[Xen-changelog] [xen staging] x86/vvmx: fix VM_EXIT_ACK_INTR_ON_EXIT handling

[patchbot@xxxxxxx]

commit a8effbffe586f020e2db400e2c25ae52e36cc1bd
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Wed Feb 5 13:50:09 2020 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Feb 5 13:50:09 2020 +0100

    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@xxxxxxxxxx>
    Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vvmx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 3d97a293b2..47eee1e5b9 100644
--- 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 &&
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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