From d86a9ad33c75ed795f09fb43243d0acecd583f24 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 1 Aug 2019 19:30:10 +0100 Subject: target/sparc: Handle bus errors in mmu_probe() Convert the mmu_probe() function to using address_space_ldl() rather than ldl_phys(), so we can explicitly detect memory transaction failures. This makes no practical difference at the moment, because ldl_phys() will return 0 on a transaction failure, and we treat transaction failures and 0 PDEs identically. However the spec says that MMU probe operations are supposed to update the fault status registers, and if we ever implement that we'll want to distinguish the difference. For the moment, just add a TODO comment about the bug. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Tested-by: Mark Cave-Ayland Message-id: 20190801183012.17564-6-peter.maydell@linaro.org --- target/sparc/mmu_helper.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) (limited to 'target/sparc/mmu_helper.c') diff --git a/target/sparc/mmu_helper.c b/target/sparc/mmu_helper.c index e99ed6d..0267ae4 100644 --- a/target/sparc/mmu_helper.c +++ b/target/sparc/mmu_helper.c @@ -288,11 +288,20 @@ target_ulong mmu_probe(CPUSPARCState *env, target_ulong address, int mmulev) CPUState *cs = env_cpu(env); hwaddr pde_ptr; uint32_t pde; + MemTxResult result; + + /* + * TODO: MMU probe operations are supposed to set the fault + * status registers, but we don't do this. + */ /* Context base + context number */ pde_ptr = (hwaddr)(env->mmuregs[1] << 4) + (env->mmuregs[2] << 2); - pde = ldl_phys(cs->as, pde_ptr); + pde = address_space_ldl(cs->as, pde_ptr, MEMTXATTRS_UNSPECIFIED, &result); + if (result != MEMTX_OK) { + return 0; + } switch (pde & PTE_ENTRYTYPE_MASK) { default: @@ -305,7 +314,11 @@ target_ulong mmu_probe(CPUSPARCState *env, target_ulong address, int mmulev) return pde; } pde_ptr = ((address >> 22) & ~3) + ((pde & ~3) << 4); - pde = ldl_phys(cs->as, pde_ptr); + pde = address_space_ldl(cs->as, pde_ptr, + MEMTXATTRS_UNSPECIFIED, &result); + if (result != MEMTX_OK) { + return 0; + } switch (pde & PTE_ENTRYTYPE_MASK) { default: @@ -319,7 +332,11 @@ target_ulong mmu_probe(CPUSPARCState *env, target_ulong address, int mmulev) return pde; } pde_ptr = ((address & 0xfc0000) >> 16) + ((pde & ~3) << 4); - pde = ldl_phys(cs->as, pde_ptr); + pde = address_space_ldl(cs->as, pde_ptr, + MEMTXATTRS_UNSPECIFIED, &result); + if (result != MEMTX_OK) { + return 0; + } switch (pde & PTE_ENTRYTYPE_MASK) { default: @@ -333,7 +350,11 @@ target_ulong mmu_probe(CPUSPARCState *env, target_ulong address, int mmulev) return pde; } pde_ptr = ((address & 0x3f000) >> 10) + ((pde & ~3) << 4); - pde = ldl_phys(cs->as, pde_ptr); + pde = address_space_ldl(cs->as, pde_ptr, + MEMTXATTRS_UNSPECIFIED, &result); + if (result != MEMTX_OK) { + return 0; + } switch (pde & PTE_ENTRYTYPE_MASK) { default: -- cgit v1.1