Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

acpi,pc,test bug fixes

More small fixes all over the place.
Notably fixes for big-endian hosts by Marcel.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Mon 24 Mar 2014 10:41:07 GMT using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream:
  tests/acpi-test: do not fail if iasl is broken
  vl.c: Use MAX_CPUMASK_BITS macro instead of hardcoded constant
  sysemu.h: Document what MAX_CPUMASK_BITS really limits
  acpi: fix endian-ness for table ids
  acpi-test: signature endian-ness fixes
  i386/acpi-build: support hotplug of VCPU with APIC ID 0xFF
  acpi-test: rebuild SSDT
  i386/acpi-build: allow more than 255 elements in CPON
  pc: Refuse max_cpus if it results in too large APIC ID
  acpi: Don't use MAX_CPUMASK_BITS for APIC ID bitmap
  acpi: Assert sts array limit on AcpiCpuHotplug_add()
  pc: Refuse CPU hotplug if the resulting APIC ID is too large
  acpi: Add ACPI_CPU_HOTPLUG_ID_LIMIT macro
  acpi-test: update expected SSDT files
  acpi-build: fix misaligned access

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

10 files changed, 107 insertions, 61 deletions

diff --git a/hw/acpi/cpu_hotplug.c b/hw/acpi/cpu_hotplug.c
index 48928dc0ea..2ad83a0ede 100644
--- a/hw/acpi/cpu_hotplug.c
+++ b/hw/acpi/cpu_hotplug.c
@@ -43,6 +43,7 @@ void AcpiCpuHotplug_add(ACPIGPE *gpe, AcpiCpuHotplug *g, CPUState *cpu)
 
     *gpe->sts = *gpe->sts | ACPI_CPU_HOTPLUG_STATUS;
     cpu_id = k->get_arch_id(CPU(cpu));
+    g_assert((cpu_id / 8) < ACPI_GPE_PROC_LEN);
     g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
 }
 
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 7ecfd7004b..f1054dd831 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -52,7 +52,7 @@
 #include "qom/qom-qobject.h"
 
 typedef struct AcpiCpuInfo {
-    DECLARE_BITMAP(found_cpus, MAX_CPUMASK_BITS + 1);
+    DECLARE_BITMAP(found_cpus, ACPI_CPU_HOTPLUG_ID_LIMIT);
 } AcpiCpuInfo;
 
 typedef struct AcpiMcfgInfo {
@@ -117,7 +117,7 @@ int acpi_add_cpu_info(Object *o, void *opaque)
 
     if (object_dynamic_cast(o, TYPE_CPU)) {
         apic_id = object_property_get_int(o, "apic-id", NULL);
-        assert(apic_id <= MAX_CPUMASK_BITS);
+        assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 
         set_bit(apic_id, cpu->found_cpus);
     }
@@ -226,14 +226,14 @@ static void acpi_get_pci_info(PcPciInfo *info)
 
 static void
 build_header(GArray *linker, GArray *table_data,
-             AcpiTableHeader *h, uint32_t sig, int len, uint8_t rev)
+             AcpiTableHeader *h, const char *sig, int len, uint8_t rev)
 {
-    h->signature = cpu_to_le32(sig);
+    memcpy(&h->signature, sig, 4);
     h->length = cpu_to_le32(len);
     h->revision = rev;
     memcpy(h->oem_id, ACPI_BUILD_APPNAME6, 6);
     memcpy(h->oem_table_id, ACPI_BUILD_APPNAME4, 4);
-    memcpy(h->oem_table_id + 4, (void *)&sig, 4);
+    memcpy(h->oem_table_id + 4, sig, 4);
     h->oem_revision = cpu_to_le32(1);
     memcpy(h->asl_compiler_id, ACPI_BUILD_APPNAME4, 4);
     h->asl_compiler_revision = cpu_to_le32(1);
@@ -495,7 +495,7 @@ static void
 build_facs(GArray *table_data, GArray *linker, PcGuestInfo *guest_info)
 {
     AcpiFacsDescriptorRev1 *facs = acpi_data_push(table_data, sizeof *facs);
-    facs->signature = cpu_to_le32(ACPI_FACS_SIGNATURE);
+    memcpy(&facs->signature, "FACS", 4);
     facs->length = cpu_to_le32(sizeof(*facs));
 }
 
@@ -552,7 +552,7 @@ build_fadt(GArray *table_data, GArray *linker, AcpiPmInfo *pm,
     fadt_setup(fadt, pm);
 
     build_header(linker, table_data,
-                 (void *)fadt, ACPI_FACP_SIGNATURE, sizeof(*fadt), 1);
+                 (void *)fadt, "FACP", sizeof(*fadt), 1);
 }
 
 static void
@@ -621,7 +621,7 @@ build_madt(GArray *table_data, GArray *linker, AcpiCpuInfo *cpu,
     local_nmi->lint         = 1; /* ACPI_LINT1 */
 
     build_header(linker, table_data,
-                 (void *)(table_data->data + madt_start), ACPI_APIC_SIGNATURE,
+                 (void *)(table_data->data + madt_start), "APIC",
                  table_data->len - madt_start, 1);
 }
 
@@ -999,11 +999,16 @@ build_ssdt(GArray *table_data, GArray *linker,
            AcpiCpuInfo *cpu, AcpiPmInfo *pm, AcpiMiscInfo *misc,
            PcPciInfo *pci, PcGuestInfo *guest_info)
 {
-    int acpi_cpus = MIN(0xff, guest_info->apic_id_limit);
+    unsigned acpi_cpus = guest_info->apic_id_limit;
     int ssdt_start = table_data->len;
     uint8_t *ssdt_ptr;
     int i;
 
+    /* The current AML generator can cover the APIC ID range [0..255],
+     * inclusive, for VCPU hotplug. */
+    QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
+    g_assert(acpi_cpus <= ACPI_CPU_HOTPLUG_ID_LIMIT);
+
     /* Copy header and patch values in the S3_ / S4_ / S5_ packages */
     ssdt_ptr = acpi_data_push(table_data, sizeof(ssdp_misc_aml));
     memcpy(ssdt_ptr, ssdp_misc_aml, sizeof(ssdp_misc_aml));
@@ -1019,8 +1024,8 @@ build_ssdt(GArray *table_data, GArray *linker,
 
     patch_pci_windows(pci, ssdt_ptr, sizeof(ssdp_misc_aml));
 
-    *(uint16_t *)(ssdt_ptr + *ssdt_isa_pest) =
-        cpu_to_le16(misc->pvpanic_port);
+    ACPI_BUILD_SET_LE(ssdt_ptr, sizeof(ssdp_misc_aml),
+                      ssdt_isa_pest[0], 16, misc->pvpanic_port);
 
     {
         GArray *sb_scope = build_alloc_array();
@@ -1050,9 +1055,9 @@ build_ssdt(GArray *table_data, GArray *linker,
 
         {
             GArray *package = build_alloc_array();
-            uint8_t op = 0x12; /* PackageOp */
+            uint8_t op = 0x13; /* VarPackageOp */
 
-            build_append_byte(package, acpi_cpus); /* NumElements */
+            build_append_int(package, acpi_cpus); /* VarNumElements */
             for (i = 0; i < acpi_cpus; i++) {
                 uint8_t b = test_bit(i, cpu->found_cpus) ? 0x01 : 0x00;
                 build_append_byte(package, b);
@@ -1093,7 +1098,7 @@ build_ssdt(GArray *table_data, GArray *linker,
 
     build_header(linker, table_data,
                  (void *)(table_data->data + ssdt_start),
-                 ACPI_SSDT_SIGNATURE, table_data->len - ssdt_start, 1);
+                 "SSDT", table_data->len - ssdt_start, 1);
 }
 
 static void
@@ -1108,7 +1113,7 @@ build_hpet(GArray *table_data, GArray *linker)
     hpet->timer_block_id = cpu_to_le32(0x8086a201);
     hpet->addr.address = cpu_to_le64(HPET_BASE);
     build_header(linker, table_data,
-                 (void *)hpet, ACPI_HPET_SIGNATURE, sizeof(*hpet), 1);
+                 (void *)hpet, "HPET", sizeof(*hpet), 1);
 }
 
 static void
@@ -1200,7 +1205,7 @@ build_srat(GArray *table_data, GArray *linker,
 
     build_header(linker, table_data,
                  (void *)(table_data->data + srat_start),
-                 ACPI_SRAT_SIGNATURE,
+                 "SRAT",
                  table_data->len - srat_start, 1);
 }
 
@@ -1208,7 +1213,7 @@ static void
 build_mcfg_q35(GArray *table_data, GArray *linker, AcpiMcfgInfo *info)
 {
     AcpiTableMcfg *mcfg;
-    uint32_t sig;
+    const char *sig;
     int len = sizeof(*mcfg) + 1 * sizeof(mcfg->allocation[0]);
 
     mcfg = acpi_data_push(table_data, len);
@@ -1225,9 +1230,10 @@ build_mcfg_q35(GArray *table_data, GArray *linker, AcpiMcfgInfo *info)
      * ACPI spec requires OSPMs to ignore such tables.
      */
     if (info->mcfg_base == PCIE_BASE_ADDR_UNMAPPED) {
-        sig = ACPI_RSRV_SIGNATURE;
+        /* Reserved signature: ignored by OSPM */
+        sig = "QEMU";
     } else {
-        sig = ACPI_MCFG_SIGNATURE;
+        sig = "MCFG";
     }
     build_header(linker, table_data, (void *)mcfg, sig, len, 1);
 }
@@ -1243,7 +1249,7 @@ build_dsdt(GArray *table_data, GArray *linker, AcpiMiscInfo *misc)
     memcpy(dsdt, misc->dsdt_code, misc->dsdt_size);
 
     memset(dsdt, 0, sizeof *dsdt);
-    build_header(linker, table_data, dsdt, ACPI_DSDT_SIGNATURE,
+    build_header(linker, table_data, dsdt, "DSDT",
                  misc->dsdt_size, 1);
 }
 
@@ -1268,7 +1274,7 @@ build_rsdt(GArray *table_data, GArray *linker, GArray *table_offsets)
                                        sizeof(uint32_t));
     }
     build_header(linker, table_data,
-                 (void *)rsdt, ACPI_RSDT_SIGNATURE, rsdt_len, 1);
+                 (void *)rsdt, "RSDT", rsdt_len, 1);
 }
 
 static GArray *
@@ -1279,7 +1285,7 @@ build_rsdp(GArray *rsdp_table, GArray *linker, unsigned rsdt)
     bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, 1,
                              true /* fseg memory */);
 
-    rsdp->signature = cpu_to_le64(ACPI_RSDP_SIGNATURE);
+    memcpy(&rsdp->signature, "RSD PTR ", 8);
     memcpy(rsdp->oem_id, ACPI_BUILD_APPNAME6, 6);
     rsdp->rsdt_physical_address = cpu_to_le32(rsdt);
     /* Address to be filled by Guest linker */
diff --git a/hw/i386/acpi-defs.h b/hw/i386/acpi-defs.h
index 78ca20489f..e93babb026 100644
--- a/hw/i386/acpi-defs.h
+++ b/hw/i386/acpi-defs.h
@@ -52,8 +52,6 @@ struct Acpi20GenericAddress {
 } QEMU_PACKED;
 typedef struct Acpi20GenericAddress Acpi20GenericAddress;
 
-#define ACPI_RSDP_SIGNATURE 0x2052545020445352LL // "RSD PTR "
-
 struct AcpiRsdpDescriptor {        /* Root System Descriptor Pointer */
     uint64_t signature;              /* ACPI signature, contains "RSD PTR " */
     uint8_t  checksum;               /* To make sum of struct == 0 */
@@ -92,7 +90,6 @@ typedef struct AcpiTableHeader AcpiTableHeader;
 /*
  * ACPI 1.0 Fixed ACPI Description Table (FADT)
  */
-#define ACPI_FACP_SIGNATURE 0x50434146 // FACP
 struct AcpiFadtDescriptorRev1
 {
     ACPI_TABLE_HEADER_DEF     /* ACPI common table header */
@@ -141,7 +138,6 @@ typedef struct AcpiFadtDescriptorRev1 AcpiFadtDescriptorRev1;
 /*
  * ACPI 1.0 Root System Description Table (RSDT)
  */
-#define ACPI_RSDT_SIGNATURE 0x54445352 // RSDT
 struct AcpiRsdtDescriptorRev1
 {
     ACPI_TABLE_HEADER_DEF       /* ACPI common table header */
@@ -153,7 +149,6 @@ typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
 /*
  * ACPI 1.0 Firmware ACPI Control Structure (FACS)
  */
-#define ACPI_FACS_SIGNATURE 0x53434146 // FACS
 struct AcpiFacsDescriptorRev1
 {
     uint32_t signature;           /* ACPI Signature */
@@ -169,7 +164,6 @@ typedef struct AcpiFacsDescriptorRev1 AcpiFacsDescriptorRev1;
 /*
  * Differentiated System Description Table (DSDT)
  */
-#define ACPI_DSDT_SIGNATURE 0x54445344 // DSDT
 
 /*
  * MADT values and structures
@@ -182,7 +176,6 @@ typedef struct AcpiFacsDescriptorRev1 AcpiFacsDescriptorRev1;
 
 /* Master MADT */
 
-#define ACPI_APIC_SIGNATURE 0x43495041 // APIC
 struct AcpiMultipleApicTable
 {
     ACPI_TABLE_HEADER_DEF     /* ACPI common table header */
@@ -253,7 +246,6 @@ typedef struct AcpiMadtLocalNmi AcpiMadtLocalNmi;
 /*
  * HPET Description Table
  */
-#define ACPI_HPET_SIGNATURE 0x54455048 // HPET
 struct Acpi20Hpet {
     ACPI_TABLE_HEADER_DEF                    /* ACPI common table header */
     uint32_t           timer_block_id;
@@ -268,7 +260,6 @@ typedef struct Acpi20Hpet Acpi20Hpet;
  * SRAT (NUMA topology description) table
  */
 
-#define ACPI_SRAT_SIGNATURE 0x54415253 // SRAT
 struct AcpiSystemResourceAffinityTable
 {
     ACPI_TABLE_HEADER_DEF
@@ -316,11 +307,6 @@ struct AcpiMcfgAllocation {
 } QEMU_PACKED;
 typedef struct AcpiMcfgAllocation AcpiMcfgAllocation;
 
-#define ACPI_MCFG_SIGNATURE 0x4746434d       // MCFG
-
-/* Reserved signature: ignored by OSPM */
-#define ACPI_RSRV_SIGNATURE 0x554d4551       // QEMU
-
 struct AcpiTableMcfg {
     ACPI_TABLE_HEADER_DEF;
     uint8_t reserved[8];
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index e715a3312d..14f0d91f76 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -53,6 +53,7 @@
 #include "qemu/bitmap.h"
 #include "qemu/config-file.h"
 #include "hw/acpi/acpi.h"
+#include "hw/acpi/cpu_hotplug.h"
 #include "hw/cpu/icc_bus.h"
 #include "hw/boards.h"
 #include "hw/pci/pci_host.h"
@@ -974,6 +975,13 @@ void pc_hot_add_cpu(const int64_t id, Error **errp)
         return;
     }
 
+    if (apic_id >= ACPI_CPU_HOTPLUG_ID_LIMIT) {
+        error_setg(errp, "Unable to add CPU: %" PRIi64
+                   ", resulting APIC ID (%" PRIi64 ") is too large",
+                   id, apic_id);
+        return;
+    }
+
     icc_bridge = DEVICE(object_resolve_path_type("icc-bridge",
                                                  TYPE_ICC_BRIDGE, NULL));
     pc_new_cpu(current_cpu_model, apic_id, icc_bridge, errp);
@@ -984,6 +992,7 @@ void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
     int i;
     X86CPU *cpu = NULL;
     Error *error = NULL;
+    unsigned long apic_id_limit;
 
     /* init CPUs */
     if (cpu_model == NULL) {
@@ -995,6 +1004,13 @@ void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
     }
     current_cpu_model = cpu_model;
 
+    apic_id_limit = pc_apic_id_limit(max_cpus);
+    if (apic_id_limit > ACPI_CPU_HOTPLUG_ID_LIMIT) {
+        error_report("max_cpus is too large. APIC ID of last CPU is %lu",
+                     apic_id_limit - 1);
+        exit(1);
+    }
+
     for (i = 0; i < smp_cpus; i++) {
         cpu = pc_new_cpu(cpu_model, x86_cpu_apic_id_from_index(i),
                          icc_bridge, &error);
diff --git a/include/hw/acpi/cpu_hotplug_defs.h b/include/hw/acpi/cpu_hotplug_defs.h
index 2725b50aac..9f33663511 100644
--- a/include/hw/acpi/cpu_hotplug_defs.h
+++ b/include/hw/acpi/cpu_hotplug_defs.h
@@ -17,7 +17,15 @@
  * between C and ASL code.
  */
 #define ACPI_CPU_HOTPLUG_STATUS 4
+
+/* Limit for CPU arch IDs for CPU hotplug. All hotpluggable CPUs should
+ * have CPUClass.get_arch_id() < ACPI_CPU_HOTPLUG_ID_LIMIT.
+ */
+#define ACPI_CPU_HOTPLUG_ID_LIMIT 256
+
+/* 256 CPU IDs, 8 bits per entry: */
 #define ACPI_GPE_PROC_LEN 32
+
 #define ICH9_CPU_HOTPLUG_IO_BASE 0x0CD8
 #define PIIX4_CPU_HOTPLUG_IO_BASE 0xaf00
 
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 3915ce3204..ba5c7f8093 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -133,7 +133,14 @@ extern uint8_t qemu_extra_params_fw[2];
 extern QEMUClockType rtc_clock;
 
 #define MAX_NODES 64
+
+/* The following shall be true for all CPUs:
+ *   cpu->cpu_index < max_cpus <= MAX_CPUMASK_BITS
+ *
+ * Note that cpu->get_arch_id() may be larger than MAX_CPUMASK_BITS.
+ */
 #define MAX_CPUMASK_BITS 255
+
 extern int nb_numa_nodes;
 extern uint64_t node_mem[MAX_NODES];
 extern unsigned long *node_cpumask[MAX_NODES];
diff --git a/tests/acpi-test-data/pc/SSDT b/tests/acpi-test-data/pc/SSDT
index ae5a9a57d6..727853eece 100644
--- a/tests/acpi-test-data/pc/SSDT
+++ b/tests/acpi-test-data/pc/SSDT
diff --git a/tests/acpi-test-data/q35/SSDT b/tests/acpi-test-data/q35/SSDT
index 634b4817fc..c7e20ffad2 100644
--- a/tests/acpi-test-data/q35/SSDT
+++ b/tests/acpi-test-data/q35/SSDT
diff --git a/tests/acpi-test.c b/tests/acpi-test.c
index 185309a241..76fbccfa4b 100644
--- a/tests/acpi-test.c
+++ b/tests/acpi-test.c
@@ -23,7 +23,6 @@
 #define MACHINE_Q35 "q35"
 
 #define ACPI_REBUILD_EXPECTED_AML "TEST_ACPI_REBUILD_AML"
-#define ACPI_SSDT_SIGNATURE 0x54445353 /* SSDT */
 
 /* DSDT and SSDTs format */
 typedef struct {
@@ -101,6 +100,20 @@ typedef struct {
         ACPI_READ_FIELD((table)->asl_compiler_revision, addr);   \
     } while (0);
 
+#define ACPI_ASSERT_CMP(actual, expected) do { \
+    uint32_t ACPI_ASSERT_CMP_le = cpu_to_le32(actual); \
+    char ACPI_ASSERT_CMP_str[5] = {}; \
+    memcpy(ACPI_ASSERT_CMP_str, &ACPI_ASSERT_CMP_le, 4); \
+    g_assert_cmpstr(ACPI_ASSERT_CMP_str, ==, expected); \
+} while (0)
+
+#define ACPI_ASSERT_CMP64(actual, expected) do { \
+    uint64_t ACPI_ASSERT_CMP_le = cpu_to_le64(actual); \
+    char ACPI_ASSERT_CMP_str[9] = {}; \
+    memcpy(ACPI_ASSERT_CMP_str, &ACPI_ASSERT_CMP_le, 8); \
+    g_assert_cmpstr(ACPI_ASSERT_CMP_str, ==, expected); \
+} while (0)
+
 /* Boot sector code: write SIGNATURE into memory,
  * then halt.
  * Q35 machine requires a minimum 0x7e000 bytes disk.
@@ -213,7 +226,7 @@ static void test_acpi_rsdp_table(test_data *data)
     uint32_t addr = data->rsdp_addr;
 
     ACPI_READ_FIELD(rsdp_table->signature, addr);
-    g_assert_cmphex(rsdp_table->signature, ==, ACPI_RSDP_SIGNATURE);
+    ACPI_ASSERT_CMP64(rsdp_table->signature, "RSD PTR ");
 
     ACPI_READ_FIELD(rsdp_table->checksum, addr);
     ACPI_READ_ARRAY(rsdp_table->oem_id, addr);
@@ -235,7 +248,7 @@ static void test_acpi_rsdt_table(test_data *data)
 
     /* read the header */
     ACPI_READ_TABLE_HEADER(rsdt_table, addr);
-    g_assert_cmphex(rsdt_table->signature, ==, ACPI_RSDT_SIGNATURE);
+    ACPI_ASSERT_CMP(rsdt_table->signature, "RSDT");
 
     /* compute the table entries in rsdt */
     tables_nr = (rsdt_table->length - sizeof(AcpiRsdtDescriptorRev1)) /
@@ -304,7 +317,7 @@ static void test_acpi_fadt_table(test_data *data)
     ACPI_READ_FIELD(fadt_table->reserved4b, addr);
     ACPI_READ_FIELD(fadt_table->flags, addr);
 
-    g_assert_cmphex(fadt_table->signature, ==, ACPI_FACP_SIGNATURE);
+    ACPI_ASSERT_CMP(fadt_table->signature, "FACP");
     g_assert(!acpi_checksum((uint8_t *)fadt_table, fadt_table->length));
 }
 
@@ -321,7 +334,7 @@ static void test_acpi_facs_table(test_data *data)
     ACPI_READ_FIELD(facs_table->flags, addr);
     ACPI_READ_ARRAY(facs_table->resverved3, addr);
 
-    g_assert_cmphex(facs_table->signature, ==, ACPI_FACS_SIGNATURE);
+    ACPI_ASSERT_CMP(facs_table->signature, "FACS");
 }
 
 static void test_dst_table(AcpiSdtTable *sdt_table, uint32_t addr)
@@ -348,7 +361,7 @@ static void test_acpi_dsdt_table(test_data *data)
     data->tables = g_array_new(false, true, sizeof(AcpiSdtTable));
 
     test_dst_table(&dsdt_table, addr);
-    g_assert_cmphex(dsdt_table.header.signature, ==, ACPI_DSDT_SIGNATURE);
+    ACPI_ASSERT_CMP(dsdt_table.header.signature, "DSDT");
 
     /* Place DSDT first */
     g_array_append_val(data->tables, dsdt_table);
@@ -383,8 +396,9 @@ static void dump_aml_files(test_data *data, bool rebuild)
         g_assert(sdt->aml);
 
         if (rebuild) {
+            uint32_t signature = cpu_to_le32(sdt->header.signature);
             aml_file = g_strdup_printf("%s/%s/%.4s", data_dir, data->machine,
-                                       (gchar *)&sdt->header.signature);
+                                       (gchar *)&signature);
             fd = g_open(aml_file, O_WRONLY|O_TRUNC|O_CREAT,
                         S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH);
         } else {
@@ -406,9 +420,9 @@ static void dump_aml_files(test_data *data, bool rebuild)
     }
 }
 
-static bool compare_signature(AcpiSdtTable *sdt, uint32_t signature)
+static bool compare_signature(AcpiSdtTable *sdt, const char *signature)
 {
-   return sdt->header.signature == signature;
+   return !memcmp(&sdt->header.signature, signature, 4);
 }
 
 static bool load_asl(GArray *sdts, AcpiSdtTable *sdt)
@@ -427,12 +441,12 @@ static bool load_asl(GArray *sdts, AcpiSdtTable *sdt)
 
     /* build command line */
     g_string_append_printf(command_line, " -p %s ", sdt->asl_file);
-    if (compare_signature(sdt, ACPI_DSDT_SIGNATURE) ||
-        compare_signature(sdt, ACPI_SSDT_SIGNATURE)) {
+    if (compare_signature(sdt, "DSDT") ||
+        compare_signature(sdt, "SSDT")) {
         for (i = 0; i < sdts->len; ++i) {
             temp = &g_array_index(sdts, AcpiSdtTable, i);
-            if (compare_signature(temp, ACPI_DSDT_SIGNATURE) ||
-                compare_signature(temp, ACPI_SSDT_SIGNATURE)) {
+            if (compare_signature(temp, "DSDT") ||
+                compare_signature(temp, "SSDT")) {
                 g_string_append_printf(command_line, "-e %s ", temp->aml_file);
             }
         }
@@ -442,13 +456,12 @@ static bool load_asl(GArray *sdts, AcpiSdtTable *sdt)
     /* pass 'out' and 'out_err' in order to be redirected */
     ret = g_spawn_command_line_sync(command_line->str, &out, &out_err, NULL, &error);
     g_assert_no_error(error);
-
     if (ret) {
         ret = g_file_get_contents(sdt->asl_file, (gchar **)&sdt->asl,
                                   &sdt->asl_len, &error);
         g_assert(ret);
         g_assert_no_error(error);
-        g_assert(sdt->asl_len);
+        ret = (sdt->asl_len > 0);
     }
 
     g_free(out);
@@ -495,13 +508,16 @@ static GArray *load_expected_aml(test_data *data)
     GArray *exp_tables = g_array_new(false, true, sizeof(AcpiSdtTable));
     for (i = 0; i < data->tables->len; ++i) {
         AcpiSdtTable exp_sdt;
+        uint32_t signature;
+
         sdt = &g_array_index(data->tables, AcpiSdtTable, i);
 
         memset(&exp_sdt, 0, sizeof(exp_sdt));
         exp_sdt.header.signature = sdt->header.signature;
 
+        signature = cpu_to_le32(sdt->header.signature);
         aml_file = g_strdup_printf("%s/%s/%.4s", data_dir, data->machine,
-                                   (gchar *)&exp_sdt.header.signature);
+                                   (gchar *)&signature);
         exp_sdt.aml_file = aml_file;
         g_assert(g_file_test(aml_file, G_FILE_TEST_EXISTS));
         ret = g_file_get_contents(aml_file, &exp_sdt.aml,
@@ -543,14 +559,20 @@ static void test_acpi_asl(test_data *data)
         g_assert(!err || exp_err);
 
         if (g_strcmp0(asl->str, exp_asl->str)) {
-            sdt->tmp_files_retain = true;
-            exp_sdt->tmp_files_retain = true;
-            fprintf(stderr,
-                    "acpi-test: Warning! %.4s mismatch. "
-                    "Actual [asl:%s, aml:%s], Expected [asl:%s, aml:%s].\n",
-                    (gchar *)&exp_sdt->header.signature,
-                    sdt->asl_file, sdt->aml_file,
-                    exp_sdt->asl_file, exp_sdt->aml_file);
+            if (exp_err) {
+                fprintf(stderr,
+                        "Warning! iasl couldn't parse the expected aml\n");
+            } else {
+                uint32_t signature = cpu_to_le32(exp_sdt->header.signature);
+                sdt->tmp_files_retain = true;
+                exp_sdt->tmp_files_retain = true;
+                fprintf(stderr,
+                        "acpi-test: Warning! %.4s mismatch. "
+                        "Actual [asl:%s, aml:%s], Expected [asl:%s, aml:%s].\n",
+                        (gchar *)&signature,
+                        sdt->asl_file, sdt->aml_file,
+                        exp_sdt->asl_file, exp_sdt->aml_file);
+          }
         }
         g_string_free(asl, true);
         g_string_free(exp_asl, true);
diff --git a/vl.c b/vl.c
index 02bf8ec47a..acd97a841c 100644
--- a/vl.c
+++ b/vl.c
@@ -1420,7 +1420,7 @@ static void smp_parse(QemuOpts *opts)
         max_cpus = smp_cpus;
     }
 
-    if (max_cpus > 255) {
+    if (max_cpus > MAX_CPUMASK_BITS) {
         fprintf(stderr, "Unsupported number of maxcpus\n");
         exit(1);
     }