[deliverable/linux.git] / arch / s390 / kvm / diag.c

/*
 * handling diagnose instructions
 *
 * Copyright IBM Corp. 2008, 2011
 *
 * 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/kvm_host.h>
#include <asm/virtio-ccw.h>
#include "kvm-s390.h"
#include "trace.h"
#include "trace-s390.h"

static int diag_release_pages(struct kvm_vcpu *vcpu)
{
	unsigned long start, end;
	unsigned long prefix  = vcpu->arch.sie_block->prefix;

	start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
	end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;

	if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
	    || start < 2 * PAGE_SIZE)
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

	VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
	vcpu->stat.diagnose_10++;

	/* we checked for start > end above */
	if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
		gmap_discard(start, end, vcpu->arch.gmap);
	} else {
		if (start < prefix)
			gmap_discard(start, prefix, vcpu->arch.gmap);
		if (end >= prefix)
			gmap_discard(prefix + 2 * PAGE_SIZE,
				     end, vcpu->arch.gmap);
	}
	return 0;
}

static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
{
	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
	vcpu->stat.diagnose_44++;
	kvm_vcpu_on_spin(vcpu);
	return 0;
}

static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
{
	struct kvm *kvm = vcpu->kvm;
	struct kvm_vcpu *tcpu;
	int tid;
	int i;

	tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
	vcpu->stat.diagnose_9c++;
	VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);

	if (tid == vcpu->vcpu_id)
		return 0;

	kvm_for_each_vcpu(i, tcpu, kvm)
		if (tcpu->vcpu_id == tid) {
			kvm_vcpu_yield_to(tcpu);
			break;
		}

	return 0;
}

static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
{
	unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
	unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;

	VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
	switch (subcode) {
	case 3:
		vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
		break;
	case 4:
		vcpu->run->s390_reset_flags = 0;
		break;
	default:
		return -EOPNOTSUPP;
	}

	atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
	vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
	vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
	vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
	vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
	VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
	  vcpu->run->s390_reset_flags);
	trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
	return -EREMOTE;
}

static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
{
	int ret, idx;

	/* No virtio-ccw notification? Get out quickly. */
	if (!vcpu->kvm->arch.css_support ||
	    (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
		return -EOPNOTSUPP;

	idx = srcu_read_lock(&vcpu->kvm->srcu);
	/*
	 * The layout is as follows:
	 * - gpr 2 contains the subchannel id (passed as addr)
	 * - gpr 3 contains the virtqueue index (passed as datamatch)
	 * - gpr 4 contains the index on the bus (optionally)
	 */
	ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
				      vcpu->run->s.regs.gprs[2],
				      8, &vcpu->run->s.regs.gprs[3],
				      vcpu->run->s.regs.gprs[4]);
	srcu_read_unlock(&vcpu->kvm->srcu, idx);

	/*
	 * Return cookie in gpr 2, but don't overwrite the register if the
	 * diagnose will be handled by userspace.
	 */
	if (ret != -EOPNOTSUPP)
		vcpu->run->s.regs.gprs[2] = ret;
	/* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
	return ret < 0 ? ret : 0;
}

int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
{
	int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;

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

	trace_kvm_s390_handle_diag(vcpu, code);
	switch (code) {
	case 0x10:
		return diag_release_pages(vcpu);
	case 0x44:
		return __diag_time_slice_end(vcpu);
	case 0x9c:
		return __diag_time_slice_end_directed(vcpu);
	case 0x308:
		return __diag_ipl_functions(vcpu);
	case 0x500:
		return __diag_virtio_hypercall(vcpu);
	default:
		return -EOPNOTSUPP;
	}
}
Commit	Line	Data
e28acfea	1	/*
a53c8fab	2	* handling diagnose instructions
e28acfea	3	*
a53c8fab	4	* Copyright IBM Corp. 2008, 2011
e28acfea CB	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License (version 2 only)
	8	* as published by the Free Software Foundation.
	9	*
	10	* Author(s): Carsten Otte <cotte@de.ibm.com>
	11	* Christian Borntraeger <borntraeger@de.ibm.com>
	12	*/
	13
	14	#include <linux/kvm.h>
	15	#include <linux/kvm_host.h>
10ccaa1e	16	#include <asm/virtio-ccw.h>
e28acfea	17	#include "kvm-s390.h"
5786fffa	18	#include "trace.h"
ade38c31	19	#include "trace-s390.h"
e28acfea	20
388186bc CB	21	static int diag_release_pages(struct kvm_vcpu *vcpu)
	22	{
	23	unsigned long start, end;
	24	unsigned long prefix = vcpu->arch.sie_block->prefix;
	25
5a32c1af CB	26	start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
5a32c1af CB	27	end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
388186bc CB	28
	29	if (start & ~PAGE_MASK \|\| end & ~PAGE_MASK \|\| start > end
	30	\|\| start < 2 * PAGE_SIZE)
	31	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	32
	33	VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
	34	vcpu->stat.diagnose_10++;
	35
	36	/* we checked for start > end above */
	37	if (end < prefix \|\| start >= prefix + 2 * PAGE_SIZE) {
	38	gmap_discard(start, end, vcpu->arch.gmap);
	39	} else {
	40	if (start < prefix)
	41	gmap_discard(start, prefix, vcpu->arch.gmap);
	42	if (end >= prefix)
	43	gmap_discard(prefix + 2 * PAGE_SIZE,
	44	end, vcpu->arch.gmap);
	45	}
	46	return 0;
	47	}
	48
e28acfea CB	49	static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
	50	{
	51	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
	52	vcpu->stat.diagnose_44++;
8733ac36	53	kvm_vcpu_on_spin(vcpu);
e28acfea CB	54	return 0;
	55	}
	56
41628d33 KW	57	static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
	58	{
	59	struct kvm *kvm = vcpu->kvm;
	60	struct kvm_vcpu *tcpu;
	61	int tid;
	62	int i;
	63
	64	tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
	65	vcpu->stat.diagnose_9c++;
	66	VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
	67
	68	if (tid == vcpu->vcpu_id)
	69	return 0;
	70
	71	kvm_for_each_vcpu(i, tcpu, kvm)
	72	if (tcpu->vcpu_id == tid) {
	73	kvm_vcpu_yield_to(tcpu);
	74	break;
	75	}
	76
	77	return 0;
	78	}
	79
e28acfea CB	80	static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
	81	{
	82	unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
5a32c1af	83	unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
e28acfea CB	84
	85	VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
	86	switch (subcode) {
	87	case 3:
	88	vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
	89	break;
	90	case 4:
	91	vcpu->run->s390_reset_flags = 0;
	92	break;
	93	default:
b8e660b8	94	return -EOPNOTSUPP;
e28acfea CB	95	}
e28acfea CB	96
9e6dabef	97	atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
e28acfea CB	98	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_SUBSYSTEM;
	99	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_IPL;
	100	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_CPU_INIT;
	101	vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
33e19115	102	VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
e28acfea	103	vcpu->run->s390_reset_flags);
ade38c31	104	trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
e28acfea CB	105	return -EREMOTE;
	106	}
	107
10ccaa1e CH	108	static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
	109	{
	110	int ret, idx;
	111
	112	/* No virtio-ccw notification? Get out quickly. */
	113	if (!vcpu->kvm->arch.css_support \|\|
	114	(vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
	115	return -EOPNOTSUPP;
	116
	117	idx = srcu_read_lock(&vcpu->kvm->srcu);
	118	/*
	119	* The layout is as follows:
	120	* - gpr 2 contains the subchannel id (passed as addr)
	121	* - gpr 3 contains the virtqueue index (passed as datamatch)
85dfe87e	122	* - gpr 4 contains the index on the bus (optionally)
10ccaa1e	123	*/
85dfe87e CH	124	ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
	125	vcpu->run->s.regs.gprs[2],
	126	8, &vcpu->run->s.regs.gprs[3],
	127	vcpu->run->s.regs.gprs[4]);
10ccaa1e	128	srcu_read_unlock(&vcpu->kvm->srcu, idx);
85dfe87e CH	129
	130	/*
	131	* Return cookie in gpr 2, but don't overwrite the register if the
	132	* diagnose will be handled by userspace.
	133	*/
	134	if (ret != -EOPNOTSUPP)
	135	vcpu->run->s.regs.gprs[2] = ret;
	136	/* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
10ccaa1e CH	137	return ret < 0 ? ret : 0;
	138	}
	139
e28acfea CB	140	int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
	141	{
	142	int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
	143
93e1750f TH	144	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
	145	return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
	146
5786fffa	147	trace_kvm_s390_handle_diag(vcpu, code);
e28acfea	148	switch (code) {
388186bc CB	149	case 0x10:
388186bc CB	150	return diag_release_pages(vcpu);
e28acfea CB	151	case 0x44:
e28acfea CB	152	return __diag_time_slice_end(vcpu);
41628d33 KW	153	case 0x9c:
41628d33 KW	154	return __diag_time_slice_end_directed(vcpu);
e28acfea CB	155	case 0x308:
e28acfea CB	156	return __diag_ipl_functions(vcpu);
10ccaa1e CH	157	case 0x500:
10ccaa1e CH	158	return __diag_virtio_hypercall(vcpu);
e28acfea	159	default:
b8e660b8	160	return -EOPNOTSUPP;
e28acfea CB	161	}
e28acfea CB	162	}