From ebca90e4c3aaaae5ed1ee7c569dea00d5d6ed476 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sun, 26 Apr 2015 16:49:25 +0100 Subject: target-arm: Use correct memory attributes for page table walks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Factor out the page table walk memory accesses into their own function, so that we can specify the correct S/NS memory attributes for them. This will also provide a place to use the correct endianness and handle the need for a stage-2 translation when virtualization is supported. Signed-off-by: Peter Maydell Reviewed-by: Edgar E. Iglesias Reviewed-by: Alex Bennée --- target-arm/helper.c | 49 ++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 40 insertions(+), 9 deletions(-) (limited to 'target-arm/helper.c') diff --git a/target-arm/helper.c b/target-arm/helper.c index a568299cc6..a01ff7fccc 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -5129,6 +5129,29 @@ static bool get_level1_table_address(CPUARMState *env, ARMMMUIdx mmu_idx, return true; } +/* All loads done in the course of a page table walk go through here. + * TODO: rather than ignoring errors from physical memory reads (which + * are external aborts in ARM terminology) we should propagate this + * error out so that we can turn it into a Data Abort if this walk + * was being done for a CPU load/store or an address translation instruction + * (but not if it was for a debug access). + */ +static uint32_t arm_ldl_ptw(CPUState *cs, hwaddr addr, bool is_secure) +{ + MemTxAttrs attrs = {}; + + attrs.secure = is_secure; + return address_space_ldl(cs->as, addr, attrs, NULL); +} + +static uint64_t arm_ldq_ptw(CPUState *cs, hwaddr addr, bool is_secure) +{ + MemTxAttrs attrs = {}; + + attrs.secure = is_secure; + return address_space_ldq(cs->as, addr, attrs, NULL); +} + static int get_phys_addr_v5(CPUARMState *env, uint32_t address, int access_type, ARMMMUIdx mmu_idx, hwaddr *phys_ptr, int *prot, target_ulong *page_size) @@ -5151,7 +5174,7 @@ static int get_phys_addr_v5(CPUARMState *env, uint32_t address, int access_type, code = 5; goto do_fault; } - desc = ldl_phys(cs->as, table); + desc = arm_ldl_ptw(cs, table, regime_is_secure(env, mmu_idx)); type = (desc & 3); domain = (desc >> 5) & 0x0f; if (regime_el(env, mmu_idx) == 1) { @@ -5187,7 +5210,7 @@ static int get_phys_addr_v5(CPUARMState *env, uint32_t address, int access_type, /* Fine pagetable. */ table = (desc & 0xfffff000) | ((address >> 8) & 0xffc); } - desc = ldl_phys(cs->as, table); + desc = arm_ldl_ptw(cs, table, regime_is_secure(env, mmu_idx)); switch (desc & 3) { case 0: /* Page translation fault. */ code = 7; @@ -5261,7 +5284,7 @@ static int get_phys_addr_v6(CPUARMState *env, uint32_t address, int access_type, code = 5; goto do_fault; } - desc = ldl_phys(cs->as, table); + desc = arm_ldl_ptw(cs, table, regime_is_secure(env, mmu_idx)); type = (desc & 3); if (type == 0 || (type == 3 && !arm_feature(env, ARM_FEATURE_PXN))) { /* Section translation fault, or attempt to use the encoding @@ -5310,7 +5333,7 @@ static int get_phys_addr_v6(CPUARMState *env, uint32_t address, int access_type, ns = extract32(desc, 3, 1); /* Lookup l2 entry. */ table = (desc & 0xfffffc00) | ((address >> 10) & 0x3fc); - desc = ldl_phys(cs->as, table); + desc = arm_ldl_ptw(cs, table, regime_is_secure(env, mmu_idx)); ap = ((desc >> 4) & 3) | ((desc >> 7) & 4); switch (desc & 3) { case 0: /* Page translation fault. */ @@ -5525,13 +5548,20 @@ static int get_phys_addr_lpae(CPUARMState *env, target_ulong address, descaddr = extract64(ttbr, 0, 48); descaddr &= ~((1ULL << (va_size - tsz - (granule_sz * (4 - level)))) - 1); - tableattrs = 0; + /* Secure accesses start with the page table in secure memory and + * can be downgraded to non-secure at any step. Non-secure accesses + * remain non-secure. We implement this by just ORing in the NSTable/NS + * bits at each step. + */ + tableattrs = regime_is_secure(env, mmu_idx) ? 0 : (1 << 4); for (;;) { uint64_t descriptor; + bool nstable; descaddr |= (address >> (granule_sz * (4 - level))) & descmask; descaddr &= ~7ULL; - descriptor = ldq_phys(cs->as, descaddr); + nstable = extract32(tableattrs, 4, 1); + descriptor = arm_ldq_ptw(cs, descaddr, !nstable); if (!(descriptor & 1) || (!(descriptor & 2) && (level == 3))) { /* Invalid, or the Reserved level 3 encoding */ @@ -5566,7 +5596,7 @@ static int get_phys_addr_lpae(CPUARMState *env, target_ulong address, if (extract32(tableattrs, 2, 1)) { attrs &= ~(1 << 4); } - attrs |= extract32(tableattrs, 4, 1) << 3; /* NS */ + attrs |= nstable << 3; /* NS */ break; } /* Here descaddr is the final physical address, and attributes @@ -5705,8 +5735,9 @@ static inline int get_phys_addr(CPUARMState *env, target_ulong address, { if (mmu_idx == ARMMMUIdx_S12NSE0 || mmu_idx == ARMMMUIdx_S12NSE1) { /* TODO: when we support EL2 we should here call ourselves recursively - * to do the stage 1 and then stage 2 translations. The ldl_phys - * calls for stage 1 will also need changing. + * to do the stage 1 and then stage 2 translations. The arm_ld*_ptw + * functions will also need changing to perform ARMMMUIdx_S2NS loads + * rather than direct physical memory loads when appropriate. * For non-EL2 CPUs a stage1+stage2 translation is just stage 1. */ assert(!arm_feature(env, ARM_FEATURE_EL2)); -- cgit v1.2.1