diff --git a/tools/firmware/hvmloader/acpi/build.c b/tools/firmware/hvmloader/acpi/build.c
index 306d1105b8..d81f1dc2a2 100644
--- a/tools/firmware/hvmloader/acpi/build.c
+++ b/tools/firmware/hvmloader/acpi/build.c
@@ -297,6 +297,20 @@ static int construct_secondary_tables(unsigned long *table_ptrs,
     return nr_tables;
 }
 
+unsigned long new_vm_gid(void)
+{
+    uint64_t gid;
+    unsigned char *buf;
+
+    buf = mem_alloc(8, 8);
+    if (!buf) return 0;
+
+    gid = strtoll(xenstore_read("platform/generation-id", "0"), NULL, 0);
+    *(uint64_t *)buf = gid;
+
+    return virt_to_phys(buf);    
+}
+
 void acpi_build_tables(struct acpi_config *config, unsigned int physical)
 {
     struct acpi_info *acpi_info;
@@ -309,6 +323,7 @@ void acpi_build_tables(struct acpi_config *config, unsigned int physical)
     unsigned char       *dsdt;
     unsigned long        secondary_tables[16];
     int                  nr_secondaries, i;
+    unsigned long        vm_gid_addr;
 
     /* Allocate and initialise the acpi info area. */
     mem_hole_populate_ram(ACPI_INFO_PHYSICAL_ADDRESS >> PAGE_SHIFT, 1);
@@ -421,12 +436,16 @@ void acpi_build_tables(struct acpi_config *config, unsigned int physical)
                  offsetof(struct acpi_20_rsdp, extended_checksum),
                  sizeof(struct acpi_20_rsdp));
 
+    vm_gid_addr = new_vm_gid();
+    if (!vm_gid_addr) goto oom;
+
     acpi_info->com1_present = uart_exists(0x3f8);
     acpi_info->com2_present = uart_exists(0x2f8);
     acpi_info->lpt1_present = lpt_exists(0x378);
     acpi_info->hpet_present = hpet_exists(ACPI_HPET_ADDRESS);
     acpi_info->pci_min = pci_mem_start;
     acpi_info->pci_len = pci_mem_end - pci_mem_start;
+    acpi_info->vm_gid_addr = vm_gid_addr;
 
     return;
 
diff --git a/tools/firmware/hvmloader/util.c b/tools/firmware/hvmloader/util.c
index 1bad9bcf09..b0e28217c2 100644
--- a/tools/firmware/hvmloader/util.c
+++ b/tools/firmware/hvmloader/util.c
@@ -205,6 +205,78 @@ strlen(const char *s)
     return i;
 }
 
+static inline int __digit(char c, int base)
+{
+    int d = -1;
+
+    if ( (c >= '0') && (c <= '9') )
+        d = c - '0';
+
+    if ( (c >= 'A') && (c <= 'Z') )
+        d = c - 'A' + 10;
+
+    if ( (c >= 'a') && (c <= 'z') )
+        d = c - 'a' + 10;
+
+    if (d >= base)
+        d = -1;
+
+    return d;
+}
+
+long long
+strtoll(const char *s, char **end, int base)
+{
+    long long v = 0;
+    int sign = 1;
+
+    while ( (*s != '\0') && isspace(*s) )
+        s++;
+
+    if ( *s == '\0' ) goto out;
+
+    if ( *s == '-' ) {
+        sign = -1;
+        s++;
+    } else {
+        if ( *s == '+' )
+            s++;
+    }
+
+    if ( *s == '\0' ) goto out;
+
+    if ( *s == '0' ) {
+        s++;
+        if ( *s == '\0' ) goto out;
+
+        if ( *s == 'x' ) {
+            if ( base != 0 && base != 16) goto out;
+            base = 16;
+            s++;
+        } else {
+            if ( base != 0 && base != 8) goto out;
+            base = 8;
+        }
+    } else {
+        if (base != 0 && base != 10) goto out;
+        base = 10;
+    }
+
+    while ( *s != '\0' ) {
+        int d = __digit(*s, base);
+
+        if ( d < 0 ) goto out;
+
+        v = (v * base) + d;
+        s++;
+    }
+
+out:
+    if (end) *end = (char *)s;
+
+    return sign * v;
+}
+
 void *
 memset(void *s, int c, unsigned n)
 {
diff --git a/tools/firmware/hvmloader/util.h b/tools/firmware/hvmloader/util.h
index fa73ba7a38..ed844462b2 100644
--- a/tools/firmware/hvmloader/util.h
+++ b/tools/firmware/hvmloader/util.h
@@ -152,6 +152,7 @@ int strncmp(const char *s1, const char *s2, uint32_t n);
 char *strcpy(char *dest, const char *src);
 char *strncpy(char *dest, const char *src, unsigned n);
 unsigned strlen(const char *s);
+long long strtoll(const char *s, char **end, int base);
 int memcmp(const void *s1, const void *s2, unsigned n);
 void *memcpy(void *dest, const void *src, unsigned n);
 void *memmove(void *dest, const void *src, unsigned n);