KVM: s390: In-kernel handling of I/O instructions.

Explicitely catch all channel I/O related instructions intercepts
in the kernel and set condition code 3 for them.

This paves the way for properly handling these instructions later
on.

Note: This is not architecture compliant (the previous code wasn't
either) since setting cc 3 is not the correct thing to do for some
of these instructions. For Linux guests, however, it still has the
intended effect of stopping css probing.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 39 insertions, 17 deletions

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index d3cbcd3c9ada..8ad776f87856 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -127,20 +127,9 @@ static int handle_skey(struct kvm_vcpu *vcpu)
         return 0;
 }
 
-static int handle_stsch(struct kvm_vcpu *vcpu)
+static int handle_io_inst(struct kvm_vcpu *vcpu)
 {
-        vcpu->stat.instruction_stsch++;
-        VCPU_EVENT(vcpu, 4, "%s", "store subchannel - CC3");
-        /* condition code 3 */
-        vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
-        vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
-        return 0;
-}
-
-static int handle_chsc(struct kvm_vcpu *vcpu)
-{
-        vcpu->stat.instruction_chsc++;
-        VCPU_EVENT(vcpu, 4, "%s", "channel subsystem call - CC3");
+        VCPU_EVENT(vcpu, 4, "%s", "I/O instruction");
         /* condition code 3 */
         vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
         vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
@@ -375,7 +364,7 @@ out_fail:
         return 0;
 }
 
-static const intercept_handler_t priv_handlers[256] = {
+static const intercept_handler_t b2_handlers[256] = {
         [0x02] = handle_stidp,
         [0x10] = handle_set_prefix,
         [0x11] = handle_store_prefix,
@@ -383,8 +372,22 @@ static const intercept_handler_t priv_handlers[256] = {
         [0x29] = handle_skey,
         [0x2a] = handle_skey,
         [0x2b] = handle_skey,
-        [0x34] = handle_stsch,
-        [0x5f] = handle_chsc,
+        [0x30] = handle_io_inst,
+        [0x31] = handle_io_inst,
+        [0x32] = handle_io_inst,
+        [0x33] = handle_io_inst,
+        [0x34] = handle_io_inst,
+        [0x35] = handle_io_inst,
+        [0x36] = handle_io_inst,
+        [0x37] = handle_io_inst,
+        [0x38] = handle_io_inst,
+        [0x39] = handle_io_inst,
+        [0x3a] = handle_io_inst,
+        [0x3b] = handle_io_inst,
+        [0x3c] = handle_io_inst,
+        [0x5f] = handle_io_inst,
+        [0x74] = handle_io_inst,
+        [0x76] = handle_io_inst,
         [0x7d] = handle_stsi,
         [0xb1] = handle_stfl,
         [0xb2] = handle_lpswe,
@@ -401,7 +404,7 @@ int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
          * state bit and (a) handle the instruction or (b) send a code 2
          * program check.
          * Anything else goes to userspace.*/
-        handler = priv_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
+        handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
         if (handler) {
                 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                         return kvm_s390_inject_program_int(vcpu,
@@ -432,6 +435,7 @@ static int handle_epsw(struct kvm_vcpu *vcpu)
 
 static const intercept_handler_t b9_handlers[256] = {
         [0x8d] = handle_epsw,
+        [0x9c] = handle_io_inst,
 };
 
 int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
@@ -451,6 +455,24 @@ int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
         return -EOPNOTSUPP;
 }
 
+static const intercept_handler_t eb_handlers[256] = {
+        [0x8a] = handle_io_inst,
+};
+
+int kvm_s390_handle_priv_eb(struct kvm_vcpu *vcpu)
+{
+        intercept_handler_t handler;
+
+        /* All eb instructions that end up here are privileged. */
+        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
+                return kvm_s390_inject_program_int(vcpu,
+                                                   PGM_PRIVILEGED_OPERATION);
+        handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
+        if (handler)
+                return handler(vcpu);
+        return -EOPNOTSUPP;
+}
+
 static int handle_tprot(struct kvm_vcpu *vcpu)
 {
         u64 address1, address2;