[Qemu-devel] [PULL 41/69] target/s390x: remove some Linux assumptions from IPTE

[Richard Henderson <rth@twiddle.net>]

From: Aurelien Jarno <aurelien@aurel32.net>

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <20170531220129.27724-3-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target/s390x/cpu.h        |  2 ++
 target/s390x/mem_helper.c | 17 ++++++++++-------
 target/s390x/mmu_helper.c |  2 --
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index fdb2f50..a4d31df 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -1035,6 +1035,8 @@ struct sysib_322 {
 #define _SEGMENT_ENTRY_RO       0x200     /* page protection bit              */
 #define _SEGMENT_ENTRY_INV      0x20      /* invalid segment table entry      */
 
+#define VADDR_PX                0xff000   /* page index bits                  */
+
 #define _PAGE_RO        0x200            /* HW read-only bit  */
 #define _PAGE_INVALID   0x400            /* HW invalid bit    */
 #define _PAGE_RES0      0x800            /* bit must be zero  */
diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index e35571e..0ebd65d 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -1073,19 +1073,22 @@ uint32_t HELPER(mvcp)(CPUS390XState *env, uint64_t l, uint64_t a1, uint64_t a2)
 }
 
 /* invalidate pte */
-void HELPER(ipte)(CPUS390XState *env, uint64_t pte_addr, uint64_t vaddr)
+void HELPER(ipte)(CPUS390XState *env, uint64_t pto, uint64_t vaddr)
 {
     CPUState *cs = CPU(s390_env_get_cpu(env));
     uint64_t page = vaddr & TARGET_PAGE_MASK;
-    uint64_t pte = 0;
+    uint64_t pte_addr, pte;
 
     /* XXX broadcast to other CPUs */
 
-    /* XXX Linux is nice enough to give us the exact pte address.
-       According to spec we'd have to find it out ourselves */
-    /* XXX Linux is fine with overwriting the pte, the spec requires
-       us to only set the invalid bit */
-    stq_phys(cs->as, pte_addr, pte | _PAGE_INVALID);
+    /* Compute the page table entry address */
+    pte_addr = (pto & _SEGMENT_ENTRY_ORIGIN);
+    pte_addr += (vaddr & _VADDR_PX) >> 9;
+
+    /* Mark the page table entry as invalid */
+    pte = ldq_phys(cs->as, pte_addr);
+    pte |= _PAGE_INVALID;
+    stq_phys(cs->as, pte_addr, pte);
 
     /* XXX we exploit the fact that Linux passes the exact virtual
        address here - it's not obliged to! */
diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c
index 31eb9ef..501e390 100644
--- a/target/s390x/mmu_helper.c
+++ b/target/s390x/mmu_helper.c
@@ -143,8 +143,6 @@ static int mmu_translate_pte(CPUS390XState *env, target_ulong vaddr,
     return 0;
 }
 
-#define VADDR_PX    0xff000         /* Page index bits */
-
 /* Decode segment table entry */
 static int mmu_translate_segment(CPUS390XState *env, target_ulong vaddr,
                                  uint64_t asc, uint64_t st_entry,
-- 
2.9.4