From: Paolo Bonzini <pbonzini@redhat.com>
Date: Sat, 25 May 2024 08:47:31 +0000 (+0200)
Subject: target/i386: fix INHIBIT_IRQ/TF/RF handling for PAUSE
X-Git-Tag: qemu-xen-4.20.0~119^2~34
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=3718523d011e898d414f09a4ed43cf13d76de0b4;p=qemu-xen.git

target/i386: fix INHIBIT_IRQ/TF/RF handling for PAUSE

PAUSE uses DISAS_NORETURN because the corresponding helper
calls cpu_loop_exit().  However, while HLT clear HF_INHIBIT_IRQ_MASK
to correctly handle "STI; HLT", the same is missing from PAUSE.
And also gen_eob() clears HF_RF_MASK and synthesizes a #DB exception
if single-step is active; none of this is done by HLT and PAUSE.
Start fixing PAUSE, HLT will follow.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/target/i386/tcg/misc_helper.c b/target/i386/tcg/misc_helper.c
index 8316d42ffc..ed4cda8001 100644
--- a/target/i386/tcg/misc_helper.c
+++ b/target/i386/tcg/misc_helper.c
@@ -92,6 +92,10 @@ G_NORETURN void helper_pause(CPUX86State *env)
 {
     CPUState *cs = env_cpu(env);
 
+    /* Do gen_eob() tasks before going back to the main loop.  */
+    do_end_instruction(env);
+    helper_rechecking_single_step(env);
+
     /* Just let another CPU run.  */
     cs->exception_index = EXCP_INTERRUPT;
     cpu_loop_exit(cs);