diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index 24ac92718288..c5c5b8716521 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -2010,24 +2010,12 @@ proccount procpkg stepping
 
 =back
 
-List of keys taking a character:
+List of keys taking a character can be found in the public header file
+L<arch-x86/cpufeatureset.h|http://xenbits.xen.org/docs/unstable/hypercall/x86_64/include,public,arch-x86,cpufeatureset.h.html>
 
-=over 4
-
-3dnow 3dnowext 3dnowprefetch abm acpi adx aes altmovcr8 apic arat avx avx2
-avx512-4fmaps avx512-4vnniw avx512bw avx512cd avx512dq avx512er avx512f
-avx512ifma avx512pf avx512vbmi avx512vl bmi1 bmi2 clflushopt clfsh clwb cmov
-cmplegacy cmpxchg16 cmpxchg8 cmt cntxid dca de ds dscpl dtes64 erms est extapic
-f16c ffxsr fma fma4 fpu fsgsbase fxsr hle htt hypervisor ia64 ibs invpcid
-invtsc lahfsahf lm lwp mca mce misalignsse mmx mmxext monitor movbe mpx msr
-mtrr nodeid nx ospke osvw osxsave pae page1gb pat pbe pcid pclmulqdq pdcm
-perfctr_core perfctr_nb pge pku popcnt pse pse36 psn rdrand rdseed rdtscp rtm
-sha skinit smap smep smx ss sse sse2 sse3 sse4.1 sse4.2 sse4_1 sse4_2 sse4a
-ssse3 svm svm_decode svm_lbrv svm_npt svm_nrips svm_pausefilt svm_tscrate
-svm_vmcbclean syscall sysenter tbm tm tm2 topoext tsc tsc-deadline tsc_adjust
-umip vme vmx wdt x2apic xop xsave xtpr
-
-=back
+Note that C<clflush> is described as an option that takes a value, and that
+takes precedence over the C<clflush> flag in C<cpufeatureset.h>.  The feature
+flag must be referenced as C<clfsh>.
 
 =back
 
diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c
index f5ce9f97959c..0c7ffff416fe 100644
--- a/tools/libs/light/libxl_cpuid.c
+++ b/tools/libs/light/libxl_cpuid.c
@@ -14,6 +14,8 @@
 
 #include "libxl_internal.h"
 
+#include <xen/lib/x86/cpu-policy.h>
+
 int libxl__cpuid_policy_is_empty(libxl_cpuid_policy_list *pl)
 {
     return !libxl_cpuid_policy_list_length(pl);
@@ -51,7 +53,7 @@ void libxl_cpuid_dispose(libxl_cpuid_policy_list *p_cpuid_list)
  * Used for the static structure describing all features.
  */
 struct cpuid_flags {
-    char* name;
+    const char* name;
     uint32_t leaf;
     uint32_t subleaf;
     int reg;
@@ -81,6 +83,14 @@ static libxl_cpuid_policy_list cpuid_find_match(libxl_cpuid_policy_list *list,
     return *list + i;
 }
 
+static int search_feature(const void *a, const void *b)
+{
+    const char *key = a;
+    const char *feat = ((struct { const char *n; } *)b)->n;
+
+    return strncmp(key, feat, strlen(key)) ?: strlen(key) - strlen(feat);
+}
+
 /* parse a single key=value pair and translate it into the libxc
  * used interface using 32-characters strings for each register.
  * Will overwrite earlier entries and thus can be called multiple
@@ -101,208 +111,37 @@ int libxl_cpuid_parse_config(libxl_cpuid_policy_list *cpuid, const char* str)
         {"proccount",    0x00000001, NA, CPUID_REG_EBX, 16,  8},
         {"localapicid",  0x00000001, NA, CPUID_REG_EBX, 24,  8},
 
-        {"sse3",         0x00000001, NA, CPUID_REG_ECX,  0,  1},
-        {"pclmulqdq",    0x00000001, NA, CPUID_REG_ECX,  1,  1},
-        {"dtes64",       0x00000001, NA, CPUID_REG_ECX,  2,  1},
-        {"monitor",      0x00000001, NA, CPUID_REG_ECX,  3,  1},
-        {"dscpl",        0x00000001, NA, CPUID_REG_ECX,  4,  1},
-        {"vmx",          0x00000001, NA, CPUID_REG_ECX,  5,  1},
-        {"smx",          0x00000001, NA, CPUID_REG_ECX,  6,  1},
         {"est",          0x00000001, NA, CPUID_REG_ECX,  7,  1},
-        {"tm2",          0x00000001, NA, CPUID_REG_ECX,  8,  1},
-        {"ssse3",        0x00000001, NA, CPUID_REG_ECX,  9,  1},
         {"cntxid",       0x00000001, NA, CPUID_REG_ECX, 10,  1},
-        {"fma",          0x00000001, NA, CPUID_REG_ECX, 12,  1},
         {"cmpxchg16",    0x00000001, NA, CPUID_REG_ECX, 13,  1},
-        {"xtpr",         0x00000001, NA, CPUID_REG_ECX, 14,  1},
-        {"pdcm",         0x00000001, NA, CPUID_REG_ECX, 15,  1},
-        {"pcid",         0x00000001, NA, CPUID_REG_ECX, 17,  1},
-        {"dca",          0x00000001, NA, CPUID_REG_ECX, 18,  1},
         /* Linux uses sse4_{1,2}.  Keep sse4.{1,2} for compatibility */
-        {"sse4_1",       0x00000001, NA, CPUID_REG_ECX, 19,  1},
         {"sse4.1",       0x00000001, NA, CPUID_REG_ECX, 19,  1},
-        {"sse4_2",       0x00000001, NA, CPUID_REG_ECX, 20,  1},
         {"sse4.2",       0x00000001, NA, CPUID_REG_ECX, 20,  1},
-        {"x2apic",       0x00000001, NA, CPUID_REG_ECX, 21,  1},
-        {"movbe",        0x00000001, NA, CPUID_REG_ECX, 22,  1},
-        {"popcnt",       0x00000001, NA, CPUID_REG_ECX, 23,  1},
-        {"tsc-deadline", 0x00000001, NA, CPUID_REG_ECX, 24,  1},
         {"aes",          0x00000001, NA, CPUID_REG_ECX, 25,  1},
-        {"xsave",        0x00000001, NA, CPUID_REG_ECX, 26,  1},
-        {"osxsave",      0x00000001, NA, CPUID_REG_ECX, 27,  1},
-        {"avx",          0x00000001, NA, CPUID_REG_ECX, 28,  1},
-        {"f16c",         0x00000001, NA, CPUID_REG_ECX, 29,  1},
-        {"rdrand",       0x00000001, NA, CPUID_REG_ECX, 30,  1},
-        {"hypervisor",   0x00000001, NA, CPUID_REG_ECX, 31,  1},
-
-        {"fpu",          0x00000001, NA, CPUID_REG_EDX,  0,  1},
-        {"vme",          0x00000001, NA, CPUID_REG_EDX,  1,  1},
-        {"de",           0x00000001, NA, CPUID_REG_EDX,  2,  1},
-        {"pse",          0x00000001, NA, CPUID_REG_EDX,  3,  1},
-        {"tsc",          0x00000001, NA, CPUID_REG_EDX,  4,  1},
-        {"msr",          0x00000001, NA, CPUID_REG_EDX,  5,  1},
-        {"pae",          0x00000001, NA, CPUID_REG_EDX,  6,  1},
-        {"mce",          0x00000001, NA, CPUID_REG_EDX,  7,  1},
+
         {"cmpxchg8",     0x00000001, NA, CPUID_REG_EDX,  8,  1},
-        {"apic",         0x00000001, NA, CPUID_REG_EDX,  9,  1},
         {"sysenter",     0x00000001, NA, CPUID_REG_EDX, 11,  1},
-        {"mtrr",         0x00000001, NA, CPUID_REG_EDX, 12,  1},
-        {"pge",          0x00000001, NA, CPUID_REG_EDX, 13,  1},
-        {"mca",          0x00000001, NA, CPUID_REG_EDX, 14,  1},
-        {"cmov",         0x00000001, NA, CPUID_REG_EDX, 15,  1},
-        {"pat",          0x00000001, NA, CPUID_REG_EDX, 16,  1},
-        {"pse36",        0x00000001, NA, CPUID_REG_EDX, 17,  1},
         {"psn",          0x00000001, NA, CPUID_REG_EDX, 18,  1},
         {"clfsh",        0x00000001, NA, CPUID_REG_EDX, 19,  1},
-        {"ds",           0x00000001, NA, CPUID_REG_EDX, 21,  1},
-        {"acpi",         0x00000001, NA, CPUID_REG_EDX, 22,  1},
-        {"mmx",          0x00000001, NA, CPUID_REG_EDX, 23,  1},
-        {"fxsr",         0x00000001, NA, CPUID_REG_EDX, 24,  1},
-        {"sse",          0x00000001, NA, CPUID_REG_EDX, 25,  1},
-        {"sse2",         0x00000001, NA, CPUID_REG_EDX, 26,  1},
-        {"ss",           0x00000001, NA, CPUID_REG_EDX, 27,  1},
-        {"htt",          0x00000001, NA, CPUID_REG_EDX, 28,  1},
         {"tm",           0x00000001, NA, CPUID_REG_EDX, 29,  1},
         {"ia64",         0x00000001, NA, CPUID_REG_EDX, 30,  1},
         {"pbe",          0x00000001, NA, CPUID_REG_EDX, 31,  1},
 
         {"arat",         0x00000006, NA, CPUID_REG_EAX,  2,  1},
 
-        {"fsgsbase",     0x00000007,  0, CPUID_REG_EBX,  0,  1},
-        {"tsc_adjust",   0x00000007,  0, CPUID_REG_EBX,  1,  1},
-        {"bmi1",         0x00000007,  0, CPUID_REG_EBX,  3,  1},
-        {"hle",          0x00000007,  0, CPUID_REG_EBX,  4,  1},
-        {"avx2",         0x00000007,  0, CPUID_REG_EBX,  5,  1},
-        {"smep",         0x00000007,  0, CPUID_REG_EBX,  7,  1},
-        {"bmi2",         0x00000007,  0, CPUID_REG_EBX,  8,  1},
-        {"erms",         0x00000007,  0, CPUID_REG_EBX,  9,  1},
-        {"invpcid",      0x00000007,  0, CPUID_REG_EBX, 10,  1},
-        {"rtm",          0x00000007,  0, CPUID_REG_EBX, 11,  1},
-        {"cmt",          0x00000007,  0, CPUID_REG_EBX, 12,  1},
-        {"mpx",          0x00000007,  0, CPUID_REG_EBX, 14,  1},
-        {"avx512f",      0x00000007,  0, CPUID_REG_EBX, 16,  1},
-        {"avx512dq",     0x00000007,  0, CPUID_REG_EBX, 17,  1},
-        {"rdseed",       0x00000007,  0, CPUID_REG_EBX, 18,  1},
-        {"adx",          0x00000007,  0, CPUID_REG_EBX, 19,  1},
-        {"smap",         0x00000007,  0, CPUID_REG_EBX, 20,  1},
-        {"avx512-ifma",  0x00000007,  0, CPUID_REG_EBX, 21,  1},
-        {"clflushopt",   0x00000007,  0, CPUID_REG_EBX, 23,  1},
-        {"clwb",         0x00000007,  0, CPUID_REG_EBX, 24,  1},
-        {"proc-trace",   0x00000007,  0, CPUID_REG_EBX, 25,  1},
-        {"avx512pf",     0x00000007,  0, CPUID_REG_EBX, 26,  1},
-        {"avx512er",     0x00000007,  0, CPUID_REG_EBX, 27,  1},
-        {"avx512cd",     0x00000007,  0, CPUID_REG_EBX, 28,  1},
-        {"sha",          0x00000007,  0, CPUID_REG_EBX, 29,  1},
-        {"avx512bw",     0x00000007,  0, CPUID_REG_EBX, 30,  1},
-        {"avx512vl",     0x00000007,  0, CPUID_REG_EBX, 31,  1},
-
-        {"prefetchwt1",  0x00000007,  0, CPUID_REG_ECX,  0,  1},
-        {"avx512-vbmi",  0x00000007,  0, CPUID_REG_ECX,  1,  1},
-        {"umip",         0x00000007,  0, CPUID_REG_ECX,  2,  1},
-        {"pku",          0x00000007,  0, CPUID_REG_ECX,  3,  1},
-        {"ospke",        0x00000007,  0, CPUID_REG_ECX,  4,  1},
-        {"avx512-vbmi2", 0x00000007,  0, CPUID_REG_ECX,  6,  1},
-        {"cet-ss",       0x00000007,  0, CPUID_REG_ECX,  7,  1},
-        {"gfni",         0x00000007,  0, CPUID_REG_ECX,  8,  1},
-        {"vaes",         0x00000007,  0, CPUID_REG_ECX,  9,  1},
-        {"vpclmulqdq",   0x00000007,  0, CPUID_REG_ECX, 10,  1},
-        {"avx512-vnni",  0x00000007,  0, CPUID_REG_ECX, 11,  1},
-        {"avx512-bitalg",0x00000007,  0, CPUID_REG_ECX, 12,  1},
-        {"avx512-vpopcntdq",0x00000007,0,CPUID_REG_ECX, 14,  1},
-        {"rdpid",        0x00000007,  0, CPUID_REG_ECX, 22,  1},
-        {"cldemote",     0x00000007,  0, CPUID_REG_ECX, 25,  1},
-        {"pks",          0x00000007,  0, CPUID_REG_ECX, 31,  1},
-
-        {"avx512-4vnniw",0x00000007,  0, CPUID_REG_EDX,  2,  1},
-        {"avx512-4fmaps",0x00000007,  0, CPUID_REG_EDX,  3,  1},
-        {"fsrm",         0x00000007,  0, CPUID_REG_EDX,  4,  1},
-        {"avx512-vp2intersect",0x00000007,0,CPUID_REG_EDX,8, 1},
-        {"srbds-ctrl",   0x00000007,  0, CPUID_REG_EDX,  9,  1},
-        {"md-clear",     0x00000007,  0, CPUID_REG_EDX, 10,  1},
-        {"serialize",    0x00000007,  0, CPUID_REG_EDX, 14,  1},
-        {"tsxldtrk",     0x00000007,  0, CPUID_REG_EDX, 16,  1},
-        {"cet-ibt",      0x00000007,  0, CPUID_REG_EDX, 20,  1},
-        {"avx512-fp16",  0x00000007,  0, CPUID_REG_EDX, 23,  1},
-        {"ibrsb",        0x00000007,  0, CPUID_REG_EDX, 26,  1},
-        {"stibp",        0x00000007,  0, CPUID_REG_EDX, 27,  1},
-        {"l1d-flush",    0x00000007,  0, CPUID_REG_EDX, 28,  1},
-        {"arch-caps",    0x00000007,  0, CPUID_REG_EDX, 29,  1},
-        {"core-caps",    0x00000007,  0, CPUID_REG_EDX, 30,  1},
-        {"ssbd",         0x00000007,  0, CPUID_REG_EDX, 31,  1},
-
-        {"avx-vnni",     0x00000007,  1, CPUID_REG_EAX,  4,  1},
-        {"avx512-bf16",  0x00000007,  1, CPUID_REG_EAX,  5,  1},
-        {"fzrm",         0x00000007,  1, CPUID_REG_EAX, 10,  1},
-        {"fsrs",         0x00000007,  1, CPUID_REG_EAX, 11,  1},
-        {"fsrcs",        0x00000007,  1, CPUID_REG_EAX, 12,  1},
-        {"wrmsrns",      0x00000007,  1, CPUID_REG_EAX, 19,  1},
-        {"avx-ifma",     0x00000007,  1, CPUID_REG_EAX, 23,  1},
-
-        {"avx-vnni-int8",0x00000007,  1, CPUID_REG_EDX,  4,  1},
-        {"avx-ne-convert",0x00000007, 1, CPUID_REG_EDX,  5,  1},
-        {"cet-sss",      0x00000007,  1, CPUID_REG_EDX, 18,  1},
-
-        {"intel-psfd",   0x00000007,  2, CPUID_REG_EDX,  0,  1},
-        {"ipred-ctrl",   0x00000007,  2, CPUID_REG_EDX,  1,  1},
-        {"rrsba-ctrl",   0x00000007,  2, CPUID_REG_EDX,  2,  1},
-        {"ddp-ctrl",     0x00000007,  2, CPUID_REG_EDX,  3,  1},
-        {"bhi-ctrl",     0x00000007,  2, CPUID_REG_EDX,  4,  1},
-        {"mcdt-no",      0x00000007,  2, CPUID_REG_EDX,  5,  1},
-
         {"lahfsahf",     0x80000001, NA, CPUID_REG_ECX,  0,  1},
         {"cmplegacy",    0x80000001, NA, CPUID_REG_ECX,  1,  1},
-        {"svm",          0x80000001, NA, CPUID_REG_ECX,  2,  1},
-        {"extapic",      0x80000001, NA, CPUID_REG_ECX,  3,  1},
         {"altmovcr8",    0x80000001, NA, CPUID_REG_ECX,  4,  1},
-        {"abm",          0x80000001, NA, CPUID_REG_ECX,  5,  1},
-        {"sse4a",        0x80000001, NA, CPUID_REG_ECX,  6,  1},
-        {"misalignsse",  0x80000001, NA, CPUID_REG_ECX,  7,  1},
-        {"3dnowprefetch",0x80000001, NA, CPUID_REG_ECX,  8,  1},
-        {"osvw",         0x80000001, NA, CPUID_REG_ECX,  9,  1},
-        {"ibs",          0x80000001, NA, CPUID_REG_ECX, 10,  1},
-        {"xop",          0x80000001, NA, CPUID_REG_ECX, 11,  1},
-        {"skinit",       0x80000001, NA, CPUID_REG_ECX, 12,  1},
-        {"wdt",          0x80000001, NA, CPUID_REG_ECX, 13,  1},
-        {"lwp",          0x80000001, NA, CPUID_REG_ECX, 15,  1},
-        {"fma4",         0x80000001, NA, CPUID_REG_ECX, 16,  1},
         {"nodeid",       0x80000001, NA, CPUID_REG_ECX, 19,  1},
-        {"tbm",          0x80000001, NA, CPUID_REG_ECX, 21,  1},
-        {"topoext",      0x80000001, NA, CPUID_REG_ECX, 22,  1},
         {"perfctr_core", 0x80000001, NA, CPUID_REG_ECX, 23,  1},
         {"perfctr_nb",   0x80000001, NA, CPUID_REG_ECX, 24,  1},
 
-        {"syscall",      0x80000001, NA, CPUID_REG_EDX, 11,  1},
-        {"nx",           0x80000001, NA, CPUID_REG_EDX, 20,  1},
-        {"mmxext",       0x80000001, NA, CPUID_REG_EDX, 22,  1},
-        {"ffxsr",        0x80000001, NA, CPUID_REG_EDX, 25,  1},
-        {"page1gb",      0x80000001, NA, CPUID_REG_EDX, 26,  1},
-        {"rdtscp",       0x80000001, NA, CPUID_REG_EDX, 27,  1},
-        {"lm",           0x80000001, NA, CPUID_REG_EDX, 29,  1},
-        {"3dnowext",     0x80000001, NA, CPUID_REG_EDX, 30,  1},
-        {"3dnow",        0x80000001, NA, CPUID_REG_EDX, 31,  1},
-
         {"procpkg",      0x00000004,  0, CPUID_REG_EAX, 26,  6},
 
         {"invtsc",       0x80000007, NA, CPUID_REG_EDX,  8,  1},
 
-        {"clzero",       0x80000008, NA, CPUID_REG_EBX,  0,  1},
-        {"rstr-fp-err-ptrs", 0x80000008, NA, CPUID_REG_EBX, 2, 1},
-        {"wbnoinvd",     0x80000008, NA, CPUID_REG_EBX,  9,  1},
-        {"ibpb",         0x80000008, NA, CPUID_REG_EBX, 12,  1},
-        {"ibrs",         0x80000008, NA, CPUID_REG_EBX, 14,  1},
-        {"amd-stibp",    0x80000008, NA, CPUID_REG_EBX, 15,  1},
-        {"ibrs-always",  0x80000008, NA, CPUID_REG_EBX, 16,  1},
-        {"stibp-always", 0x80000008, NA, CPUID_REG_EBX, 17,  1},
-        {"ibrs-fast",    0x80000008, NA, CPUID_REG_EBX, 18,  1},
-        {"ibrs-same-mode", 0x80000008, NA, CPUID_REG_EBX, 19,  1},
-        {"no-lmsl",      0x80000008, NA, CPUID_REG_EBX, 20,  1},
         {"ppin",         0x80000008, NA, CPUID_REG_EBX, 23,  1},
-        {"amd-ssbd",     0x80000008, NA, CPUID_REG_EBX, 24,  1},
-        {"virt-ssbd",    0x80000008, NA, CPUID_REG_EBX, 25,  1},
-        {"ssb-no",       0x80000008, NA, CPUID_REG_EBX, 26,  1},
-        {"psfd",         0x80000008, NA, CPUID_REG_EBX, 28,  1},
         {"btc-no",       0x80000008, NA, CPUID_REG_EBX, 29,  1},
-        {"ibpb-ret",     0x80000008, NA, CPUID_REG_EBX, 30,  1},
 
         {"nc",           0x80000008, NA, CPUID_REG_ECX,  0,  8},
         {"apicidsize",   0x80000008, NA, CPUID_REG_ECX, 12,  4},
@@ -316,22 +155,55 @@ int libxl_cpuid_parse_config(libxl_cpuid_policy_list *cpuid, const char* str)
         {"svm_pausefilt",0x8000000a, NA, CPUID_REG_EDX, 10,  1},
 
         {"lfence+",      0x80000021, NA, CPUID_REG_EAX,  2,  1},
-        {"nscb",         0x80000021, NA, CPUID_REG_EAX,  6,  1},
-        {"auto-ibrs",    0x80000021, NA, CPUID_REG_EAX,  8,  1},
-        {"cpuid-user-dis", 0x80000021, NA, CPUID_REG_EAX, 17, 1},
 
         {"maxhvleaf",    0x40000000, NA, CPUID_REG_EAX,  0,  8},
 
         {NULL, 0, NA, CPUID_REG_INV, 0, 0}
     };
+    static const struct feature_name {
+        const char *name;
+        unsigned int bit;
+    } features[] = INIT_FEATURE_NAMES;
+    /*
+     * NB: if we switch to using a cpu_policy derived object instead of a
+     * libxl_cpuid_policy_list we could get rid of the featureset -> cpuid leaf
+     * conversion table and use a featureset directly as we have conversions
+     * to/from featureset and cpu_policy.
+     */
+    static const struct {
+        uint32_t leaf, subleaf;
+        unsigned int reg;
+    } feature_to_cpuid[] = {
+        {0x00000001, NA, CPUID_REG_EDX},
+        {0x00000001, NA, CPUID_REG_ECX},
+        {0x80000001, NA, CPUID_REG_EDX},
+        {0x80000001, NA, CPUID_REG_ECX},
+        {0x0000000D,  1, CPUID_REG_EAX},
+        {0x00000007,  0, CPUID_REG_EBX},
+        {0x00000007,  0, CPUID_REG_ECX},
+        {0x80000007, NA, CPUID_REG_EDX},
+        {0x80000008, NA, CPUID_REG_EBX},
+        {0x00000007,  0, CPUID_REG_EDX},
+        {0x00000007,  1, CPUID_REG_EAX},
+        {0x80000021, NA, CPUID_REG_EAX},
+        {0x00000007,  1, CPUID_REG_EBX},
+        {0x00000007,  2, CPUID_REG_EDX},
+        {0x00000007,  1, CPUID_REG_ECX},
+        {0x00000007,  1, CPUID_REG_EDX},
+        {        NA, NA, CPUID_REG_INV}, /* MSR_ARCH_CAPS.eax */
+        {        NA, NA, CPUID_REG_INV}, /* MSR_ARCH_CAPS.edx */
+    };
 #undef NA
     char *sep, *val, *endptr;
     int i;
     const struct cpuid_flags *flag;
+    struct cpuid_flags f;
     struct xc_xend_cpuid *entry;
     unsigned long num;
     char flags[33], *resstr;
 
+    BUILD_BUG_ON(ARRAY_SIZE(feature_to_cpuid) != FEATURESET_NR_ENTRIES);
+
     sep = strchr(str, '=');
     if (sep == NULL) {
         return 1;
@@ -342,6 +214,28 @@ int libxl_cpuid_parse_config(libxl_cpuid_policy_list *cpuid, const char* str)
         if(!strncmp(str, flag->name, sep - str) && flag->name[sep - str] == 0)
             break;
     }
+    if (flag->name == NULL) {
+        const struct feature_name *feat;
+        /* Provide a NUL terminated feature name to the search helper. */
+        char *name = strndup(str, sep - str);
+
+        if (name == NULL)
+            return 4;
+
+        feat = bsearch(name, features, ARRAY_SIZE(features), sizeof(features[0]),
+                       search_feature);
+        free(name);
+
+        if (feat != NULL) {
+                f.name = feat->name;
+                f.leaf = feature_to_cpuid[feat->bit / 32].leaf;
+                f.subleaf = feature_to_cpuid[feat->bit / 32].subleaf;
+                f.reg = feature_to_cpuid[feat->bit / 32].reg;
+                f.bit = feat->bit % 32;
+                f.length = 1,
+                flag = &f;
+        }
+    }
     if (flag->name == NULL) {
         return 2;
     }
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 1f6f47daf4e1..80b189dea0c1 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -2620,6 +2620,9 @@ skip_usbdev:
                 case 3:
                     errstr = "illegal CPUID value (must be: [0|1|x|k|s])";
                     break;
+                case 4:
+                    errstr = "out of memory";
+                    break;
                 default:
                     errstr = "unknown error";
                     break;
