From 3736b874a39a1df2a94186c357aabeb6a7d7d4f6 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 25 Mar 2013 17:22:52 +0100 Subject: [PATCH] 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: Heiko Carstens Acked-by: Cornelia Huck Signed-off-by: Cornelia Huck Signed-off-by: Gleb Natapov --- arch/s390/kvm/priv.c | 58 ++++++++++++++++++-------------------------- 1 file changed, 24 insertions(+), 34 deletions(-) diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 9d32c56fb02c..05d186c21eca 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -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; }