// SPDX-License-Identifier: GPL-2.0
/*
* handling interprocessor communication
*
* Copyright IBM Corp. 2008, 2013
*
* Author(s): Carsten Otte <[email protected]>
* Christian Borntraeger <[email protected]>
* Christian Ehrhardt <[email protected]>
*/
#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_gpa_in_memslot(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;
}
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