From 2731d605d5478052a10ac5a7c80f7aa7e1788cc5 Mon Sep 17 00:00:00 2001 From: Nina Schoetterl-Glausch Date: Tue, 19 Dec 2023 15:08:50 +0100 Subject: KVM: s390: vsie: Fix STFLE interpretive execution identification STFLE can be interpretively executed. This occurs when the facility list designation is unequal to zero. Perform the check before applying the address mask instead of after. Fixes: 66b630d5b7f2 ("KVM: s390: vsie: support STFLE interpretation") Reviewed-by: Claudio Imbrenda Acked-by: David Hildenbrand Signed-off-by: Nina Schoetterl-Glausch Reviewed-by: Christian Borntraeger Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20231219140854.1042599-2-nsg@linux.ibm.com Signed-off-by: Janosch Frank Message-ID: <20231219140854.1042599-2-nsg@linux.ibm.com> --- arch/s390/kvm/vsie.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 02dcbe82a8e5..3cf95bc0401d 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -988,10 +988,15 @@ static void retry_vsie_icpt(struct vsie_page *vsie_page) static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; - __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U; + __u32 fac = READ_ONCE(vsie_page->scb_o->fac); if (fac && test_kvm_facility(vcpu->kvm, 7)) { retry_vsie_icpt(vsie_page); + /* + * The facility list origin (FLO) is in bits 1 - 28 of the FLD + * so we need to mask here before reading. + */ + fac = fac & 0x7ffffff8U; if (read_guest_real(vcpu, fac, &vsie_page->fac, sizeof(vsie_page->fac))) return set_validity_icpt(scb_s, 0x1090U); -- cgit v1.2.3