[PATCH v1 6/6] nestedsvm: Allow destroying the domain fully

[Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>]

Unmapping the virtual VMCB is performed near the end of the domain
destroy procedure but the mapped guest frame prevents domain destroy
from getting to that point. This means guests that call VMRUN cannot
be fully destroyed.

Move the unmap of the virtual VMCB earlier to fix the issue.

Fixes: bcf557675d85 ("x86: properly use map_domain_page() in nested HVM code")
Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
---
 xen/arch/x86/hvm/svm/nestedhvm.h |  1 +
 xen/arch/x86/hvm/svm/nestedsvm.c | 15 +++++++++++++--
 xen/arch/x86/hvm/svm/svm.c       |  1 +
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/svm/nestedhvm.h b/xen/arch/x86/hvm/svm/nestedhvm.h
index 9bfed5ffd71b..9bb04a043430 100644
--- a/xen/arch/x86/hvm/svm/nestedhvm.h
+++ b/xen/arch/x86/hvm/svm/nestedhvm.h
@@ -48,6 +48,7 @@ bool cf_check nsvm_vmcb_guest_intercepts_event(
     struct vcpu *v, unsigned int vector, int errcode);
 bool cf_check nsvm_vmcb_hap_enabled(struct vcpu *v);
 enum hvm_intblk cf_check nsvm_intr_blocked(struct vcpu *v);
+void cf_check nsvm_domain_relinquish_resources(struct domain *d);
 
 /* Interrupts, vGIF */
 void svm_vmexit_do_clgi(struct cpu_user_regs *regs, struct vcpu *v);
diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index d4fd838ca0b6..6f4684f5c21b 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -110,8 +110,6 @@ void cf_check nsvm_vcpu_destroy(struct vcpu *v)
         svm->ns_merged_msrpm = NULL;
     }
 
-    hvm_unmap_guest_frame(nv->nv_vvmcx, 1);
-    nv->nv_vvmcx = NULL;
     if ( nv->nv_n2vmcx )
     {
         free_vmcb(nv->nv_n2vmcx);
@@ -122,6 +120,19 @@ void cf_check nsvm_vcpu_destroy(struct vcpu *v)
     svm->ns_iomap = NULL;
 }
 
+void cf_check nsvm_domain_relinquish_resources(struct domain *d)
+{
+    struct vcpu *v;
+    struct nestedvcpu *nv;
+
+    for_each_vcpu ( d, v )
+    {
+        nv = &vcpu_nestedhvm(v);
+        hvm_unmap_guest_frame(nv->nv_vvmcx, 1);
+        nv->nv_vvmcx = NULL;
+    }
+}
+
 int cf_check nsvm_vcpu_reset(struct vcpu *v)
 {
     struct nestedsvm *svm = &vcpu_nestedsvm(v);
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 209edcba321a..e6b5c9ec3b9c 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2422,6 +2422,7 @@ static struct hvm_function_table __initdata_cf_clobber 
svm_function_table = {
     .nhvm_vmcx_hap_enabled = nsvm_vmcb_hap_enabled,
     .nhvm_intr_blocked = nsvm_intr_blocked,
     .nhvm_hap_walk_L1_p2m = nsvm_hap_walk_L1_p2m,
+    .nhvm_domain_relinquish_resources = nsvm_domain_relinquish_resources,
 
     .get_reg = svm_get_reg,
     .set_reg = svm_set_reg,
-- 
2.53.0