arch/s390/kvm/priv.c - kernel/msm-5.4 - Gitiles

 /*
  * handling privileged instructions
  *
  * Copyright IBM Corp. 2008
  *
  * 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/current.h>
 #include <asm/debug.h>
 #include <asm/ebcdic.h>
 #include <asm/sysinfo.h>
 #include <asm/ptrace.h>
 #include <asm/compat.h>
 #include "gaccess.h"
 #include "kvm-s390.h"
 #include "trace.h"

 static int handle_set_prefix(struct kvm_vcpu *vcpu)
 {
 	u64 operand2;
 	u32 address = 0;
 	u8 tmp;

 	vcpu->stat.instruction_spx++;

 	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 */
 	if (get_guest(vcpu, address, (u32 __user *) operand2))
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

 	address = address & 0x7fffe000u;

 	/* make sure that the new value is valid memory */
 	if (copy_from_guest_absolute(vcpu, &tmp, address, 1) ||
 	   (copy_from_guest_absolute(vcpu, &tmp, address + PAGE_SIZE, 1)))
 		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;

 	vcpu->stat.instruction_stpx++;

 	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 = vcpu->arch.sie_block->prefix;
 	address = address & 0x7fffe000u;

 	/* get the value */
 	if (put_guest(vcpu, address, (u32 __user *)operand2))
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

 	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)
 {
 	u64 useraddr;

 	vcpu->stat.instruction_stap++;

 	useraddr = kvm_s390_get_base_disp_s(vcpu);

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

 	if (put_guest(vcpu, vcpu->vcpu_id, (u16 __user *)useraddr))
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

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

 static int handle_skey(struct kvm_vcpu *vcpu)
 {
 	vcpu->stat.instruction_storage_key++;
 	vcpu->arch.sie_block->gpsw.addr -= 4;
 	VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
 	return 0;
 }

 static int handle_tpi(struct kvm_vcpu *vcpu)
 {
 	struct kvm_s390_interrupt_info *inti;
 	u64 addr;
 	int cc;

 	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->run->s.regs.crs[6], 0);
 	if (!inti)
 		goto no_interrupt;
 	cc = 1;
 	if (addr) {
 		/*
 		 * Store the two-word I/O interruption code into the
 		 * provided area.
 		 */
 		put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) addr);
 		put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) (addr + 2));
 		put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) (addr + 4));
 	} else {
 		/*
 		 * Store the three-word I/O interruption code into
 		 * the appropriate lowcore area.
 		 */
 		put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) __LC_SUBCHANNEL_ID);
 		put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) __LC_SUBCHANNEL_NR);
 		put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) __LC_IO_INT_PARM);
 		put_guest(vcpu, inti->io.io_int_word, (u32 __user *) __LC_IO_INT_WORD);
 	}
 	kfree(inti);
 no_interrupt:
 	/* Set condition code and we're done. */
 	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 	vcpu->arch.sie_block->gpsw.mask |= (cc & 3ul) << 44;
 	return 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->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 issueing channel
 		 * I/O instructions.
 		 */
 		vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 		vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
 		return 0;
 	}
 }

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

 	vcpu->stat.instruction_stfl++;
 	/* only pass the facility bits, which we can handle */
 	facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3;

 	rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
 			   &facility_list, sizeof(facility_list));
 	if (rc)
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 	VCPU_EVENT(vcpu, 5, "store facility list value %x", facility_list);
 	trace_kvm_s390_handle_stfl(vcpu, facility_list);
 	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

 static 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;
 	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;

 	if (gpsw->mask & PSW_MASK_PSTATE)
 		return kvm_s390_inject_program_int(vcpu,
 						   PGM_PRIVILEGED_OPERATION);
 	addr = kvm_s390_get_base_disp_s(vcpu);
 	if (addr & 7)
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 	if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 	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;

 	addr = kvm_s390_get_base_disp_s(vcpu);
 	if (addr & 7)
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 	if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 	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 operand2;

 	vcpu->stat.instruction_stidp++;

 	operand2 = kvm_s390_get_base_disp_s(vcpu);

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

 	if (put_guest(vcpu, vcpu->arch.stidp_data, (u64 __user *)operand2))
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

 	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)
 {
 	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
 	int cpus = 0;
 	int n;

 	spin_lock(&fi->lock);
 	for (n = 0; n < KVM_MAX_VCPUS; n++)
 		if (fi->local_int[n])
 			cpus++;
 	spin_unlock(&fi->lock);

 	/* 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);

 	operand2 = kvm_s390_get_base_disp_s(vcpu);

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

 	switch (fc) {
 	case 0:
 		vcpu->run->s.regs.gprs[0] = 3 << 28;
 		vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 		return 0;
 	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;
 	default:
 		goto out_no_data;
 	}

 	if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) {
 		rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 		goto out_exception;
 	}
 	trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
 	free_page(mem);
 	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 	vcpu->run->s.regs.gprs[0] = 0;
 	return 0;
 out_no_data:
 	/* condition code 3 */
 	vcpu->arch.sie_block->gpsw.mask |= 3ul << 44;
 out_exception:
 	free_page(mem);
 	return rc;
 }

 static const intercept_handler_t b2_handlers[256] = {
 	[0x02] = handle_stidp,
 	[0x10] = handle_set_prefix,
 	[0x11] = handle_store_prefix,
 	[0x12] = handle_store_cpu_address,
 	[0x29] = handle_skey,
 	[0x2a] = handle_skey,
 	[0x2b] = handle_skey,
 	[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,
 	[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. We first check for
 	 * the privileged ones, that we can handle in the kernel. If the
 	 * kernel can handle this instruction, we check for the problem
 	 * state bit and (a) handle the instruction or (b) send a code 2
 	 * program check.
 	 * Anything else goes to userspace.*/
 	handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
 	if (handler) {
 		if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 			return kvm_s390_inject_program_int(vcpu,
 						   PGM_PRIVILEGED_OPERATION);
 		else
 			return handler(vcpu);
 	}
 	return -EOPNOTSUPP;
 }

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

 	reg1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 24;
 	reg2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16;

 	/* This basically extracts the mask half of the psw. */
 	vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00000000;
 	vcpu->run->s.regs.gprs[reg1] |= vcpu->arch.sie_block->gpsw.mask >> 32;
 	if (reg2) {
 		vcpu->run->s.regs.gprs[reg2] &= 0xffffffff00000000;
 		vcpu->run->s.regs.gprs[reg2] |=
 			vcpu->arch.sie_block->gpsw.mask & 0x00000000ffffffff;
 	}
 	return 0;
 }

 static const intercept_handler_t b9_handlers[256] = {
 	[0x8d] = handle_epsw,
 	[0x9c] = handle_io_inst,
 };

 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) {
 		if ((handler != handle_epsw) &&
 		    (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE))
 			return kvm_s390_inject_program_int(vcpu,
 						   PGM_PRIVILEGED_OPERATION);
 		else
 			return handler(vcpu);
 	}
 	return -EOPNOTSUPP;
 }

 static const intercept_handler_t eb_handlers[256] = {
 	[0x8a] = handle_io_inst,
 };

 int kvm_s390_handle_priv_eb(struct kvm_vcpu *vcpu)
 {
 	intercept_handler_t handler;

 	/* All eb instructions that end up here are privileged. */
 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 		return kvm_s390_inject_program_int(vcpu,
 						   PGM_PRIVILEGED_OPERATION);
 	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;
 	struct vm_area_struct *vma;
 	unsigned long user_address;

 	vcpu->stat.instruction_tprot++;

 	kvm_s390_get_base_disp_sse(vcpu, &address1, &address2);

 	/* we only handle the Linux memory detection case:
 	 * access key == 0
 	 * guest DAT == off
 	 * everything else goes to userspace. */
 	if (address2 & 0xf0)
 		return -EOPNOTSUPP;
 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
 		return -EOPNOTSUPP;

 	down_read(&current->mm->mmap_sem);
 	user_address = __gmap_translate(address1, vcpu->arch.gmap);
 	if (IS_ERR_VALUE(user_address))
 		goto out_inject;
 	vma = find_vma(current->mm, user_address);
 	if (!vma)
 		goto out_inject;
 	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 	if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ))
 		vcpu->arch.sie_block->gpsw.mask |= (1ul << 44);
 	if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ))
 		vcpu->arch.sie_block->gpsw.mask |= (2ul << 44);

 	up_read(&current->mm->mmap_sem);
 	return 0;

 out_inject:
 	up_read(&current->mm->mmap_sem);
 	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 }

 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_OPERATION);

 	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;
 }
	/*
	* handling privileged instructions
	*
	* Copyright IBM Corp. 2008
	*
	* 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/current.h>
	#include <asm/debug.h>
	#include <asm/ebcdic.h>
	#include <asm/sysinfo.h>
	#include <asm/ptrace.h>
	#include <asm/compat.h>
	#include "gaccess.h"
	#include "kvm-s390.h"
	#include "trace.h"

	static int handle_set_prefix(struct kvm_vcpu *vcpu)
	{
	u64 operand2;
	u32 address = 0;
	u8 tmp;

	vcpu->stat.instruction_spx++;

	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 */
	if (get_guest(vcpu, address, (u32 __user *) operand2))
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

	address = address & 0x7fffe000u;

	/* make sure that the new value is valid memory */
	if (copy_from_guest_absolute(vcpu, &tmp, address, 1) \|\|
	(copy_from_guest_absolute(vcpu, &tmp, address + PAGE_SIZE, 1)))
	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;

	vcpu->stat.instruction_stpx++;

	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 = vcpu->arch.sie_block->prefix;
	address = address & 0x7fffe000u;

	/* get the value */
	if (put_guest(vcpu, address, (u32 __user *)operand2))
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

	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)
	{
	u64 useraddr;

	vcpu->stat.instruction_stap++;

	useraddr = kvm_s390_get_base_disp_s(vcpu);

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

	if (put_guest(vcpu, vcpu->vcpu_id, (u16 __user *)useraddr))
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

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

	static int handle_skey(struct kvm_vcpu *vcpu)
	{
	vcpu->stat.instruction_storage_key++;
	vcpu->arch.sie_block->gpsw.addr -= 4;
	VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
	return 0;
	}

	static int handle_tpi(struct kvm_vcpu *vcpu)
	{
	struct kvm_s390_interrupt_info *inti;
	u64 addr;
	int cc;

	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->run->s.regs.crs[6], 0);
	if (!inti)
	goto no_interrupt;
	cc = 1;
	if (addr) {
	/*
	* Store the two-word I/O interruption code into the
	* provided area.
	*/
	put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) addr);
	put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) (addr + 2));
	put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) (addr + 4));
	} else {
	/*
	* Store the three-word I/O interruption code into
	* the appropriate lowcore area.
	*/
	put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) __LC_SUBCHANNEL_ID);
	put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) __LC_SUBCHANNEL_NR);
	put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) __LC_IO_INT_PARM);
	put_guest(vcpu, inti->io.io_int_word, (u32 __user *) __LC_IO_INT_WORD);
	}
	kfree(inti);
	no_interrupt:
	/* Set condition code and we're done. */
	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
	vcpu->arch.sie_block->gpsw.mask \|= (cc & 3ul) << 44;
	return 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->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 issueing channel
	* I/O instructions.
	*/
	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
	vcpu->arch.sie_block->gpsw.mask \|= (3 & 3ul) << 44;
	return 0;
	}
	}

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

	vcpu->stat.instruction_stfl++;
	/* only pass the facility bits, which we can handle */
	facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3;

	rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
	&facility_list, sizeof(facility_list));
	if (rc)
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
	VCPU_EVENT(vcpu, 5, "store facility list value %x", facility_list);
	trace_kvm_s390_handle_stfl(vcpu, facility_list);
	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

	static 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;
	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;

	if (gpsw->mask & PSW_MASK_PSTATE)
	return kvm_s390_inject_program_int(vcpu,
	PGM_PRIVILEGED_OPERATION);
	addr = kvm_s390_get_base_disp_s(vcpu);
	if (addr & 7)
	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
	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;

	addr = kvm_s390_get_base_disp_s(vcpu);
	if (addr & 7)
	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
	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 operand2;

	vcpu->stat.instruction_stidp++;

	operand2 = kvm_s390_get_base_disp_s(vcpu);

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

	if (put_guest(vcpu, vcpu->arch.stidp_data, (u64 __user *)operand2))
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

	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)
	{
	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
	int cpus = 0;
	int n;

	spin_lock(&fi->lock);
	for (n = 0; n < KVM_MAX_VCPUS; n++)
	if (fi->local_int[n])
	cpus++;
	spin_unlock(&fi->lock);

	/* 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);

	operand2 = kvm_s390_get_base_disp_s(vcpu);

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

	switch (fc) {
	case 0:
	vcpu->run->s.regs.gprs[0] = 3 << 28;
	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
	return 0;
	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;
	default:
	goto out_no_data;
	}

	if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) {
	rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
	goto out_exception;
	}
	trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
	free_page(mem);
	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
	vcpu->run->s.regs.gprs[0] = 0;
	return 0;
	out_no_data:
	/* condition code 3 */
	vcpu->arch.sie_block->gpsw.mask \|= 3ul << 44;
	out_exception:
	free_page(mem);
	return rc;
	}

	static const intercept_handler_t b2_handlers[256] = {
	[0x02] = handle_stidp,
	[0x10] = handle_set_prefix,
	[0x11] = handle_store_prefix,
	[0x12] = handle_store_cpu_address,
	[0x29] = handle_skey,
	[0x2a] = handle_skey,
	[0x2b] = handle_skey,
	[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,
	[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. We first check for
	* the privileged ones, that we can handle in the kernel. If the
	* kernel can handle this instruction, we check for the problem
	* state bit and (a) handle the instruction or (b) send a code 2
	* program check.
	* Anything else goes to userspace.*/
	handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
	if (handler) {
	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
	return kvm_s390_inject_program_int(vcpu,
	PGM_PRIVILEGED_OPERATION);
	else
	return handler(vcpu);
	}
	return -EOPNOTSUPP;
	}

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

	reg1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 24;
	reg2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16;

	/* This basically extracts the mask half of the psw. */
	vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00000000;
	vcpu->run->s.regs.gprs[reg1] \|= vcpu->arch.sie_block->gpsw.mask >> 32;
	if (reg2) {
	vcpu->run->s.regs.gprs[reg2] &= 0xffffffff00000000;
	vcpu->run->s.regs.gprs[reg2] \|=
	vcpu->arch.sie_block->gpsw.mask & 0x00000000ffffffff;
	}
	return 0;
	}

	static const intercept_handler_t b9_handlers[256] = {
	[0x8d] = handle_epsw,
	[0x9c] = handle_io_inst,
	};

	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) {
	if ((handler != handle_epsw) &&
	(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE))
	return kvm_s390_inject_program_int(vcpu,
	PGM_PRIVILEGED_OPERATION);
	else
	return handler(vcpu);
	}
	return -EOPNOTSUPP;
	}

	static const intercept_handler_t eb_handlers[256] = {
	[0x8a] = handle_io_inst,
	};

	int kvm_s390_handle_priv_eb(struct kvm_vcpu *vcpu)
	{
	intercept_handler_t handler;

	/* All eb instructions that end up here are privileged. */
	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
	return kvm_s390_inject_program_int(vcpu,
	PGM_PRIVILEGED_OPERATION);
	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;
	struct vm_area_struct *vma;
	unsigned long user_address;

	vcpu->stat.instruction_tprot++;

	kvm_s390_get_base_disp_sse(vcpu, &address1, &address2);

	/* we only handle the Linux memory detection case:
	* access key == 0
	* guest DAT == off
	* everything else goes to userspace. */
	if (address2 & 0xf0)
	return -EOPNOTSUPP;
	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
	return -EOPNOTSUPP;

	down_read(&current->mm->mmap_sem);
	user_address = __gmap_translate(address1, vcpu->arch.gmap);
	if (IS_ERR_VALUE(user_address))
	goto out_inject;
	vma = find_vma(current->mm, user_address);
	if (!vma)
	goto out_inject;
	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
	if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ))
	vcpu->arch.sie_block->gpsw.mask \|= (1ul << 44);
	if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ))
	vcpu->arch.sie_block->gpsw.mask \|= (2ul << 44);

	up_read(&current->mm->mmap_sem);
	return 0;

	out_inject:
	up_read(&current->mm->mmap_sem);
	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
	}

	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_OPERATION);

	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;
	}