diff options
Diffstat (limited to 'arch/s390/kvm/sigp.c')
| -rw-r--r-- | arch/s390/kvm/sigp.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c new file mode 100644 index 000000000..d9696b530 --- /dev/null +++ b/arch/s390/kvm/sigp.c @@ -0,0 +1,495 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * handling interprocessor communication + * + * Copyright IBM Corp. 2008, 2013 + * + * Author(s): Carsten Otte <cotte@de.ibm.com> + * Christian Borntraeger <borntraeger@de.ibm.com> + * Christian Ehrhardt <ehrhardt@de.ibm.com> + */ + +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/slab.h> +#include <asm/sigp.h> +#include "gaccess.h" +#include "kvm-s390.h" +#include "trace.h" + +static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu, + u64 *reg) +{ + const bool stopped = kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED); + int rc; + int ext_call_pending; + + ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu); + if (!stopped && !ext_call_pending) + rc = SIGP_CC_ORDER_CODE_ACCEPTED; + else { + *reg &= 0xffffffff00000000UL; + if (ext_call_pending) + *reg |= SIGP_STATUS_EXT_CALL_PENDING; + if (stopped) + *reg |= SIGP_STATUS_STOPPED; + rc = SIGP_CC_STATUS_STORED; + } + + VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id, + rc); + return rc; +} + +static int __inject_sigp_emergency(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu) +{ + struct kvm_s390_irq irq = { + .type = KVM_S390_INT_EMERGENCY, + .u.emerg.code = vcpu->vcpu_id, + }; + int rc = 0; + + rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); + if (!rc) + VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", + dst_vcpu->vcpu_id); + + return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED; +} + +static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu) +{ + return __inject_sigp_emergency(vcpu, dst_vcpu); +} + +static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu, + u16 asn, u64 *reg) +{ + const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT; + u16 p_asn, s_asn; + psw_t *psw; + bool idle; + + idle = is_vcpu_idle(vcpu); + psw = &dst_vcpu->arch.sie_block->gpsw; + p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff; /* Primary ASN */ + s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff; /* Secondary ASN */ + + /* Inject the emergency signal? */ + if (!is_vcpu_stopped(vcpu) + || (psw->mask & psw_int_mask) != psw_int_mask + || (idle && psw->addr != 0) + || (!idle && (asn == p_asn || asn == s_asn))) { + return __inject_sigp_emergency(vcpu, dst_vcpu); + } else { + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_INCORRECT_STATE; + return SIGP_CC_STATUS_STORED; + } +} + +static int __sigp_external_call(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu, u64 *reg) +{ + struct kvm_s390_irq irq = { + .type = KVM_S390_INT_EXTERNAL_CALL, + .u.extcall.code = vcpu->vcpu_id, + }; + int rc; + + rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); + if (rc == -EBUSY) { + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_EXT_CALL_PENDING; + return SIGP_CC_STATUS_STORED; + } else if (rc == 0) { + VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x", + dst_vcpu->vcpu_id); + } + + return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED; +} + +static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu) +{ + struct kvm_s390_irq irq = { + .type = KVM_S390_SIGP_STOP, + }; + int rc; + + rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); + if (rc == -EBUSY) + rc = SIGP_CC_BUSY; + else if (rc == 0) + VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", + dst_vcpu->vcpu_id); + + return rc; +} + +static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu, u64 *reg) +{ + struct kvm_s390_irq irq = { + .type = KVM_S390_SIGP_STOP, + .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS, + }; + int rc; + + rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); + if (rc == -EBUSY) + rc = SIGP_CC_BUSY; + else if (rc == 0) + VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x", + dst_vcpu->vcpu_id); + + return rc; +} + +static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter, + u64 *status_reg) +{ + *status_reg &= 0xffffffff00000000UL; + + /* Reject set arch order, with czam we're always in z/Arch mode. */ + *status_reg |= SIGP_STATUS_INVALID_PARAMETER; + return SIGP_CC_STATUS_STORED; +} + +static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu, + u32 address, u64 *reg) +{ + struct kvm_s390_irq irq = { + .type = KVM_S390_SIGP_SET_PREFIX, + .u.prefix.address = address & 0x7fffe000u, + }; + int rc; + + /* + * Make sure the new value is valid memory. We only need to check the + * first page, since address is 8k aligned and memory pieces are always + * at least 1MB aligned and have at least a size of 1MB. + */ + if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) { + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_INVALID_PARAMETER; + return SIGP_CC_STATUS_STORED; + } + + rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); + if (rc == -EBUSY) { + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_INCORRECT_STATE; + return SIGP_CC_STATUS_STORED; + } + + return rc; +} + +static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu, + u32 addr, u64 *reg) +{ + int rc; + + if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) { + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_INCORRECT_STATE; + return SIGP_CC_STATUS_STORED; + } + + addr &= 0x7ffffe00; + rc = kvm_s390_store_status_unloaded(dst_vcpu, addr); + if (rc == -EFAULT) { + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_INVALID_PARAMETER; + rc = SIGP_CC_STATUS_STORED; + } + return rc; +} + +static int __sigp_sense_running(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu, u64 *reg) +{ + int rc; + + if (!test_kvm_facility(vcpu->kvm, 9)) { + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_INVALID_ORDER; + return SIGP_CC_STATUS_STORED; + } + + if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) { + /* running */ + rc = SIGP_CC_ORDER_CODE_ACCEPTED; + } else { + /* not running */ + *reg &= 0xffffffff00000000UL; + *reg |= SIGP_STATUS_NOT_RUNNING; + rc = SIGP_CC_STATUS_STORED; + } + + VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x", + dst_vcpu->vcpu_id, rc); + + return rc; +} + +static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu, u8 order_code) +{ + struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int; + /* handle (RE)START in user space */ + int rc = -EOPNOTSUPP; + + /* make sure we don't race with STOP irq injection */ + spin_lock(&li->lock); + if (kvm_s390_is_stop_irq_pending(dst_vcpu)) + rc = SIGP_CC_BUSY; + spin_unlock(&li->lock); + + return rc; +} + +static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu, u8 order_code) +{ + /* handle (INITIAL) CPU RESET in user space */ + return -EOPNOTSUPP; +} + +static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu, + struct kvm_vcpu *dst_vcpu) +{ + /* handle unknown orders in user space */ + return -EOPNOTSUPP; +} + +static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code, + u16 cpu_addr, u32 parameter, u64 *status_reg) +{ + int rc; + struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr); + + if (!dst_vcpu) + return SIGP_CC_NOT_OPERATIONAL; + + /* + * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders + * are processed asynchronously. Until the affected VCPU finishes + * its work and calls back into KVM to clear the (RESTART or STOP) + * interrupt, we need to return any new non-reset orders "busy". + * + * This is important because a single VCPU could issue: + * 1) SIGP STOP $DESTINATION + * 2) SIGP SENSE $DESTINATION + * + * If the SIGP SENSE would not be rejected as "busy", it could + * return an incorrect answer as to whether the VCPU is STOPPED + * or OPERATING. + */ + if (order_code != SIGP_INITIAL_CPU_RESET && + order_code != SIGP_CPU_RESET) { + /* + * Lockless check. Both SIGP STOP and SIGP (RE)START + * properly synchronize everything while processing + * their orders, while the guest cannot observe a + * difference when issuing other orders from two + * different VCPUs. + */ + if (kvm_s390_is_stop_irq_pending(dst_vcpu) || + kvm_s390_is_restart_irq_pending(dst_vcpu)) + return SIGP_CC_BUSY; + } + + switch (order_code) { + case SIGP_SENSE: + vcpu->stat.instruction_sigp_sense++; + rc = __sigp_sense(vcpu, dst_vcpu, status_reg); + break; + case SIGP_EXTERNAL_CALL: + vcpu->stat.instruction_sigp_external_call++; + rc = __sigp_external_call(vcpu, dst_vcpu, status_reg); + break; + case SIGP_EMERGENCY_SIGNAL: + vcpu->stat.instruction_sigp_emergency++; + rc = __sigp_emergency(vcpu, dst_vcpu); + break; + case SIGP_STOP: + vcpu->stat.instruction_sigp_stop++; + rc = __sigp_stop(vcpu, dst_vcpu); + break; + case SIGP_STOP_AND_STORE_STATUS: + vcpu->stat.instruction_sigp_stop_store_status++; + rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg); + break; + case SIGP_STORE_STATUS_AT_ADDRESS: + vcpu->stat.instruction_sigp_store_status++; + rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter, + status_reg); + break; + case SIGP_SET_PREFIX: + vcpu->stat.instruction_sigp_prefix++; + rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg); + break; + case SIGP_COND_EMERGENCY_SIGNAL: + vcpu->stat.instruction_sigp_cond_emergency++; + rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter, + status_reg); + break; + case SIGP_SENSE_RUNNING: + vcpu->stat.instruction_sigp_sense_running++; + rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg); + break; + case SIGP_START: + vcpu->stat.instruction_sigp_start++; + rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code); + break; + case SIGP_RESTART: + vcpu->stat.instruction_sigp_restart++; + rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code); + break; + case SIGP_INITIAL_CPU_RESET: + vcpu->stat.instruction_sigp_init_cpu_reset++; + rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code); + break; + case SIGP_CPU_RESET: + vcpu->stat.instruction_sigp_cpu_reset++; + rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code); + break; + default: + vcpu->stat.instruction_sigp_unknown++; + rc = __prepare_sigp_unknown(vcpu, dst_vcpu); + } + + if (rc == -EOPNOTSUPP) + VCPU_EVENT(vcpu, 4, + "sigp order %u -> cpu %x: handled in user space", + order_code, dst_vcpu->vcpu_id); + + return rc; +} + +static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code, + u16 cpu_addr) +{ + 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_STORE_ADDITIONAL_STATUS: + vcpu->stat.instruction_sigp_store_adtl_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, 3, "SIGP: order %u for CPU %d handled in userspace", + order_code, cpu_addr); + + return 1; +} + +int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu) +{ + int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4; + int r3 = vcpu->arch.sie_block->ipa & 0x000f; + u32 parameter; + u16 cpu_addr = vcpu->run->s.regs.gprs[r3]; + u8 order_code; + int rc; + + /* sigp in userspace can exit */ + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) + return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); + + order_code = kvm_s390_get_base_disp_rs(vcpu, NULL); + if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr)) + return -EOPNOTSUPP; + + if (r1 % 2) + parameter = vcpu->run->s.regs.gprs[r1]; + else + parameter = vcpu->run->s.regs.gprs[r1 + 1]; + + trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter); + switch (order_code) { + case SIGP_SET_ARCHITECTURE: + vcpu->stat.instruction_sigp_arch++; + rc = __sigp_set_arch(vcpu, parameter, + &vcpu->run->s.regs.gprs[r1]); + break; + default: + rc = handle_sigp_dst(vcpu, order_code, cpu_addr, + parameter, + &vcpu->run->s.regs.gprs[r1]); + } + + if (rc < 0) + return rc; + + kvm_s390_set_psw_cc(vcpu, rc); + return 0; +} + +/* + * Handle SIGP partial execution interception. + * + * This interception will occur at the source cpu when a source cpu sends an + * external call to a target cpu and the target cpu has the WAIT bit set in + * its cpuflags. Interception will occur after the interrupt indicator bits at + * the target cpu have been set. All error cases will lead to instruction + * interception, therefore nothing is to be checked or prepared. + */ +int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu) +{ + int r3 = vcpu->arch.sie_block->ipa & 0x000f; + u16 cpu_addr = vcpu->run->s.regs.gprs[r3]; + struct kvm_vcpu *dest_vcpu; + u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL); + + if (order_code == SIGP_EXTERNAL_CALL) { + trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr); + + dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr); + BUG_ON(dest_vcpu == NULL); + + kvm_s390_vcpu_wakeup(dest_vcpu); + kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED); + return 0; + } + + return -EOPNOTSUPP; +} |