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GiedriusSyuwata
GiedriusS
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yuwata
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condition: add CPUFeature
Taking a stab at implementing systemd#14479. Add {Condition,Assert}CPUFeature to `systemd-analyze` & friends. Implement it by executing the CPUID instruction. Add tables for common x86/i386 features. Tested via unit tests + checked that commands such as: ```bash systemd-analyze condition 'AssertCPUFeature = rdrand' ``` Succeed as expected and that commands such as ```bash systemd-analyze condition 'AssertCPUFeature = foobar' ``` Fail as expected. Finally, I have amended the `systemd.unit` manual page with the new condition and the list of all currently supported flags.
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‎man/systemd.unit.xml‎

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@@ -1489,6 +1489,68 @@
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to the container and not the physically available ones.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>ConditionCPUFeature=</varname></term>
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<listitem><para>Verify that a given CPU feature is available via the <literal>CPUID</literal>
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instruction. This condition only does something on i386 and x86-64 processors. On other
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processors it is assumed that the CPU does not support the given feature. It checks the leaves
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<literal>1</literal>, <literal>7</literal>, <literal>0x80000001</literal>, and
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<literal>0x80000007</literal>. Valid values are:
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<literal>fpu</literal>,
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<literal>vme</literal>,
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<literal>de</literal>,
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<literal>pse</literal>,
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<literal>tsc</literal>,
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<literal>msr</literal>,
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<literal>pae</literal>,
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<literal>mce</literal>,
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<literal>cx8</literal>,
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<literal>apic</literal>,
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<literal>sep</literal>,
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<literal>mtrr</literal>,
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<literal>pge</literal>,
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<literal>mca</literal>,
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<literal>cmov</literal>,
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<literal>pat</literal>,
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<literal>pse36</literal>,
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<literal>clflush</literal>,
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<literal>mmx</literal>,
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<literal>fxsr</literal>,
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<literal>sse</literal>,
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<literal>sse2</literal>,
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<literal>ht</literal>,
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<literal>pni</literal>,
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<literal>pclmul</literal>,
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<literal>monitor</literal>,
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<literal>ssse3</literal>,
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<literal>fma3</literal>,
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<literal>cx16</literal>,
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<literal>sse4_1</literal>,
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<literal>sse4_2</literal>,
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<literal>movbe</literal>,
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<literal>popcnt</literal>,
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<literal>aes</literal>,
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<literal>xsave</literal>,
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<literal>osxsave</literal>,
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<literal>avx</literal>,
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<literal>f16c</literal>,
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<literal>rdrand</literal>,
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<literal>bmi1</literal>,
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<literal>avx2</literal>,
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<literal>bmi2</literal>,
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<literal>rdseed</literal>,
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<literal>adx</literal>,
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<literal>sha_ni</literal>,
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<literal>syscall</literal>,
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<literal>rdtscp</literal>,
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<literal>lm</literal>,
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<literal>lahf_lm</literal>,
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<literal>abm</literal>,
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<literal>constant_tsc</literal>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>AssertArchitecture=</varname></term>
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<term><varname>AssertVirtualization=</varname></term>

‎src/basic/virt.c‎

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@@ -786,6 +786,131 @@ int running_in_chroot(void) {
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return r == 0;
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}
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#if defined(__i386__) || defined(__x86_64__)
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struct cpuid_table_entry {
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uint32_t flag_bit;
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const char *name;
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};
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static const struct cpuid_table_entry leaf1_edx[] = {
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{ 0, "fpu" },
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{ 1, "vme" },
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{ 2, "de" },
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{ 3, "pse" },
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{ 4, "tsc" },
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{ 5, "msr" },
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{ 6, "pae" },
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{ 7, "mce" },
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{ 8, "cx8" },
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{ 9, "apic" },
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{ 11, "sep" },
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{ 12, "mtrr" },
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{ 13, "pge" },
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{ 14, "mca" },
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{ 15, "cmov" },
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{ 16, "pat" },
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{ 17, "pse36" },
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{ 19, "clflush" },
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{ 23, "mmx" },
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{ 24, "fxsr" },
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{ 25, "sse" },
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{ 26, "sse2" },
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{ 28, "ht" },
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};
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static const struct cpuid_table_entry leaf1_ecx[] = {
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{ 0, "pni" },
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{ 1, "pclmul" },
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{ 3, "monitor" },
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{ 9, "ssse3" },
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{ 12, "fma3" },
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{ 13, "cx16" },
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{ 19, "sse4_1" },
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{ 20, "sse4_2" },
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{ 22, "movbe" },
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{ 23, "popcnt" },
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{ 25, "aes" },
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{ 26, "xsave" },
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{ 27, "osxsave" },
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{ 28, "avx" },
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{ 29, "f16c" },
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{ 30, "rdrand" },
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};
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static const struct cpuid_table_entry leaf7_ebx[] = {
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{ 3, "bmi1" },
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{ 5, "avx2" },
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{ 8, "bmi2" },
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{ 18, "rdseed" },
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{ 19, "adx" },
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{ 29, "sha_ni" },
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};
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static const struct cpuid_table_entry leaf81_edx[] = {
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{ 11, "syscall" },
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{ 27, "rdtscp" },
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{ 29, "lm" },
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};
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static const struct cpuid_table_entry leaf81_ecx[] = {
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{ 0, "lahf_lm" },
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{ 5, "abm" },
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};
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static const struct cpuid_table_entry leaf87_edx[] = {
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{ 8, "constant_tsc" },
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};
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static bool given_flag_in_set(const char *flag, const struct cpuid_table_entry *set, size_t set_size, uint32_t val) {
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for (size_t i = 0; i < set_size; i++) {
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if ((UINT32_C(1) << set[i].flag_bit) & val &&
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streq(flag, set[i].name))
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return true;
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}
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return false;
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}
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static bool real_has_cpu_with_flag(const char *flag) {
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uint32_t eax, ebx, ecx, edx;
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if (__get_cpuid(1, &eax, &ebx, &ecx, &edx)) {
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if (given_flag_in_set(flag, leaf1_ecx, ELEMENTSOF(leaf1_ecx), ecx))
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return true;
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if (given_flag_in_set(flag, leaf1_edx, ELEMENTSOF(leaf1_edx), edx))
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return true;
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}
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if (__get_cpuid(7, &eax, &ebx, &ecx, &edx)) {
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if (given_flag_in_set(flag, leaf7_ebx, ELEMENTSOF(leaf7_ebx), ebx))
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return true;
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}
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if (__get_cpuid(0x80000001U, &eax, &ebx, &ecx, &edx)) {
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if (given_flag_in_set(flag, leaf81_ecx, ELEMENTSOF(leaf81_ecx), ecx))
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return true;
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if (given_flag_in_set(flag, leaf81_edx, ELEMENTSOF(leaf81_edx), edx))
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return true;
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}
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if (__get_cpuid(0x80000007U, &eax, &ebx, &ecx, &edx))
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if (given_flag_in_set(flag, leaf87_edx, ELEMENTSOF(leaf87_edx), edx))
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return true;
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return false;
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}
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#endif
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bool has_cpu_with_flag(const char *flag) {
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/* CPUID is an x86 specific interface. Assume on all others that no CPUs have those flags. */
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#if defined(__i386__) || defined(__x86_64__)
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return real_has_cpu_with_flag(flag);
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#else
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return false;
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#endif
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}
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static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
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[VIRTUALIZATION_NONE] = "none",
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[VIRTUALIZATION_KVM] = "kvm",

‎src/basic/virt.h‎

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const char *virtualization_to_string(int v) _const_;
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int virtualization_from_string(const char *s) _pure_;
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bool has_cpu_with_flag(const char *flag);

‎src/shared/condition.c‎

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@@ -756,6 +756,14 @@ static int condition_test_path_is_read_write(Condition *c, char **env) {
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return path_is_read_only_fs(c->parameter) <= 0;
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}
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static int condition_test_cpufeature(Condition *c, char **env) {
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assert(c);
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assert(c->parameter);
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assert(c->type == CONDITION_CPU_FEATURE);
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return has_cpu_with_flag(ascii_strlower(c->parameter));
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}
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static int condition_test_path_is_encrypted(Condition *c, char **env) {
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int r;
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@@ -834,6 +842,7 @@ int condition_test(Condition *c, char **env) {
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[CONDITION_CPUS] = condition_test_cpus,
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[CONDITION_MEMORY] = condition_test_memory,
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[CONDITION_ENVIRONMENT] = condition_test_environment,
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[CONDITION_CPU_FEATURE] = condition_test_cpufeature,
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};
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int r, b;
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[CONDITION_CPUS] = "ConditionCPUs",
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[CONDITION_MEMORY] = "ConditionMemory",
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[CONDITION_ENVIRONMENT] = "ConditionEnvironment",
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[CONDITION_CPU_FEATURE] = "ConditionCPUFeature",
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};
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961971
DEFINE_STRING_TABLE_LOOKUP(condition_type, ConditionType);
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[CONDITION_CPUS] = "AssertCPUs",
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[CONDITION_MEMORY] = "AssertMemory",
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[CONDITION_ENVIRONMENT] = "AssertEnvironment",
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[CONDITION_CPU_FEATURE] = "AssertCPUFeature",
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};
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DEFINE_STRING_TABLE_LOOKUP(assert_type, ConditionType);

‎src/shared/condition.h‎

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@@ -19,6 +19,7 @@ typedef enum ConditionType {
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CONDITION_MEMORY,
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CONDITION_CPUS,
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CONDITION_ENVIRONMENT,
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CONDITION_CPU_FEATURE,
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CONDITION_NEEDS_UPDATE,
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CONDITION_FIRST_BOOT,

‎src/test/test-condition.c‎

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@@ -439,6 +439,27 @@ static void test_condition_test_kernel_version(void) {
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condition_free(condition);
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}
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#if defined(__i386__) || defined(__x86_64__)
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static void test_condition_test_cpufeature(void) {
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Condition *condition;
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condition = condition_new(CONDITION_CPU_FEATURE, "fpu", false, false);
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assert_se(condition);
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assert_se(condition_test(condition, environ) > 0);
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condition_free(condition);
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condition = condition_new(CONDITION_CPU_FEATURE, "somecpufeaturethatreallydoesntmakesense", false, false);
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assert_se(condition);
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assert_se(condition_test(condition, environ) == 0);
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condition_free(condition);
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condition = condition_new(CONDITION_CPU_FEATURE, "a", false, false);
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assert_se(condition);
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assert_se(condition_test(condition, environ) == 0);
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condition_free(condition);
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}
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#endif
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442463
static void test_condition_test_security(void) {
443464
Condition *condition;
444465

@@ -864,6 +885,9 @@ int main(int argc, char *argv[]) {
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test_condition_test_cpus();
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test_condition_test_memory();
866887
test_condition_test_environment();
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#if defined(__i386__) || defined(__x86_64__)
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test_condition_test_cpufeature();
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#endif
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return 0;
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}

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