target/i386: Added VGIF V_IRQ masking capability

VGIF provides masking capability for when virtual interrupts
are taken. (APM2)

Signed-off-by: Lara Lazier <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

Author: Lara Lazier

target/i386/cpu.c

@@ -5657,6 +5657,7 @@ static void x86_cpu_reset(DeviceState *dev)
     /* init to reset state */
     env->int_ctl = 0;
     env->hflags2 |= HF2_GIF_MASK;
+    env->hflags2 |= HF2_VGIF_MASK;
     env->hflags &= ~HF_GUEST_MASK;
 
     cpu_x86_update_cr0(env, 0x60000010);
@@ -6540,10 +6541,12 @@ int x86_cpu_pending_interrupt(CPUState *cs, int interrupt_request)
                       !(env->hflags & HF_INHIBIT_IRQ_MASK))))) {
             return CPU_INTERRUPT_HARD;
 #if !defined(CONFIG_USER_ONLY)
-        } else if ((interrupt_request & CPU_INTERRUPT_VIRQ) &&
+        } else if (env->hflags2 & HF2_VGIF_MASK) {
+            if((interrupt_request & CPU_INTERRUPT_VIRQ) &&
                    (env->eflags & IF_MASK) &&
                    !(env->hflags & HF_INHIBIT_IRQ_MASK)) {
-            return CPU_INTERRUPT_VIRQ;
+                        return CPU_INTERRUPT_VIRQ;
+            }
 #endif
         }
     }

target/i386/cpu.h

@@ -203,6 +203,7 @@ typedef enum X86Seg {
 #define HF2_MPX_PR_SHIFT         5 /* BNDCFGx.BNDPRESERVE */
 #define HF2_NPT_SHIFT            6 /* Nested Paging enabled */
 #define HF2_IGNNE_SHIFT          7 /* Ignore CR0.NE=0 */
+#define HF2_VGIF_SHIFT           8 /* Can take VIRQ*/
 
 #define HF2_GIF_MASK            (1 << HF2_GIF_SHIFT)
 #define HF2_HIF_MASK            (1 << HF2_HIF_SHIFT)
@@ -212,6 +213,7 @@ typedef enum X86Seg {
 #define HF2_MPX_PR_MASK         (1 << HF2_MPX_PR_SHIFT)
 #define HF2_NPT_MASK            (1 << HF2_NPT_SHIFT)
 #define HF2_IGNNE_MASK          (1 << HF2_IGNNE_SHIFT)
+#define HF2_VGIF_MASK           (1 << HF2_VGIF_SHIFT)
 
 #define CR0_PE_SHIFT 0
 #define CR0_MP_SHIFT 1

target/i386/tcg/sysemu/svm_helper.c

@@ -130,6 +130,11 @@ static inline bool virtual_gif_enabled(CPUX86State *env)
     return false;
 }
 
+static inline bool virtual_gif_set(CPUX86State *env)
+{
+    return !virtual_gif_enabled(env) || (env->int_ctl & V_GIF_MASK);
+}
+
 void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend)
 {
     CPUState *cs = env_cpu(env);
@@ -364,6 +369,10 @@ void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend)
         cs->interrupt_request |= CPU_INTERRUPT_VIRQ;
     }
 
+    if (virtual_gif_set(env)) {
+        env->hflags2 |= HF2_VGIF_MASK;
+    }
+
     /* maybe we need to inject an event */
     event_inj = x86_ldl_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
                                                  control.event_inj));
@@ -520,6 +529,7 @@ void helper_stgi(CPUX86State *env)
 
     if (virtual_gif_enabled(env)) {
         env->int_ctl |= V_GIF_MASK;
+        env->hflags2 |= HF2_VGIF_MASK;
     } else {
         env->hflags2 |= HF2_GIF_MASK;
     }
@@ -531,6 +541,7 @@ void helper_clgi(CPUX86State *env)
 
     if (virtual_gif_enabled(env)) {
         env->int_ctl &= ~V_GIF_MASK;
+        env->hflags2 &= ~HF2_VGIF_MASK;
     } else {
         env->hflags2 &= ~HF2_GIF_MASK;
     }
@@ -812,6 +823,7 @@ void do_vmexit(CPUX86State *env)
              env->vm_vmcb + offsetof(struct vmcb, control.event_inj), 0);
 
     env->hflags2 &= ~HF2_GIF_MASK;
+    env->hflags2 &= ~HF2_VGIF_MASK;
     /* FIXME: Resets the current ASID register to zero (host ASID). */
 
     /* Clears the V_IRQ and V_INTR_MASKING bits inside the processor. */