[PATCH v1 2/5] s390x/mmu: Implement ESOP-2 and access-exception-fetch/store-indication facility

From: David Hildenbrand <david@redhat.com>
To: qemu-devel@nongnu.org
Cc: Thomas Huth <thuth@redhat.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	David Hildenbrand <david@redhat.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Halil Pasic <pasic@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	qemu-s390x@nongnu.org, Richard Henderson <rth@twiddle.net>
Subject: [PATCH v1 2/5] s390x/mmu: Implement ESOP-2 and access-exception-fetch/store-indication facility
Date: Thu, 26 Sep 2019 12:16:24 +0200	[thread overview]
Message-ID: <20190926101627.23376-3-david@redhat.com> (raw)
In-Reply-To: <20190926101627.23376-1-david@redhat.com>

We already implement ESOP-1. For ESOP-2, we only have to indicate all
protection exceptions properly. Due to EDAT-1, we already indicate DAT
exceptions properly. We don't trigger KCP/ALCP/IEP exceptions yet.

So all we have to do is set the TEID (TEC) to the right values
(bit 56, 60, 61) in case of LAP.

We don't have any side-effects (e.g., no guarded-storage facility),
therefore, bit 64 of the TEID (TEC) is always 0.

We always have to indicate whether it is a fetch or a store for all access
exceptions. This is only missing for LAP exceptions.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/mmu_helper.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c
index 54f54137ec..8abc5d31d8 100644
--- a/target/s390x/mmu_helper.c
+++ b/target/s390x/mmu_helper.c
@@ -384,7 +384,9 @@ int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,
         *flags |= PAGE_WRITE_INV;
         if (is_low_address(vaddr) && rw == MMU_DATA_STORE) {
             if (exc) {
-                trigger_access_exception(env, PGM_PROTECTION, ILEN_AUTO, 0);
+                /* LAP sets bit 56 */
+                tec |= 0x80;
+                trigger_access_exception(env, PGM_PROTECTION, ilen, tec);
             }
             return -EACCES;
         }
@@ -540,6 +542,10 @@ void s390_cpu_virt_mem_handle_exc(S390CPU *cpu, uintptr_t ra)
 int mmu_translate_real(CPUS390XState *env, target_ulong raddr, int rw,
                        target_ulong *addr, int *flags)
 {
+    /* Code accesses have an undefined ilc, let's use 2 bytes. */
+    const int ilen = (rw == MMU_INST_FETCH) ? 2 : ILEN_AUTO;
+    uint64_t tec = (raddr & TARGET_PAGE_MASK) |
+                   (rw == MMU_DATA_STORE ? FS_WRITE : FS_READ);
     const bool lowprot_enabled = env->cregs[0] & CR0_LOWPROT;
 
     *flags = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
@@ -547,7 +553,9 @@ int mmu_translate_real(CPUS390XState *env, target_ulong raddr, int rw,
         /* see comment in mmu_translate() how this works */
         *flags |= PAGE_WRITE_INV;
         if (is_low_address(raddr) && rw == MMU_DATA_STORE) {
-            trigger_access_exception(env, PGM_PROTECTION, ILEN_AUTO, 0);
+            /* LAP sets bit 56 */
+            tec |= 0x80;
+            trigger_access_exception(env, PGM_PROTECTION, ilen, tec);
             return -EACCES;
         }
     }
-- 
2.21.0


