kvm_arch_vcpu_ioctl_get_fpu does not set the mxcsr in the kvm_fpu struct; conversely kvm_arch_vcpu_ioctl_set_fpu does not set the mxcsr value in the fxregs_state struct of the vcpu. This leads to the KVM_GET_FPU ioctl returning 0 as the mxcsr value, regardless of the actual value on the vcpu; while KVM_SET_FPU leaves the MXCSR on the vcpu untouched. Fix kvm_arch_vcpu_ioctl_{get,set}_fpu to properly handle MXCSR. Signed-off-by: Justinien Bouron <justinien.bouron@xxxxxxxxx> --- arch/x86/kvm/x86.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 43a6a7efc6ec..c33a2599a497 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11462,6 +11462,7 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) fpu->last_ip = fxsave->rip; fpu->last_dp = fxsave->rdp; memcpy(fpu->xmm, fxsave->xmm_space, sizeof(fxsave->xmm_space)); + fpu->mxcsr = fxsave->mxcsr; vcpu_put(vcpu); return 0; @@ -11486,6 +11487,7 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) fxsave->rip = fpu->last_ip; fxsave->rdp = fpu->last_dp; memcpy(fxsave->xmm_space, fpu->xmm, sizeof(fxsave->xmm_space)); + fxsave->mxcsr = fpu->mxcsr; vcpu_put(vcpu); return 0; -- 2.25.1