/*
 * handling privileged instructions
 *
 * Copyright IBM Corp. 2008, 2013
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License (version 2 only)
 * as published by the Free Software Foundation.
 *
 *    Author(s): Carsten Otte <cotte@de.ibm.com>
 *               Christian Borntraeger <borntraeger@de.ibm.com>
 */

#include <linux/kvm.h>
#include <linux/gfp.h>
#include <linux/errno.h>
#include <linux/compat.h>
#include <asm/asm-offsets.h>
#include <asm/facility.h>
#include <asm/current.h>
#include <asm/debug.h>
#include <asm/ebcdic.h>
#include <asm/sysinfo.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/io.h>
#include <asm/ptrace.h>
#include <asm/compat.h>
#include "gaccess.h"
#include "kvm-s390.h"
#include "trace.h"

/* Handle SCK (SET CLOCK) interception */
static int handle_set_clock(struct kvm_vcpu *vcpu)
{
        struct kvm_vcpu *cpup;
        s64 hostclk, val;
        int i, rc;
        u64 op2;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        op2 = kvm_s390_get_base_disp_s(vcpu);
        if (op2 & 7)    /* Operand must be on a doubleword boundary */
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        rc = read_guest(vcpu, op2, &val, sizeof(val));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);

        if (store_tod_clock(&hostclk)) {
                kvm_s390_set_psw_cc(vcpu, 3);
                return 0;
        }
        val = (val - hostclk) & ~0x3fUL;

        mutex_lock(&vcpu->kvm->lock);
        kvm_for_each_vcpu(i, cpup, vcpu->kvm)
                cpup->arch.sie_block->epoch = val;
        mutex_unlock(&vcpu->kvm->lock);

        kvm_s390_set_psw_cc(vcpu, 0);
        return 0;
}

static int handle_set_prefix(struct kvm_vcpu *vcpu)
{
        u64 operand2;
        u32 address;
        int rc;

        vcpu->stat.instruction_spx++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        operand2 = kvm_s390_get_base_disp_s(vcpu);

        /* must be word boundary */
        if (operand2 & 3)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        /* get the value */
        rc = read_guest(vcpu, operand2, &address, sizeof(address));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);

        address &= 0x7fffe000u;

        /*
         * 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, address))
                return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

        kvm_s390_set_prefix(vcpu, address);

        VCPU_EVENT(vcpu, 5, "setting prefix to %x", address);
        trace_kvm_s390_handle_prefix(vcpu, 1, address);
        return 0;
}

static int handle_store_prefix(struct kvm_vcpu *vcpu)
{
        u64 operand2;
        u32 address;
        int rc;

        vcpu->stat.instruction_stpx++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        operand2 = kvm_s390_get_base_disp_s(vcpu);

        /* must be word boundary */
        if (operand2 & 3)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        address = kvm_s390_get_prefix(vcpu);

        /* get the value */
        rc = write_guest(vcpu, operand2, &address, sizeof(address));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);

        VCPU_EVENT(vcpu, 5, "storing prefix to %x", address);
        trace_kvm_s390_handle_prefix(vcpu, 0, address);
        return 0;
}

static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
{
        u16 vcpu_id = vcpu->vcpu_id;
        u64 ga;
        int rc;

        vcpu->stat.instruction_stap++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        ga = kvm_s390_get_base_disp_s(vcpu);

        if (ga & 1)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        rc = write_guest(vcpu, ga, &vcpu_id, sizeof(vcpu_id));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);

        VCPU_EVENT(vcpu, 5, "storing cpu address to %llx", ga);
        trace_kvm_s390_handle_stap(vcpu, ga);
        return 0;
}

static void __skey_check_enable(struct kvm_vcpu *vcpu)
{
        if (!(vcpu->arch.sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)))
                return;

        s390_enable_skey();
        trace_kvm_s390_skey_related_inst(vcpu);
        vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE);
}


static int handle_skey(struct kvm_vcpu *vcpu)
{
        __skey_check_enable(vcpu);

        vcpu->stat.instruction_storage_key++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        vcpu->arch.sie_block->gpsw.addr =
                __rewind_psw(vcpu->arch.sie_block->gpsw, 4);
        VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
        return 0;
}

static int handle_ipte_interlock(struct kvm_vcpu *vcpu)
{
        psw_t *psw = &vcpu->arch.sie_block->gpsw;

        vcpu->stat.instruction_ipte_interlock++;
        if (psw_bits(*psw).p)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
        wait_event(vcpu->kvm->arch.ipte_wq, !ipte_lock_held(vcpu));
        psw->addr = __rewind_psw(*psw, 4);
        VCPU_EVENT(vcpu, 4, "%s", "retrying ipte interlock operation");
        return 0;
}

static int handle_test_block(struct kvm_vcpu *vcpu)
{
        gpa_t addr;
        int reg2;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        kvm_s390_get_regs_rre(vcpu, NULL, &reg2);
        addr = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
        addr = kvm_s390_logical_to_effective(vcpu, addr);
        if (kvm_s390_check_low_addr_protection(vcpu, addr))
                return kvm_s390_inject_prog_irq(vcpu, &vcpu->arch.pgm);
        addr = kvm_s390_real_to_abs(vcpu, addr);

        if (kvm_is_error_gpa(vcpu->kvm, addr))
                return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
        /*
         * We don't expect errors on modern systems, and do not care
         * about storage keys (yet), so let's just clear the page.
         */
        if (kvm_clear_guest(vcpu->kvm, addr, PAGE_SIZE))
                return -EFAULT;
        kvm_s390_set_psw_cc(vcpu, 0);
        vcpu->run->s.regs.gprs[0] = 0;
        return 0;
}

static int handle_tpi(struct kvm_vcpu *vcpu)
{
        struct kvm_s390_interrupt_info *inti;
        unsigned long len;
        u32 tpi_data[3];
        int cc, rc;
        u64 addr;

        rc = 0;
        addr = kvm_s390_get_base_disp_s(vcpu);
        if (addr & 3)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        cc = 0;
        inti = kvm_s390_get_io_int(vcpu->kvm, vcpu->arch.sie_block->gcr[6], 0);
        if (!inti)
                goto no_interrupt;
        cc = 1;
        tpi_data[0] = inti->io.subchannel_id << 16 | inti->io.subchannel_nr;
        tpi_data[1] = inti->io.io_int_parm;
        tpi_data[2] = inti->io.io_int_word;
        if (addr) {
                /*
                 * Store the two-word I/O interruption code into the
                 * provided area.
                 */
                len = sizeof(tpi_data) - 4;
                rc = write_guest(vcpu, addr, &tpi_data, len);
                if (rc)
                        return kvm_s390_inject_prog_cond(vcpu, rc);
        } else {
                /*
                 * Store the three-word I/O interruption code into
                 * the appropriate lowcore area.
                 */
                len = sizeof(tpi_data);
                if (write_guest_lc(vcpu, __LC_SUBCHANNEL_ID, &tpi_data, len))
                        rc = -EFAULT;
        }
        /*
         * If we encounter a problem storing the interruption code, the
         * instruction is suppressed from the guest's view: reinject the
         * interrupt.
         */
        if (!rc)
                kfree(inti);
        else
                kvm_s390_reinject_io_int(vcpu->kvm, inti);
no_interrupt:
        /* Set condition code and we're done. */
        if (!rc)
                kvm_s390_set_psw_cc(vcpu, cc);
        return rc ? -EFAULT : 0;
}

static int handle_tsch(struct kvm_vcpu *vcpu)
{
        struct kvm_s390_interrupt_info *inti;

        inti = kvm_s390_get_io_int(vcpu->kvm, 0,
                                   vcpu->run->s.regs.gprs[1]);

        /*
         * Prepare exit to userspace.
         * We indicate whether we dequeued a pending I/O interrupt
         * so that userspace can re-inject it if the instruction gets
         * a program check. While this may re-order the pending I/O
         * interrupts, this is no problem since the priority is kept
         * intact.
         */
        vcpu->run->exit_reason = KVM_EXIT_S390_TSCH;
        vcpu->run->s390_tsch.dequeued = !!inti;
        if (inti) {
                vcpu->run->s390_tsch.subchannel_id = inti->io.subchannel_id;
                vcpu->run->s390_tsch.subchannel_nr = inti->io.subchannel_nr;
                vcpu->run->s390_tsch.io_int_parm = inti->io.io_int_parm;
                vcpu->run->s390_tsch.io_int_word = inti->io.io_int_word;
        }
        vcpu->run->s390_tsch.ipb = vcpu->arch.sie_block->ipb;
        kfree(inti);
        return -EREMOTE;
}

static int handle_io_inst(struct kvm_vcpu *vcpu)
{
        VCPU_EVENT(vcpu, 4, "%s", "I/O instruction");

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        if (vcpu->kvm->arch.css_support) {
                /*
                 * Most I/O instructions will be handled by userspace.
                 * Exceptions are tpi and the interrupt portion of tsch.
                 */
                if (vcpu->arch.sie_block->ipa == 0xb236)
                        return handle_tpi(vcpu);
                if (vcpu->arch.sie_block->ipa == 0xb235)
                        return handle_tsch(vcpu);
                /* Handle in userspace. */
                return -EOPNOTSUPP;
        } else {
                /*
                 * Set condition code 3 to stop the guest from issuing channel
                 * I/O instructions.
                 */
                kvm_s390_set_psw_cc(vcpu, 3);
                return 0;
        }
}

static int handle_stfl(struct kvm_vcpu *vcpu)
{
        int rc;

        vcpu->stat.instruction_stfl++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        rc = write_guest_lc(vcpu, offsetof(struct _lowcore, stfl_fac_list),
                            vfacilities, 4);
        if (rc)
                return rc;
        VCPU_EVENT(vcpu, 5, "store facility list value %x",
                   *(unsigned int *) vfacilities);
        trace_kvm_s390_handle_stfl(vcpu, *(unsigned int *) vfacilities);
        return 0;
}

static void handle_new_psw(struct kvm_vcpu *vcpu)
{
        /* Check whether the new psw is enabled for machine checks. */
        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_MCHECK)
                kvm_s390_deliver_pending_machine_checks(vcpu);
}

#define PSW_MASK_ADDR_MODE (PSW_MASK_EA | PSW_MASK_BA)
#define PSW_MASK_UNASSIGNED 0xb80800fe7fffffffUL
#define PSW_ADDR_24 0x0000000000ffffffUL
#define PSW_ADDR_31 0x000000007fffffffUL

int is_valid_psw(psw_t *psw)
{
        if (psw->mask & PSW_MASK_UNASSIGNED)
                return 0;
        if ((psw->mask & PSW_MASK_ADDR_MODE) == PSW_MASK_BA) {
                if (psw->addr & ~PSW_ADDR_31)
                        return 0;
        }
        if (!(psw->mask & PSW_MASK_ADDR_MODE) && (psw->addr & ~PSW_ADDR_24))
                return 0;
        if ((psw->mask & PSW_MASK_ADDR_MODE) ==  PSW_MASK_EA)
                return 0;
        if (psw->addr & 1)
                return 0;
        return 1;
}

int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu)
{
        psw_t *gpsw = &vcpu->arch.sie_block->gpsw;
        psw_compat_t new_psw;
        u64 addr;
        int rc;

        if (gpsw->mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        addr = kvm_s390_get_base_disp_s(vcpu);
        if (addr & 7)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        rc = read_guest(vcpu, addr, &new_psw, sizeof(new_psw));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);
        if (!(new_psw.mask & PSW32_MASK_BASE))
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        gpsw->mask = (new_psw.mask & ~PSW32_MASK_BASE) << 32;
        gpsw->mask |= new_psw.addr & PSW32_ADDR_AMODE;
        gpsw->addr = new_psw.addr & ~PSW32_ADDR_AMODE;
        if (!is_valid_psw(gpsw))
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        handle_new_psw(vcpu);
        return 0;
}

static int handle_lpswe(struct kvm_vcpu *vcpu)
{
        psw_t new_psw;
        u64 addr;
        int rc;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        addr = kvm_s390_get_base_disp_s(vcpu);
        if (addr & 7)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        rc = read_guest(vcpu, addr, &new_psw, sizeof(new_psw));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);
        vcpu->arch.sie_block->gpsw = new_psw;
        if (!is_valid_psw(&vcpu->arch.sie_block->gpsw))
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        handle_new_psw(vcpu);
        return 0;
}

static int handle_stidp(struct kvm_vcpu *vcpu)
{
        u64 stidp_data = vcpu->arch.stidp_data;
        u64 operand2;
        int rc;

        vcpu->stat.instruction_stidp++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        operand2 = kvm_s390_get_base_disp_s(vcpu);

        if (operand2 & 7)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        rc = write_guest(vcpu, operand2, &stidp_data, sizeof(stidp_data));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);

        VCPU_EVENT(vcpu, 5, "%s", "store cpu id");
        return 0;
}

static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem)
{
        int cpus = 0;
        int n;

        cpus = atomic_read(&vcpu->kvm->online_vcpus);

        /* deal with other level 3 hypervisors */
        if (stsi(mem, 3, 2, 2))
                mem->count = 0;
        if (mem->count < 8)
                mem->count++;
        for (n = mem->count - 1; n > 0 ; n--)
                memcpy(&mem->vm[n], &mem->vm[n - 1], sizeof(mem->vm[0]));

        mem->vm[0].cpus_total = cpus;
        mem->vm[0].cpus_configured = cpus;
        mem->vm[0].cpus_standby = 0;
        mem->vm[0].cpus_reserved = 0;
        mem->vm[0].caf = 1000;
        memcpy(mem->vm[0].name, "KVMguest", 8);
        ASCEBC(mem->vm[0].name, 8);
        memcpy(mem->vm[0].cpi, "KVM/Linux       ", 16);
        ASCEBC(mem->vm[0].cpi, 16);
}

static int handle_stsi(struct kvm_vcpu *vcpu)
{
        int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28;
        int sel1 = vcpu->run->s.regs.gprs[0] & 0xff;
        int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff;
        unsigned long mem = 0;
        u64 operand2;
        int rc = 0;

        vcpu->stat.instruction_stsi++;
        VCPU_EVENT(vcpu, 4, "stsi: fc: %x sel1: %x sel2: %x", fc, sel1, sel2);

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        if (fc > 3) {
                kvm_s390_set_psw_cc(vcpu, 3);
                return 0;
        }

        if (vcpu->run->s.regs.gprs[0] & 0x0fffff00
            || vcpu->run->s.regs.gprs[1] & 0xffff0000)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        if (fc == 0) {
                vcpu->run->s.regs.gprs[0] = 3 << 28;
                kvm_s390_set_psw_cc(vcpu, 0);
                return 0;
        }

        operand2 = kvm_s390_get_base_disp_s(vcpu);

        if (operand2 & 0xfff)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        switch (fc) {
        case 1: /* same handling for 1 and 2 */
        case 2:
                mem = get_zeroed_page(GFP_KERNEL);
                if (!mem)
                        goto out_no_data;
                if (stsi((void *) mem, fc, sel1, sel2))
                        goto out_no_data;
                break;
        case 3:
                if (sel1 != 2 || sel2 != 2)
                        goto out_no_data;
                mem = get_zeroed_page(GFP_KERNEL);
                if (!mem)
                        goto out_no_data;
                handle_stsi_3_2_2(vcpu, (void *) mem);
                break;
        }

        rc = write_guest(vcpu, operand2, (void *)mem, PAGE_SIZE);
        if (rc) {
                rc = kvm_s390_inject_prog_cond(vcpu, rc);
                goto out;
        }
        trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
        free_page(mem);
        kvm_s390_set_psw_cc(vcpu, 0);
        vcpu->run->s.regs.gprs[0] = 0;
        return 0;
out_no_data:
        kvm_s390_set_psw_cc(vcpu, 3);
out:
        free_page(mem);
        return rc;
}

static const intercept_handler_t b2_handlers[256] = {
        [0x02] = handle_stidp,
        [0x04] = handle_set_clock,
        [0x10] = handle_set_prefix,
        [0x11] = handle_store_prefix,
        [0x12] = handle_store_cpu_address,
        [0x21] = handle_ipte_interlock,
        [0x29] = handle_skey,
        [0x2a] = handle_skey,
        [0x2b] = handle_skey,
        [0x2c] = handle_test_block,
        [0x30] = handle_io_inst,
        [0x31] = handle_io_inst,
        [0x32] = handle_io_inst,
        [0x33] = handle_io_inst,
        [0x34] = handle_io_inst,
        [0x35] = handle_io_inst,
        [0x36] = handle_io_inst,
        [0x37] = handle_io_inst,
        [0x38] = handle_io_inst,
        [0x39] = handle_io_inst,
        [0x3a] = handle_io_inst,
        [0x3b] = handle_io_inst,
        [0x3c] = handle_io_inst,
        [0x50] = handle_ipte_interlock,
        [0x5f] = handle_io_inst,
        [0x74] = handle_io_inst,
        [0x76] = handle_io_inst,
        [0x7d] = handle_stsi,
        [0xb1] = handle_stfl,
        [0xb2] = handle_lpswe,
};

int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
{
        intercept_handler_t handler;

        /*
         * A lot of B2 instructions are priviledged. Here we check for
         * the privileged ones, that we can handle in the kernel.
         * Anything else goes to userspace.
         */
        handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
        if (handler)
                return handler(vcpu);

        return -EOPNOTSUPP;
}

static int handle_epsw(struct kvm_vcpu *vcpu)
{
        int reg1, reg2;

        kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);

        /* This basically extracts the mask half of the psw. */
        vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00000000UL;
        vcpu->run->s.regs.gprs[reg1] |= vcpu->arch.sie_block->gpsw.mask >> 32;
        if (reg2) {
                vcpu->run->s.regs.gprs[reg2] &= 0xffffffff00000000UL;
                vcpu->run->s.regs.gprs[reg2] |=
                        vcpu->arch.sie_block->gpsw.mask & 0x00000000ffffffffUL;
        }
        return 0;
}

#define PFMF_RESERVED   0xfffc0101UL
#define PFMF_SK         0x00020000UL
#define PFMF_CF         0x00010000UL
#define PFMF_UI         0x00008000UL
#define PFMF_FSC        0x00007000UL
#define PFMF_NQ         0x00000800UL
#define PFMF_MR         0x00000400UL
#define PFMF_MC         0x00000200UL
#define PFMF_KEY        0x000000feUL

static int handle_pfmf(struct kvm_vcpu *vcpu)
{
        int reg1, reg2;
        unsigned long start, end;

        vcpu->stat.instruction_pfmf++;

        kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);

        if (!MACHINE_HAS_PFMF)
                return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        if (vcpu->run->s.regs.gprs[reg1] & PFMF_RESERVED)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        /* Only provide non-quiescing support if the host supports it */
        if (vcpu->run->s.regs.gprs[reg1] & PFMF_NQ && !test_facility(14))
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        /* No support for conditional-SSKE */
        if (vcpu->run->s.regs.gprs[reg1] & (PFMF_MR | PFMF_MC))
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        start = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
        if (vcpu->run->s.regs.gprs[reg1] & PFMF_CF) {
                if (kvm_s390_check_low_addr_protection(vcpu, start))
                        return kvm_s390_inject_prog_irq(vcpu, &vcpu->arch.pgm);
        }

        switch (vcpu->run->s.regs.gprs[reg1] & PFMF_FSC) {
        case 0x00000000:
                end = (start + (1UL << 12)) & ~((1UL << 12) - 1);
                break;
        case 0x00001000:
                end = (start + (1UL << 20)) & ~((1UL << 20) - 1);
                break;
        /* We dont support EDAT2
        case 0x00002000:
                end = (start + (1UL << 31)) & ~((1UL << 31) - 1);
                break;*/
        default:
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        }
        while (start < end) {
                unsigned long useraddr, abs_addr;

                /* Translate guest address to host address */
                if ((vcpu->run->s.regs.gprs[reg1] & PFMF_FSC) == 0)
                        abs_addr = kvm_s390_real_to_abs(vcpu, start);
                else
                        abs_addr = start;
                useraddr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(abs_addr));
                if (kvm_is_error_hva(useraddr))
                        return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

                if (vcpu->run->s.regs.gprs[reg1] & PFMF_CF) {
                        if (clear_user((void __user *)useraddr, PAGE_SIZE))
                                return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
                }

                if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK) {
                        __skey_check_enable(vcpu);
                        if (set_guest_storage_key(current->mm, useraddr,
                                        vcpu->run->s.regs.gprs[reg1] & PFMF_KEY,
                                        vcpu->run->s.regs.gprs[reg1] & PFMF_NQ))
                                return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
                }

                start += PAGE_SIZE;
        }
        if (vcpu->run->s.regs.gprs[reg1] & PFMF_FSC)
                vcpu->run->s.regs.gprs[reg2] = end;
        return 0;
}

static int handle_essa(struct kvm_vcpu *vcpu)
{
        /* entries expected to be 1FF */
        int entries = (vcpu->arch.sie_block->cbrlo & ~PAGE_MASK) >> 3;
        unsigned long *cbrlo, cbrle;
        struct gmap *gmap;
        int i;

        VCPU_EVENT(vcpu, 5, "cmma release %d pages", entries);
        gmap = vcpu->arch.gmap;
        vcpu->stat.instruction_essa++;
        if (!kvm_s390_cmma_enabled(vcpu->kvm))
                return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        if (((vcpu->arch.sie_block->ipb & 0xf0000000) >> 28) > 6)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        /* Rewind PSW to repeat the ESSA instruction */
        vcpu->arch.sie_block->gpsw.addr =
                __rewind_psw(vcpu->arch.sie_block->gpsw, 4);
        vcpu->arch.sie_block->cbrlo &= PAGE_MASK;       /* reset nceo */
        cbrlo = phys_to_virt(vcpu->arch.sie_block->cbrlo);
        down_read(&gmap->mm->mmap_sem);
        for (i = 0; i < entries; ++i) {
                cbrle = cbrlo[i];
                if (unlikely(cbrle & ~PAGE_MASK || cbrle < 2 * PAGE_SIZE))
                        /* invalid entry */
                        break;
                /* try to free backing */
                __gmap_zap(cbrle, gmap);
        }
        up_read(&gmap->mm->mmap_sem);
        if (i < entries)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
        return 0;
}

static const intercept_handler_t b9_handlers[256] = {
        [0x8a] = handle_ipte_interlock,
        [0x8d] = handle_epsw,
        [0x8e] = handle_ipte_interlock,
        [0x8f] = handle_ipte_interlock,
        [0xab] = handle_essa,
        [0xaf] = handle_pfmf,
};

int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
{
        intercept_handler_t handler;

        /* This is handled just as for the B2 instructions. */
        handler = b9_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
        if (handler)
                return handler(vcpu);

        return -EOPNOTSUPP;
}

int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu)
{
        int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
        int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
        u32 val = 0;
        int reg, rc;
        u64 ga;

        vcpu->stat.instruction_lctl++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        ga = kvm_s390_get_base_disp_rs(vcpu);

        if (ga & 3)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x, addr:%llx", reg1, reg3, ga);
        trace_kvm_s390_handle_lctl(vcpu, 0, reg1, reg3, ga);

        reg = reg1;
        do {
                rc = read_guest(vcpu, ga, &val, sizeof(val));
                if (rc)
                        return kvm_s390_inject_prog_cond(vcpu, rc);
                vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
                vcpu->arch.sie_block->gcr[reg] |= val;
                ga += 4;
                if (reg == reg3)
                        break;
                reg = (reg + 1) % 16;
        } while (1);

        return 0;
}

int kvm_s390_handle_stctl(struct kvm_vcpu *vcpu)
{
        int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
        int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
        u64 ga;
        u32 val;
        int reg, rc;

        vcpu->stat.instruction_stctl++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        ga = kvm_s390_get_base_disp_rs(vcpu);

        if (ga & 3)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        VCPU_EVENT(vcpu, 5, "stctl r1:%x, r3:%x, addr:%llx", reg1, reg3, ga);
        trace_kvm_s390_handle_stctl(vcpu, 0, reg1, reg3, ga);

        reg = reg1;
        do {
                val = vcpu->arch.sie_block->gcr[reg] &  0x00000000fffffffful;
                rc = write_guest(vcpu, ga, &val, sizeof(val));
                if (rc)
                        return kvm_s390_inject_prog_cond(vcpu, rc);
                ga += 4;
                if (reg == reg3)
                        break;
                reg = (reg + 1) % 16;
        } while (1);

        return 0;
}

static int handle_lctlg(struct kvm_vcpu *vcpu)
{
        int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
        int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
        u64 ga, val;
        int reg, rc;

        vcpu->stat.instruction_lctlg++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        ga = kvm_s390_get_base_disp_rsy(vcpu);

        if (ga & 7)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        reg = reg1;

        VCPU_EVENT(vcpu, 5, "lctlg r1:%x, r3:%x, addr:%llx", reg1, reg3, ga);
        trace_kvm_s390_handle_lctl(vcpu, 1, reg1, reg3, ga);

        do {
                rc = read_guest(vcpu, ga, &val, sizeof(val));
                if (rc)
                        return kvm_s390_inject_prog_cond(vcpu, rc);
                vcpu->arch.sie_block->gcr[reg] = val;
                ga += 8;
                if (reg == reg3)
                        break;
                reg = (reg + 1) % 16;
        } while (1);

        return 0;
}

static int handle_stctg(struct kvm_vcpu *vcpu)
{
        int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
        int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
        u64 ga, val;
        int reg, rc;

        vcpu->stat.instruction_stctg++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        ga = kvm_s390_get_base_disp_rsy(vcpu);

        if (ga & 7)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

        reg = reg1;

        VCPU_EVENT(vcpu, 5, "stctg r1:%x, r3:%x, addr:%llx", reg1, reg3, ga);
        trace_kvm_s390_handle_stctl(vcpu, 1, reg1, reg3, ga);

        do {
                val = vcpu->arch.sie_block->gcr[reg];
                rc = write_guest(vcpu, ga, &val, sizeof(val));
                if (rc)
                        return kvm_s390_inject_prog_cond(vcpu, rc);
                ga += 8;
                if (reg == reg3)
                        break;
                reg = (reg + 1) % 16;
        } while (1);

        return 0;
}

static const intercept_handler_t eb_handlers[256] = {
        [0x2f] = handle_lctlg,
        [0x25] = handle_stctg,
};

int kvm_s390_handle_eb(struct kvm_vcpu *vcpu)
{
        intercept_handler_t handler;

        handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
        if (handler)
                return handler(vcpu);
        return -EOPNOTSUPP;
}

static int handle_tprot(struct kvm_vcpu *vcpu)
{
        u64 address1, address2;
        unsigned long hva, gpa;
        int ret = 0, cc = 0;
        bool writable;

        vcpu->stat.instruction_tprot++;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        kvm_s390_get_base_disp_sse(vcpu, &address1, &address2);

        /* we only handle the Linux memory detection case:
         * access key == 0
         * everything else goes to userspace. */
        if (address2 & 0xf0)
                return -EOPNOTSUPP;
        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
                ipte_lock(vcpu);
        ret = guest_translate_address(vcpu, address1, &gpa, 1);
        if (ret == PGM_PROTECTION) {
                /* Write protected? Try again with read-only... */
                cc = 1;
                ret = guest_translate_address(vcpu, address1, &gpa, 0);
        }
        if (ret) {
                if (ret == PGM_ADDRESSING || ret == PGM_TRANSLATION_SPEC) {
                        ret = kvm_s390_inject_program_int(vcpu, ret);
                } else if (ret > 0) {
                        /* Translation not available */
                        kvm_s390_set_psw_cc(vcpu, 3);
                        ret = 0;
                }
                goto out_unlock;
        }

        hva = gfn_to_hva_prot(vcpu->kvm, gpa_to_gfn(gpa), &writable);
        if (kvm_is_error_hva(hva)) {
                ret = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
        } else {
                if (!writable)
                        cc = 1;         /* Write not permitted ==> read-only */
                kvm_s390_set_psw_cc(vcpu, cc);
                /* Note: CC2 only occurs for storage keys (not supported yet) */
        }
out_unlock:
        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
                ipte_unlock(vcpu);
        return ret;
}

int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
{
        /* For e5xx... instructions we only handle TPROT */
        if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01)
                return handle_tprot(vcpu);
        return -EOPNOTSUPP;
}

static int handle_sckpf(struct kvm_vcpu *vcpu)
{
        u32 value;

        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

        if (vcpu->run->s.regs.gprs[0] & 0x00000000ffff0000)
                return kvm_s390_inject_program_int(vcpu,
                                                   PGM_SPECIFICATION);

        value = vcpu->run->s.regs.gprs[0] & 0x000000000000ffff;
        vcpu->arch.sie_block->todpr = value;

        return 0;
}

static const intercept_handler_t x01_handlers[256] = {
        [0x07] = handle_sckpf,
};

int kvm_s390_handle_01(struct kvm_vcpu *vcpu)
{
        intercept_handler_t handler;

        handler = x01_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
        if (handler)
                return handler(vcpu);
        return -EOPNOTSUPP;
}