From 8eeba194a32e0f50329354a696baaa2e3d9accc5 Mon Sep 17 00:00:00 2001 From: Eric Farman Date: Fri, 8 Oct 2021 22:31:07 +0200 Subject: [PATCH] KVM: s390: Simplify SIGP Set Arch handling The Principles of Operations describe the various reasons that each individual SIGP orders might be rejected, and the status bit that are set for each condition. For example, for the Set Architecture order, it states: "If it is not true that all other CPUs in the configu- ration are in the stopped or check-stop state, ... bit 54 (incorrect state) ... is set to one." However, it also states: "... if the CZAM facility is installed, ... bit 55 (invalid parameter) ... is set to one." Since the Configuration-z/Architecture-Architectural Mode (CZAM) facility is unconditionally presented, there is no need to examine each VCPU to determine if it is started/stopped. It can simply be rejected outright with the Invalid Parameter bit. Fixes: b697e435aeee ("KVM: s390: Support Configuration z/Architecture Mode") Signed-off-by: Eric Farman Reviewed-by: Thomas Huth Reviewed-by: Claudio Imbrenda Reviewed-by: David Hildenbrand Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20211008203112.1979843-2-farman@linux.ibm.com Signed-off-by: Christian Borntraeger --- arch/s390/kvm/sigp.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c index 683036c1c92a8..cf4de80bd5410 100644 --- a/arch/s390/kvm/sigp.c +++ b/arch/s390/kvm/sigp.c @@ -151,22 +151,10 @@ static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu, static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter, u64 *status_reg) { - unsigned int i; - struct kvm_vcpu *v; - bool all_stopped = true; - - kvm_for_each_vcpu(i, v, vcpu->kvm) { - if (v == vcpu) - continue; - if (!is_vcpu_stopped(v)) - all_stopped = false; - } - *status_reg &= 0xffffffff00000000UL; /* Reject set arch order, with czam we're always in z/Arch mode. */ - *status_reg |= (all_stopped ? SIGP_STATUS_INVALID_PARAMETER : - SIGP_STATUS_INCORRECT_STATE); + *status_reg |= SIGP_STATUS_INVALID_PARAMETER; return SIGP_CC_STATUS_STORED; } -- 2.30.2