From cf3d958b14e21fde929e67262b6e192592d95359 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Wed, 11 Nov 2020 12:03:15 -0500
Subject: [PATCH 15/18] s390x: pv: Remove sclp boundary checks

RH-Author: Thomas Huth <thuth@redhat.com>
Message-id: <20201111120316.707489-12-thuth@redhat.com>
Patchwork-id: 99508
O-Subject: [RHEL-8.4.0 qemu-kvm PATCH v2 11/12] s390x: pv: Remove sclp boundary checks
Bugzilla: 1798506
RH-Acked-by: Jens Freimann <jfreimann@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: David Hildenbrand <david@redhat.com>

From: Janosch Frank <frankja@linux.ibm.com>

The SCLP boundary cross check is done by the Ultravisor for a
protected guest, hence we don't need to do it. As QEMU doesn't get a
valid SCCB address in protected mode this is even problematic and can
lead to QEMU reporting a false boundary cross error.

Fixes: db13387ca0 ("s390/sclp: rework sclp boundary checks")
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Collin Walling <walling@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Message-Id: <20201022103135.126033-2-frankja@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
(cherry picked from commit 3df4843d0e612a3c838e8d94c3e9c24520f2e680)
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 hw/s390x/sclp.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
index 2931046f456..03f847b2c8a 100644
--- a/hw/s390x/sclp.c
+++ b/hw/s390x/sclp.c
@@ -285,11 +285,6 @@ int sclp_service_call_protected(CPUS390XState *env, uint64_t sccb,
         goto out_write;
     }
 
-    if (!sccb_verify_boundary(sccb, be16_to_cpu(work_sccb->h.length), code)) {
-        work_sccb->h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
-        goto out_write;
-    }
-
     sclp_c->execute(sclp, work_sccb, code);
 out_write:
     s390_cpu_pv_mem_write(env_archcpu(env), 0, work_sccb,
-- 
2.27.0

