[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/pgalloc.h>
#include <asm/gmap.h>
#include <asm/virtio-ccw.h>
#include "kvm-s390.h"
#include "trace.h"
#include "trace-s390.h"
#include "gaccess.h"

static int diag_release_pages(struct kvm_vcpu *vcpu)
{
	unsigned long start, end;
	unsigned long prefix  = kvm_s390_get_prefix(vcpu);

	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;
	vcpu->stat.diagnose_10++;

	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);

	/*
	 * We checked for start >= end above, so lets check for the
	 * fast path (no prefix swap page involved)
	 */
	if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) {
		gmap_discard(vcpu->arch.gmap, start, end);
	} else {
		/*
		 * This is slow path.  gmap_discard will check for start
		 * so lets split this into before prefix, prefix, after
		 * prefix and let gmap_discard make some of these calls
		 * NOPs.
		 */
		gmap_discard(vcpu->arch.gmap, start, prefix);
		if (start <= prefix)
			gmap_discard(vcpu->arch.gmap, 0, 4096);
		if (end > prefix + 4096)
			gmap_discard(vcpu->arch.gmap, 4096, 8192);
		gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end);
	}
	return 0;
}

static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
{
	struct prs_parm {
		u16 code;
		u16 subcode;
		u16 parm_len;
		u16 parm_version;
		u64 token_addr;
		u64 select_mask;
		u64 compare_mask;
		u64 zarch;
	};
	struct prs_parm parm;
	int rc;
	u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
	u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);

	VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
		   vcpu->run->s.regs.gprs[rx]);
	vcpu->stat.diagnose_258++;
	if (vcpu->run->s.regs.gprs[rx] & 7)
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
	if (rc)
		return kvm_s390_inject_prog_cond(vcpu, rc);
	if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

	switch (parm.subcode) {
	case 0: /* TOKEN */
		VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx "
			   "select mask 0x%llx compare mask 0x%llx",
			   parm.token_addr, parm.select_mask, parm.compare_mask);
		if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
			/*
			 * If the pagefault handshake is already activated,
			 * the token must not be changed.  We have to return
			 * decimal 8 instead, as mandated in SC24-6084.
			 */
			vcpu->run->s.regs.gprs[ry] = 8;
			return 0;
		}

		if ((parm.compare_mask & parm.select_mask) != parm.compare_mask ||
		    parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL)
			return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

		if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
			return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

		vcpu->arch.pfault_token = parm.token_addr;
		vcpu->arch.pfault_select = parm.select_mask;
		vcpu->arch.pfault_compare = parm.compare_mask;
		vcpu->run->s.regs.gprs[ry] = 0;
		rc = 0;
		break;
	case 1: /*
		 * CANCEL
		 * Specification allows to let already pending tokens survive
		 * the cancel, therefore to reduce code complexity, we assume
		 * all outstanding tokens are already pending.
		 */
		VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
		if (parm.token_addr || parm.select_mask ||
		    parm.compare_mask || parm.zarch)
			return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

		vcpu->run->s.regs.gprs[ry] = 0;
		/*
		 * If the pfault handling was not established or is already
		 * canceled SC24-6084 requests to return decimal 4.
		 */
		if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
			vcpu->run->s.regs.gprs[ry] = 4;
		else
			vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;

		rc = 0;
		break;
	default:
		rc = -EOPNOTSUPP;
		break;
	}

	return rc;
}

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_vcpu *tcpu;
	int tid;

	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;

	tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
	if (tcpu)
		kvm_vcpu_yield_to(tcpu);
	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, 3, "diag ipl functions, subcode %lx", subcode);
	vcpu->stat.diagnose_308++;
	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;
	}

	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
		kvm_s390_vcpu_stop(vcpu);
	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;

	vcpu->stat.diagnose_500++;
	/* 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;

	/*
	 * 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_VIRTIO_CCW_NOTIFY_BUS,
				      vcpu->run->s.regs.gprs[2] & 0xffffffff,
				      8, &vcpu->run->s.regs.gprs[3],
				      vcpu->run->s.regs.gprs[4]);

	/*
	 * 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 = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;

	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 0x258:
		return __diag_page_ref_service(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>
deedabb2	16	#include <asm/pgalloc.h>
1e133ab2	17	#include <asm/gmap.h>
10ccaa1e	18	#include <asm/virtio-ccw.h>
e28acfea	19	#include "kvm-s390.h"
5786fffa	20	#include "trace.h"
ade38c31	21	#include "trace-s390.h"
3c038e6b	22	#include "gaccess.h"
e28acfea	23
388186bc CB	24	static int diag_release_pages(struct kvm_vcpu *vcpu)
	25	{
	26	unsigned long start, end;
fda902cb	27	unsigned long prefix = kvm_s390_get_prefix(vcpu);
388186bc	28
5a32c1af CB	29	start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
5a32c1af CB	30	end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
175a5c9e	31	vcpu->stat.diagnose_10++;
388186bc	32
f7a960af	33	if (start & ~PAGE_MASK \|\| end & ~PAGE_MASK \|\| start >= end
388186bc CB	34	\|\| start < 2 * PAGE_SIZE)
	35	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	36
	37	VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
388186bc	38
f7a960af CB	39	/*
	40	* We checked for start >= end above, so lets check for the
	41	* fast path (no prefix swap page involved)
	42	*/
	43	if (end <= prefix \|\| start >= prefix + 2 * PAGE_SIZE) {
6e0a0431	44	gmap_discard(vcpu->arch.gmap, start, end);
388186bc	45	} else {
f7a960af CB	46	/*
	47	* This is slow path. gmap_discard will check for start
	48	* so lets split this into before prefix, prefix, after
	49	* prefix and let gmap_discard make some of these calls
	50	* NOPs.
	51	*/
	52	gmap_discard(vcpu->arch.gmap, start, prefix);
	53	if (start <= prefix)
	54	gmap_discard(vcpu->arch.gmap, 0, 4096);
	55	if (end > prefix + 4096)
	56	gmap_discard(vcpu->arch.gmap, 4096, 8192);
	57	gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end);
388186bc CB	58	}
	59	return 0;
	60	}
	61
3c038e6b DD	62	static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
	63	{
	64	struct prs_parm {
	65	u16 code;
	66	u16 subcode;
	67	u16 parm_len;
	68	u16 parm_version;
	69	u64 token_addr;
	70	u64 select_mask;
	71	u64 compare_mask;
	72	u64 zarch;
	73	};
	74	struct prs_parm parm;
	75	int rc;
	76	u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
	77	u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);
3c038e6b	78
15e8b5da CB	79	VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
15e8b5da CB	80	vcpu->run->s.regs.gprs[rx]);
175a5c9e	81	vcpu->stat.diagnose_258++;
3c038e6b DD	82	if (vcpu->run->s.regs.gprs[rx] & 7)
3c038e6b DD	83	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
8ae04b8f	84	rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
81480cc1 HC	85	if (rc)
81480cc1 HC	86	return kvm_s390_inject_prog_cond(vcpu, rc);
3c038e6b DD	87	if (parm.parm_version != 2 \|\| parm.parm_len < 5 \|\| parm.code != 0x258)
	88	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	89
	90	switch (parm.subcode) {
	91	case 0: /* TOKEN */
ab7090a6 CB	92	VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx "
	93	"select mask 0x%llx compare mask 0x%llx",
	94	parm.token_addr, parm.select_mask, parm.compare_mask);
3c038e6b DD	95	if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
	96	/*
	97	* If the pagefault handshake is already activated,
	98	* the token must not be changed. We have to return
	99	* decimal 8 instead, as mandated in SC24-6084.
	100	*/
	101	vcpu->run->s.regs.gprs[ry] = 8;
	102	return 0;
	103	}
	104
	105	if ((parm.compare_mask & parm.select_mask) != parm.compare_mask \|\|
	106	parm.token_addr & 7 \|\| parm.zarch != 0x8000000000000000ULL)
	107	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	108
81480cc1	109	if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
3c038e6b DD	110	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
	111
	112	vcpu->arch.pfault_token = parm.token_addr;
	113	vcpu->arch.pfault_select = parm.select_mask;
	114	vcpu->arch.pfault_compare = parm.compare_mask;
	115	vcpu->run->s.regs.gprs[ry] = 0;
	116	rc = 0;
	117	break;
	118	case 1: /*
	119	* CANCEL
	120	* Specification allows to let already pending tokens survive
	121	* the cancel, therefore to reduce code complexity, we assume
	122	* all outstanding tokens are already pending.
	123	*/
ab7090a6	124	VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
3c038e6b DD	125	if (parm.token_addr \|\| parm.select_mask \|\|
	126	parm.compare_mask \|\| parm.zarch)
	127	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	128
	129	vcpu->run->s.regs.gprs[ry] = 0;
	130	/*
	131	* If the pfault handling was not established or is already
	132	* canceled SC24-6084 requests to return decimal 4.
	133	*/
	134	if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
	135	vcpu->run->s.regs.gprs[ry] = 4;
	136	else
	137	vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
	138
	139	rc = 0;
	140	break;
	141	default:
	142	rc = -EOPNOTSUPP;
	143	break;
	144	}
	145
	146	return rc;
	147	}
	148
e28acfea CB	149	static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
	150	{
	151	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
	152	vcpu->stat.diagnose_44++;
8733ac36	153	kvm_vcpu_on_spin(vcpu);
e28acfea CB	154	return 0;
	155	}
	156
41628d33 KW	157	static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
41628d33 KW	158	{
41628d33 KW	159	struct kvm_vcpu *tcpu;
41628d33 KW	160	int tid;
41628d33 KW	161
	162	tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
	163	vcpu->stat.diagnose_9c++;
	164	VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
	165
	166	if (tid == vcpu->vcpu_id)
	167	return 0;
	168
e09fefde DH	169	tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
	170	if (tcpu)
	171	kvm_vcpu_yield_to(tcpu);
41628d33 KW	172	return 0;
	173	}
	174
e28acfea CB	175	static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
	176	{
	177	unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
5a32c1af	178	unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
e28acfea	179
15e8b5da	180	VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode);
175a5c9e	181	vcpu->stat.diagnose_308++;
e28acfea CB	182	switch (subcode) {
	183	case 3:
	184	vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
	185	break;
	186	case 4:
	187	vcpu->run->s390_reset_flags = 0;
	188	break;
	189	default:
b8e660b8	190	return -EOPNOTSUPP;
e28acfea CB	191	}
e28acfea CB	192
6352e4d2 DH	193	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
6352e4d2 DH	194	kvm_s390_vcpu_stop(vcpu);
e28acfea CB	195	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_SUBSYSTEM;
	196	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_IPL;
	197	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_CPU_INIT;
	198	vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
33e19115	199	VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
e28acfea	200	vcpu->run->s390_reset_flags);
ade38c31	201	trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
e28acfea CB	202	return -EREMOTE;
	203	}
	204
10ccaa1e CH	205	static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
10ccaa1e CH	206	{
800c1065	207	int ret;
10ccaa1e	208
175a5c9e	209	vcpu->stat.diagnose_500++;
10ccaa1e CH	210	/* No virtio-ccw notification? Get out quickly. */
	211	if (!vcpu->kvm->arch.css_support \|\|
	212	(vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
	213	return -EOPNOTSUPP;
	214
10ccaa1e CH	215	/*
	216	* The layout is as follows:
	217	* - gpr 2 contains the subchannel id (passed as addr)
	218	* - gpr 3 contains the virtqueue index (passed as datamatch)
85dfe87e	219	* - gpr 4 contains the index on the bus (optionally)
10ccaa1e	220	*/
e32edf4f	221	ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
ff1f3cb4	222	vcpu->run->s.regs.gprs[2] & 0xffffffff,
85dfe87e CH	223	8, &vcpu->run->s.regs.gprs[3],
85dfe87e CH	224	vcpu->run->s.regs.gprs[4]);
85dfe87e CH	225
	226	/*
	227	* Return cookie in gpr 2, but don't overwrite the register if the
	228	* diagnose will be handled by userspace.
	229	*/
	230	if (ret != -EOPNOTSUPP)
	231	vcpu->run->s.regs.gprs[2] = ret;
	232	/* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
10ccaa1e CH	233	return ret < 0 ? ret : 0;
	234	}
	235
e28acfea CB	236	int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
e28acfea CB	237	{
8ae04b8f	238	int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;
e28acfea	239
93e1750f TH	240	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
	241	return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
	242
5786fffa	243	trace_kvm_s390_handle_diag(vcpu, code);
e28acfea	244	switch (code) {
388186bc CB	245	case 0x10:
388186bc CB	246	return diag_release_pages(vcpu);
e28acfea CB	247	case 0x44:
e28acfea CB	248	return __diag_time_slice_end(vcpu);
41628d33 KW	249	case 0x9c:
41628d33 KW	250	return __diag_time_slice_end_directed(vcpu);
3c038e6b DD	251	case 0x258:
3c038e6b DD	252	return __diag_page_ref_service(vcpu);
e28acfea CB	253	case 0x308:
e28acfea CB	254	return __diag_ipl_functions(vcpu);
10ccaa1e CH	255	case 0x500:
10ccaa1e CH	256	return __diag_virtio_hypercall(vcpu);
e28acfea	257	default:
b8e660b8	258	return -EOPNOTSUPP;
e28acfea CB	259	}
e28acfea CB	260	}