[Xen-devel] [v3][PATCH 06/16] hvmloader: get guest memory map into memory_map[]

[Tiejun Chen <tiejun.chen@xxxxxxxxx>]

Now we get this map layout by call XENMEM_memory_map then
save them into one global variable memory_map[]. It should
include lowmem range, rdm range and highmem range. Note
rdm range and highmem range may not exist in some cases.

And here we need to check if any reserved memory conflicts with
[RESERVED_MEMORY_DYNAMIC_START - 1, RESERVED_MEMORY_DYNAMIC_END].
This range is used to allocate memory in hvmloder level, and
we would lead hvmloader failed in case of conflict since its
another rare possibility in real world.

Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
---
 tools/firmware/hvmloader/e820.h      |  7 +++++++
 tools/firmware/hvmloader/hvmloader.c | 37 ++++++++++++++++++++++++++++++++++++
 tools/firmware/hvmloader/util.c      | 26 +++++++++++++++++++++++++
 tools/firmware/hvmloader/util.h      | 11 +++++++++++
 4 files changed, 81 insertions(+)

diff --git a/tools/firmware/hvmloader/e820.h b/tools/firmware/hvmloader/e820.h
index b2ead7f..8b5a9e0 100644
--- a/tools/firmware/hvmloader/e820.h
+++ b/tools/firmware/hvmloader/e820.h
@@ -15,6 +15,13 @@ struct e820entry {
     uint32_t type;
 } __attribute__((packed));
 
+#define E820MAX        128
+
+struct e820map {
+    unsigned int nr_map;
+    struct e820entry map[E820MAX];
+};
+
 #endif /* __HVMLOADER_E820_H__ */
 
 /*
diff --git a/tools/firmware/hvmloader/hvmloader.c 
b/tools/firmware/hvmloader/hvmloader.c
index 25b7f08..c9f170e 100644
--- a/tools/firmware/hvmloader/hvmloader.c
+++ b/tools/firmware/hvmloader/hvmloader.c
@@ -107,6 +107,8 @@ asm (
     "    .text                       \n"
     );
 
+struct e820map memory_map;
+
 unsigned long scratch_start = SCRATCH_PHYSICAL_ADDRESS;
 
 static void init_hypercalls(void)
@@ -199,6 +201,39 @@ static void apic_setup(void)
     ioapic_write(0x11, SET_APIC_ID(LAPIC_ID(0)));
 }
 
+void memory_map_setup(void)
+{
+    unsigned int nr_entries = E820MAX, i;
+    int rc;
+    uint64_t alloc_addr = RESERVED_MEMORY_DYNAMIC_START - 1;
+    uint64_t alloc_size = RESERVED_MEMORY_DYNAMIC_END - alloc_addr;
+
+    rc = get_mem_mapping_layout(memory_map.map, &nr_entries);
+
+    if ( rc )
+    {
+        printf("Failed to get guest memory map.\n");
+        BUG();
+    }
+
+    BUG_ON(!nr_entries);
+    memory_map.nr_map = nr_entries;
+
+    for ( i = 0; i < nr_entries; i++ )
+    {
+        if ( memory_map.map[i].type == E820_RESERVED )
+        {
+            if ( check_overlap(alloc_addr, alloc_size,
+                               memory_map.map[i].addr,
+                               memory_map.map[i].size) )
+            {
+                printf("RDM conflicts Memory allocation.\n");
+                BUG();
+            }
+        }
+    }
+}
+
 struct bios_info {
     const char *key;
     const struct bios_config *bios;
@@ -262,6 +297,8 @@ int main(void)
 
     init_hypercalls();
 
+    memory_map_setup();
+
     xenbus_setup();
 
     bios = detect_bios();
diff --git a/tools/firmware/hvmloader/util.c b/tools/firmware/hvmloader/util.c
index 80d822f..122e3fa 100644
--- a/tools/firmware/hvmloader/util.c
+++ b/tools/firmware/hvmloader/util.c
@@ -27,6 +27,17 @@
 #include <xen/memory.h>
 #include <xen/sched.h>
 
+/*
+ * Check whether there exists overlap in the specified memory range.
+ * Returns true if exists, else returns false.
+ */
+bool check_overlap(uint64_t start, uint64_t size,
+                   uint64_t reserved_start, uint64_t reserved_size)
+{
+    return (start + size > reserved_start) &&
+            (start < reserved_start + reserved_size);
+}
+
 void wrmsr(uint32_t idx, uint64_t v)
 {
     asm volatile (
@@ -368,6 +379,21 @@ uuid_to_string(char *dest, uint8_t *uuid)
     *p = '\0';
 }
 
+int get_mem_mapping_layout(struct e820entry entries[], uint32_t *max_entries)
+{
+    int rc;
+    struct xen_memory_map memmap = {
+        .nr_entries = *max_entries
+    };
+
+    set_xen_guest_handle(memmap.buffer, entries);
+
+    rc = hypercall_memory_op(XENMEM_memory_map, &memmap);
+    *max_entries = memmap.nr_entries;
+
+    return rc;
+}
+
 void mem_hole_populate_ram(xen_pfn_t mfn, uint32_t nr_mfns)
 {
     static int over_allocated;
diff --git a/tools/firmware/hvmloader/util.h b/tools/firmware/hvmloader/util.h
index a70e4aa..70e19c4 100644
--- a/tools/firmware/hvmloader/util.h
+++ b/tools/firmware/hvmloader/util.h
@@ -4,8 +4,10 @@
 #include <stdarg.h>
 #include <stdint.h>
 #include <stddef.h>
+#include <stdbool.h>
 #include <xen/xen.h>
 #include <xen/hvm/hvm_info_table.h>
+#include "e820.h"
 
 #define __STR(...) #__VA_ARGS__
 #define STR(...) __STR(__VA_ARGS__)
@@ -222,6 +224,9 @@ int hvm_param_set(uint32_t index, uint64_t value);
 /* Setup PCI bus */
 void pci_setup(void);
 
+/* Setup memory map  */
+void memory_map_setup(void);
+
 /* Prepare the 32bit BIOS */
 uint32_t rombios_highbios_setup(void);
 
@@ -249,6 +254,12 @@ void perform_tests(void);
 
 extern char _start[], _end[];
 
+int get_mem_mapping_layout(struct e820entry entries[], uint32_t *max_entries);
+
+extern struct e820map memory_map;
+bool check_overlap(uint64_t start, uint64_t size,
+                   uint64_t reserved_start, uint64_t reserved_size);
+
 #endif /* __HVMLOADER_UTIL_H__ */
 
 /*
-- 
1.9.1


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