static const uint32_t __initconst pv_featuremask[] = INIT_PV_FEATURES;
static const uint32_t __initconst hvm_shadow_featuremask[] = INIT_HVM_SHADOW_FEATURES;
static const uint32_t __initconst hvm_hap_featuremask[] = INIT_HVM_HAP_FEATURES;
+static const uint32_t __initconst deep_features[] = INIT_DEEP_FEATURES;
uint32_t __read_mostly raw_featureset[FSCAPINTS];
uint32_t __read_mostly pv_featureset[FSCAPINTS];
static void __init sanitise_featureset(uint32_t *fs)
{
+ /* for_each_set_bit() uses unsigned longs. Extend with zeroes. */
+ uint32_t disabled_features[
+ ROUNDUP(FSCAPINTS, sizeof(unsigned long)/sizeof(uint32_t))] = {};
unsigned int i;
for ( i = 0; i < FSCAPINTS; ++i )
{
/* Clamp to known mask. */
fs[i] &= known_features[i];
+
+ /*
+ * Identify which features with deep dependencies have been
+ * disabled.
+ */
+ disabled_features[i] = ~fs[i] & deep_features[i];
+ }
+
+ for_each_set_bit(i, (void *)disabled_features,
+ sizeof(disabled_features) * 8)
+ {
+ const uint32_t *dfs = lookup_deep_deps(i);
+ unsigned int j;
+
+ ASSERT(dfs); /* deep_features[] should guarentee this. */
+
+ for ( j = 0; j < FSCAPINTS; ++j )
+ {
+ fs[j] &= ~dfs[j];
+ disabled_features[j] &= ~dfs[j];
+ }
}
/*
calculate_hvm_featureset();
}
+const uint32_t * __init lookup_deep_deps(uint32_t feature)
+{
+ static const struct {
+ uint32_t feature;
+ uint32_t fs[FSCAPINTS];
+ } deep_deps[] __initconst = INIT_DEEP_DEPS;
+ unsigned int start = 0, end = ARRAY_SIZE(deep_deps);
+
+ BUILD_BUG_ON(ARRAY_SIZE(deep_deps) != NR_DEEP_DEPS);
+
+ /* Fast early exit. */
+ if ( !test_bit(feature, deep_features) )
+ return NULL;
+
+ /* deep_deps[] is sorted. Perform a binary search. */
+ while ( start < end )
+ {
+ unsigned int mid = start + ((end - start) / 2);
+
+ if ( deep_deps[mid].feature > feature )
+ end = mid;
+ else if ( deep_deps[mid].feature < feature )
+ start = mid + 1;
+ else
+ return deep_deps[mid].fs;
+ }
+
+ return NULL;
+}
+
static void __init __maybe_unused build_assertions(void)
{
BUILD_BUG_ON(ARRAY_SIZE(known_features) != FSCAPINTS);
BUILD_BUG_ON(ARRAY_SIZE(pv_featuremask) != FSCAPINTS);
BUILD_BUG_ON(ARRAY_SIZE(hvm_shadow_featuremask) != FSCAPINTS);
BUILD_BUG_ON(ARRAY_SIZE(hvm_hap_featuremask) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(deep_features) != FSCAPINTS);
}
/*
state.hvm_shadow = featureset_to_uint32s(state.raw_hvm_shadow, nr_entries)
state.hvm_hap = featureset_to_uint32s(state.raw_hvm_hap, nr_entries)
+ #
+ # Feature dependency information.
+ #
+ # !!! WARNING !!!
+ #
+ # A lot of this information is derived from the written text of vendors
+ # software manuals, rather than directly from a statement. As such, it
+ # does contain guesswork and assumptions, and may not accurately match
+ # hardware implementations.
+ #
+ # It is however designed to create an end result for a guest which does
+ # plausibly match real hardware.
+ #
+ # !!! WARNING !!!
+ #
+ # The format of this dictionary is that the feature in the key is a direct
+ # prerequisite of each feature in the value.
+ #
+ # The first consideration is about which functionality is physically built
+ # on top of other features. The second consideration, which is more
+ # subjective, is whether real hardware would ever be found supporting
+ # feature X but not Y.
+ #
+ deps = {
+ # FPU is taken to mean support for the x87 regisers as well as the
+ # instructions. MMX is documented to alias the %MM registers over the
+ # x87 %ST registers in hardware.
+ FPU: [MMX],
+
+ # The PSE36 feature indicates that reserved bits in a PSE superpage
+ # may be used as extra physical address bits.
+ PSE: [PSE36],
+
+ # Entering Long Mode requires that %CR4.PAE is set. The NX pagetable
+ # bit is only representable in the 64bit PTE format offered by PAE.
+ PAE: [LM, NX],
+
+ # APIC is special, but X2APIC does depend on APIC being available in
+ # the first place.
+ APIC: [X2APIC],
+
+ # AMD built MMXExtentions and 3DNow as extentions to MMX.
+ MMX: [MMXEXT, _3DNOW],
+
+ # The FXSAVE/FXRSTOR instructions were introduced into hardware before
+ # SSE, which is why they behave differently based on %CR4.OSFXSAVE and
+ # have their own feature bit. AMD however introduce the Fast FXSR
+ # feature as an optimisation.
+ FXSR: [FFXSR, SSE],
+
+ # SSE is taken to mean support for the %XMM registers as well as the
+ # instructions. Several futher instruction sets are built on core
+ # %XMM support, without specific inter-dependencies.
+ SSE: [SSE2, SSE3, SSSE3, SSE4A,
+ AESNI, SHA],
+
+ # SSE2 was re-specified as core instructions for 64bit.
+ SSE2: [LM],
+
+ # SSE4.1 explicitly depends on SSE3 and SSSE3
+ SSE3: [SSE4_1],
+ SSSE3: [SSE4_1],
+
+ # SSE4.2 explicitly depends on SSE4.1
+ SSE4_1: [SSE4_2],
+
+ # AMD specify no relationship between POPCNT and SSE4.2. Intel
+ # document that SSE4.2 should be checked for before checking for
+ # POPCNT. However, it has its own feature bit, and operates on GPRs
+ # rather than %XMM state, so doesn't inherently depend on SSE.
+ # Therefore, we do not specify a dependency between SSE4_2 and POPCNT.
+ #
+ # SSE4_2: [POPCNT]
+
+ # The INVPCID instruction depends on PCID infrastructure being
+ # available.
+ PCID: [INVPCID],
+
+ # XSAVE is an extra set of instructions for state management, but
+ # doesn't constitue new state itself. Some of the dependent features
+ # are instructions built on top of base XSAVE, while others are new
+ # instruction groups which are specified to require XSAVE for state
+ # management.
+ XSAVE: [XSAVEOPT, XSAVEC, XGETBV1, XSAVES,
+ AVX, MPX, PKU, LWP],
+
+ # AVX is taken to mean hardware support for VEX encoded instructions,
+ # 256bit registers, and the instructions themselves. Each of these
+ # subsequent instruction groups may only be VEX encoded.
+ AVX: [FMA, FMA4, F16C, AVX2, XOP],
+
+ # CX16 is only encodable in Long Mode. LAHF_LM indicates that the
+ # SAHF/LAHF instructions are reintroduced in Long Mode. 1GB
+ # superpages, PCID and PKU are only available in 4 level paging.
+ LM: [CX16, PCID, LAHF_LM, PAGE1GB, PKU],
+
+ # AMD K6-2+ and K6-III processors shipped with 3DNow+, beyond the
+ # standard 3DNow in the earlier K6 processors.
+ _3DNOW: [_3DNOWEXT],
+ }
+
+ deep_features = tuple(sorted(deps.keys()))
+ state.deep_deps = {}
+
+ for feat in deep_features:
+
+ seen = [feat]
+ to_process = list(deps[feat])
+
+ while len(to_process):
+
+ # To debug, uncomment the following lines:
+ # def repl(l):
+ # return "[" + ", ".join((state.names[x] for x in l)) + "]"
+ # print >>sys.stderr, "Feature %s, seen %s, to_process %s " % \
+ # (state.names[feat], repl(seen), repl(to_process))
+
+ f = to_process.pop(0)
+
+ if f in seen:
+ raise Fail("ERROR: Cycle found with %s when processing %s"
+ % (state.names[f], state.names[feat]))
+
+ seen.append(f)
+ to_process = list(set(to_process + deps.get(f, [])))
+
+ state.deep_deps[feat] = seen[1:]
+
+ state.deep_features = featureset_to_uint32s(deps.keys(), nr_entries)
+ state.nr_deep_deps = len(state.deep_deps.keys())
+
+ for k, v in state.deep_deps.iteritems():
+ state.deep_deps[k] = featureset_to_uint32s(v, nr_entries)
+
def write_results(state):
state.output.write(
#define CPUID_COMMON_1D_FEATURES %s
-#define INIT_KNOWN_FEATURES { \\\n%s\n}
+#define INIT_KNOWN_FEATURES { \\\n%s\n}
+
+#define INIT_SPECIAL_FEATURES { \\\n%s\n}
-#define INIT_SPECIAL_FEATURES { \\\n%s\n}
+#define INIT_PV_FEATURES { \\\n%s\n}
-#define INIT_PV_FEATURES { \\\n%s\n}
+#define INIT_HVM_SHADOW_FEATURES { \\\n%s\n}
-#define INIT_HVM_SHADOW_FEATURES { \\\n%s\n}
+#define INIT_HVM_HAP_FEATURES { \\\n%s\n}
-#define INIT_HVM_HAP_FEATURES { \\\n%s\n}
+#define NR_DEEP_DEPS %sU
+
+#define INIT_DEEP_FEATURES { \\\n%s\n}
+
+#define INIT_DEEP_DEPS { \\
""" % (state.nr_entries,
state.common_1d,
format_uint32s(state.known, 4),
format_uint32s(state.pv, 4),
format_uint32s(state.hvm_shadow, 4),
format_uint32s(state.hvm_hap, 4),
+ state.nr_deep_deps,
+ format_uint32s(state.deep_features, 4),
))
+ for dep in sorted(state.deep_deps.keys()):
+ state.output.write(
+ " { %#xU, /* %s */ { \\\n%s\n }, }, \\\n"
+ % (dep, state.names[dep],
+ format_uint32s(state.deep_deps[dep], 8)
+ ))
+
state.output.write(
-"""
+"""}
+
#endif /* __XEN_X86__FEATURESET_DATA__ */
""")
projects / xen.git / commitdiff