[RFC][v2][PATCH 10/14] tools: extend XENMEM_set_memory_map

[Tiejun Chen <tiejun.chen@intel.com>]

Here we'll construct a basic guest e820 table via
XENMEM_set_memory_map. This table includes lowmem, highmem
and RDMs if they exist. And hvmloader would need this info
later.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 tools/libxl/libxl_dom.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)

diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 84d5465..cc4b1a6 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -913,6 +913,87 @@ out:
     return rc;
 }
 
+/*
+ * Here we're just trying to set these kinds of e820 mappings:
+ *
+ * #1. Low memory region
+ *
+ * Low RAM starts at least from 1M to make sure all standard regions
+ * of the PC memory map, like BIOS, VGA memory-mapped I/O and vgabios,
+ * have enough space.
+ * Note: Those stuffs below 1M are still constructed with multiple
+ * e820 entries by hvmloader. At this point we don't change anything.
+ *
+ * #2. RDM region if it exists
+ *
+ * #3. High memory region if it exists
+ *
+ * Note: these regions are not overlapping since we already check
+ * to adjust them. Please refer to libxl__domain_device_construct_rdm().
+ */
+#define GUEST_LOW_MEM_START_DEFAULT 0x100000
+static int libxl__domain_construct_memmap(libxl__gc *gc,
+                                          libxl_domain_config *d_config,
+                                          uint32_t domid,
+                                          struct xc_hvm_build_args *args)
+{
+    libxl_ctx *ctx = libxl__gc_owner(gc);
+    unsigned int nr = 0, i;
+    /* We always own at least one lowmem entry. */
+    unsigned int e820_entries = 1;
+    uint64_t highmem_end = 0, highmem_size = args->mem_size - args->lowmem_size;
+    struct e820entry *e820 = NULL;
+
+    /* Add all rdm entries. */
+    e820_entries += d_config->num_rdms;
+
+    /* If we should have a highmem range. */
+    if (highmem_size)
+    {
+        highmem_end = (1ull<<32) + highmem_size;
+        e820_entries++;
+    }
+
+    if (e820_entries >= E820MAX) {
+        LOG(ERROR, "Ooops! Too many entries in the memory map!\n");
+        return -1;
+    }
+
+    e820 = libxl__malloc(gc, sizeof(struct e820entry) * e820_entries);
+
+    /* Low memory */
+    e820[nr].addr = GUEST_LOW_MEM_START_DEFAULT;
+    e820[nr].size = args->lowmem_size - GUEST_LOW_MEM_START_DEFAULT;
+    e820[nr].type = E820_RAM;
+    nr++;
+
+    /* RDM mapping */
+    for (i = 0; i < d_config->num_rdms; i++) {
+        /*
+         * We should drop this kind of rdm entry.
+         */
+        if (d_config->rdms[i].flag == LIBXL_RDM_RESERVE_FLAG_INVALID)
+            continue;
+
+        e820[nr].addr = d_config->rdms[i].start;
+        e820[nr].size = d_config->rdms[i].size;
+        e820[nr].type = E820_RESERVED;
+        nr++;
+    }
+
+    /* High memory */
+    if (highmem_size) {
+        e820[nr].addr = ((uint64_t)1 << 32);
+        e820[nr].size = highmem_size;
+        e820[nr].type = E820_RAM;
+    }
+
+    if (xc_domain_set_memory_map(ctx->xch, domid, e820, e820_entries) != 0)
+        return -1;
+
+    return 0;
+}
+
 int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
               libxl_domain_config *d_config,
               libxl__domain_build_state *state)
@@ -1016,6 +1097,12 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
         ret = set_vnuma_info(gc, domid, info, state);
         if (ret) goto out;
     }
+
+    if (libxl__domain_construct_memmap(gc, d_config, domid, &args)) {
+        LOG(ERROR, "setting domain rdm memory map failed");
+        goto out;
+    }
+
     ret = hvm_build_set_params(ctx->xch, domid, info, state->store_port,
                                &state->store_mfn, state->console_port,
                                &state->console_mfn, state->store_domid,
-- 
1.9.1