x86/vvmx: fix VM_EXIT_ACK_INTR_ON_EXIT handling

When VM_EXIT_ACK_INTR_ON_EXIT is clear in the vmexit control vmcs
register the bit 31 of VM_EXIT_INTR_INFO must be 0, in order to denote
that the field doesn't contain any interrupt information. This is not
currently acknowledged as the field always get filled with valid
interrupt information, regardless of whether VM_EXIT_ACK_INTR_ON_EXIT
is set.

Fix this and only fill VM_EXIT_INTR_INFO when VM_EXIT_ACK_INTR_ON_EXIT
is set. Note that this requires one minor change in
nvmx_update_apicv in order to obtain the interrupt information from
the internal state rather than the nested vmcs register.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 3d97a293b249e134d51c097a0b6706cde3cad19c..47eee1e5b9ab3f97687dc50c53b7860710b4ad99 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -1283,6 +1283,7 @@ static void load_vvmcs_host_state(struct vcpu *v)
 static void sync_exception_state(struct vcpu *v)
 {
     struct nestedvmx *nvmx = &vcpu_2_nvmx(v);
+    uint32_t exit_ctrl = get_vvmcs(v, VM_EXIT_CONTROLS);
 
     if ( !(nvmx->intr.intr_info & INTR_INFO_VALID_MASK) )
         return;
@@ -1294,7 +1295,8 @@ static void sync_exception_state(struct vcpu *v)
         set_vvmcs(v, VM_EXIT_REASON, EXIT_REASON_EXTERNAL_INTERRUPT);
         set_vvmcs(v, EXIT_QUALIFICATION, 0);
         set_vvmcs(v, VM_EXIT_INTR_INFO,
-                    nvmx->intr.intr_info);
+                  (exit_ctrl & VM_EXIT_ACK_INTR_ON_EXIT) ? nvmx->intr.intr_info
+                                                         : 0);
         break;
 
     case X86_EVENTTYPE_HW_EXCEPTION:
@@ -1320,7 +1322,7 @@ static void nvmx_update_apicv(struct vcpu *v)
 {
     struct nestedvmx *nvmx = &vcpu_2_nvmx(v);
     unsigned long reason = get_vvmcs(v, VM_EXIT_REASON);
-    uint32_t intr_info = get_vvmcs(v, VM_EXIT_INTR_INFO);
+    uint32_t intr_info = nvmx->intr.intr_info;
 
     if ( reason == EXIT_REASON_EXTERNAL_INTERRUPT &&
          nvmx->intr.source == hvm_intsrc_lapic &&