[PATCH for-4.9] x86/emul: Drop more redundant ctxt.event_pending checks

* [PATCH for-4.9] x86/emul: Drop more redundant ctxt.event_pending checks
@ 2017-04-10 12:14 Andrew Cooper
  2017-04-10 12:24 ` Paul Durrant
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Andrew Cooper @ 2017-04-10 12:14 UTC (permalink / raw)
  To: Xen-devel
  Cc: Kevin Tian, Jan Beulich, Andrew Cooper, Tim Deegan, Julien Grall,
	Paul Durrant, Jun Nakajima

Since c/s 92cf67888a, x86_emulate_wrapper() asserts stricter behaviour about
the relationship between X86EMUL_EXCEPTION and ctxt.event_pending.

These removals should have been included in the aforementioned changeset, and
were only omitted due an oversight.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Tim Deegan <tim@xen.org>
CC: Paul Durrant <paul.durrant@citrix.com>
CC: Jun Nakajima <jun.nakajima@intel.com>
CC: Kevin Tian <kevin.tian@intel.com>
CC: Julien Grall <julien.grall@arm.com>
---
 xen/arch/x86/hvm/emulate.c      |  6 ++----
 xen/arch/x86/hvm/hvm.c          |  3 +--
 xen/arch/x86/hvm/io.c           |  3 +--
 xen/arch/x86/hvm/vmx/realmode.c | 15 ---------------
 xen/arch/x86/mm/shadow/multi.c  |  2 +-
 xen/arch/x86/traps.c            |  9 ---------
 6 files changed, 5 insertions(+), 33 deletions(-)

diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index 06b8f1b..91e269f 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -2035,8 +2035,7 @@ int hvm_emulate_one_mmio(unsigned long mfn, unsigned long gla)
         hvm_dump_emulation_state(XENLOG_G_WARNING "MMCFG", &ctxt);
         break;
     case X86EMUL_EXCEPTION:
-        if ( ctxt.ctxt.event_pending )
-            hvm_inject_event(&ctxt.ctxt.event);
+        hvm_inject_event(&ctxt.ctxt.event);
         /* fallthrough */
     default:
         hvm_emulate_writeback(&ctxt);
@@ -2095,8 +2094,7 @@ void hvm_emulate_one_vm_event(enum emul_kind kind, unsigned int trapnr,
         hvm_inject_hw_exception(trapnr, errcode);
         break;
     case X86EMUL_EXCEPTION:
-        if ( ctx.ctxt.event_pending )
-            hvm_inject_event(&ctx.ctxt.event);
+        hvm_inject_event(&ctx.ctxt.event);
         break;
     }
 
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index f50d15f..9ffe702 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3696,8 +3696,7 @@ void hvm_ud_intercept(struct cpu_user_regs *regs)
         hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
         break;
     case X86EMUL_EXCEPTION:
-        if ( ctxt.ctxt.event_pending )
-            hvm_inject_event(&ctxt.ctxt.event);
+        hvm_inject_event(&ctxt.ctxt.event);
         /* fall through */
     default:
         hvm_emulate_writeback(&ctxt);
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 9e00409..67528d9 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -100,8 +100,7 @@ bool hvm_emulate_one_insn(hvm_emulate_validate_t *validate)
         return false;
 
     case X86EMUL_EXCEPTION:
-        if ( ctxt.ctxt.event_pending )
-            hvm_inject_event(&ctxt.ctxt.event);
+        hvm_inject_event(&ctxt.ctxt.event);
         break;
     }
 
diff --git a/xen/arch/x86/hvm/vmx/realmode.c b/xen/arch/x86/hvm/vmx/realmode.c
index 7b908c7..4eb4232 100644
--- a/xen/arch/x86/hvm/vmx/realmode.c
+++ b/xen/arch/x86/hvm/vmx/realmode.c
@@ -114,21 +114,6 @@ void vmx_realmode_emulate_one(struct hvm_emulate_ctxt *hvmemul_ctxt)
 
     if ( rc == X86EMUL_EXCEPTION )
     {
-        if ( !hvmemul_ctxt->ctxt.event_pending )
-        {
-            unsigned long intr_info;
-
-            __vmread(VM_ENTRY_INTR_INFO, &intr_info);
-            __vmwrite(VM_ENTRY_INTR_INFO, 0);
-            if ( !(intr_info & INTR_INFO_VALID_MASK) )
-            {
-                gdprintk(XENLOG_ERR, "Exception pending but no info.\n");
-                goto fail;
-            }
-            hvmemul_ctxt->ctxt.event.vector = (uint8_t)intr_info;
-            hvmemul_ctxt->ctxt.event.insn_len = 0;
-        }
-
         if ( unlikely(curr->domain->debugger_attached) &&
              ((hvmemul_ctxt->ctxt.event.vector == TRAP_debug) ||
               (hvmemul_ctxt->ctxt.event.vector == TRAP_int3)) )
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index 5195d61..2fb0125 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -3457,7 +3457,7 @@ static int sh_page_fault(struct vcpu *v,
 
     r = x86_emulate(&emul_ctxt.ctxt, emul_ops);
 
-    if ( r == X86EMUL_EXCEPTION && emul_ctxt.ctxt.event_pending )
+    if ( r == X86EMUL_EXCEPTION )
     {
         /*
          * This emulation covers writes to shadow pagetables.  We tolerate #PF
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index d69769f..ca0a04a 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -3185,15 +3185,9 @@ static void emulate_gate_op(struct cpu_user_regs *regs)
     if ( IS_ERR_OR_NULL(state) )
     {
         if ( PTR_ERR(state) == -X86EMUL_EXCEPTION )
-        {
-            ASSERT(ctxt.ctxt.event_pending);
             pv_inject_event(&ctxt.ctxt.event);
-        }
         else
-        {
-            ASSERT(!ctxt.ctxt.event_pending);
             do_guest_trap(TRAP_gp_fault, regs);
-        }
         return;
     }
 
@@ -3234,13 +3228,10 @@ static void emulate_gate_op(struct cpu_user_regs *regs)
 
     if ( rc == X86EMUL_EXCEPTION )
     {
-        ASSERT(ctxt.ctxt.event_pending);
         pv_inject_event(&ctxt.ctxt.event);
         return;
     }
 
-    ASSERT(!ctxt.ctxt.event_pending);
-
     if ( rc != X86EMUL_OKAY ||
          jump < 0 ||
          (opnd_sel & ~3) != regs->error_code ||
-- 
2.1.4


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