[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;

	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(vcpu->arch.gmap, start, end);
	} else {
		if (start < prefix)
			gmap_discard(vcpu->arch.gmap, start, prefix);
		if (end >= prefix)
			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);

	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], &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 */
		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.
		 */
		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 *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;
	}

	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;

	/* 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, 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) & 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;
388186bc CB	30
	31	if (start & ~PAGE_MASK \|\| end & ~PAGE_MASK \|\| start > end
	32	\|\| start < 2 * PAGE_SIZE)
	33	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	34
	35	VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
	36	vcpu->stat.diagnose_10++;
	37
	38	/* we checked for start > end above */
	39	if (end < prefix \|\| start >= prefix + 2 * PAGE_SIZE) {
6e0a0431	40	gmap_discard(vcpu->arch.gmap, start, end);
388186bc CB	41	} else {
388186bc CB	42	if (start < prefix)
6e0a0431	43	gmap_discard(vcpu->arch.gmap, start, prefix);
388186bc	44	if (end >= prefix)
6e0a0431 MS	45	gmap_discard(vcpu->arch.gmap,
6e0a0431 MS	46	prefix + 2 * PAGE_SIZE, end);
388186bc CB	47	}
	48	return 0;
	49	}
	50
3c038e6b DD	51	static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
	52	{
	53	struct prs_parm {
	54	u16 code;
	55	u16 subcode;
	56	u16 parm_len;
	57	u16 parm_version;
	58	u64 token_addr;
	59	u64 select_mask;
	60	u64 compare_mask;
	61	u64 zarch;
	62	};
	63	struct prs_parm parm;
	64	int rc;
	65	u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
	66	u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);
3c038e6b DD	67
	68	if (vcpu->run->s.regs.gprs[rx] & 7)
	69	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
81480cc1 HC	70	rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], &parm, sizeof(parm));
	71	if (rc)
	72	return kvm_s390_inject_prog_cond(vcpu, rc);
3c038e6b DD	73	if (parm.parm_version != 2 \|\| parm.parm_len < 5 \|\| parm.code != 0x258)
	74	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	75
	76	switch (parm.subcode) {
	77	case 0: /* TOKEN */
	78	if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
	79	/*
	80	* If the pagefault handshake is already activated,
	81	* the token must not be changed. We have to return
	82	* decimal 8 instead, as mandated in SC24-6084.
	83	*/
	84	vcpu->run->s.regs.gprs[ry] = 8;
	85	return 0;
	86	}
	87
	88	if ((parm.compare_mask & parm.select_mask) != parm.compare_mask \|\|
	89	parm.token_addr & 7 \|\| parm.zarch != 0x8000000000000000ULL)
	90	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	91
81480cc1	92	if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
3c038e6b DD	93	return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
	94
	95	vcpu->arch.pfault_token = parm.token_addr;
	96	vcpu->arch.pfault_select = parm.select_mask;
	97	vcpu->arch.pfault_compare = parm.compare_mask;
	98	vcpu->run->s.regs.gprs[ry] = 0;
	99	rc = 0;
	100	break;
	101	case 1: /*
	102	* CANCEL
	103	* Specification allows to let already pending tokens survive
	104	* the cancel, therefore to reduce code complexity, we assume
	105	* all outstanding tokens are already pending.
	106	*/
	107	if (parm.token_addr \|\| parm.select_mask \|\|
	108	parm.compare_mask \|\| parm.zarch)
	109	return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	110
	111	vcpu->run->s.regs.gprs[ry] = 0;
	112	/*
	113	* If the pfault handling was not established or is already
	114	* canceled SC24-6084 requests to return decimal 4.
	115	*/
	116	if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
	117	vcpu->run->s.regs.gprs[ry] = 4;
	118	else
	119	vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
	120
	121	rc = 0;
	122	break;
	123	default:
	124	rc = -EOPNOTSUPP;
	125	break;
	126	}
	127
	128	return rc;
	129	}
	130
e28acfea CB	131	static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
	132	{
	133	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
	134	vcpu->stat.diagnose_44++;
8733ac36	135	kvm_vcpu_on_spin(vcpu);
e28acfea CB	136	return 0;
	137	}
	138
41628d33 KW	139	static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
	140	{
	141	struct kvm *kvm = vcpu->kvm;
	142	struct kvm_vcpu *tcpu;
	143	int tid;
	144	int i;
	145
	146	tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
	147	vcpu->stat.diagnose_9c++;
	148	VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
	149
	150	if (tid == vcpu->vcpu_id)
	151	return 0;
	152
	153	kvm_for_each_vcpu(i, tcpu, kvm)
	154	if (tcpu->vcpu_id == tid) {
	155	kvm_vcpu_yield_to(tcpu);
	156	break;
	157	}
	158
	159	return 0;
	160	}
	161
e28acfea CB	162	static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
	163	{
	164	unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
5a32c1af	165	unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
e28acfea CB	166
	167	VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
	168	switch (subcode) {
	169	case 3:
	170	vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
	171	break;
	172	case 4:
	173	vcpu->run->s390_reset_flags = 0;
	174	break;
	175	default:
b8e660b8	176	return -EOPNOTSUPP;
e28acfea CB	177	}
e28acfea CB	178
6352e4d2 DH	179	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
6352e4d2 DH	180	kvm_s390_vcpu_stop(vcpu);
e28acfea CB	181	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_SUBSYSTEM;
	182	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_IPL;
	183	vcpu->run->s390_reset_flags \|= KVM_S390_RESET_CPU_INIT;
	184	vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
33e19115	185	VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
e28acfea	186	vcpu->run->s390_reset_flags);
ade38c31	187	trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
e28acfea CB	188	return -EREMOTE;
	189	}
	190
10ccaa1e CH	191	static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
10ccaa1e CH	192	{
800c1065	193	int ret;
10ccaa1e CH	194
	195	/* No virtio-ccw notification? Get out quickly. */
	196	if (!vcpu->kvm->arch.css_support \|\|
	197	(vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
	198	return -EOPNOTSUPP;
	199
10ccaa1e CH	200	/*
	201	* The layout is as follows:
	202	* - gpr 2 contains the subchannel id (passed as addr)
	203	* - gpr 3 contains the virtqueue index (passed as datamatch)
85dfe87e	204	* - gpr 4 contains the index on the bus (optionally)
10ccaa1e	205	*/
85dfe87e	206	ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
ff1f3cb4	207	vcpu->run->s.regs.gprs[2] & 0xffffffff,
85dfe87e CH	208	8, &vcpu->run->s.regs.gprs[3],
85dfe87e CH	209	vcpu->run->s.regs.gprs[4]);
85dfe87e CH	210
	211	/*
	212	* Return cookie in gpr 2, but don't overwrite the register if the
	213	* diagnose will be handled by userspace.
	214	*/
	215	if (ret != -EOPNOTSUPP)
	216	vcpu->run->s.regs.gprs[2] = ret;
	217	/* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
10ccaa1e CH	218	return ret < 0 ? ret : 0;
	219	}
	220
e28acfea CB	221	int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
e28acfea CB	222	{
743db27c	223	int code = kvm_s390_get_base_disp_rs(vcpu) & 0xffff;
e28acfea	224
93e1750f TH	225	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
	226	return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
	227
5786fffa	228	trace_kvm_s390_handle_diag(vcpu, code);
e28acfea	229	switch (code) {
388186bc CB	230	case 0x10:
388186bc CB	231	return diag_release_pages(vcpu);
e28acfea CB	232	case 0x44:
e28acfea CB	233	return __diag_time_slice_end(vcpu);
41628d33 KW	234	case 0x9c:
41628d33 KW	235	return __diag_time_slice_end_directed(vcpu);
3c038e6b DD	236	case 0x258:
3c038e6b DD	237	return __diag_page_ref_service(vcpu);
e28acfea CB	238	case 0x308:
e28acfea CB	239	return __diag_ipl_functions(vcpu);
10ccaa1e CH	240	case 0x500:
10ccaa1e CH	241	return __diag_virtio_hypercall(vcpu);
e28acfea	242	default:
b8e660b8	243	return -EOPNOTSUPP;
e28acfea CB	244	}
e28acfea CB	245	}