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

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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: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
This commit is contained in:
Heiko Carstens 2013-03-25 17:22:52 +01:00 committed by Gleb Natapov
parent 6fd0fcc93b
commit 3736b874a3
1 changed files with 24 additions and 34 deletions
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58
arch/s390/kvm/priv.c
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@ -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;
}