From 0ffe5b7ba883c6adbbf821f9be03475d96a2e35c Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 27 Feb 2023 12:58:32 -1000 Subject: [PATCH] target/arm: Rewrite check_s2_mmu_setup Integrate neighboring code from get_phys_addr_lpae which computed starting level, as it is easier to validate when doing both at the same time. Mirror the checks at the start of AArch{64,32}.S2Walk, especially S2InvalidSL and S2InconsistentSL. This reverts 49ba115bb74, which was incorrect -- there is nothing in the ARM pseudocode that depends on TxSZ, i.e. outputsize; the pseudocode is consistent in referencing PAMax. Fixes: 49ba115bb74 ("target/arm: Pass outputsize down to check_s2_mmu_setup") Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-id: 20230227225832.816605-5-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- target/arm/ptw.c | 173 ++++++++++++++++++++++++++--------------------- 1 file changed, 97 insertions(+), 76 deletions(-) diff --git a/target/arm/ptw.c b/target/arm/ptw.c index 8541ef56d6..ec3f51782a 100644 --- a/target/arm/ptw.c +++ b/target/arm/ptw.c @@ -1081,70 +1081,119 @@ static ARMVAParameters aa32_va_parameters(CPUARMState *env, uint32_t va, * check_s2_mmu_setup * @cpu: ARMCPU * @is_aa64: True if the translation regime is in AArch64 state - * @startlevel: Suggested starting level - * @inputsize: Bitsize of IPAs + * @tcr: VTCR_EL2 or VSTCR_EL2 + * @ds: Effective value of TCR.DS. + * @iasize: Bitsize of IPAs * @stride: Page-table stride (See the ARM ARM) * - * Returns true if the suggested S2 translation parameters are OK and - * false otherwise. + * Decode the starting level of the S2 lookup, returning INT_MIN if + * the configuration is invalid. */ -static bool check_s2_mmu_setup(ARMCPU *cpu, bool is_aa64, int level, - int inputsize, int stride, int outputsize) +static int check_s2_mmu_setup(ARMCPU *cpu, bool is_aa64, uint64_t tcr, + bool ds, int iasize, int stride) { - const int grainsize = stride + 3; - int startsizecheck; - - /* - * Negative levels are usually not allowed... - * Except for FEAT_LPA2, 4k page table, 52-bit address space, which - * begins with level -1. Note that previous feature tests will have - * eliminated this combination if it is not enabled. - */ - if (level < (inputsize == 52 && stride == 9 ? -1 : 0)) { - return false; - } - - startsizecheck = inputsize - ((3 - level) * stride + grainsize); - if (startsizecheck < 1 || startsizecheck > stride + 4) { - return false; - } + int sl0, sl2, startlevel, granulebits, levels; + int s1_min_iasize, s1_max_iasize; + sl0 = extract32(tcr, 6, 2); if (is_aa64) { + /* + * AArch64.S2InvalidTxSZ: While we checked tsz_oob near the top of + * get_phys_addr_lpae, that used aa64_va_parameters which apply + * to aarch64. If Stage1 is aarch32, the min_txsz is larger. + * See AArch64.S2MinTxSZ, where min_tsz is 24, translated to + * inputsize is 64 - 24 = 40. + */ + if (iasize < 40 && !arm_el_is_aa64(&cpu->env, 1)) { + goto fail; + } + + /* + * AArch64.S2InvalidSL: Interpretation of SL depends on the page size, + * so interleave AArch64.S2StartLevel. + */ switch (stride) { - case 13: /* 64KB Pages. */ - if (level == 0 || (level == 1 && outputsize <= 42)) { - return false; + case 9: /* 4KB */ + /* SL2 is RES0 unless DS=1 & 4KB granule. */ + sl2 = extract64(tcr, 33, 1); + if (ds && sl2) { + if (sl0 != 0) { + goto fail; + } + startlevel = -1; + } else { + startlevel = 2 - sl0; + switch (sl0) { + case 2: + if (arm_pamax(cpu) < 44) { + goto fail; + } + break; + case 3: + if (!cpu_isar_feature(aa64_st, cpu)) { + goto fail; + } + startlevel = 3; + break; + } } break; - case 11: /* 16KB Pages. */ - if (level == 0 || (level == 1 && outputsize <= 40)) { - return false; + case 11: /* 16KB */ + switch (sl0) { + case 2: + if (arm_pamax(cpu) < 42) { + goto fail; + } + break; + case 3: + if (!ds) { + goto fail; + } + break; } + startlevel = 3 - sl0; break; - case 9: /* 4KB Pages. */ - if (level == 0 && outputsize <= 42) { - return false; + case 13: /* 64KB */ + switch (sl0) { + case 2: + if (arm_pamax(cpu) < 44) { + goto fail; + } + break; + case 3: + goto fail; } + startlevel = 3 - sl0; break; default: g_assert_not_reached(); } - - /* Inputsize checks. */ - if (inputsize > outputsize && - (arm_el_is_aa64(&cpu->env, 1) || inputsize > 40)) { - /* This is CONSTRAINED UNPREDICTABLE and we choose to fault. */ - return false; - } } else { - /* AArch32 only supports 4KB pages. Assert on that. */ + /* + * Things are simpler for AArch32 EL2, with only 4k pages. + * There is no separate S2InvalidSL function, but AArch32.S2Walk + * begins with walkparms.sl0 in {'1x'}. + */ assert(stride == 9); - - if (level == 0) { - return false; + if (sl0 >= 2) { + goto fail; } + startlevel = 2 - sl0; } - return true; + + /* AArch{64,32}.S2InconsistentSL are functionally equivalent. */ + levels = 3 - startlevel; + granulebits = stride + 3; + + s1_min_iasize = levels * stride + granulebits + 1; + s1_max_iasize = s1_min_iasize + (stride - 1) + 4; + + if (iasize >= s1_min_iasize && iasize <= s1_max_iasize) { + return startlevel; + } + + fail: + return INT_MIN; } /** @@ -1300,38 +1349,10 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw, */ level = 4 - (inputsize - 4) / stride; } else { - /* - * For stage 2 translations the starting level is specified by the - * VTCR_EL2.SL0 field (whose interpretation depends on the page size) - */ - uint32_t sl0 = extract32(tcr, 6, 2); - uint32_t sl2 = extract64(tcr, 33, 1); - int32_t startlevel; - bool ok; - - /* SL2 is RES0 unless DS=1 & 4kb granule. */ - if (param.ds && stride == 9 && sl2) { - if (sl0 != 0) { - level = 0; - goto do_translation_fault; - } - startlevel = -1; - } else if (!aarch64 || stride == 9) { - /* AArch32 or 4KB pages */ - startlevel = 2 - sl0; - - if (cpu_isar_feature(aa64_st, cpu)) { - startlevel &= 3; - } - } else { - /* 16KB or 64KB pages */ - startlevel = 3 - sl0; - } - - /* Check that the starting level is valid. */ - ok = check_s2_mmu_setup(cpu, aarch64, startlevel, - inputsize, stride, outputsize); - if (!ok) { + int startlevel = check_s2_mmu_setup(cpu, aarch64, tcr, param.ds, + inputsize, stride); + if (startlevel == INT_MIN) { + level = 0; goto do_translation_fault; } level = startlevel;