KVM: s390: introduce the format-1 GISA

The patch modifies the previously defined GISA data structure to be
able to store two GISA formats, format-0 and format-1. Additionally,
it verifies the availability of the GISA format facility and enables
the use of a format-1 GISA in the SIE control block accordingly.

A format-1 can do everything that format-0 can and we will need it
for real HW passthrough. As there are systems with only format-0
we keep both variants.

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

3 files changed, 37 insertions, 13 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 76d6f0ef3dbd..59dd46adf0e8 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -228,6 +228,7 @@ struct kvm_s390_sie_block {
         __u8    epdx;                   /* 0x0069 */
         __u8    reserved6a[2];          /* 0x006a */
         __u32   todpr;                  /* 0x006c */
+#define GISA_FORMAT1 0x00000001
         __u32   gd;                     /* 0x0070 */
         __u8    reserved74[12];         /* 0x0074 */
         __u64   mso;                    /* 0x0080 */
@@ -719,15 +720,38 @@ struct kvm_s390_crypto_cb {
 };
 
 struct kvm_s390_gisa {
-        u32 next_alert;
-        u8 ipm;
-        u8 reserved01;
-        u8 : 6;
-        u8 g : 1;
-        u8 c : 1;
-        u8 iam;
-        u8 reserved02[4];
-        u32 airq_count;
+        union {
+                struct { /* common to all formats */
+                        u32 next_alert;
+                        u8  ipm;
+                        u8  reserved01[2];
+                        u8  iam;
+                };
+                struct { /* format 0 */
+                        u32 next_alert;
+                        u8  ipm;
+                        u8  reserved01;
+                        u8  : 6;
+                        u8  g : 1;
+                        u8  c : 1;
+                        u8  iam;
+                        u8  reserved02[4];
+                        u32 airq_count;
+                } g0;
+                struct { /* format 1 */
+                        u32 next_alert;
+                        u8  ipm;
+                        u8  simm;
+                        u8  nimm;
+                        u8  iam;
+                        u8  aism[8];
+                        u8  : 6;
+                        u8  g : 1;
+                        u8  c : 1;
+                        u8  reserved03[11];
+                        u32 airq_count;
+                } g1;
+        };
 };
 
 /*
@@ -738,7 +762,7 @@ struct sie_page2 {
         __u64 fac_list[S390_ARCH_FAC_LIST_SIZE_U64];    /* 0x0000 */
         struct kvm_s390_crypto_cb crycb;                /* 0x0800 */
         struct kvm_s390_gisa gisa;                      /* 0x0900 */
-        u8 reserved910[0x1000 - 0x910];                 /* 0x0910 */
+        u8 reserved920[0x1000 - 0x920];                 /* 0x0920 */
 };
 
 struct kvm_s390_vsie {
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 488ecc7ea2a1..aabf46f5f883 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2842,9 +2842,7 @@ void kvm_s390_gisa_clear(struct kvm *kvm)
 
 void kvm_s390_gisa_init(struct kvm *kvm)
 {
-        if (!css_general_characteristics.aiv)
-                kvm->arch.gisa = NULL;
-        else {
+        if (css_general_characteristics.aiv) {
                 kvm->arch.gisa = &kvm->arch.sie_page2->gisa;
                 VM_EVENT(kvm, 3, "gisa 0x%pK initialized", kvm->arch.gisa);
                 kvm_s390_gisa_clear(kvm);
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 2c5e25b39435..f85a405e2595 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2531,6 +2531,8 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
         vcpu->arch.sie_block->icpua = id;
         spin_lock_init(&vcpu->arch.local_int.lock);
         vcpu->arch.sie_block->gd = (u32)(u64)kvm->arch.gisa;
+        if (vcpu->arch.sie_block->gd && sclp.has_gisaf)
+                vcpu->arch.sie_block->gd |= GISA_FORMAT1;
         seqcount_init(&vcpu->arch.cputm_seqcount);
 
         rc = kvm_vcpu_init(vcpu, kvm, id);