[Xen-devel] [PATCH 1/3] x86/svm: update VGIF support

[Brian Woods <brian.woods@xxxxxxx>]

There are places where the GIF value is checked.  A guest with VGIF
enabled can change the GIF value without the host being involved,
therefore it needs to check the GIF value in the VMCB rather the one in
the nestedsvm struct.

Signed-off-by: Brian Woods <brian.woods@xxxxxxx>
---
 xen/arch/x86/hvm/svm/nestedsvm.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index b6f6449d75..1f7b0d3e88 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -800,8 +800,13 @@ nsvm_vcpu_vmexit_inject(struct vcpu *v, struct 
cpu_user_regs *regs,
     struct nestedvcpu *nv = &vcpu_nestedhvm(v);
     struct nestedsvm *svm = &vcpu_nestedsvm(v);
     struct vmcb_struct *ns_vmcb;
+    struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb;
+
+    if ( vmcb->_vintr.fields.vgif_enable )
+        ASSERT(vmcb->_vintr.fields.vgif == 0);
+    else
+        ASSERT(svm->ns_gif == 0);
 
-    ASSERT(svm->ns_gif == 0);
     ns_vmcb = nv->nv_vvmcx;
 
     if (nv->nv_vmexit_pending) {
@@ -1343,8 +1348,13 @@ nestedsvm_vmexit_defer(struct vcpu *v,
     uint64_t exitcode, uint64_t exitinfo1, uint64_t exitinfo2)
 {
     struct nestedsvm *svm = &vcpu_nestedsvm(v);
+    struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb;
+
+    if ( vmcb->_vintr.fields.vgif_enable )
+        vmcb->_vintr.fields.vgif = 0;
+    else
+        nestedsvm_vcpu_clgi(v);
 
-    nestedsvm_vcpu_clgi(v);
     svm->ns_vmexit.exitcode = exitcode;
     svm->ns_vmexit.exitinfo1 = exitinfo1;
     svm->ns_vmexit.exitinfo2 = exitinfo2;
-- 
2.11.0


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