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