path: root/arch/s390/kvm/priv.c

// SPDX-License-Identifier: GPL-2.0
/*
 * handling privileged instructions
 *
 * Copyright IBM Corp. 2008, 2020
 *
 *    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 <linux/mm_types.h>
#include <linux/pgtable.h>

#include <asm/asm-offsets.h>
#include <asm/facility.h>
#include <asm/current.h>
#include <asm/debug.h>
#include <asm/ebcdic.h>
#include <asm/sysinfo.h>
#include <asm/page-states.h>
#include <asm/gmap.h>
#include <asm/io.h>
#include <asm/ptrace.h>
#include <asm/sclp.h>
#include <asm/ap.h>
#include "gaccess.h"
#include "kvm-s390.h"
#include "trace.h"

static int handle_ri(struct kvm_vcpu *vcpu)
{
	vcpu->stat.instruction_ri++;

	if (test_kvm_facility(vcpu->kvm, 64)) {
		VCPU_EVENT(vcpu, 3, "%s", "ENABLE: RI (lazy)");
		vcpu->arch.sie_block->ecb3 |= ECB3_RI;
		kvm_s390_retry_instr(vcpu);
		return 0;
	} else
		return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
}

int kvm_s390_handle_aa(struct kvm_vcpu *vcpu)
{
	if ((vcpu->arch.sie_block->ipa & 0xf) <= 4)
		return handle_ri(vcpu);
	else
		return -EOPNOTSUPP;
}

static int handle_gs(struct kvm_vcpu *vcpu)
{
	vcpu->stat.instruction_gs++;

	if (test_kvm_facility(vcpu->kvm, 133)) {
		VCPU_EVENT(vcpu, 3, "%s", "ENABLE: GS (lazy)");
		preempt_disable();
		__ctl_set_bit(2, 4);
		current->thread.gs_cb = (struct gs_cb *)&vcpu->run->s.regs.gscb;
		restore_gs_cb(current->thread.gs_cb);
		preempt_enable();
		vcpu->arch.sie_block->ecb |= ECB_GS;
		vcpu->arch.sie_block->ecd |= ECD_HOSTREGMGMT;
		vcpu->arch.gs_enabled = 1;
		kvm_s390_retry_instr(vcpu);
		return 0;
	} else
		return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
}

int kvm_s390_handle_e3(struct kvm_vcpu *vcpu)
{
	int code = vcpu->arch.sie_block->ipb & 0xff;

	if (code == 0x49 || code == 0x4d)
		return handle_gs(vcpu);
	else
		return -EOPNOTSUPP;
}
/* Handle SCK (SET CLOCK) interception */
static int handle_set_clock(struct kvm_vcpu *vcpu)
{
	struct kvm_s390_vm_tod_clock gtod = { 0 };
	int rc;
	u8 ar;
	u64 op2;

	vcpu->stat.instruction_sck++;

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

	op2 = kvm_s390_get_base_disp_s(vcpu, &ar);
	if (op2 & 7)	/* Operand must be on a doubleword boundary */
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	rc = read_guest(vcpu, op2, ar, &gtod.tod, sizeof(gtod.tod));
	if (rc)
		return kvm_s390_inject_prog_cond(vcpu, rc);

	VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", gtod.tod);
	kvm_s390_set_tod_clock(vcpu->kvm, &gtod);

	kvm_s390_set_psw_cc(vcpu, 0);
	return 0;
}

static int handle_set_prefix(struct kvm_vcpu *vcpu)
{
	u64 operand2;
	u32 address;
	int rc;
	u8 ar;

	vcpu->stat.instruction_spx++;

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

	operand2 = kvm_s390_get_base_disp_s(vcpu, &ar);

	/* must be word boundary */
	if (operand2 & 3)
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

	/* get the value */
	rc = read_guest(vcpu, operand2, ar, &address, sizeof(address));
	if (rc)
		return kvm_s390_inject_prog_cond(vcpu, rc);

	address &= 0x7fffe000u;

	/*
	 * Make sure the new value is valid memory. We only need to check the
	 * first page, since address is 8k aligned and memory pieces are always
	 * at least 1MB aligned and have at least a size of 1MB.
	 */
	if (kvm_is_error_gpa(vcpu->kvm, address))
		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

	kvm_s390_set_prefix(vcpu, address);
	trace_kvm_s390_handle_prefix(vcpu, 1, address);
	return 0;
}

static int handle_store_prefix(struct kvm_vcpu *vcpu)
{
	u64 operand2;
	u32 address;
	int rc;
	u8 ar;

	vcpu->stat.instruction_stpx++;

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

	operand2 = kvm_s390_get_base_disp_s(vcpu, &ar);

	/* must be word boundary */
	if (operand2 & 3)
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

	address = kvm_s390_get_prefix(vcpu);

	/* get the value */
	rc = write_guest(vcpu, operand2, ar, &address, sizeof(address));
	if (rc)
		return kvm_s390_inject_prog_cond(vcpu, rc);

	VCPU_EVENT(vcpu, 3, "STPX: storing prefix 0x%x into 0x%llx", address, operand2);
	trace_kvm_s390_handle_prefix(vcpu, 0, address);
	return 0;
}

static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
{
	u16 vcpu_id = vcpu->vcpu_id;
	u64 ga;
	int rc;
	u8 ar;

	vcpu->stat.instruction_stap++;

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

	ga = kvm_s390_get_base_disp_s(vcpu, &ar);

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

	rc = write_guest(vcpu, ga, ar, &vcpu_id, sizeof(vcpu_id));
	if (rc)
		return kvm_s390_inject_prog_cond(vcpu, rc);

	VCPU_EVENT(vcpu, 3, "STAP: storing cpu address (%u) to 0x%llx", vcpu_id, ga);
	trace_kvm_s390_handle_stap(vcpu, ga);
	return 0;
}

int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu)
{
	int rc;

	trace_kvm_s390_skey_related_inst(vcpu);
	/* Already enabled? */
	if (vcpu->arch.skey_enabled)
		return 0;

	rc = s390_enable_skey();
	VCPU_EVENT(vcpu, 3, "enabling storage keys for guest: %d", rc);
	if (rc)
		return rc;

	if (kvm_s390_test_cpuflags(vcpu, CPUSTAT_KSS))
		kvm_s390_clear_cpuflags(vcpu, CPUSTAT_KSS);
	if (!vcpu->kvm->arch.use_skf)
		vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
	else
		vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE);
	vcpu->arch.skey_enabled = true;
	return 0;
}

static int try_handle_skey(struct kvm_vcpu *vcpu)
{
	int rc;

	rc = kvm_s390_skey_check_enable(vcpu);
	if (rc)
		return rc;
	if (vcpu->kvm->arch.use_skf) {
		/* with storage-key facility, SIE interprets it for us */
		kvm_s390_retry_instr(vcpu);
		VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
		return -EAGAIN;
	}
	return 0;
}

static int handle_iske(struct kvm_vcpu *vcpu)
{
	unsigned long gaddr, vmaddr;
	unsigned char key;
	int reg1, reg2;
	bool unlocked;
	int rc;

	vcpu->stat.instruction_iske++;

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

	rc = try_handle_skey(vcpu);
	if (rc)
		return rc != -EAGAIN ? rc : 0;

	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);

	gaddr = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
	gaddr = kvm_s390_logical_to_effective(vcpu, gaddr);
	gaddr = kvm_s390_real_to_abs(vcpu, gaddr);
	vmaddr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(gaddr));
	if (kvm_is_error_hva(vmaddr))
		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING