From ec352d0cab58a7bf66019057d0dfcffd9e7785a8 Mon Sep 17 00:00:00 2001 From: Georg Kotheimer Date: Fri, 19 Mar 2021 15:14:59 +0100 Subject: [PATCH] target/riscv: Add proper two-stage lookup exception detection The current two-stage lookup detection in riscv_cpu_do_interrupt falls short of its purpose, as all it checks is whether two-stage address translation either via the hypervisor-load store instructions or the MPRV feature would be allowed. What we really need instead is whether two-stage address translation was active when the exception was raised. However, in riscv_cpu_do_interrupt we do not have the information to reliably detect this. Therefore, when we raise a memory fault exception we have to record whether two-stage address translation is active. Signed-off-by: Georg Kotheimer Reviewed-by: Alistair Francis Message-id: 20210319141459.1196741-1-georg.kotheimer@kernkonzept.com Signed-off-by: Alistair Francis --- target/riscv/cpu.c | 1 + target/riscv/cpu.h | 4 ++++ target/riscv/cpu_helper.c | 21 ++++++++------------- 3 files changed, 13 insertions(+), 13 deletions(-) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 2a990f6253..7d6ed80f6b 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -356,6 +356,7 @@ static void riscv_cpu_reset(DeviceState *dev) env->mstatus &= ~(MSTATUS_MIE | MSTATUS_MPRV); env->mcause = 0; env->pc = env->resetvec; + env->two_stage_lookup = false; #endif cs->exception_index = EXCP_NONE; env->load_res = -1; diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 0edb2826a2..0a33d387ba 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -213,6 +213,10 @@ struct CPURISCVState { target_ulong satp_hs; uint64_t mstatus_hs; + /* Signals whether the current exception occurred with two-stage address + translation active. */ + bool two_stage_lookup; + target_ulong scounteren; target_ulong mcounteren; diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index 8d4a62988d..21c54ef561 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -654,6 +654,7 @@ static void raise_mmu_exception(CPURISCVState *env, target_ulong address, g_assert_not_reached(); } env->badaddr = address; + env->two_stage_lookup = two_stage; } hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) @@ -695,6 +696,8 @@ void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr, } env->badaddr = addr; + env->two_stage_lookup = riscv_cpu_virt_enabled(env) || + riscv_cpu_two_stage_lookup(mmu_idx); riscv_raise_exception(&cpu->env, cs->exception_index, retaddr); } @@ -718,6 +721,8 @@ void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr, g_assert_not_reached(); } env->badaddr = addr; + env->two_stage_lookup = riscv_cpu_virt_enabled(env) || + riscv_cpu_two_stage_lookup(mmu_idx); riscv_raise_exception(env, cs->exception_index, retaddr); } #endif /* !CONFIG_USER_ONLY */ @@ -967,16 +972,8 @@ void riscv_cpu_do_interrupt(CPUState *cs) /* handle the trap in S-mode */ if (riscv_has_ext(env, RVH)) { target_ulong hdeleg = async ? env->hideleg : env->hedeleg; - bool two_stage_lookup = false; - if (env->priv == PRV_M || - (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) || - (env->priv == PRV_U && !riscv_cpu_virt_enabled(env) && - get_field(env->hstatus, HSTATUS_HU))) { - two_stage_lookup = true; - } - - if ((riscv_cpu_virt_enabled(env) || two_stage_lookup) && write_tval) { + if (env->two_stage_lookup && write_tval) { /* * If we are writing a guest virtual address to stval, set * this to 1. If we are trapping to VS we will set this to 0 @@ -1014,10 +1011,7 @@ void riscv_cpu_do_interrupt(CPUState *cs) riscv_cpu_set_force_hs_excep(env, 0); } else { /* Trap into HS mode */ - if (!two_stage_lookup) { - env->hstatus = set_field(env->hstatus, HSTATUS_SPV, - riscv_cpu_virt_enabled(env)); - } + env->hstatus = set_field(env->hstatus, HSTATUS_SPV, false); htval = env->guest_phys_fault_addr; } } @@ -1073,6 +1067,7 @@ void riscv_cpu_do_interrupt(CPUState *cs) * RISC-V ISA Specification. */ + env->two_stage_lookup = false; #endif cs->exception_index = EXCP_NONE; /* mark handled to qemu */ } -- 2.11.0