3 files changed, 26 insertions, 3 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index a27d0d5a6f86..1cd02f6073a0 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -99,7 +99,9 @@ struct kvm_s390_sie_block {
         __u8    reservedd0[48];         /* 0x00d0 */
         __u64   gcr[16];                /* 0x0100 */
         __u64   gbea;                   /* 0x0180 */
-        __u8    reserved188[120];       /* 0x0188 */
+        __u8    reserved188[24];        /* 0x0188 */
+        __u32   fac;                    /* 0x01a0 */
+        __u8    reserved1a4[92];        /* 0x01a4 */
 } __attribute__((packed));
 
 struct kvm_vcpu_stat {
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index c18b21d6991c..90d9d1ba258b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -25,6 +25,7 @@
 #include <asm/lowcore.h>
 #include <asm/pgtable.h>
 #include <asm/nmi.h>
+#include <asm/system.h>
 #include "kvm-s390.h"
 #include "gaccess.h"
 
@@ -69,6 +70,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
         { NULL }
 };
 
+static unsigned long long *facilities;
 
 /* Section: not file related */
 void kvm_arch_hardware_enable(void *garbage)
@@ -288,6 +290,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
         vcpu->arch.sie_block->gmsor = vcpu->kvm->arch.guest_origin;
         vcpu->arch.sie_block->ecb   = 2;
         vcpu->arch.sie_block->eca   = 0xC1002001U;
+        vcpu->arch.sie_block->fac   = (int) (long) facilities;
         hrtimer_init(&vcpu->arch.ckc_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
         tasklet_init(&vcpu->arch.tasklet, kvm_s390_tasklet,
                      (unsigned long) vcpu);
@@ -739,11 +742,29 @@ gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
 
 static int __init kvm_s390_init(void)
 {
-        return kvm_init(NULL, sizeof(struct kvm_vcpu), THIS_MODULE);
+        int ret;
+        ret = kvm_init(NULL, sizeof(struct kvm_vcpu), THIS_MODULE);
+        if (ret)
+                return ret;
+
+        /*
+         * guests can ask for up to 255+1 double words, we need a full page
+         * to hold the maximum amount of facilites. On the other hand, we
+         * only set facilities that are known to work in KVM.
+         */
+        facilities = (unsigned long long *) get_zeroed_page(GFP_DMA);
+        if (!facilities) {
+                kvm_exit();
+                return -ENOMEM;
+        }
+        stfle(facilities, 1);
+        facilities[0] &= 0xff00fff3f0700000ULL;
+        return 0;
 }
 
 static void __exit kvm_s390_exit(void)
 {
+        free_page((unsigned long) facilities);
         kvm_exit();
 }
 
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 93ecd06e1a74..d426aac8095d 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -158,7 +158,7 @@ static int handle_stfl(struct kvm_vcpu *vcpu)
 
         vcpu->stat.instruction_stfl++;
         /* only pass the facility bits, which we can handle */
-        facility_list &= 0xfe00fff3;
+        facility_list &= 0xff00fff3;
 
         rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
                            &facility_list, sizeof(facility_list));