test case to compare full CPUID dump for unexpected ABI changes

This adds a new test function to the cpuid.py test module, where the
CPUID data exposed by QEMU is compared with a full CPUID dump extracted
previously.

The new test code ensures that there are no ABI changes for a given
machine-type + CPU model combination, between QEMU versions.

The reference dumps were generated using the build-qemu-and-dump-cpus,
and copied using the copy-ref-dumps script.

There are some known QEMU bugs and past ABI changes that require
ignoring some differences. Those cases handled as rules that set
ignore_cpuid_leaves on qemu_cpu.cfg.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

qemu/tests/cfg/qemu_cpu.cfg

@@ -117,6 +117,139 @@
             # 486 is excluded due to not supporting cpuid
             no 486
             variants:
+                - full_dump:
+                    # machine types:
+                    # parameter is named "machine_type_to_check" because
+                    # somehow "machine_type" is being overwritten by another
+                    # config file section somewhere
+                    variants:
+                        - machine.rhel:
+                            only (qemu_flavor = rhel)
+                            variants:
+                                - rhel600:
+                                    machine_type_to_check = "rhel6.0.0"
+                                - rhel610:
+                                    machine_type_to_check = "rhel6.1.0"
+                                - rhel620:
+                                    machine_type_to_check = "rhel6.2.0"
+                                - rhel630:
+                                    machine_type_to_check = "rhel6.3.0"
+                                - rhel640:
+                                    machine_type_to_check = "rhel6.4.0"
+                        - machine.upstream:
+                            only (qemu_flavor = upstream)
+                            variants:
+                                - pc_1_0:
+                                    machine_type_to_check = "pc-1.0"
+                                - pc_1_1:
+                                    machine_type_to_check = "pc-1.1"
+                                - pc_1_2:
+                                    machine_type_to_check = "pc-1.2"
+                                - pc_1_3:
+                                    machine_type_to_check = "pc-1.3"
+                                - pc_q35_1_4:
+                                    machine_type_to_check = "pc-q35-1.4"
+                                - pc_i440fx_1_4:
+                                    machine_type_to_check = "pc-i440fx-1.4"
+                                - pc_q35_1_5:
+                                    machine_type_to_check = "pc-q35-1.5"
+                                - pc_i440fx_1_5:
+                                    machine_type_to_check = "pc-i440fx-1.5"
+
+                    test_type = "check_cpuid_dump"
+                    no cpu.unset
+
+                    #FEATURE: Ignore vendor string on KVM because it depends on host
+                    # CPU vendor:
+                    kvm:
+                        ignore_cpuid_leaves += " 0,0,ebx 0,0,ecx 0,0,edx"
+
+                    #KNOWN BUG: Processor Extended State leaf depends on host,
+                    # currently:
+                    ignore_cpuid_leaves += " 0xd,0"
+
+                    #KNOWN BUG: ignore brand string on those CPU models because
+                    # they change depending on QEMU version:
+                    cpu.intel.qemu32:
+                        ignore_cpuid_leaves += " 0x80000002 0x80000003 0x80000004"
+                    cpu.amd.qemu64:
+                        ignore_cpuid_leaves += " 0x80000002 0x80000003 0x80000004"
+                    cpu.amd.athlon:
+                        ignore_cpuid_leaves += " 0x80000002 0x80000003 0x80000004"
+
+                    #FIXED BUG: QEMU v1.1 and older have unstable host-dependent
+                    # data on the KVM leaf, so we will ignore it by now:
+                    machine.upstream.pc_1_0:
+                        ignore_cpuid_leaves += " 0x40000001,0x00,eax"
+                    machine.upstream.pc_1_1:
+                        ignore_cpuid_leaves += " 0x40000001,0x00,eax"
+
+                    #FIXED BUG: QEMU v1.0 had broken feature aliases on
+                    # 0x80000001.EDX, so ignore it:
+                    machine.upstream.pc_1_0:
+                        cpu.intel:
+                            ignore_cpuid_leaves += " 0x80000001,0x00,edx"
+
+                    #KNOWN BUG: the PMU CPUID leaf is unstable on QEMU 1.5 and
+                    # older, so ignore it:
+                    # (to be fixed on QEMU 1.6.0)
+                    ignore_cpuid_leaves += " 0xA"
+
+                    #KNOWN BUG: PCLMULQDQ compatibility on pc-1.4 and older is
+                    # known to be broken since v1.5.0, as the bit was enabled
+                    # without machine-type compatibility code
+                    # (see commit 41cb383f42d0cb51d8e3e25e3ecebc954dd4196f)
+                    cpu.intel.Westmere:
+                        machine.upstream.pc_i440fx_1_4:
+                            ignore_cpuid_leaves += " 1,0,ecx,1"
+                        machine.upstream.pc_q35_1_4:
+                            ignore_cpuid_leaves += " 1,0,ecx,1"
+                        machine.upstream.pc_1_3:
+                            ignore_cpuid_leaves += " 1,0,ecx,1"
+                        machine.upstream.pc_1_2:
+                            ignore_cpuid_leaves += " 1,0,ecx,1"
+                        machine.upstream.pc_1_1:
+                            ignore_cpuid_leaves += " 1,0,ecx,1"
+                        machine.upstream.pc_1_0:
+                            ignore_cpuid_leaves += " 1,0,ecx,1"
+
+                    # CPU models without the "apic" feature can't boot
+                    # using RHEL-6 Seabios
+                    machine.rhel:
+                        no cpu.intel.pentium, cpu.intel.pentium2, cpu.intel.pentium3
+
+                    # known RHEL-6 ABI breakage bugs:
+                    machine.rhel:
+                        # Max physical address depends on host:
+                        ignore_cpuid_leaves += " 0x80000008,0,eax"
+                        # KVM features depend on host kernel, as well:
+                        ignore_cpuid_leaves += " 0x40000001,0,eax"
+
+                    # SEP bit depended on host kernel on 6.3 and older:
+                    machine.rhel.rhel630:
+                        ignore_cpuid_leaves += " 1,0,edx,11"
+                    machine.rhel.rhel620:
+                        ignore_cpuid_leaves += " 1,0,edx,11"
+                    machine.rhel.rhel610:
+                        ignore_cpuid_leaves += " 1,0,edx,11"
+                    machine.rhel.rhel600:
+                        ignore_cpuid_leaves += " 1,0,edx,11"
+
+                    # unsupported-bits behavior changed between some RHEL-6
+                    # versions, and 0xC0000000 looks different now:
+                    machine.rhel:
+                        ignore_cpuid_leaves += " 0xc0000000,0x0"
+
+                    # RHEL-6.0 QEMU had broken feature aliases on
+                    # 0x80000001.EDX, so ignore it:
+                    machine.rhel.rhel600:
+                        cpu.intel:
+                            ignore_cpuid_leaves += " 0x80000001,0x00,edx"
+
+                    # bz#819562: broken passthrough mode of CPUID leaf 7
+                    machine.rhel.rhel620:
+                        ignore_cpuid_leaves += " 7,0"
+
                 - default.vendor:
                     test_type = "default_vendor"
                     kvm:

qemu/tests/cpuid.py

@@ -4,7 +4,7 @@ Group of cpuid tests for X86 CPU
 import re, sys, os, string
 from autotest.client.shared import error, utils
 from autotest.client.shared import test as test_module
-from virttest import utils_misc, env_process
+from virttest import utils_misc, env_process, virt_vm
 
 import logging
 logger = logging.getLogger(__name__)
@@ -480,6 +480,73 @@ def run_cpuid(test, params, env):
         if (has_error is False) and (xfail is True):
             raise error.TestFail("Test was expected to fail, but it didn't")
 
+    def check_cpuid_dump(self):
+        """
+        Compare full CPUID dump data
+        """
+        machine_type = params.get("machine_type_to_check","")
+        kvm_enabled = params.get("enable_kvm", "yes") == "yes"
+
+        ignore_cpuid_leaves = params.get("ignore_cpuid_leaves", "")
+        ignore_cpuid_leaves = ignore_cpuid_leaves.split()
+        whitelist = []
+        for l in ignore_cpuid_leaves:
+            l = l.split(',')
+            # syntax of ignore_cpuid_leaves:
+            # <in_eax>[,<in_ecx>[,<register>[ ,<bit>]]] ...
+            for i in 0,1,3: # integer fields:
+                if len(l) > i:
+                    l[i] = int(l[i], 0)
+            whitelist.append(tuple(l))
+
+        if not machine_type:
+            raise error.TestNAError("No machine_type_to_check defined")
+        ref_file = os.path.join(test.virtdir, "deps",
+                                "cpuid_dumps",
+                                kvm_enabled and "kvm" or "nokvm",
+                                machine_type, '%s-dump.txt' % (cpu_model))
+        if not os.path.exists(ref_file):
+            raise error.TestNAError("no cpuid dump file: %s" % (ref_file))
+        reference = open(ref_file, 'r').read()
+        if not reference:
+            raise error.TestNAError("no cpuid dump data on file: %s" % (ref_file))
+        reference = parse_cpuid_dump(reference)
+        if reference is None:
+            raise error.TestNAError("couldn't parse reference cpuid dump from file; %s" % (ref_file))
+        try:
+            out = get_guest_cpuid(self, cpu_model, 'enforce',
+                                  extra_params=dict(machine_type=machine_type, smp=1))
+        except virt_vm.VMCreateError,e:
+            if "host doesn't support requested feature:" in e.output \
+                or ("host cpuid" in e.output and \
+                    "lacks requested flag" in e.output):
+                raise error.TestNAError("Can't run CPU model %s on this host" % (cpu_model))
+            else:
+                raise
+        dbg('ref_file: %r', ref_file)
+        dbg('ref: %r', reference)
+        dbg('out: %r', out)
+        ok = True
+        for k in reference.keys():
+            in_eax,in_ecx = k
+            if k not in out:
+                info("Missing CPUID data from output: CPUID[0x%x,0x%x]", in_eax, in_ecx)
+                ok = False
+                continue
+            diffs = compare_cpuid_output(reference[k], out[k])
+            for d in diffs:
+                reg, bit, vreference, vout =d
+                whitelisted = (in_eax,) in whitelist \
+                    or (in_eax, in_ecx) in whitelist \
+                    or (in_eax, in_ecx, reg) in whitelist \
+                    or (in_eax, in_ecx, reg, bit) in whitelist
+                info("Non-matching bit: CPUID[0x%x,0x%x].%s[%d]: found %s instead of %s%s",
+                     in_eax, in_ecx, reg, bit, vout, vreference,
+                     whitelisted and " (whitelisted)" or "")
+                if not whitelisted:
+                    ok = False
+        if not ok:
+            raise error.TestFail("Unexpected CPUID data")
 
     # subtests runner
     test_type = params["test_type"]