From 656a5dcc1fd6fac455a469a39383ceeb4533f1f7 Mon Sep 17 00:00:00 2001
From: Justin Miller <justin.miller@reactos.org>
Date: Wed, 12 Mar 2025 05:24:36 -0700
Subject: [PATCH] [NTOS:KE] Implement KeI386VirtualIntExtensions code paths for
 INT and IRET. CORE-19049 (#7742)
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Co-authored-by: Thomas Faber <thomas.faber@reactos.org>
Co-authored-by: Hermès BÉLUSCA - MAÏTO <hermes.belusca-maito@reactos.org>

Continued from PR #6070

JIRA issue: CORE-19049
---
 ntoskrnl/ke/i386/v86vdm.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/ntoskrnl/ke/i386/v86vdm.c b/ntoskrnl/ke/i386/v86vdm.c
index a50f3aba188..b4790d146f6 100644
--- a/ntoskrnl/ke/i386/v86vdm.c
+++ b/ntoskrnl/ke/i386/v86vdm.c
@@ -191,13 +191,21 @@ KiVdmOpcodeINTnn(IN PKTRAP_FRAME TrapFrame,
     V86EFlags &= (EFLAGS_ALIGN_CHECK | EFLAGS_INTERRUPT_MASK);
 
     /* Check for VME support */
-    ASSERT(KeI386VirtualIntExtensions == FALSE);
+    if (KeI386VirtualIntExtensions)
+    {
+        /* Set IF based on VIF */
+        V86EFlags &= ~EFLAGS_INTERRUPT_MASK;
+        if (TrapEFlags & EFLAGS_VIF)
+        {
+            V86EFlags |= EFLAGS_INTERRUPT_MASK;
+        }
+    }
 
     /* Mask in the relevant V86 EFlags into the trap flags */
     V86EFlags |= (TrapEFlags & ~EFLAGS_INTERRUPT_MASK);
 
     /* And mask out the VIF, nested task and TF flag from the trap flags */
-    TrapFrame->EFlags = TrapEFlags &~ (EFLAGS_VIF | EFLAGS_NESTED_TASK | EFLAGS_TF);
+    TrapFrame->EFlags = TrapEFlags & ~(EFLAGS_VIF | EFLAGS_NESTED_TASK | EFLAGS_TF);
 
     /* Add the IOPL flag to the local trap flags */
     V86EFlags |= EFLAGS_IOPL;
@@ -299,11 +307,17 @@ KiVdmOpcodeIRET(IN PKTRAP_FRAME TrapFrame,
     }
 
     /* Mask out EFlags */
-    EFlags &= ~(EFLAGS_IOPL + EFLAGS_VIF + EFLAGS_NESTED_TASK + EFLAGS_VIP);
+    EFlags &= ~(EFLAGS_VIP | EFLAGS_VIF | EFLAGS_NESTED_TASK | EFLAGS_IOPL);
     V86EFlags = EFlags;
 
     /* Check for VME support */
-    ASSERT(KeI386VirtualIntExtensions == FALSE);
+    if (KeI386VirtualIntExtensions)
+    {
+        if (EFlags & EFLAGS_INTERRUPT_MASK)
+        {
+            EFlags |= EFLAGS_VIF;
+        }
+    }
 
     /* Add V86 and Interrupt flag */
     EFlags |= EFLAGS_V86_MASK | EFLAGS_INTERRUPT_MASK;