[PATCH 2/4] target/i386: Added VGIF V_IRQ masking capability

From: Lara Lazier <laramglazier@gmail.com>
To: qemu-devel@nongnu.org
Cc: pbonzini@redhat.com, Lara Lazier <laramglazier@gmail.com>
Subject: [PATCH 2/4] target/i386: Added VGIF V_IRQ masking capability
Date: Fri, 20 Aug 2021 16:15:56 +0200	[thread overview]
Message-ID: <20210820141558.9031-3-laramglazier@gmail.com> (raw)
In-Reply-To: <20210820141558.9031-1-laramglazier@gmail.com>

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

Signed-off-by: Lara Lazier <laramglazier@gmail.com>
---
 target/i386/cpu.c                   |  7 +++++--
 target/i386/cpu.h                   |  2 ++
 target/i386/tcg/sysemu/svm_helper.c | 12 ++++++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 5dcdab3b80..b2094175d9 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5649,6 +5649,7 @@ 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);
@@ -6532,10 +6533,12 @@ 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
         }
     }
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index e27a1aab99..d26df6de6b 100644
--- a/target/i386/cpu.h
+++ b/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
diff --git a/target/i386/tcg/sysemu/svm_helper.c b/target/i386/tcg/sysemu/svm_helper.c
index 9ef2454779..2c44bdb243 100644
--- a/target/i386/tcg/sysemu/svm_helper.c
+++ b/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);
@@ -363,6 +368,10 @@ 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));
@@ -519,6 +528,7 @@ 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;
     }
@@ -530,6 +540,7 @@ 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;
     }
@@ -811,6 +822,7 @@ 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. */
-- 
2.25.1


