diff mbox series

[4/5] x86/pv: Drop priv_op_ctxt.bpmatch and use pending_dbg instead

Message ID 20230912232113.402347-5-andrew.cooper3@citrix.com (mailing list archive)
State Superseded
Headers show
Series x86/pv: #DB vs %dr6 fixes, part 2 | expand

Commit Message

Andrew Cooper Sept. 12, 2023, 11:21 p.m. UTC 
With a full pending_dbg field in x86_emulate_ctxt, use it rather than using a
local bpmatch field.

This simplifies the OKAY/DONE path as singlestep is already accumulated by
x86_emulate() when appropriate.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Wei Liu <wl@xen.org>
CC: Jinoh Kang <jinoh.kang.kr@gmail.com>
---
 xen/arch/x86/pv/emul-priv-op.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

Comments

Jan Beulich Sept. 14, 2023, 3:12 p.m. UTC | #1 
On 13.09.2023 01:21, Andrew Cooper wrote:
> With a full pending_dbg field in x86_emulate_ctxt, use it rather than using a
> local bpmatch field.
> 
> This simplifies the OKAY/DONE path as singlestep is already accumulated by
> x86_emulate() when appropriate.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff mbox series

Patch

diff --git a/xen/arch/x86/pv/emul-priv-op.c b/xen/arch/x86/pv/emul-priv-op.c
index 257891a2a2dd..6963db35c960 100644
--- a/xen/arch/x86/pv/emul-priv-op.c
+++ b/xen/arch/x86/pv/emul-priv-op.c
@@ -34,7 +34,6 @@  struct priv_op_ctxt {
         unsigned long base, limit;
     } cs;
     char *io_emul_stub;
-    unsigned int bpmatch;
 };
 
 /* I/O emulation helpers.  Use non-standard calling conventions. */
@@ -367,7 +366,8 @@  static int cf_check read_io(
     if ( !guest_io_okay(port, bytes, curr, ctxt->regs) )
         return X86EMUL_UNHANDLEABLE;
 
-    poc->bpmatch = check_guest_io_breakpoint(curr, port, bytes);
+    poc->ctxt.retire.pending_dbg |=
+        check_guest_io_breakpoint(curr, port, bytes);
 
     if ( admin_io_okay(port, bytes, currd) )
     {
@@ -472,7 +472,8 @@  static int cf_check write_io(
     if ( !guest_io_okay(port, bytes, curr, ctxt->regs) )
         return X86EMUL_UNHANDLEABLE;
 
-    poc->bpmatch = check_guest_io_breakpoint(curr, port, bytes);
+    poc->ctxt.retire.pending_dbg |=
+        check_guest_io_breakpoint(curr, port, bytes);
 
     if ( admin_io_okay(port, bytes, currd) )
     {
@@ -636,7 +637,8 @@  static int cf_check rep_ins(
         return X86EMUL_EXCEPTION;
     }
 
-    poc->bpmatch = check_guest_io_breakpoint(curr, port, bytes_per_rep);
+    poc->ctxt.retire.pending_dbg |=
+        check_guest_io_breakpoint(curr, port, bytes_per_rep);
 
     while ( *reps < goal )
     {
@@ -658,7 +660,7 @@  static int cf_check rep_ins(
 
         ++*reps;
 
-        if ( poc->bpmatch || hypercall_preempt_check() )
+        if ( poc->ctxt.retire.pending_dbg || hypercall_preempt_check() )
             break;
 
         /* x86_emulate() clips the repetition count to ensure we don't wrap. */
@@ -703,7 +705,8 @@  static int cf_check rep_outs(
         return X86EMUL_EXCEPTION;
     }
 
-    poc->bpmatch = check_guest_io_breakpoint(curr, port, bytes_per_rep);
+    poc->ctxt.retire.pending_dbg |=
+        check_guest_io_breakpoint(curr, port, bytes_per_rep);
 
     while ( *reps < goal )
     {
@@ -726,7 +729,7 @@  static int cf_check rep_outs(
 
         ++*reps;
 
-        if ( poc->bpmatch || hypercall_preempt_check() )
+        if ( poc->ctxt.retire.pending_dbg || hypercall_preempt_check() )
             break;
 
         /* x86_emulate() clips the repetition count to ensure we don't wrap. */
@@ -1361,12 +1364,9 @@  int pv_emulate_privileged_op(struct cpu_user_regs *regs)
     case X86EMUL_DONE:
         ASSERT(!curr->arch.pv.trap_bounce.flags);
 
-        if ( ctxt.ctxt.retire.singlestep )
-            ctxt.bpmatch |= DR_STEP;
-
-        if ( ctxt.bpmatch )
+        if ( ctxt.ctxt.retire.pending_dbg )
         {
-            curr->arch.dr6 |= ctxt.bpmatch | DR_STATUS_RESERVED_ONE;
+            curr->arch.dr6 |= ctxt.ctxt.retire.pending_dbg | DR_STATUS_RESERVED_ONE;
             pv_inject_hw_exception(X86_EXC_DB, X86_EVENT_NO_EC);
         }