hvm: Remove guest-triggerable assertions from vlapic emulation.

Currently our VLAPIC will happily deliver interrupts on vectors <
16. This could be emulated better, but probably does not matter.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

2 files changed, 14 insertions, 29 deletions

diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 059b64538d..000cbbfc04 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -120,14 +120,9 @@ static void vlapic_clear_irr(int vector, struct vlapic *vlapic)
     vlapic_clear_vector(vector, &vlapic->regs->data[APIC_IRR]);
 }
 
-int vlapic_find_highest_irr(struct vlapic *vlapic)
+static int vlapic_find_highest_irr(struct vlapic *vlapic)
 {
-    int result;
-
-    result = vlapic_find_highest_vector(&vlapic->regs->data[APIC_IRR]);
-    ASSERT((result == -1) || (result >= 16));
-
-    return result;
+    return vlapic_find_highest_vector(&vlapic->regs->data[APIC_IRR]);
 }
 
 int vlapic_set_irq(struct vlapic *vlapic, uint8_t vec, uint8_t trig)
@@ -142,14 +137,9 @@ int vlapic_set_irq(struct vlapic *vlapic, uint8_t vec, uint8_t trig)
     return ret;
 }
 
-int vlapic_find_highest_isr(struct vlapic *vlapic)
+static int vlapic_find_highest_isr(struct vlapic *vlapic)
 {
-    int result;
-
-    result = vlapic_find_highest_vector(&vlapic->regs->data[APIC_ISR]);
-    ASSERT((result == -1) || (result >= 16));
-
-    return result;
+    return vlapic_find_highest_vector(&vlapic->regs->data[APIC_ISR]);
 }
 
 uint32_t vlapic_get_ppr(struct vlapic *vlapic)
@@ -454,11 +444,9 @@ static void vlapic_set_tdcr(struct vlapic *vlapic, unsigned int val)
                 "timer_divisor: %d", vlapic->hw.timer_divisor);
 }
 
-static void vlapic_read_aligned(struct vlapic *vlapic, unsigned int offset,
-                         unsigned int len, unsigned int *result)
+static void vlapic_read_aligned(
+    struct vlapic *vlapic, unsigned int offset, unsigned int *result)
 {
-    ASSERT((len == 4) && (offset >= 0) && (offset <= APIC_TDCR));
-
     switch ( offset )
     {
     case APIC_PROCPRI:
@@ -487,15 +475,9 @@ static unsigned long vlapic_read(struct vcpu *v, unsigned long address,
     if ( offset > APIC_TDCR )
         return 0;
 
-    /* some bugs on kernel cause read this with byte*/
-    if ( len != 4 )
-        HVM_DBG_LOG(DBG_LEVEL_VLAPIC,
-                    "read with len=0x%lx, should be 4 instead",
-                    len);
-
     alignment = offset & 0x3;
 
-    vlapic_read_aligned(vlapic, offset & ~0x3, 4, &tmp);
+    vlapic_read_aligned(vlapic, offset & ~0x3, &tmp);
     switch ( len )
     {
     case 1:
@@ -503,12 +485,14 @@ static unsigned long vlapic_read(struct vcpu *v, unsigned long address,
         break;
 
     case 2:
-        ASSERT( alignment != 3 );
+        if ( alignment == 3 )
+            goto unaligned_exit_and_crash;
         result = *(unsigned short *)((unsigned char *)&tmp + alignment);
         break;
 
     case 4:
-        ASSERT( alignment == 0 );
+        if ( alignment != 0 )
+            goto unaligned_exit_and_crash;
         result = *(unsigned int *)((unsigned char *)&tmp + alignment);
         break;
 
@@ -523,6 +507,9 @@ static unsigned long vlapic_read(struct vcpu *v, unsigned long address,
 
     return result;
 
+ unaligned_exit_and_crash:
+    gdprintk(XENLOG_ERR, "Unaligned LAPIC read len=0x%lx at offset=0x%x.\n",
+             len, offset);
  exit_and_crash:
     domain_crash(v->domain);
     return 0;
diff --git a/xen/include/asm-x86/hvm/vlapic.h b/xen/include/asm-x86/hvm/vlapic.h
index d20a627882..edefa2c055 100644
--- a/xen/include/asm-x86/hvm/vlapic.h
+++ b/xen/include/asm-x86/hvm/vlapic.h
@@ -73,8 +73,6 @@ static inline void vlapic_set_reg(
 
 int vlapic_set_irq(struct vlapic *vlapic, uint8_t vec, uint8_t trig);
 
-int vlapic_find_highest_irr(struct vlapic *vlapic);
-
 int vlapic_has_pending_irq(struct vcpu *v);
 int vlapic_ack_pending_irq(struct vcpu *v, int vector);