From 31928aa5863e71535ee942f506ca9ac8ce1c4315 Mon Sep 17 00:00:00 2001 From: Dominik Dingel Date: Thu, 4 Dec 2014 15:47:07 +0100 Subject: KVM: remove unneeded return value of vcpu_postcreate The return value of kvm_arch_vcpu_postcreate is not checked in its caller. This is okay, because only x86 provides vcpu_postcreate right now and it could only fail if vcpu_load failed. But that is not possible during KVM_CREATE_VCPU (kvm_arch_vcpu_load is void, too), so just get rid of the unchecked return value. Signed-off-by: Dominik Dingel Acked-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- include/linux/kvm_host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 26f106022c88..a82432c710c9 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -652,7 +652,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu); void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu); struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id); int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu); -int kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu); +void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu); void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu); int kvm_arch_hardware_enable(void); -- cgit v1.2.3 From 2822545f9fe264ec62d4abc69c17ae759eafe4ce Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 15 Oct 2014 16:48:16 +0200 Subject: KVM: s390: new parameter for SIGP STOP irqs In order to get rid of the action_flags and to properly migrate pending SIGP STOP irqs triggered e.g. by SIGP STOP AND STORE STATUS, we need to remember whether to store the status when stopping. For this reason, a new parameter (flags) for the SIGP STOP irq is introduced. These flags further define details of the requested STOP and can be easily migrated. Reviewed-by: Thomas Huth Acked-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/api.txt | 2 +- arch/s390/include/asm/kvm_host.h | 2 ++ arch/s390/kvm/interrupt.c | 18 +++++++++++++++++- include/uapi/linux/kvm.h | 6 ++++++ 4 files changed, 26 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 0007fef4ed81..3ca6e0e9a769 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2312,7 +2312,7 @@ struct kvm_s390_interrupt { type can be one of the following: -KVM_S390_SIGP_STOP (vcpu) - sigp restart +KVM_S390_SIGP_STOP (vcpu) - sigp stop; optional flags in parm KVM_S390_PROGRAM_INT (vcpu) - program check; code in parm KVM_S390_SIGP_SET_PREFIX (vcpu) - sigp set prefix; prefix address in parm KVM_S390_RESTART (vcpu) - restart diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 9cba74d5d853..5eafe84a7b3d 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -378,6 +378,7 @@ struct kvm_s390_interrupt_info { struct kvm_s390_emerg_info emerg; struct kvm_s390_extcall_info extcall; struct kvm_s390_prefix_info prefix; + struct kvm_s390_stop_info stop; struct kvm_s390_mchk_info mchk; }; }; @@ -393,6 +394,7 @@ struct kvm_s390_irq_payload { struct kvm_s390_emerg_info emerg; struct kvm_s390_extcall_info extcall; struct kvm_s390_prefix_info prefix; + struct kvm_s390_stop_info stop; struct kvm_s390_mchk_info mchk; }; diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 7fbbcbcea6ac..73bafc3d0f41 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -394,13 +394,20 @@ static int __must_check __deliver_restart(struct kvm_vcpu *vcpu) static int __must_check __deliver_stop(struct kvm_vcpu *vcpu) { + struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int; + struct kvm_s390_stop_info *stop = &li->irq.stop; + + spin_lock(&li->lock); + stop->flags = 0; + clear_bit(IRQ_PEND_SIGP_STOP, &li->pending_irqs); + spin_unlock(&li->lock); + VCPU_EVENT(vcpu, 4, "%s", "interrupt: cpu stop"); vcpu->stat.deliver_stop_signal++; trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, KVM_S390_SIGP_STOP, 0, 0); __set_cpuflag(vcpu, CPUSTAT_STOP_INT); - clear_bit(IRQ_PEND_SIGP_STOP, &vcpu->arch.local_int.pending_irqs); return 0; } @@ -1031,13 +1038,19 @@ static int __inject_set_prefix(struct kvm_vcpu *vcpu, struct kvm_s390_irq *irq) return 0; } +#define KVM_S390_STOP_SUPP_FLAGS 0 static int __inject_sigp_stop(struct kvm_vcpu *vcpu, struct kvm_s390_irq *irq) { struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int; + struct kvm_s390_stop_info *stop = &li->irq.stop; trace_kvm_s390_inject_vcpu(vcpu->vcpu_id, KVM_S390_SIGP_STOP, 0, 0, 2); + if (irq->u.stop.flags & ~KVM_S390_STOP_SUPP_FLAGS) + return -EINVAL; + li->action_bits |= ACTION_STOP_ON_STOP; + stop->flags = irq->u.stop.flags; set_bit(IRQ_PEND_SIGP_STOP, &li->pending_irqs); return 0; } @@ -1306,6 +1319,9 @@ int s390int_to_s390irq(struct kvm_s390_interrupt *s390int, case KVM_S390_SIGP_SET_PREFIX: irq->u.prefix.address = s390int->parm; break; + case KVM_S390_SIGP_STOP: + irq->u.stop.flags = s390int->parm; + break; case KVM_S390_INT_EXTERNAL_CALL: if (irq->u.extcall.code & 0xffff0000) return -EINVAL; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index a37fd1224f36..adc24a3fd23e 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -491,6 +491,11 @@ struct kvm_s390_emerg_info { __u16 code; }; +#define KVM_S390_STOP_FLAG_STORE_STATUS 0x01 +struct kvm_s390_stop_info { + __u32 flags; +}; + struct kvm_s390_mchk_info { __u64 cr14; __u64 mcic; @@ -509,6 +514,7 @@ struct kvm_s390_irq { struct kvm_s390_emerg_info emerg; struct kvm_s390_extcall_info extcall; struct kvm_s390_prefix_info prefix; + struct kvm_s390_stop_info stop; struct kvm_s390_mchk_info mchk; char reserved[64]; } u; -- cgit v1.2.3 From 2444b352c3acf54897b0e2803a7c4e66699f9f43 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 9 Oct 2014 14:10:13 +0200 Subject: KVM: s390: forward most SIGP orders to user space Most SIGP orders are handled partially in kernel and partially in user space. In order to: - Get a correct SIGP SET PREFIX handler that informs user space - Avoid race conditions between concurrently executed SIGP orders - Serialize SIGP orders per VCPU We need to handle all "slow" SIGP orders in user space. The remaining ones to be handled completely in kernel are: - SENSE - SENSE RUNNING - EXTERNAL CALL - EMERGENCY SIGNAL - CONDITIONAL EMERGENCY SIGNAL According to the PoP, they have to be fast. They can be executed without conflicting to the actions of other pending/concurrently executing orders (e.g. STOP vs. START). This patch introduces a new capability that will - when enabled - forward all but the mentioned SIGP orders to user space. The instruction counters in the kernel are still updated. Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/api.txt | 20 ++++++++++++++++ arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/kvm-s390.c | 5 ++++ arch/s390/kvm/sigp.c | 49 +++++++++++++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 1 + 5 files changed, 76 insertions(+) (limited to 'include') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 3ca6e0e9a769..df19837e94d4 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3225,3 +3225,23 @@ userspace from doing that. If the hcall number specified is not one that has an in-kernel implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL error. + +7.2 KVM_CAP_S390_USER_SIGP + +Architectures: s390 +Parameters: none + +This capability controls which SIGP orders will be handled completely in user +space. With this capability enabled, all fast orders will be handled completely +in the kernel: +- SENSE +- SENSE RUNNING +- EXTERNAL CALL +- EMERGENCY SIGNAL +- CONDITIONAL EMERGENCY SIGNAL + +All other orders will be handled completely in user space. + +Only privileged operation exceptions will be checked for in the kernel (or even +in the hardware prior to interception). If this capability is not enabled, the +old way of handling SIGP orders is used (partially in kernel and user space). diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index b6170520380b..a2dcd0e099f7 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -521,6 +521,7 @@ struct kvm_arch{ int use_irqchip; int use_cmma; int user_cpu_state_ctrl; + int user_sigp; struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS]; wait_queue_head_t ipte_wq; int ipte_lock_count; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index bfb2b990da9b..3677b8ca647f 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -166,6 +166,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_S390_IRQCHIP: case KVM_CAP_VM_ATTRIBUTES: case KVM_CAP_MP_STATE: + case KVM_CAP_S390_USER_SIGP: r = 1; break; case KVM_CAP_NR_VCPUS: @@ -254,6 +255,10 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) kvm->arch.use_irqchip = 1; r = 0; break; + case KVM_CAP_S390_USER_SIGP: + kvm->arch.user_sigp = 1; + r = 0; + break; default: r = -EINVAL; break; diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c index 1524be9120ad..23b1e86b2122 100644 --- a/arch/s390/kvm/sigp.c +++ b/arch/s390/kvm/sigp.c @@ -371,6 +371,53 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code, return rc; } +static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code) +{ + if (!vcpu->kvm->arch.user_sigp) + return 0; + + switch (order_code) { + case SIGP_SENSE: + case SIGP_EXTERNAL_CALL: + case SIGP_EMERGENCY_SIGNAL: + case SIGP_COND_EMERGENCY_SIGNAL: + case SIGP_SENSE_RUNNING: + return 0; + /* update counters as we're directly dropping to user space */ + case SIGP_STOP: + vcpu->stat.instruction_sigp_stop++; + break; + case SIGP_STOP_AND_STORE_STATUS: + vcpu->stat.instruction_sigp_stop_store_status++; + break; + case SIGP_STORE_STATUS_AT_ADDRESS: + vcpu->stat.instruction_sigp_store_status++; + break; + case SIGP_SET_PREFIX: + vcpu->stat.instruction_sigp_prefix++; + break; + case SIGP_START: + vcpu->stat.instruction_sigp_start++; + break; + case SIGP_RESTART: + vcpu->stat.instruction_sigp_restart++; + break; + case SIGP_INITIAL_CPU_RESET: + vcpu->stat.instruction_sigp_init_cpu_reset++; + break; + case SIGP_CPU_RESET: + vcpu->stat.instruction_sigp_cpu_reset++; + break; + default: + vcpu->stat.instruction_sigp_unknown++; + } + + VCPU_EVENT(vcpu, 4, "sigp order %u: completely handled in user space", + order_code); + + return 1; +} + int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu) { int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4; @@ -385,6 +432,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu) return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); order_code = kvm_s390_get_base_disp_rs(vcpu); + if (handle_sigp_order_in_user_space(vcpu, order_code)) + return -EOPNOTSUPP; if (r1 % 2) parameter = vcpu->run->s.regs.gprs[r1]; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index adc24a3fd23e..37f71c3040c3 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -759,6 +759,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_PPC_FIXUP_HCALL 103 #define KVM_CAP_PPC_ENABLE_HCALL 104 #define KVM_CAP_CHECK_EXTENSION_VM 105 +#define KVM_CAP_S390_USER_SIGP 106 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3