With the USER_SIGP capability, the kernel will pass most (but not all) SIGP orders to userspace for processing. But that means that the kernel is unable to determine if/when the order has been completed by userspace, and could potentially return an incorrect answer (CC1 with status bits versus CC2 indicating BUSY) for one of the remaining in-kernel orders.
With a new USER_SIGP_BUSY capability, userspace can tell the kernel when it is started processing a SIGP order and when it has finished, such that the in-kernel orders can be returned with the BUSY condition between the two IOCTLs. Let's use the new capability in QEMU. Signed-off-by: Eric Farman <far...@linux.ibm.com> --- target/s390x/cpu-sysemu.c | 15 +++++++++++++++ target/s390x/cpu.c | 1 + target/s390x/cpu.h | 8 ++++++++ target/s390x/kvm/kvm.c | 16 ++++++++++++++++ target/s390x/kvm/kvm_s390x.h | 2 ++ target/s390x/sigp.c | 19 ++++++++++++++++++- 6 files changed, 60 insertions(+), 1 deletion(-) diff --git a/target/s390x/cpu-sysemu.c b/target/s390x/cpu-sysemu.c index 5471e01ee8..60dff5bcd9 100644 --- a/target/s390x/cpu-sysemu.c +++ b/target/s390x/cpu-sysemu.c @@ -254,6 +254,21 @@ unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu) return s390_count_running_cpus(); } +int s390_cpu_set_sigp_busy(S390CPU *cpu) +{ + if (kvm_enabled()) { + return kvm_s390_vcpu_set_sigp_busy(cpu); + } + return 0; +} + +void s390_cpu_reset_sigp_busy(S390CPU *cpu) +{ + if (kvm_enabled()) { + kvm_s390_vcpu_reset_sigp_busy(cpu); + } +} + int s390_set_memory_limit(uint64_t new_limit, uint64_t *hw_limit) { if (kvm_enabled()) { diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c index 7b7b05f1d3..b5fdca05cf 100644 --- a/target/s390x/cpu.c +++ b/target/s390x/cpu.c @@ -115,6 +115,7 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type) scc->parent_reset(dev); cpu->env.sigp_order = 0; + s390_cpu_reset_sigp_busy(cpu); s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu); switch (type) { diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h index ca3845d023..ef3d3a5b10 100644 --- a/target/s390x/cpu.h +++ b/target/s390x/cpu.h @@ -780,11 +780,19 @@ int s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch_id, int vq, bool assign); #ifndef CONFIG_USER_ONLY unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu); +int s390_cpu_set_sigp_busy(S390CPU *cpu); +void s390_cpu_reset_sigp_busy(S390CPU *cpu); #else static inline unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu) { return 0; } +static inline int s390_cpu_set_sigp_busy(S390CPU *cpu) +{ +} +static inline void s390_cpu_reset_sigp_busy(S390CPU *cpu) +{ +} #endif /* CONFIG_USER_ONLY */ static inline uint8_t s390_cpu_get_state(S390CPU *cpu) { diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c index 5b1fdb55c4..533747de34 100644 --- a/target/s390x/kvm/kvm.c +++ b/target/s390x/kvm/kvm.c @@ -360,6 +360,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s) cap_protected = kvm_check_extension(s, KVM_CAP_S390_PROTECTED); kvm_vm_enable_cap(s, KVM_CAP_S390_USER_SIGP, 0); + kvm_vm_enable_cap(s, KVM_CAP_S390_USER_SIGP_BUSY, 0); kvm_vm_enable_cap(s, KVM_CAP_S390_VECTOR_REGISTERS, 0); kvm_vm_enable_cap(s, KVM_CAP_S390_USER_STSI, 0); if (ri_allowed()) { @@ -2558,6 +2559,21 @@ void kvm_s390_stop_interrupt(S390CPU *cpu) kvm_s390_vcpu_interrupt(cpu, &irq); } +int kvm_s390_vcpu_set_sigp_busy(S390CPU *cpu) +{ + CPUState *cs = CPU(cpu); + + return kvm_vcpu_ioctl(cs, KVM_S390_VCPU_SET_SIGP_BUSY); +} + +void kvm_s390_vcpu_reset_sigp_busy(S390CPU *cpu) +{ + CPUState *cs = CPU(cpu); + + /* Don't care about the response from this */ + kvm_vcpu_ioctl(cs, KVM_S390_VCPU_RESET_SIGP_BUSY); +} + bool kvm_arch_cpu_check_are_resettable(void) { return true; diff --git a/target/s390x/kvm/kvm_s390x.h b/target/s390x/kvm/kvm_s390x.h index 05a5e1e6f4..de148b68c4 100644 --- a/target/s390x/kvm/kvm_s390x.h +++ b/target/s390x/kvm/kvm_s390x.h @@ -45,5 +45,7 @@ void kvm_s390_crypto_reset(void); void kvm_s390_restart_interrupt(S390CPU *cpu); void kvm_s390_stop_interrupt(S390CPU *cpu); void kvm_s390_set_diag318(CPUState *cs, uint64_t diag318_info); +int kvm_s390_vcpu_set_sigp_busy(S390CPU *cpu); +void kvm_s390_vcpu_reset_sigp_busy(S390CPU *cpu); #endif /* KVM_S390X_H */ diff --git a/target/s390x/sigp.c b/target/s390x/sigp.c index 51c727834c..8f191df42a 100644 --- a/target/s390x/sigp.c +++ b/target/s390x/sigp.c @@ -111,12 +111,14 @@ static void sigp_stop(CPUState *cs, run_on_cpu_data arg) if (s390_cpu_get_state(cpu) != S390_CPU_STATE_OPERATING) { si->cc = SIGP_CC_ORDER_CODE_ACCEPTED; + s390_cpu_reset_sigp_busy(cpu); return; } /* disabled wait - sleeping in user space */ if (cs->halted) { s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu); + s390_cpu_reset_sigp_busy(cpu); } else { /* execute the stop function */ cpu->env.sigp_order = SIGP_STOP; @@ -139,12 +141,13 @@ static void sigp_stop_and_store_status(CPUState *cs, run_on_cpu_data arg) case S390_CPU_STATE_OPERATING: cpu->env.sigp_order = SIGP_STOP_STORE_STATUS; cpu_inject_stop(cpu); - /* store will be performed in do_stop_interrup() */ + /* store will be performed in do_stop_interrupt() */ break; case S390_CPU_STATE_STOPPED: /* already stopped, just store the status */ cpu_synchronize_state(cs); s390_store_status(cpu, S390_STORE_STATUS_DEF_ADDR, true); + s390_cpu_reset_sigp_busy(cpu); break; } si->cc = SIGP_CC_ORDER_CODE_ACCEPTED; @@ -375,6 +378,10 @@ static int handle_sigp_single_dst(S390CPU *cpu, S390CPU *dst_cpu, uint8_t order, return SIGP_CC_BUSY; } + if (s390_cpu_set_sigp_busy(dst_cpu) == -EBUSY) { + return SIGP_CC_BUSY; + } + switch (order) { case SIGP_SENSE: sigp_sense(dst_cpu, &si); @@ -422,6 +429,15 @@ static int handle_sigp_single_dst(S390CPU *cpu, S390CPU *dst_cpu, uint8_t order, set_sigp_status(&si, SIGP_STAT_INVALID_ORDER); } + switch (order) { + case SIGP_STOP: + case SIGP_STOP_STORE_STATUS: + /* These orders will clean up the indicator when they are finished */ + break; + default: + s390_cpu_reset_sigp_busy(dst_cpu); + } + return si.cc; } @@ -487,6 +503,7 @@ void do_stop_interrupt(CPUS390XState *env) } env->sigp_order = 0; env->pending_int &= ~INTERRUPT_STOP; + s390_cpu_reset_sigp_busy(cpu); } void s390_init_sigp(void) -- 2.25.1