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kernel/arch/s390/kvm/intercept.c
Christian Borntraeger a5e0acea9e KVM: s390: add exit io request stats and simplify code 
We want to count IO exit requests in kvm_stat. At the same time
we can get rid of the handle_noop function.

Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-14 19:21:11 +00:00

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// SPDX-License-Identifier: GPL-2.0
/*
* in-kernel handling for sie intercepts
*
* Copyright IBM Corp. 2008, 2014
*
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Christian Borntraeger <borntraeger@de.ibm.com>
*/
#include <linux/kvm_host.h>
#include <linux/errno.h>
#include <linux/pagemap.h>
#include <asm/kvm_host.h>
#include <asm/asm-offsets.h>
#include <asm/irq.h>
#include <asm/sysinfo.h>
#include "kvm-s390.h"
#include "gaccess.h"
#include "trace.h"
#include "trace-s390.h"
u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
{
struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
u8 ilen = 0;
switch (vcpu->arch.sie_block->icptcode) {
case ICPT_INST:
case ICPT_INSTPROGI:
case ICPT_OPEREXC:
case ICPT_PARTEXEC:
case ICPT_IOINST:
/* instruction only stored for these icptcodes */
ilen = insn_length(vcpu->arch.sie_block->ipa >> 8);
/* Use the length of the EXECUTE instruction if necessary */
if (sie_block->icptstatus & 1) {
ilen = (sie_block->icptstatus >> 4) & 0x6;
if (!ilen)
ilen = 4;
}
break;
case ICPT_PROGI:
/* bit 1+2 of pgmilc are the ilc, so we directly get ilen */
ilen = vcpu->arch.sie_block->pgmilc & 0x6;
break;
}
return ilen;
}
static int handle_stop(struct kvm_vcpu *vcpu)
{
struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
int rc = 0;
uint8_t flags, stop_pending;
vcpu->stat.exit_stop_request++;
/* delay the stop if any non-stop irq is pending */
if (kvm_s390_vcpu_has_irq(vcpu, 1))
return 0;
/* avoid races with the injection/SIGP STOP code */
spin_lock(&li->lock);
flags = li->irq.stop.flags;
stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
spin_unlock(&li->lock);
trace_kvm_s390_stop_request(stop_pending, flags);
if (!stop_pending)
return 0;
if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
rc = kvm_s390_vcpu_store_status(vcpu,
KVM_S390_STORE_STATUS_NOADDR);
if (rc)
return rc;
}
if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
kvm_s390_vcpu_stop(vcpu);
return -EOPNOTSUPP;
}
static int handle_validity(struct kvm_vcpu *vcpu)
{
int viwhy = vcpu->arch.sie_block->ipb >> 16;
vcpu->stat.exit_validity++;
trace_kvm_s390_intercept_validity(vcpu, viwhy);
KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%pK)", viwhy,
current->pid, vcpu->kvm);
/* do not warn on invalid runtime instrumentation mode */
WARN_ONCE(viwhy != 0x44, "kvm: unhandled validity intercept 0x%x\n",
viwhy);
return -EINVAL;
}
static int handle_instruction(struct kvm_vcpu *vcpu)
{
vcpu->stat.exit_instruction++;
trace_kvm_s390_intercept_instruction(vcpu,
vcpu->arch.sie_block->ipa,
vcpu->arch.sie_block->ipb);
switch (vcpu->arch.sie_block->ipa >> 8) {
case 0x01:
return kvm_s390_handle_01(vcpu);
case 0x82:
return kvm_s390_handle_lpsw(vcpu);
case 0x83:
return kvm_s390_handle_diag(vcpu);
case 0xaa:
return kvm_s390_handle_aa(vcpu);
case 0xae:
return kvm_s390_handle_sigp(vcpu);
case 0xb2:
return kvm_s390_handle_b2(vcpu);
case 0xb6:
return kvm_s390_handle_stctl(vcpu);
case 0xb7:
return kvm_s390_handle_lctl(vcpu);
case 0xb9:
return kvm_s390_handle_b9(vcpu);
case 0xe3:
return kvm_s390_handle_e3(vcpu);
case 0xe5:
return kvm_s390_handle_e5(vcpu);
case 0xeb:
return kvm_s390_handle_eb(vcpu);
default:
return -EOPNOTSUPP;
}
}
static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)
{
struct kvm_s390_pgm_info pgm_info = {
.code = vcpu->arch.sie_block->iprcc,
/* the PSW has already been rewound */
.flags = KVM_S390_PGM_FLAGS_NO_REWIND,
};
switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
case PGM_AFX_TRANSLATION:
case PGM_ASX_TRANSLATION:
case PGM_EX_TRANSLATION:
case PGM_LFX_TRANSLATION:
case PGM_LSTE_SEQUENCE:
case PGM_LSX_TRANSLATION:
case PGM_LX_TRANSLATION:
case PGM_PRIMARY_AUTHORITY:
case PGM_SECONDARY_AUTHORITY:
case PGM_SPACE_SWITCH:
pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
break;
case PGM_ALEN_TRANSLATION:
case PGM_ALE_SEQUENCE:
case PGM_ASTE_INSTANCE:
case PGM_ASTE_SEQUENCE:
case PGM_ASTE_VALIDITY:
case PGM_EXTENDED_AUTHORITY:
pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
break;
case PGM_ASCE_TYPE:
case PGM_PAGE_TRANSLATION:
case PGM_REGION_FIRST_TRANS:
case PGM_REGION_SECOND_TRANS:
case PGM_REGION_THIRD_TRANS:
case PGM_SEGMENT_TRANSLATION:
pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
pgm_info.op_access_id = vcpu->arch.sie_block->oai;
break;
case PGM_MONITOR:
pgm_info.mon_class_nr = vcpu->arch.sie_block->mcn;
pgm_info.mon_code = vcpu->arch.sie_block->tecmc;
break;
case PGM_VECTOR_PROCESSING:
case PGM_DATA:
pgm_info.data_exc_code = vcpu->arch.sie_block->dxc;
break;
case PGM_PROTECTION:
pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
break;
default:
break;
}
if (vcpu->arch.sie_block->iprcc & PGM_PER) {
pgm_info.per_code = vcpu->arch.sie_block->perc;
pgm_info.per_atmid = vcpu->arch.sie_block->peratmid;
pgm_info.per_address = vcpu->arch.sie_block->peraddr;
pgm_info.per_access_id = vcpu->arch.sie_block->peraid;
}
return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
}
/*
* restore ITDB to program-interruption TDB in guest lowcore
* and set TX abort indication if required
*/
static int handle_itdb(struct kvm_vcpu *vcpu)
{
struct kvm_s390_itdb *itdb;
int rc;
if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
return 0;
if (current->thread.per_flags & PER_FLAG_NO_TE)
return 0;
itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
if (rc)
return rc;
memset(itdb, 0, sizeof(*itdb));
return 0;
}
#define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
static int handle_prog(struct kvm_vcpu *vcpu)
{
psw_t psw;
int rc;
vcpu->stat.exit_program_interruption++;
if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
rc = kvm_s390_handle_per_event(vcpu);
if (rc)
return rc;
/* the interrupt might have been filtered out completely */
if (vcpu->arch.sie_block->iprcc == 0)
return 0;
}
trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
if (rc)
return rc;
/* Avoid endless loops of specification exceptions */
if (!is_valid_psw(&psw))
return -EOPNOTSUPP;
}
rc = handle_itdb(vcpu);
if (rc)
return rc;
return inject_prog_on_prog_intercept(vcpu);
}
/**
* handle_external_interrupt - used for external interruption interceptions
*
* This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
* the new PSW does not have external interrupts disabled. In the first case,
* we've got to deliver the interrupt manually, and in the second case, we
* drop to userspace to handle the situation there.
*/
static int handle_external_interrupt(struct kvm_vcpu *vcpu)
{
u16 eic = vcpu->arch.sie_block->eic;
struct kvm_s390_irq irq;
psw_t newpsw;
int rc;
vcpu->stat.exit_external_interrupt++;
rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
if (rc)
return rc;
/* We can not handle clock comparator or timer interrupt with bad PSW */
if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
(newpsw.mask & PSW_MASK_EXT))
return -EOPNOTSUPP;
switch (eic) {
case EXT_IRQ_CLK_COMP:
irq.type = KVM_S390_INT_CLOCK_COMP;
break;
case EXT_IRQ_CPU_TIMER:
irq.type = KVM_S390_INT_CPU_TIMER;
break;
case EXT_IRQ_EXTERNAL_CALL:
irq.type = KVM_S390_INT_EXTERNAL_CALL;
irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
rc = kvm_s390_inject_vcpu(vcpu, &irq);
/* ignore if another external call is already pending */
if (rc == -EBUSY)
return 0;
return rc;
default:
return -EOPNOTSUPP;
}
return kvm_s390_inject_vcpu(vcpu, &irq);
}
/**
* Handle MOVE PAGE partial execution interception.
*
* This interception can only happen for guests with DAT disabled and
* addresses that are currently not mapped in the host. Thus we try to
* set up the mappings for the corresponding user pages here (or throw
* addressing exceptions in case of illegal guest addresses).
*/
static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
{
unsigned long srcaddr, dstaddr;
int reg1, reg2, rc;
kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
/* Make sure that the source is paged-in */
rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
reg2, &srcaddr, GACC_FETCH);
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
if (rc != 0)
return rc;
/* Make sure that the destination is paged-in */
rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
reg1, &dstaddr, GACC_STORE);
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
if (rc != 0)
return rc;
kvm_s390_retry_instr(vcpu);
return 0;
}
static int handle_partial_execution(struct kvm_vcpu *vcpu)
{
vcpu->stat.exit_pei++;
if (vcpu->arch.sie_block->ipa == 0xb254) /* MVPG */
return handle_mvpg_pei(vcpu);
if (vcpu->arch.sie_block->ipa >> 8 == 0xae) /* SIGP */
return kvm_s390_handle_sigp_pei(vcpu);
return -EOPNOTSUPP;
}
/*
* Handle the sthyi instruction that provides the guest with system
* information, like current CPU resources available at each level of
* the machine.
*/
int handle_sthyi(struct kvm_vcpu *vcpu)
{
int reg1, reg2, r = 0;
u64 code, addr, cc = 0, rc = 0;
struct sthyi_sctns *sctns = NULL;
if (!test_kvm_facility(vcpu->kvm, 74))
return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
code = vcpu->run->s.regs.gprs[reg1];
addr = vcpu->run->s.regs.gprs[reg2];
vcpu->stat.instruction_sthyi++;
VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr);
trace_kvm_s390_handle_sthyi(vcpu, code, addr);
if (reg1 == reg2 || reg1 & 1 || reg2 & 1)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
if (code & 0xffff) {
cc = 3;
rc = 4;
goto out;
}
if (addr & ~PAGE_MASK)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
sctns = (void *)get_zeroed_page(GFP_KERNEL);
if (!sctns)
return -ENOMEM;
cc = sthyi_fill(sctns, &rc);
out:
if (!cc) {
r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
if (r) {
free_page((unsigned long)sctns);
return kvm_s390_inject_prog_cond(vcpu, r);
}
}
free_page((unsigned long)sctns);
vcpu->run->s.regs.gprs[reg2 + 1] = rc;
kvm_s390_set_psw_cc(vcpu, cc);
return r;
}
static int handle_operexc(struct kvm_vcpu *vcpu)
{
psw_t oldpsw, newpsw;
int rc;
vcpu->stat.exit_operation_exception++;
trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
vcpu->arch.sie_block->ipb);
if (vcpu->arch.sie_block->ipa == 0xb256)
return handle_sthyi(vcpu);
if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
return -EOPNOTSUPP;
rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &newpsw, sizeof(psw_t));
if (rc)
return rc;
/*
* Avoid endless loops of operation exceptions, if the pgm new
* PSW will cause a new operation exception.
* The heuristic checks if the pgm new psw is within 6 bytes before
* the faulting psw address (with same DAT, AS settings) and the
* new psw is not a wait psw and the fault was not triggered by
* problem state.
*/
oldpsw = vcpu->arch.sie_block->gpsw;
if (oldpsw.addr - newpsw.addr <= 6 &&
!(newpsw.mask & PSW_MASK_WAIT) &&
!(oldpsw.mask & PSW_MASK_PSTATE) &&
(newpsw.mask & PSW_MASK_ASC) == (oldpsw.mask & PSW_MASK_ASC) &&
(newpsw.mask & PSW_MASK_DAT) == (oldpsw.mask & PSW_MASK_DAT))
return -EOPNOTSUPP;
return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
}
int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
{
int rc, per_rc = 0;
if (kvm_is_ucontrol(vcpu->kvm))
return -EOPNOTSUPP;
switch (vcpu->arch.sie_block->icptcode) {
case ICPT_EXTREQ:
vcpu->stat.exit_external_request++;
return 0;
case ICPT_IOREQ:
vcpu->stat.exit_io_request++;
return 0;
case ICPT_INST:
rc = handle_instruction(vcpu);
break;
case ICPT_PROGI:
return handle_prog(vcpu);
case ICPT_EXTINT:
return handle_external_interrupt(vcpu);
case ICPT_WAIT:
return kvm_s390_handle_wait(vcpu);
case ICPT_VALIDITY:
return handle_validity(vcpu);
case ICPT_STOP:
return handle_stop(vcpu);
case ICPT_OPEREXC:
rc = handle_operexc(vcpu);
break;
case ICPT_PARTEXEC:
rc = handle_partial_execution(vcpu);
break;
case ICPT_KSS:
rc = kvm_s390_skey_check_enable(vcpu);
break;
default:
return -EOPNOTSUPP;
}
/* process PER, also if the instrution is processed in user space */
if (vcpu->arch.sie_block->icptstatus & 0x02 &&
(!rc || rc == -EOPNOTSUPP))
per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
return per_rc ? per_rc : rc;
}
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