Implement the QARMA3 cryptographic algorithm for PAC calculation. Implement a cpu feature to select the algorithm and document it.
Signed-off-by: Aaron Lindsay <aa...@os.amperecomputing.com> Reviewed-by: Peter Maydell <peter.mayd...@linaro.org> Reviewed-by: Richard Henderson <richard.hender...@linaro.org> Message-Id: <20230609172324.982888-4-aa...@os.amperecomputing.com> [rth: Merge cpu feature addition from another patch.] Signed-off-by: Richard Henderson <richard.hender...@linaro.org> --- docs/system/arm/cpu-features.rst | 21 ++++++++----- docs/system/arm/emulation.rst | 3 ++ target/arm/cpu.h | 1 + target/arm/arm-qmp-cmds.c | 2 +- target/arm/cpu64.c | 24 ++++++++++++-- target/arm/tcg/pauth_helper.c | 54 ++++++++++++++++++++++++++------ tests/qtest/arm-cpu-features.c | 12 ++++++- 7 files changed, 94 insertions(+), 23 deletions(-) diff --git a/docs/system/arm/cpu-features.rst b/docs/system/arm/cpu-features.rst index 6bb88a40c7..a5fb929243 100644 --- a/docs/system/arm/cpu-features.rst +++ b/docs/system/arm/cpu-features.rst @@ -210,15 +210,20 @@ TCG VCPU Features TCG VCPU features are CPU features that are specific to TCG. Below is the list of TCG VCPU features and their descriptions. -``pauth-impdef`` - When ``FEAT_Pauth`` is enabled, either the *impdef* (Implementation - Defined) algorithm is enabled or the *architected* QARMA algorithm - is enabled. By default the impdef algorithm is disabled, and QARMA - is enabled. +``pauth`` + Enable or disable ``FEAT_Pauth`` entirely. - The architected QARMA algorithm has good cryptographic properties, - but can be quite slow to emulate. The impdef algorithm used by QEMU - is non-cryptographic but significantly faster. +``pauth-impdef`` + When ``pauth`` is enabled, select the QEMU implementation defined algorithm. + +``pauth-qarma3`` + When ``pauth`` is enabled, select the architected QARMA3 algorithm. + +Without either ``pauth-impdef`` or ``pauth-qarma3`` enabled, +the architected QARMA5 algorithm is used. The architected QARMA5 +and QARMA3 algorithms have good cryptographic properties, but can +be quite slow to emulate. The impdef algorithm used by QEMU is +non-cryptographic but significantly faster. SVE CPU Properties ================== diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst index bdafc68819..06af20d10f 100644 --- a/docs/system/arm/emulation.rst +++ b/docs/system/arm/emulation.rst @@ -55,6 +55,9 @@ the following architecture extensions: - FEAT_MTE (Memory Tagging Extension) - FEAT_MTE2 (Memory Tagging Extension) - FEAT_MTE3 (MTE Asymmetric Fault Handling) +- FEAT_PACIMP (Pointer authentication - IMPLEMENTATION DEFINED algorithm) +- FEAT_PACQARMA3 (Pointer authentication - QARMA3 algorithm) +- FEAT_PACQARMA5 (Pointer authentication - QARMA5 algorithm) - FEAT_PAN (Privileged access never) - FEAT_PAN2 (AT S1E1R and AT S1E1W instruction variants affected by PSTATE.PAN) - FEAT_PAN3 (Support for SCTLR_ELx.EPAN) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 0e2545d631..cfca42293a 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1072,6 +1072,7 @@ struct ArchCPU { */ bool prop_pauth; bool prop_pauth_impdef; + bool prop_pauth_qarma3; bool prop_lpa2; /* DCZ blocksize, in log_2(words), ie low 4 bits of DCZID_EL0 */ diff --git a/target/arm/arm-qmp-cmds.c b/target/arm/arm-qmp-cmds.c index c8fa524002..b53d5efe13 100644 --- a/target/arm/arm-qmp-cmds.c +++ b/target/arm/arm-qmp-cmds.c @@ -95,7 +95,7 @@ static const char *cpu_model_advertised_features[] = { "sve640", "sve768", "sve896", "sve1024", "sve1152", "sve1280", "sve1408", "sve1536", "sve1664", "sve1792", "sve1920", "sve2048", "kvm-no-adjvtime", "kvm-steal-time", - "pauth", "pauth-impdef", + "pauth", "pauth-impdef", "pauth-qarma3", NULL }; diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c index fd584a31da..f3d87e001f 100644 --- a/target/arm/cpu64.c +++ b/target/arm/cpu64.c @@ -474,7 +474,7 @@ void aarch64_add_sme_properties(Object *obj) void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp) { ARMPauthFeature features = cpu_isar_feature(pauth_feature, cpu); - uint64_t isar1; + uint64_t isar1, isar2; /* * These properties enable or disable Pauth as a whole, or change @@ -490,6 +490,10 @@ void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp) isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, API, 0); isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPI, 0); + isar2 = cpu->isar.id_aa64isar2; + isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, APA3, 0); + isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, GPA3, 0); + if (kvm_enabled() || hvf_enabled()) { /* * Exit early if PAuth is enabled and fall through to disable it. @@ -510,26 +514,39 @@ void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp) } if (cpu->prop_pauth) { + if (cpu->prop_pauth_impdef && cpu->prop_pauth_qarma3) { + error_setg(errp, + "cannot enable both pauth-impdef and pauth-qarma3"); + return; + } + if (cpu->prop_pauth_impdef) { isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, API, features); isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPI, 1); + } else if (cpu->prop_pauth_qarma3) { + isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, APA3, features); + isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, GPA3, 1); } else { isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, APA, features); isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPA, 1); } - } else if (cpu->prop_pauth_impdef) { - error_setg(errp, "cannot enable pauth-impdef without pauth"); + } else if (cpu->prop_pauth_impdef || cpu->prop_pauth_qarma3) { + error_setg(errp, "cannot enable pauth-impdef or " + "pauth-qarma3 without pauth"); error_append_hint(errp, "Add pauth=on to the CPU property list.\n"); } } cpu->isar.id_aa64isar1 = isar1; + cpu->isar.id_aa64isar2 = isar2; } static Property arm_cpu_pauth_property = DEFINE_PROP_BOOL("pauth", ARMCPU, prop_pauth, true); static Property arm_cpu_pauth_impdef_property = DEFINE_PROP_BOOL("pauth-impdef", ARMCPU, prop_pauth_impdef, false); +static Property arm_cpu_pauth_qarma3_property = + DEFINE_PROP_BOOL("pauth-qarma3", ARMCPU, prop_pauth_qarma3, false); void aarch64_add_pauth_properties(Object *obj) { @@ -549,6 +566,7 @@ void aarch64_add_pauth_properties(Object *obj) cpu->prop_pauth = cpu_isar_feature(aa64_pauth, cpu); } else { qdev_property_add_static(DEVICE(obj), &arm_cpu_pauth_impdef_property); + qdev_property_add_static(DEVICE(obj), &arm_cpu_pauth_qarma3_property); } } diff --git a/target/arm/tcg/pauth_helper.c b/target/arm/tcg/pauth_helper.c index 6271a84ec9..bb03409ee5 100644 --- a/target/arm/tcg/pauth_helper.c +++ b/target/arm/tcg/pauth_helper.c @@ -96,6 +96,21 @@ static uint64_t pac_sub(uint64_t i) return o; } +static uint64_t pac_sub1(uint64_t i) +{ + static const uint8_t sub1[16] = { + 0xa, 0xd, 0xe, 0x6, 0xf, 0x7, 0x3, 0x5, + 0x9, 0x8, 0x0, 0xc, 0xb, 0x1, 0x2, 0x4, + }; + uint64_t o = 0; + int b; + + for (b = 0; b < 64; b += 4) { + o |= (uint64_t)sub1[(i >> b) & 0xf] << b; + } + return o; +} + static uint64_t pac_inv_sub(uint64_t i) { static const uint8_t inv_sub[16] = { @@ -209,7 +224,7 @@ static uint64_t tweak_inv_shuffle(uint64_t i) } static uint64_t pauth_computepac_architected(uint64_t data, uint64_t modifier, - ARMPACKey key) + ARMPACKey key, bool isqarma3) { static const uint64_t RC[5] = { 0x0000000000000000ull, @@ -219,6 +234,7 @@ static uint64_t pauth_computepac_architected(uint64_t data, uint64_t modifier, 0x452821E638D01377ull, }; const uint64_t alpha = 0xC0AC29B7C97C50DDull; + int iterations = isqarma3 ? 2 : 4; /* * Note that in the ARM pseudocode, key0 contains bits <127:64> * and key1 contains bits <63:0> of the 128-bit key. @@ -231,7 +247,7 @@ static uint64_t pauth_computepac_architected(uint64_t data, uint64_t modifier, runningmod = modifier; workingval = data ^ key0; - for (i = 0; i <= 4; ++i) { + for (i = 0; i <= iterations; ++i) { roundkey = key1 ^ runningmod; workingval ^= roundkey; workingval ^= RC[i]; @@ -239,32 +255,48 @@ static uint64_t pauth_computepac_architected(uint64_t data, uint64_t modifier, workingval = pac_cell_shuffle(workingval); workingval = pac_mult(workingval); } - workingval = pac_sub(workingval); + if (isqarma3) { + workingval = pac_sub1(workingval); + } else { + workingval = pac_sub(workingval); + } runningmod = tweak_shuffle(runningmod); } roundkey = modk0 ^ runningmod; workingval ^= roundkey; workingval = pac_cell_shuffle(workingval); workingval = pac_mult(workingval); - workingval = pac_sub(workingval); + if (isqarma3) { + workingval = pac_sub1(workingval); + } else { + workingval = pac_sub(workingval); + } workingval = pac_cell_shuffle(workingval); workingval = pac_mult(workingval); workingval ^= key1; workingval = pac_cell_inv_shuffle(workingval); - workingval = pac_inv_sub(workingval); + if (isqarma3) { + workingval = pac_sub1(workingval); + } else { + workingval = pac_inv_sub(workingval); + } workingval = pac_mult(workingval); workingval = pac_cell_inv_shuffle(workingval); workingval ^= key0; workingval ^= runningmod; - for (i = 0; i <= 4; ++i) { - workingval = pac_inv_sub(workingval); - if (i < 4) { + for (i = 0; i <= iterations; ++i) { + if (isqarma3) { + workingval = pac_sub1(workingval); + } else { + workingval = pac_inv_sub(workingval); + } + if (i < iterations) { workingval = pac_mult(workingval); workingval = pac_cell_inv_shuffle(workingval); } runningmod = tweak_inv_shuffle(runningmod); roundkey = key1 ^ runningmod; - workingval ^= RC[4 - i]; + workingval ^= RC[iterations - i]; workingval ^= roundkey; workingval ^= alpha; } @@ -283,7 +315,9 @@ static uint64_t pauth_computepac(CPUARMState *env, uint64_t data, uint64_t modifier, ARMPACKey key) { if (cpu_isar_feature(aa64_pauth_qarma5, env_archcpu(env))) { - return pauth_computepac_architected(data, modifier, key); + return pauth_computepac_architected(data, modifier, key, false); + } else if (cpu_isar_feature(aa64_pauth_qarma3, env_archcpu(env))) { + return pauth_computepac_architected(data, modifier, key, true); } else { return pauth_computepac_impdef(data, modifier, key); } diff --git a/tests/qtest/arm-cpu-features.c b/tests/qtest/arm-cpu-features.c index 3fc33fc24d..a8a4c668ad 100644 --- a/tests/qtest/arm-cpu-features.c +++ b/tests/qtest/arm-cpu-features.c @@ -417,12 +417,22 @@ static void pauth_tests_default(QTestState *qts, const char *cpu_type) { assert_has_feature_enabled(qts, cpu_type, "pauth"); assert_has_feature_disabled(qts, cpu_type, "pauth-impdef"); + assert_has_feature_disabled(qts, cpu_type, "pauth-qarma3"); assert_set_feature(qts, cpu_type, "pauth", false); assert_set_feature(qts, cpu_type, "pauth", true); assert_set_feature(qts, cpu_type, "pauth-impdef", true); assert_set_feature(qts, cpu_type, "pauth-impdef", false); - assert_error(qts, cpu_type, "cannot enable pauth-impdef without pauth", + assert_set_feature(qts, cpu_type, "pauth-qarma3", true); + assert_set_feature(qts, cpu_type, "pauth-qarma3", false); + assert_error(qts, cpu_type, + "cannot enable pauth-impdef or pauth-qarma3 without pauth", "{ 'pauth': false, 'pauth-impdef': true }"); + assert_error(qts, cpu_type, + "cannot enable pauth-impdef or pauth-qarma3 without pauth", + "{ 'pauth': false, 'pauth-qarma3': true }"); + assert_error(qts, cpu_type, + "cannot enable both pauth-impdef and pauth-qarma3", + "{ 'pauth': true, 'pauth-impdef': true, 'pauth-qarma3': true }"); } static void test_query_cpu_model_expansion(const void *data) -- 2.34.1