[v8][PATCH 13/16] libxl: construct e820 map with RDM information for HVM guest

[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.

Note this guest e820 table would be same as before if the
platform has no any RDM or we disable RDM (by default).

CC: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
v8:

* make that core construction function as arch-specific to make sure
  we don't break ARM at this point.

v7:

* Just sync with the fallout of renaming parameters from patch #10.

v6:

* Nothing is changed.

v5:

* Rephrase patch's short log
* Make libxl__domain_construct_e820() hidden

v4:

* Use goto style error handling.
* Instead of NOGC, we shoud use libxl__malloc(gc,XXX) to allocate local e820.


 tools/libxl/libxl_arch.h |  7 ++++
 tools/libxl/libxl_arm.c  |  8 +++++
 tools/libxl/libxl_dom.c  |  5 +++
 tools/libxl/libxl_x86.c  | 83 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 103 insertions(+)

diff --git a/tools/libxl/libxl_arch.h b/tools/libxl/libxl_arch.h
index d04871c..939178a 100644
--- a/tools/libxl/libxl_arch.h
+++ b/tools/libxl/libxl_arch.h
@@ -49,4 +49,11 @@ int libxl__arch_vnuma_build_vmemrange(libxl__gc *gc,
 _hidden
 int libxl__arch_domain_map_irq(libxl__gc *gc, uint32_t domid, int irq);
 
+/* arch specific to construct memory mapping function */
+_hidden
+int libxl__arch_domain_construct_memmap(libxl__gc *gc,
+                                        libxl_domain_config *d_config,
+                                        uint32_t domid,
+                                        struct xc_hvm_build_args *args);
+
 #endif
diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index f09c860..1526467 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -926,6 +926,14 @@ int libxl__arch_domain_map_irq(libxl__gc *gc, uint32_t domid, int irq)
     return xc_domain_bind_pt_spi_irq(CTX->xch, domid, irq, irq);
 }
 
+int libxl__arch_domain_construct_memmap(libxl__gc *gc,
+                                        libxl_domain_config *d_config,
+                                        uint32_t domid,
+                                        struct xc_hvm_build_args *args)
+{
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index e41d54a..a8c6aa9 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -1004,6 +1004,11 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
         goto out;
     }
 
+    if (libxl__arch_domain_construct_memmap(gc, d_config, domid, &args)) {
+        LOG(ERROR, "setting domain 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,
diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
index ed2bd38..66b3d7f 100644
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -438,6 +438,89 @@ int libxl__arch_domain_map_irq(libxl__gc *gc, uint32_t domid, int irq)
 }
 
 /*
+ * 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
+int libxl__arch_domain_construct_memmap(libxl__gc *gc,
+                                        libxl_domain_config *d_config,
+                                        uint32_t domid,
+                                        struct xc_hvm_build_args *args)
+{
+    int rc = 0;
+    unsigned int nr = 0, i;
+    /* We always own at least one lowmem entry. */
+    unsigned int e820_entries = 1;
+    struct e820entry *e820 = NULL;
+    uint64_t highmem_size =
+                    args->highmem_end ? args->highmem_end - (1ull << 32) : 0;
+
+    /* Add all rdm entries. */
+    for (i = 0; i < d_config->num_rdms; i++)
+        if (d_config->rdms[i].policy != LIBXL_RDM_RESERVE_POLICY_INVALID)
+            e820_entries++;
+
+
+    /* If we should have a highmem range. */
+    if (highmem_size)
+        e820_entries++;
+
+    if (e820_entries >= E820MAX) {
+        LOG(ERROR, "Ooops! Too many entries in the memory map!\n");
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    e820 = libxl__malloc(gc, sizeof(struct e820entry) * e820_entries);
+
+    /* Low memory */
+    e820[nr].addr = GUEST_LOW_MEM_START_DEFAULT;
+    e820[nr].size = args->lowmem_end - GUEST_LOW_MEM_START_DEFAULT;
+    e820[nr].type = E820_RAM;
+    nr++;
+
+    /* RDM mapping */
+    for (i = 0; i < d_config->num_rdms; i++) {
+        if (d_config->rdms[i].policy == LIBXL_RDM_RESERVE_POLICY_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) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+out:
+    return rc;
+}
+
+/*
  * Local variables:
  * mode: C
  * c-basic-offset: 4
-- 
1.9.1