From 6352e4d2dd9a349024a41356148eced553e1dce4 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 10 Apr 2014 17:35:00 +0200 Subject: [PATCH] KVM: s390: implement KVM_(S|G)ET_MP_STATE for user space state control This patch - adds s390 specific MP states to linux headers and documents them - implements the KVM_{SET,GET}_MP_STATE ioctls - enables KVM_CAP_MP_STATE - allows user space to control the VCPU state on s390. If user space sets the VCPU state using the ioctl KVM_SET_MP_STATE, we can disable manual changing of the VCPU state and trust user space to do the right thing. Signed-off-by: David Hildenbrand Reviewed-by: Cornelia Huck Acked-by: Christian Borntraeger Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/api.txt | 10 +++++++-- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/diag.c | 3 ++- arch/s390/kvm/intercept.c | 3 ++- arch/s390/kvm/kvm-s390.c | 37 +++++++++++++++++++++++++++---- arch/s390/kvm/kvm-s390.h | 6 +++++ include/uapi/linux/kvm.h | 4 ++++ 7 files changed, 56 insertions(+), 8 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 904c61cdd311..a41465bd6a5c 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -974,7 +974,7 @@ for vm-wide capabilities. 4.38 KVM_GET_MP_STATE Capability: KVM_CAP_MP_STATE -Architectures: x86, ia64 +Architectures: x86, ia64, s390 Type: vcpu ioctl Parameters: struct kvm_mp_state (out) Returns: 0 on success; -1 on error @@ -998,6 +998,12 @@ Possible values are: is waiting for an interrupt [x86, ia64] - KVM_MP_STATE_SIPI_RECEIVED: the vcpu has just received a SIPI (vector accessible via KVM_GET_VCPU_EVENTS) [x86, ia64] + - KVM_MP_STATE_STOPPED: the vcpu is stopped [s390] + - KVM_MP_STATE_CHECK_STOP: the vcpu is in a special error state [s390] + - KVM_MP_STATE_OPERATING: the vcpu is operating (running or halted) + [s390] + - KVM_MP_STATE_LOAD: the vcpu is in a special load/startup state + [s390] On x86 and ia64, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an in-kernel irqchip, the multiprocessing state must be maintained by userspace on @@ -1007,7 +1013,7 @@ these architectures. 4.39 KVM_SET_MP_STATE Capability: KVM_CAP_MP_STATE -Architectures: x86, ia64 +Architectures: x86, ia64, s390 Type: vcpu ioctl Parameters: struct kvm_mp_state (in) Returns: 0 on success; -1 on error diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 4181d7baabba..c2ba0208a0e1 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -418,6 +418,7 @@ struct kvm_arch{ int css_support; int use_irqchip; int use_cmma; + int user_cpu_state_ctrl; struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS]; wait_queue_head_t ipte_wq; spinlock_t start_stop_lock; diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c index 0161675878a2..59bd8f991b98 100644 --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -176,7 +176,8 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu) return -EOPNOTSUPP; } - kvm_s390_vcpu_stop(vcpu); + if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) + kvm_s390_vcpu_stop(vcpu); vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM; vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL; vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT; diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index ac6b32585a36..eaf46291d361 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -73,7 +73,8 @@ static int handle_stop(struct kvm_vcpu *vcpu) return rc; } - kvm_s390_vcpu_stop(vcpu); + if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) + kvm_s390_vcpu_stop(vcpu); return -EOPNOTSUPP; } diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 342895350825..fdf88f7a539c 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -167,6 +167,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_DEVICE_CTRL: case KVM_CAP_ENABLE_CAP_VM: case KVM_CAP_VM_ATTRIBUTES: + case KVM_CAP_MP_STATE: r = 1; break; case KVM_CAP_NR_VCPUS: @@ -595,7 +596,8 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu) vcpu->arch.sie_block->pp = 0; vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID; kvm_clear_async_pf_completion_queue(vcpu); - kvm_s390_vcpu_stop(vcpu); + if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) + kvm_s390_vcpu_stop(vcpu); kvm_s390_clear_local_irqs(vcpu); } @@ -980,13 +982,34 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { - return -EINVAL; /* not implemented yet */ + /* CHECK_STOP and LOAD are not supported yet */ + return is_vcpu_stopped(vcpu) ? KVM_MP_STATE_STOPPED : + KVM_MP_STATE_OPERATING; } int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { - return -EINVAL; /* not implemented yet */ + int rc = 0; + + /* user space knows about this interface - let it control the state */ + vcpu->kvm->arch.user_cpu_state_ctrl = 1; + + switch (mp_state->mp_state) { + case KVM_MP_STATE_STOPPED: + kvm_s390_vcpu_stop(vcpu); + break; + case KVM_MP_STATE_OPERATING: + kvm_s390_vcpu_start(vcpu); + break; + case KVM_MP_STATE_LOAD: + case KVM_MP_STATE_CHECK_STOP: + /* fall through - CHECK_STOP and LOAD are not supported yet */ + default: + rc = -ENXIO; + } + + return rc; } bool kvm_s390_cmma_enabled(struct kvm *kvm) @@ -1284,7 +1307,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) if (vcpu->sigset_active) sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved); - kvm_s390_vcpu_start(vcpu); + if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) { + kvm_s390_vcpu_start(vcpu); + } else if (is_vcpu_stopped(vcpu)) { + pr_err_ratelimited("kvm-s390: can't run stopped vcpu %d\n", + vcpu->vcpu_id); + return -EINVAL; + } switch (kvm_run->exit_reason) { case KVM_EXIT_S390_SIEIC: diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 77ed846342d4..33a0e4bed2a5 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -129,6 +129,12 @@ static inline void kvm_s390_set_psw_cc(struct kvm_vcpu *vcpu, unsigned long cc) vcpu->arch.sie_block->gpsw.mask |= cc << 44; } +/* are cpu states controlled by user space */ +static inline int kvm_s390_user_cpu_state_ctrl(struct kvm *kvm) +{ + return kvm->arch.user_cpu_state_ctrl != 0; +} + int kvm_s390_handle_wait(struct kvm_vcpu *vcpu); enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer); void kvm_s390_tasklet(unsigned long parm); diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 37d4ec6f14d8..9b744af871d7 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -407,6 +407,10 @@ struct kvm_vapic_addr { #define KVM_MP_STATE_INIT_RECEIVED 2 #define KVM_MP_STATE_HALTED 3 #define KVM_MP_STATE_SIPI_RECEIVED 4 +#define KVM_MP_STATE_STOPPED 5 +#define KVM_MP_STATE_CHECK_STOP 6 +#define KVM_MP_STATE_OPERATING 7 +#define KVM_MP_STATE_LOAD 8 struct kvm_mp_state { __u32 mp_state; -- 2.20.1