Am 01.07.24 um 08:08 schrieb Sven Schnelle:
Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> writes:in rare cases, e.g. for injecting a machine check we do intercept all load PSW instructions via ICTL_LPSW. With facility 193 a new variant LPSWEY was added. KVM needs to handle that as well. Fixes: a3efa8429266 ("KVM: s390: gen_facilities: allow facilities 165, 193, 194 and 196") Reported-by: Marc Hartmayer <mhartmay@xxxxxxxxxxxxx> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> --- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/kvm-s390.c | 1 + arch/s390/kvm/kvm-s390.h | 15 +++++++++++++++ arch/s390/kvm/priv.c | 32 ++++++++++++++++++++++++++++++++ 4 files changed, 49 insertions(+) diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 1be19cc9d73c..1a49b89706f8 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -797,6 +797,36 @@ static int handle_lpswe(struct kvm_vcpu *vcpu) return 0; }+static int handle_lpswey(struct kvm_vcpu *vcpu)+{ + psw_t new_psw; + u64 addr; + int rc; + u8 ar; + + vcpu->stat.instruction_lpswey++; + + if (!test_kvm_facility(vcpu->kvm, 193)) + return kvm_s390_inject_program_int(vcpu, PGM_OPERATION); + + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) + return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); + + addr = kvm_s390_get_base_disp_siy(vcpu, &ar); + if (addr & 7) + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); + + rc = read_guest(vcpu, addr, ar, &new_psw, sizeof(new_psw)); + if (rc) + return kvm_s390_inject_prog_cond(vcpu, rc); + + 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);Shouldn't the gpsw get updated with new_psw after the check? POP says "The operation is suppressed on all addressing and protection exceptions."
Only for exception of the instruction but not for the target PSW. POP says: The other PSW fields which are to be loaded by the instruction are not checked for validity before they are loaded. However, immediately after loading, a speci- fication exception is recognized, and a program inter- ruption occurs, when any of the following is true for the newly loaded PSW
