Commit 3736b874 authored by Heiko Carstens's avatar Heiko Carstens Committed by Gleb Natapov
Browse files

KVM: s390: make if statements in lpsw/lpswe handlers readable 



Being unable to parse the 5- and 8-line if statements I had to split them
to be able to make any sense of them and verify that they match the
architecture.
So change the code since I guess that other people will also have a hard
time parsing such long conditional statements with line breaks.

Introduce a common is_valid_psw() function which does all the checks needed.
In case of lpsw (64 bit psw -> 128 bit psw conversion) it will do some not
needed additional checks, since a couple of bits can't be set anyway, but
that doesn't hurt.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
parent 6fd0fcc9

arch/s390/kvm/priv.c

+24 −34
Original line number Diff line number Diff line
@@ -258,68 +258,58 @@ static void handle_new_psw(struct kvm_vcpu *vcpu) 
#define PSW_ADDR_24 0x0000000000ffffffUL

#define PSW_ADDR_31 0x000000007fffffffUL



static int is_valid_psw(psw_t *psw) {

	if (psw->mask & PSW_MASK_UNASSIGNED)

		return 0;

	if ((psw->mask & PSW_MASK_ADDR_MODE) == PSW_MASK_BA) {

		if (psw->addr & ~PSW_ADDR_31)

			return 0;

	}

	if (!(psw->mask & PSW_MASK_ADDR_MODE) && (psw->addr & ~PSW_ADDR_24))

		return 0;

	if ((psw->mask & PSW_MASK_ADDR_MODE) ==  PSW_MASK_EA)

		return 0;

	return 1;

}



int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu)

{

	u64 addr;

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

	psw_compat_t new_psw;

	u64 addr;



	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)

	if (gpsw->mask & PSW_MASK_PSTATE)

		return kvm_s390_inject_program_int(vcpu,

						   PGM_PRIVILEGED_OPERATION);



	addr = kvm_s390_get_base_disp_s(vcpu);



	if (addr & 7)

		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);



	if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))

		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);



	if (!(new_psw.mask & PSW32_MASK_BASE))

		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);



	vcpu->arch.sie_block->gpsw.mask =

		(new_psw.mask & ~PSW32_MASK_BASE) << 32;

	vcpu->arch.sie_block->gpsw.mask |= new_psw.addr & PSW32_ADDR_AMODE;

	vcpu->arch.sie_block->gpsw.addr = new_psw.addr & ~PSW32_ADDR_AMODE;



	if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_UNASSIGNED) ||

	    (!(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) &&

	     (vcpu->arch.sie_block->gpsw.addr & ~PSW_ADDR_24)) ||

	    ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) ==

	     PSW_MASK_EA))

	gpsw->mask = (new_psw.mask & ~PSW32_MASK_BASE) << 32;

	gpsw->mask |= new_psw.addr & PSW32_ADDR_AMODE;

	gpsw->addr = new_psw.addr & ~PSW32_ADDR_AMODE;

	if (!is_valid_psw(gpsw))

		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);



	handle_new_psw(vcpu);

	return 0;

}



static int handle_lpswe(struct kvm_vcpu *vcpu)

{

	u64 addr;

	psw_t new_psw;

	u64 addr;



	addr = kvm_s390_get_base_disp_s(vcpu);



	if (addr & 7)

		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);



	if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))

		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);



	vcpu->arch.sie_block->gpsw.mask = new_psw.mask;

	vcpu->arch.sie_block->gpsw.addr = new_psw.addr;



	if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_UNASSIGNED) ||

	    (((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) ==

	      PSW_MASK_BA) &&

	     (vcpu->arch.sie_block->gpsw.addr & ~PSW_ADDR_31)) ||

	    (!(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) &&

	     (vcpu->arch.sie_block->gpsw.addr & ~PSW_ADDR_24)) ||

	    ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_ADDR_MODE) ==

	     PSW_MASK_EA))

	vcpu->arch.sie_block->gpsw = new_psw;

	if (!is_valid_psw(&vcpu->arch.sie_block->gpsw))

		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);



	handle_new_psw(vcpu);

	return 0;

}

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