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Commit 9a558ee3 authored by Thomas Huth's avatar Thomas Huth Committed by Christian Borntraeger
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KVM: s390: Handle MVPG partial execution interception 



When the guest executes the MVPG instruction with DAT disabled,
and the source or destination page is not mapped in the host,
the so-called partial execution interception occurs. We need to
handle this event by setting up a mapping for the corresponding
user pages.

Signed-off-by: default avatarThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 198c74f4

arch/s390/kvm/intercept.c

+54 −1
Original line number Original line Diff line number Diff line 
/*

/*

 * in-kernel handling for sie intercepts

 * in-kernel handling for sie intercepts

 *

 *

 * Copyright IBM Corp. 2008, 2009

 * Copyright IBM Corp. 2008, 2014

 *

 *

 * This program is free software; you can redistribute it and/or modify

 * 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)

 * it under the terms of the GNU General Public License (version 2 only)
@@ -234,6 +234,58 @@ static int handle_instruction_and_prog(struct kvm_vcpu *vcpu) 
	return rc2;

	return rc2;

}

}





/**

 * Handle MOVE PAGE partial execution interception.

 *

 * This interception can only happen for guests with DAT disabled and

 * addresses that are currently not mapped in the host. Thus we try to

 * set up the mappings for the corresponding user pages here (or throw

 * addressing exceptions in case of illegal guest addresses).

 */

static int handle_mvpg_pei(struct kvm_vcpu *vcpu)

{

	unsigned long hostaddr, srcaddr, dstaddr;

	psw_t *psw = &vcpu->arch.sie_block->gpsw;

	struct mm_struct *mm = current->mm;

	int reg1, reg2, rc;



	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);

	srcaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg2]);

	dstaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg1]);



	/* Make sure that the source is paged-in */

	hostaddr = gmap_fault(srcaddr, vcpu->arch.gmap);

	if (IS_ERR_VALUE(hostaddr))

		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

	down_read(&mm->mmap_sem);

	rc = get_user_pages(current, mm, hostaddr, 1, 0, 0, NULL, NULL);

	up_read(&mm->mmap_sem);

	if (rc < 0)

		return rc;



	/* Make sure that the destination is paged-in */

	hostaddr = gmap_fault(dstaddr, vcpu->arch.gmap);

	if (IS_ERR_VALUE(hostaddr))

		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

	down_read(&mm->mmap_sem);

	rc = get_user_pages(current, mm, hostaddr, 1, 1, 0, NULL, NULL);

	up_read(&mm->mmap_sem);

	if (rc < 0)

		return rc;



	psw->addr = __rewind_psw(*psw, 4);



	return 0;

}



static int handle_partial_execution(struct kvm_vcpu *vcpu)

{

	if (vcpu->arch.sie_block->ipa == 0xb254)	/* MVPG */

		return handle_mvpg_pei(vcpu);



	return -EOPNOTSUPP;

}



static const intercept_handler_t intercept_funcs[] = {

static const intercept_handler_t intercept_funcs[] = {

	[0x00 >> 2] = handle_noop,

	[0x00 >> 2] = handle_noop,

	[0x04 >> 2] = handle_instruction,

	[0x04 >> 2] = handle_instruction,
@@ -245,6 +297,7 @@ static const intercept_handler_t intercept_funcs[] = { 
	[0x1C >> 2] = kvm_s390_handle_wait,

	[0x1C >> 2] = kvm_s390_handle_wait,

	[0x20 >> 2] = handle_validity,

	[0x20 >> 2] = handle_validity,

	[0x28 >> 2] = handle_stop,

	[0x28 >> 2] = handle_stop,

	[0x38 >> 2] = handle_partial_execution,

};

};





int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)

int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)