[Xen-changelog] [xen master] x86/nhvm: properly clean up after failure to set up all vCPU-s

[patchbot@xxxxxxx]

commit 17281aea1a9a10f1ee165c6e6a2921a67b7b1df2
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Feb 22 11:21:38 2013 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Feb 22 11:21:38 2013 +0100

    x86/nhvm: properly clean up after failure to set up all vCPU-s
    
    Otherwise we may leak memory when setting up nHVM fails half way.
    
    This implies that the individual destroy functions will have to remain
    capable (in the VMX case they first need to be made so, following
    26486:7648ef657fe7 and 26489:83a3fa9c8434) of being called for a vCPU
    that the corresponding init function was never run on.
    
    Once at it, also remove a redundant check from the corresponding
    parameter validation code.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Tim Deegan <tim@xxxxxxx>
    Tested-by: Olaf Hering <olaf@xxxxxxxxx>
---
 xen/arch/x86/hvm/hvm.c       |    8 +++++---
 xen/arch/x86/hvm/nestedhvm.c |    2 +-
 xen/arch/x86/hvm/vmx/vvmx.c  |   30 ++++++++++++++++--------------
 3 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index febbffb..ea7adf6 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3918,18 +3918,20 @@ long do_hvm_op(unsigned long op, 
XEN_GUEST_HANDLE_PARAM(void) arg)
                 }
                 if ( a.value > 1 )
                     rc = -EINVAL;
-                if ( !is_hvm_domain(d) )
-                    rc = -EINVAL;
                 /* Remove the check below once we have
                  * shadow-on-shadow.
                  */
                 if ( cpu_has_svm && !paging_mode_hap(d) && a.value )
                     rc = -EINVAL;
                 /* Set up NHVM state for any vcpus that are already up */
-                if ( !d->arch.hvm_domain.params[HVM_PARAM_NESTEDHVM] )
+                if ( a.value &&
+                     !d->arch.hvm_domain.params[HVM_PARAM_NESTEDHVM] )
                     for_each_vcpu(d, v)
                         if ( rc == 0 )
                             rc = nestedhvm_vcpu_initialise(v);
+                if ( !a.value || rc )
+                    for_each_vcpu(d, v)
+                        nestedhvm_vcpu_destroy(v);
                 break;
             case HVM_PARAM_BUFIOREQ_EVTCHN:
                 rc = -EINVAL;
diff --git a/xen/arch/x86/hvm/nestedhvm.c b/xen/arch/x86/hvm/nestedhvm.c
index b3cf07d..964f58f 100644
--- a/xen/arch/x86/hvm/nestedhvm.c
+++ b/xen/arch/x86/hvm/nestedhvm.c
@@ -87,7 +87,7 @@ nestedhvm_vcpu_initialise(struct vcpu *v)
 void
 nestedhvm_vcpu_destroy(struct vcpu *v)
 {
-    if ( nestedhvm_enabled(v->domain) && hvm_funcs.nhvm_vcpu_destroy )
+    if ( hvm_funcs.nhvm_vcpu_destroy )
         hvm_funcs.nhvm_vcpu_destroy(v);
 }
 
diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 4f3f94d..bb7688f 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -62,7 +62,7 @@ int nvmx_vcpu_initialise(struct vcpu *v)
     if ( !nvcpu->nv_n2vmcx )
     {
         gdprintk(XENLOG_ERR, "nest: allocation for shadow vmcs failed\n");
-       goto out;
+        return -ENOMEM;
     }
 
     /* non-root VMREAD/VMWRITE bitmap. */
@@ -75,7 +75,7 @@ int nvmx_vcpu_initialise(struct vcpu *v)
         if ( !vmread_bitmap )
         {
             gdprintk(XENLOG_ERR, "nest: allocation for vmread bitmap 
failed\n");
-            goto out1;
+            return -ENOMEM;
         }
         v->arch.hvm_vmx.vmread_bitmap = vmread_bitmap;
 
@@ -83,7 +83,7 @@ int nvmx_vcpu_initialise(struct vcpu *v)
         if ( !vmwrite_bitmap )
         {
             gdprintk(XENLOG_ERR, "nest: allocation for vmwrite bitmap 
failed\n");
-            goto out2;
+            return -ENOMEM;
         }
         v->arch.hvm_vmx.vmwrite_bitmap = vmwrite_bitmap;
 
@@ -118,12 +118,6 @@ int nvmx_vcpu_initialise(struct vcpu *v)
     nvmx->msrbitmap = NULL;
     INIT_LIST_HEAD(&nvmx->launched_list);
     return 0;
-out2:
-    free_domheap_page(v->arch.hvm_vmx.vmread_bitmap);
-out1:
-    free_xenheap_page(nvcpu->nv_n2vmcx);
-out:
-    return -ENOMEM;
 }
  
 void nvmx_vcpu_destroy(struct vcpu *v)
@@ -147,16 +141,24 @@ void nvmx_vcpu_destroy(struct vcpu *v)
         nvcpu->nv_n2vmcx = NULL;
     }
 
-    list_for_each_entry_safe(item, n, &nvmx->launched_list, node)
-    {
-        list_del(&item->node);
-        xfree(item);
-    }
+    /* Must also cope with nvmx_vcpu_initialise() not having got called. */
+    if ( nvmx->launched_list.next )
+        list_for_each_entry_safe(item, n, &nvmx->launched_list, node)
+        {
+            list_del(&item->node);
+            xfree(item);
+        }
 
     if ( v->arch.hvm_vmx.vmread_bitmap )
+    {
         free_domheap_page(v->arch.hvm_vmx.vmread_bitmap);
+        v->arch.hvm_vmx.vmread_bitmap = NULL;
+    }
     if ( v->arch.hvm_vmx.vmwrite_bitmap )
+    {
         free_domheap_page(v->arch.hvm_vmx.vmwrite_bitmap);
+        v->arch.hvm_vmx.vmwrite_bitmap = NULL;
+    }
 }
  
 void nvmx_domain_relinquish_resources(struct domain *d)
--
generated by git-patchbot for /home/xen/git/xen.git#master

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