Merge tag 'kvm-s390-next-6.8-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

- uvdevice fixed additional data return length
- stfle (feature indication) vsie fixes and minor cleanup

1 files changed, 17 insertions, 2 deletions

diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 8207a892bbe2..fef42e2a80a2 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -19,6 +19,7 @@
 #include <asm/nmi.h>
 #include <asm/dis.h>
 #include <asm/fpu/api.h>
+#include <asm/facility.h>
 #include "kvm-s390.h"
 #include "gaccess.h"
 
@@ -984,12 +985,26 @@ 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);
 
+	/*
+	 * Alternate-STFLE-Interpretive-Execution facilities are not supported
+	 * -> format-0 flcb
+	 */
 	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;
+		/*
+		 * format-0 -> size of nested guest's facility list == guest's size
+		 * guest's size == host's size, since STFLE is interpretatively executed
+		 * using a format-0 for the guest, too.
+		 */
 		if (read_guest_real(vcpu, fac, &vsie_page->fac,
-				    sizeof(vsie_page->fac)))
+				    stfle_size() * sizeof(u64)))
 			return set_validity_icpt(scb_s, 0x1090U);
 		scb_s->fac = (__u32)(__u64) &vsie_page->fac;
 	}