diff options
| -rw-r--r-- | target/arm/cpu.h | 9 | ||||
| -rw-r--r-- | target/arm/helper.c | 27 | ||||
| -rw-r--r-- | target/arm/kvm32.c | 20 | ||||
| -rw-r--r-- | target/arm/kvm64.c | 2 | ||||
| -rw-r--r-- | target/arm/machine.c | 2 |
5 files changed, 22 insertions, 38 deletions
diff --git a/target/arm/cpu.h b/target/arm/cpu.h index ff9ba387b4..3e545a2b14 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2558,25 +2558,18 @@ bool write_list_to_cpustate(ARMCPU *cpu); /** * write_cpustate_to_list: * @cpu: ARMCPU - * @kvm_sync: true if this is for syncing back to KVM * * For each register listed in the ARMCPU cpreg_indexes list, write * its value from the ARMCPUState structure into the cpreg_values list. * This is used to copy info from TCG's working data structures into * KVM or for outbound migration. * - * @kvm_sync is true if we are doing this in order to sync the - * register state back to KVM. In this case we will only update - * values in the list if the previous list->cpustate sync actually - * successfully wrote the CPU state. Otherwise we will keep the value - * that is in the list. - * * Returns: true if all register values were read correctly, * false if some register was unknown or could not be read. * Note that we do not stop early on failure -- we will attempt * reading all registers in the list. */ -bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync); +bool write_cpustate_to_list(ARMCPU *cpu); #define ARM_CPUID_TI915T 0x54029152 #define ARM_CPUID_TI925T 0x54029252 diff --git a/target/arm/helper.c b/target/arm/helper.c index fbaa801cea..1fa282a7fc 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -265,7 +265,7 @@ static bool raw_accessors_invalid(const ARMCPRegInfo *ri) return true; } -bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync) +bool write_cpustate_to_list(ARMCPU *cpu) { /* Write the coprocessor state from cpu->env to the (index,value) list. */ int i; @@ -274,7 +274,6 @@ bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync) for (i = 0; i < cpu->cpreg_array_len; i++) { uint32_t regidx = kvm_to_cpreg_id(cpu->cpreg_indexes[i]); const ARMCPRegInfo *ri; - uint64_t newval; ri = get_arm_cp_reginfo(cpu->cp_regs, regidx); if (!ri) { @@ -284,29 +283,7 @@ bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync) if (ri->type & ARM_CP_NO_RAW) { continue; } - - newval = read_raw_cp_reg(&cpu->env, ri); - if (kvm_sync) { - /* - * Only sync if the previous list->cpustate sync succeeded. - * Rather than tracking the success/failure state for every - * item in the list, we just recheck "does the raw write we must - * have made in write_list_to_cpustate() read back OK" here. - */ - uint64_t oldval = cpu->cpreg_values[i]; - - if (oldval == newval) { - continue; - } - - write_raw_cp_reg(&cpu->env, ri, oldval); - if (read_raw_cp_reg(&cpu->env, ri) != oldval) { - continue; - } - - write_raw_cp_reg(&cpu->env, ri, newval); - } - cpu->cpreg_values[i] = newval; + cpu->cpreg_values[i] = read_raw_cp_reg(&cpu->env, ri); } return ok; } diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c index 327375f625..50327989dc 100644 --- a/target/arm/kvm32.c +++ b/target/arm/kvm32.c @@ -384,8 +384,24 @@ int kvm_arch_put_registers(CPUState *cs, int level) return ret; } - write_cpustate_to_list(cpu, true); - + /* Note that we do not call write_cpustate_to_list() + * here, so we are only writing the tuple list back to + * KVM. This is safe because nothing can change the + * CPUARMState cp15 fields (in particular gdb accesses cannot) + * and so there are no changes to sync. In fact syncing would + * be wrong at this point: for a constant register where TCG and + * KVM disagree about its value, the preceding write_list_to_cpustate() + * would not have had any effect on the CPUARMState value (since the + * register is read-only), and a write_cpustate_to_list() here would + * then try to write the TCG value back into KVM -- this would either + * fail or incorrectly change the value the guest sees. + * + * If we ever want to allow the user to modify cp15 registers via + * the gdb stub, we would need to be more clever here (for instance + * tracking the set of registers kvm_arch_get_registers() successfully + * managed to update the CPUARMState with, and only allowing those + * to be written back up into the kernel). + */ if (!write_list_to_kvmstate(cpu, level)) { return EINVAL; } diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c index e3ba149248..089af9c5f0 100644 --- a/target/arm/kvm64.c +++ b/target/arm/kvm64.c @@ -838,8 +838,6 @@ int kvm_arch_put_registers(CPUState *cs, int level) return ret; } - write_cpustate_to_list(cpu, true); - if (!write_list_to_kvmstate(cpu, level)) { return EINVAL; } diff --git a/target/arm/machine.c b/target/arm/machine.c index 124192bfc2..b292549614 100644 --- a/target/arm/machine.c +++ b/target/arm/machine.c @@ -630,7 +630,7 @@ static int cpu_pre_save(void *opaque) abort(); } } else { - if (!write_cpustate_to_list(cpu, false)) { + if (!write_cpustate_to_list(cpu)) { /* This should never fail. */ abort(); } |