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target/arm: Rewrite check_s2_mmu_setup

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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 49ba115bb7, 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: 49ba115bb7 ("target/arm: Pass outputsize down to check_s2_mmu_setup")
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230227225832.816605-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2023-02-27 12:58:32 -10:00 committed by Peter Maydell
parent fcc7404eff
commit 0ffe5b7ba8
1 changed files with 97 additions and 76 deletions
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173
target/arm/ptw.c
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@ -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;