Local variables:
diff --git a/tools/libxc/saverestore/stream_format.h b/tools/libxc/saverestore/stream_format.h
new file mode 100644
index 0000000..938d766
--- /dev/null
+++ b/tools/libxc/saverestore/stream_format.h
@@ -0,0 +1,151 @@
+#ifndef __STREAM_FORMAT__H
+#define __STREAM_FORMAT__H
+
+/*
+ * C structures for the Migration v2 stream format.
+ * See docs/specs/libxc-migration-stream.pandoc
+ */
+
+#include <inttypes.h>
+
+/*
+ * Image Header
+ */
+struct xc_sr_ihdr
+{
+    uint64_t marker;
+    uint32_t id;
+    uint32_t version;
+    uint16_t options;
+    uint16_t _res1;
+    uint32_t _res2;
+};
+
+#define IHDR_MARKER  0xffffffffffffffffULL
+#define IHDR_ID      0x58454E46U
+#define IHDR_VERSION 2
+
+#define _IHDR_OPT_ENDIAN 0
+#define IHDR_OPT_LITTLE_ENDIAN (0 << _IHDR_OPT_ENDIAN)
+#define IHDR_OPT_BIG_ENDIAN    (1 << _IHDR_OPT_ENDIAN)
+
+/*
+ * Domain Header
+ */
+struct xc_sr_dhdr
+{
+    uint32_t type;
+    uint16_t page_shift;
+    uint16_t _res1;
+    uint32_t xen_major;
+    uint32_t xen_minor;
+};
+
+#define DHDR_TYPE_X86_PV  0x00000001U
+#define DHDR_TYPE_X86_HVM 0x00000002U
+#define DHDR_TYPE_X86_PVH 0x00000003U
+#define DHDR_TYPE_ARM     0x00000004U
+
+/*
+ * Record Header
+ */
+struct xc_sr_rhdr
+{
+    uint32_t type;
+    uint32_t length;
+};
+
+/* All records must be aligned up to an 8 octet boundary */
+#define REC_ALIGN_ORDER               (3U)
+/* Somewhat arbitrary - 8MB */
+#define REC_LENGTH_MAX                (8U << 20)
+
+#define REC_TYPE_END                  0x00000000U
+#define REC_TYPE_PAGE_DATA            0x00000001U
+#define REC_TYPE_X86_PV_INFO          0x00000002U
+#define REC_TYPE_X86_PV_P2M_FRAMES    0x00000003U
+#define REC_TYPE_X86_PV_VCPU_BASIC    0x00000004U
+#define REC_TYPE_X86_PV_VCPU_EXTENDED 0x00000005U
+#define REC_TYPE_X86_PV_VCPU_XSAVE    0x00000006U
+#define REC_TYPE_SHARED_INFO          0x00000007U
+#define REC_TYPE_TSC_INFO             0x00000008U
+#define REC_TYPE_HVM_CONTEXT          0x00000009U
+#define REC_TYPE_HVM_PARAMS           0x0000000aU
+#define REC_TYPE_TOOLSTACK            0x0000000bU
+#define REC_TYPE_X86_PV_VCPU_MSRS     0x0000000cU
+#define REC_TYPE_VERIFY               0x0000000dU
+
+#define REC_TYPE_OPTIONAL             0x80000000U
+
+#define _REC_TYPE_SAVING_CPU          0x00000000U
+#define REC_TYPE_SAVING_CPU           (REC_TYPE_OPTIONAL | _REC_TYPE_SAVING_CPU)
+
+/* PAGE_DATA */
+struct xc_sr_rec_page_data_header
+{
+    uint32_t count;
+    uint32_t _res1;
+    uint64_t pfn[0];
+};
+
+#define PAGE_DATA_PFN_MASK  0x000fffffffffffffULL
+#define PAGE_DATA_TYPE_MASK 0xf000000000000000ULL
+
+/* X86_PV_INFO */
+struct xc_sr_rec_x86_pv_info
+{
+    uint8_t guest_width;
+    uint8_t pt_levels;
+    uint8_t _res[6];
+};
+
+/* X86_PV_P2M_FRAMES */
+struct xc_sr_rec_x86_pv_p2m_frames
+{
+    uint32_t start_pfn;
+    uint32_t end_pfn;
+    uint64_t p2m_pfns[0];
+};
+
+/* X86_PV_VCPU_{BASIC,EXTENDED,XSAVE,MSRS} */
+struct xc_sr_rec_x86_pv_vcpu_hdr
+{
+    uint32_t vcpu_id;
+    uint32_t _res1;
+    uint8_t context[0];
+};
+
+/* TSC_INFO */
+struct xc_sr_rec_tsc_info
+{
+    uint32_t mode;
+    uint32_t khz;
+    uint64_t nsec;
+    uint32_t incarnation;
+    uint32_t _res1;
+};
+
+/* HVM_PARAMS */
+struct xc_sr_rec_hvm_params_entry
+{
+    uint64_t index;
+    uint64_t value;
+};
+
+struct xc_sr_rec_hvm_params
+{
+    uint32_t count;
+    uint32_t _res1;
+    struct xc_sr_rec_hvm_params_entry param[0];
+};
+
+#endif
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
1.7.10.4