References: FATE#313605

# HG changeset patch
# User Jiongxi Li <jiongxi.li@intel.com>
# Date 1361176078 -3600
# Node ID 4c3355d776e115f979fd2abc135bb77ba710f0d4
# Parent  217a4fc4cd46e8de06f2f43eed727838891e9398
x86/VMX: fix live migration while enabling APICV

SVI should be restored in case guest is processing virtual interrupt
while saveing a domain state. Otherwise SVI would be missed when
virtual interrupt delivery is enabled.

Signed-off-by: Jiongxi Li <jiongxi.li@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Acked-by: Jun Nakajima <jun.nakajima@intel.com>
Committed-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -1198,6 +1198,9 @@ static int lapic_load_regs(struct domain
     if ( hvm_load_entry(LAPIC_REGS, h, s->regs) != 0 ) 
         return -EINVAL;
 
+    if ( hvm_funcs.process_isr )
+        hvm_funcs.process_isr(vlapic_find_highest_isr(s), v);
+
     vlapic_adjust_i8259_target(d);
     lapic_rearm(s);
     return 0;
--- a/xen/arch/x86/hvm/vmx/intr.c
+++ b/xen/arch/x86/hvm/vmx/intr.c
@@ -290,8 +290,8 @@ void vmx_intr_assist(void)
             vmx_set_eoi_exit_bitmap(v, pt_vector);
 
         /* we need update the RVI field */
-        status &= ~(unsigned long)0x0FF;
-        status |= (unsigned long)0x0FF &
+        status &= ~VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK;
+        status |= VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK &
                     intack.vector;
         __vmwrite(GUEST_INTR_STATUS, status);
         if (v->arch.hvm_vmx.eoi_exitmap_changed) {
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1520,6 +1520,29 @@ static int vmx_virtual_intr_delivery_ena
     return cpu_has_vmx_virtual_intr_delivery;
 }
 
+static void vmx_process_isr(int isr, struct vcpu *v)
+{
+    unsigned long status;
+    u8 old;
+
+    if ( !cpu_has_vmx_virtual_intr_delivery )
+        return;
+
+    if ( isr < 0 )
+        isr = 0;
+
+    vmx_vmcs_enter(v);
+    status = __vmread(GUEST_INTR_STATUS);
+    old = status >> VMX_GUEST_INTR_STATUS_SVI_OFFSET;
+    if ( isr != old )
+    {
+        status &= VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK;
+        status |= isr << VMX_GUEST_INTR_STATUS_SVI_OFFSET;
+        __vmwrite(GUEST_INTR_STATUS, status);
+    }
+    vmx_vmcs_exit(v);
+}
+
 static struct hvm_function_table __read_mostly vmx_function_table = {
     .name                 = "VMX",
     .cpu_up_prepare       = vmx_cpu_up_prepare,
@@ -1568,7 +1591,8 @@ static struct hvm_function_table __read_
     .nhvm_intr_blocked    = nvmx_intr_blocked,
     .nhvm_domain_relinquish_resources = nvmx_domain_relinquish_resources,
     .update_eoi_exit_bitmap = vmx_update_eoi_exit_bitmap,
-    .virtual_intr_delivery_enabled = vmx_virtual_intr_delivery_enabled
+    .virtual_intr_delivery_enabled = vmx_virtual_intr_delivery_enabled,
+    .process_isr          = vmx_process_isr,
 };
 
 struct hvm_function_table * __init start_vmx(void)
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -184,6 +184,7 @@ struct hvm_function_table {
     /* Virtual interrupt delivery */
     void (*update_eoi_exit_bitmap)(struct vcpu *v, u8 vector, u8 trig);
     int (*virtual_intr_delivery_enabled)(void);
+    void (*process_isr)(int isr, struct vcpu *v);
 };
 
 extern struct hvm_function_table hvm_funcs;
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -246,6 +246,10 @@ extern bool_t cpu_has_vmx_ins_outs_instr
 #define VMX_INTR_SHADOW_SMI             0x00000004
 #define VMX_INTR_SHADOW_NMI             0x00000008
 
+/* Guest interrupt status */
+#define VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK  0x0FF
+#define VMX_GUEST_INTR_STATUS_SVI_OFFSET        8
+
 /* VMCS field encodings. */
 enum vmcs_field {
     VIRTUAL_PROCESSOR_ID            = 0x00000000,