[PATCH v7 02/15] libxc: Prepare a start info structure for hvmloader

[Anthony PERARD <anthony.perard@citrix.com>]

... and load BIOS/UEFI firmware into guest memory.

This adds a new firmware module, system_firmware_module. It is loaded in
the guest memory and final location is provided to hvmloader via the
hvm_start_info struct.

This patch create the hvm_start_info struct for HVM guest that have a
device model, so this is now common code with HVM guest without device
model.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

---
CC: boris.ostrovsky@oracle.com
CC: roger.pau@citrix.com

Changes in V6:
- change description (for verbose output) of the allocation of
  hvm_start_info from "HVMlite start info" to "HVM start info".

Changes in V5:
- in alloc_magic_pages_hvm, check dom->device_model only once instead of
  twice (fold second if into previous else)
- rework add_module_to_list to make it easier to read
- also comment about the intended memory layout of start_info and the
  modules
- in bootlate_hvm(), drop start_page and use start_info as they point to
  the same address
- rename xc_dom_image.bios_module to xc_dom_image.system_firmware_module
- rename module name to "firmware" (was "bios")

Changes in V4:
- change title to suggest the change of beavior
- remove code to load acpi tables (dsdt)
- Update public/xen.h about hvm_start_info available on other HVM guest
  in %ebx.

Changes in V3:
- rename acpi_table_module to full_acpi_module.
- factorise module loading, using new function to load existing optinal
  module, this should not change anything
- should now use the same code to loads modules as for HVMlite VMs.
  this avoid duplication of code.
- no more generic cmdline with a list of modules, each module have its name
  in the module specific cmdline.
- scope change for common code between hvmlite and hvmloader
---
 tools/libxc/include/xc_dom.h   |   3 +
 tools/libxc/xc_dom_hvmloader.c |   3 +
 tools/libxc/xc_dom_x86.c       | 152 +++++++++++++++++++++++++++++------------
 xen/include/public/xen.h       |   2 +-
 4 files changed, 116 insertions(+), 44 deletions(-)

diff --git a/tools/libxc/include/xc_dom.h b/tools/libxc/include/xc_dom.h
index 6cb10c4..0629971 100644
--- a/tools/libxc/include/xc_dom.h
+++ b/tools/libxc/include/xc_dom.h
@@ -209,6 +209,9 @@ struct xc_dom_image {
     /* If unset disables the setup of the IOREQ pages. */
     bool device_model;
 
+    /* BIOS/Firmware passed to HVMLOADER */
+    struct xc_hvm_firmware_module system_firmware_module;
+
     /* Extra ACPI tables passed to HVMLOADER */
     struct xc_hvm_firmware_module acpi_module;
 
diff --git a/tools/libxc/xc_dom_hvmloader.c b/tools/libxc/xc_dom_hvmloader.c
index 8150b74..6eb8516 100644
--- a/tools/libxc/xc_dom_hvmloader.c
+++ b/tools/libxc/xc_dom_hvmloader.c
@@ -169,6 +169,9 @@ static int modules_init(struct xc_dom_image *dom)
 {
     int rc;
 
+    rc = module_init_one(dom, &dom->system_firmware_module,
+                         "System Firmware module");
+    if ( rc ) goto err;
     rc = module_init_one(dom, &dom->acpi_module, "ACPI module");
     if ( rc ) goto err;
     rc = module_init_one(dom, &dom->smbios_module, "SMBIOS module");
diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c
index 021f8a8..bc2dbb2 100644
--- a/tools/libxc/xc_dom_x86.c
+++ b/tools/libxc/xc_dom_x86.c
@@ -69,6 +69,9 @@
 #define round_up(addr, mask)     ((addr) | (mask))
 #define round_pg_up(addr)  (((addr) + PAGE_SIZE_X86 - 1) & ~(PAGE_SIZE_X86 - 1))
 
+#define HVMLOADER_MODULE_MAX_COUNT 1
+#define HVMLOADER_MODULE_NAME_SIZE 10
+
 struct xc_dom_params {
     unsigned levels;
     xen_vaddr_t vaddr_mask;
@@ -590,6 +593,7 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom)
     xen_pfn_t special_array[X86_HVM_NR_SPECIAL_PAGES];
     xen_pfn_t ioreq_server_array[NR_IOREQ_SERVER_PAGES];
     xc_interface *xch = dom->xch;
+    size_t start_info_size = sizeof(struct hvm_start_info);
 
     /* Allocate and clear special pages. */
     for ( i = 0; i < X86_HVM_NR_SPECIAL_PAGES; i++ )
@@ -624,8 +628,6 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom)
 
     if ( !dom->device_model )
     {
-        size_t start_info_size = sizeof(struct hvm_start_info);
-
         if ( dom->cmdline )
         {
             dom->cmdline_size = ROUNDUP(strlen(dom->cmdline) + 1, 8);
@@ -635,17 +637,18 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom)
         /* Limited to one module. */
         if ( dom->ramdisk_blob )
             start_info_size += sizeof(struct hvm_modlist_entry);
-
-        rc = xc_dom_alloc_segment(dom, &dom->start_info_seg,
-                                  "HVMlite start info", 0, start_info_size);
-        if ( rc != 0 )
-        {
-            DOMPRINTF("Unable to reserve memory for the start info");
-            goto out;
-        }
     }
     else
     {
+        start_info_size +=
+            sizeof(struct hvm_modlist_entry) * HVMLOADER_MODULE_MAX_COUNT;
+        /*
+         * Add extra space to write modules name.
+         * The HVMLOADER_MODULE_NAME_SIZE accounts for NUL byte.
+         */
+        start_info_size +=
+            HVMLOADER_MODULE_NAME_SIZE * HVMLOADER_MODULE_MAX_COUNT;
+
         /*
          * Allocate and clear additional ioreq server pages. The default
          * server will use the IOREQ and BUFIOREQ special pages above.
@@ -672,6 +675,14 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom)
                          NR_IOREQ_SERVER_PAGES);
     }
 
+    rc = xc_dom_alloc_segment(dom, &dom->start_info_seg,
+                              "HVM start info", 0, start_info_size);
+    if ( rc != 0 )
+    {
+        DOMPRINTF("Unable to reserve memory for the start info");
+        goto out;
+    }
+
     /*
      * Identity-map page table is required for running with CR0.PG=0 when
      * using Intel EPT. Create a 32-bit non-PAE page directory of superpages.
@@ -1689,42 +1700,89 @@ static int alloc_pgtables_hvm(struct xc_dom_image *dom)
     return 0;
 }
 
+/*
+ * The memory layout of the start_info page and the modules, and where the
+ * addresses are stored:
+ *
+ * /----------------------------------\
+ * | struct hvm_start_info            |
+ * +----------------------------------+ <- start_info->modlist_paddr
+ * | struct hvm_modlist_entry[0]      |
+ * +----------------------------------+
+ * | struct hvm_modlist_entry[1]      |
+ * +----------------------------------+ <- modlist[0].cmdline_paddr
+ * | cmdline of module 0              |
+ * | char[HVMLOADER_MODULE_NAME_SIZE] |
+ * +----------------------------------+ <- modlist[1].cmdline_paddr
+ * | cmdline of module 1              |
+ * +----------------------------------+
+ */
+static void add_module_to_list(struct xc_dom_image *dom,
+                               struct xc_hvm_firmware_module *module,
+                               const char *name,
+                               struct hvm_modlist_entry *modlist,
+                               struct hvm_start_info *start_info)
+{
+    uint32_t index = start_info->nr_modules;
+    void *modules_cmdline_start = modlist + HVMLOADER_MODULE_MAX_COUNT;
+    uint64_t modlist_paddr = (dom->start_info_seg.pfn << PAGE_SHIFT) +
+        ((uintptr_t)modlist - (uintptr_t)start_info);
+    uint64_t modules_cmdline_paddr = modlist_paddr +
+        sizeof(struct hvm_modlist_entry) * HVMLOADER_MODULE_MAX_COUNT;
+
+    if ( module->length == 0 )
+        return;
+
+    assert(start_info->nr_modules < HVMLOADER_MODULE_MAX_COUNT);
+    assert(strnlen(name, HVMLOADER_MODULE_NAME_SIZE)
+           < HVMLOADER_MODULE_NAME_SIZE);
+
+    modlist[index].paddr = module->guest_addr_out;
+    modlist[index].size = module->length;
+
+    strncpy(modules_cmdline_start + HVMLOADER_MODULE_NAME_SIZE * index,
+            name, HVMLOADER_MODULE_NAME_SIZE);
+    modlist[index].cmdline_paddr =
+        modules_cmdline_paddr + HVMLOADER_MODULE_NAME_SIZE * index;
+
+    start_info->nr_modules++;
+}
+
 static int bootlate_hvm(struct xc_dom_image *dom)
 {
     uint32_t domid = dom->guest_domid;
     xc_interface *xch = dom->xch;
+    struct hvm_start_info *start_info;
+    size_t start_info_size;
+    struct hvm_modlist_entry *modlist;
 
-    if ( !dom->device_model )
-    {
-        struct hvm_start_info *start_info;
-        size_t start_info_size;
-        void *start_page;
-
-        start_info_size = sizeof(*start_info) + dom->cmdline_size;
-        if ( dom->ramdisk_blob )
-            start_info_size += sizeof(struct hvm_modlist_entry);
+    start_info_size = sizeof(*start_info) + dom->cmdline_size;
+    if ( dom->ramdisk_blob )
+        start_info_size += sizeof(struct hvm_modlist_entry);
 
-        if ( start_info_size >
-             dom->start_info_seg.pages << XC_DOM_PAGE_SHIFT(dom) )
-        {
-            DOMPRINTF("Trying to map beyond start_info_seg");
-            return -1;
-        }
+    if ( start_info_size >
+         dom->start_info_seg.pages << XC_DOM_PAGE_SHIFT(dom) )
+    {
+        DOMPRINTF("Trying to map beyond start_info_seg");
+        return -1;
+    }
 
-        start_page = xc_map_foreign_range(xch, domid, start_info_size,
-                                          PROT_READ | PROT_WRITE,
-                                          dom->start_info_seg.pfn);
-        if ( start_page == NULL )
-        {
-            DOMPRINTF("Unable to map HVM start info page");
-            return -1;
-        }
+    start_info = xc_map_foreign_range(xch, domid, start_info_size,
+                                      PROT_READ | PROT_WRITE,
+                                      dom->start_info_seg.pfn);
+    if ( start_info == NULL )
+    {
+        DOMPRINTF("Unable to map HVM start info page");
+        return -1;
+    }
 
-        start_info = start_page;
+    modlist = (void*)(start_info + 1) + dom->cmdline_size;
 
+    if ( !dom->device_model )
+    {
         if ( dom->cmdline )
         {
-            char *cmdline = start_page + sizeof(*start_info);
+            char *cmdline = (void*)(start_info + 1);
 
             strncpy(cmdline, dom->cmdline, dom->cmdline_size);
             start_info->cmdline_paddr = (dom->start_info_seg.pfn << PAGE_SHIFT) +
@@ -1733,22 +1791,30 @@ static int bootlate_hvm(struct xc_dom_image *dom)
 
         if ( dom->ramdisk_blob )
         {
-            struct hvm_modlist_entry *modlist =
-                start_page + sizeof(*start_info) + dom->cmdline_size;
 
             modlist[0].paddr = dom->ramdisk_seg.vstart - dom->parms.virt_base;
             modlist[0].size = dom->ramdisk_seg.vend - dom->ramdisk_seg.vstart;
-            start_info->modlist_paddr = (dom->start_info_seg.pfn << PAGE_SHIFT) +
-                                ((uintptr_t)modlist - (uintptr_t)start_info);
             start_info->nr_modules = 1;
         }
-
-        start_info->magic = XEN_HVM_START_MAGIC_VALUE;
-
-        munmap(start_page, start_info_size);
     }
     else
     {
+        add_module_to_list(dom, &dom->system_firmware_module, "firmware",
+                           modlist, start_info);
+    }
+
+    if ( start_info->nr_modules )
+    {
+        start_info->modlist_paddr = (dom->start_info_seg.pfn << PAGE_SHIFT) +
+                            ((uintptr_t)modlist - (uintptr_t)start_info);
+    }
+
+    start_info->magic = XEN_HVM_START_MAGIC_VALUE;
+
+    munmap(start_info, start_info_size);
+
+    if ( dom->device_model )
+    {
         void *hvm_info_page;
 
         if ( (hvm_info_page = xc_map_foreign_range(
diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index b9e5e0f..427e74f 100644
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -821,7 +821,7 @@ struct start_info {
 typedef struct start_info start_info_t;
 
 /*
- * Start of day structure passed to PVH guests in %ebx.
+ * Start of day structure passed to PVH guests and to HVM guests in %ebx.
  *
  * NOTE: nothing will be loaded at physical address 0, so a 0 value in any
  * of the address fields should be treated as not present.
-- 
Anthony PERARD


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