[PATCH] xen/x86: Don't unconditionally touch the hvm_domain union during domain construction

[PATCH] xen/x86: Don't unconditionally touch the hvm_domain union during domain construction

[Andrew Cooper]

It may not be the appropriate half to touch.

Drop the superfluous mem_sharing_enabled assignment, and move the hap_enabled
assignment to a suitable conditional before it is actually needed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <JBeulich@suse.com>
---
 xen/arch/x86/domain.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 1f1550e..6e9464c 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -513,12 +513,6 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
     int i, paging_initialised = 0;
     int rc = -ENOMEM;
 
-    d->arch.hvm_domain.hap_enabled =
-        has_hvm_container_domain(d) &&
-        hvm_funcs.hap_supported &&
-        (domcr_flags & DOMCRF_hap);
-    d->arch.hvm_domain.mem_sharing_enabled = 0;
-
     d->arch.s3_integrity = !!(domcr_flags & DOMCRF_s3_integrity);
 
     INIT_LIST_HEAD(&d->arch.pdev_list);
@@ -541,7 +535,12 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
     }
 
     if ( has_hvm_container_domain(d) )
+    {
+        d->arch.hvm_domain.hap_enabled =
+            hvm_funcs.hap_supported && (domcr_flags & DOMCRF_hap);
+
         rc = create_perdomain_mapping(d, PERDOMAIN_VIRT_START, 0, NULL, NULL);
+    }
     else if ( is_idle_domain(d) )
         rc = 0;
     else
-- 
1.7.10.4

Re: [PATCH] xen/x86: Don't unconditionally touch the hvm_domain union during domain construction

[Don Slutz]

On 05/19/15 16:12, Andrew Cooper wrote:
> It may not be the appropriate half to touch.
> 
> Drop the superfluous mem_sharing_enabled assignment, and move the hap_enabled
> assignment to a suitable conditional before it is actually needed.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> CC: Keir Fraser <keir@xen.org>
> CC: Jan Beulich <JBeulich@suse.com>
> ---
>  xen/arch/x86/domain.c |   11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index 1f1550e..6e9464c 100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -513,12 +513,6 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
>      int i, paging_initialised = 0;
>      int rc = -ENOMEM;
>  
> -    d->arch.hvm_domain.hap_enabled =
> -        has_hvm_container_domain(d) &&
> -        hvm_funcs.hap_supported &&
> -        (domcr_flags & DOMCRF_hap);
> -    d->arch.hvm_domain.mem_sharing_enabled = 0;
> -
>      d->arch.s3_integrity = !!(domcr_flags & DOMCRF_s3_integrity);
>  
>      INIT_LIST_HEAD(&d->arch.pdev_list);
> @@ -541,7 +535,12 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
>      }
>  
>      if ( has_hvm_container_domain(d) )
> +    {
> +        d->arch.hvm_domain.hap_enabled =
> +            hvm_funcs.hap_supported && (domcr_flags & DOMCRF_hap);
> +
>          rc = create_perdomain_mapping(d, PERDOMAIN_VIRT_START, 0, NULL, NULL);
> +    }
>      else if ( is_idle_domain(d) )
>          rc = 0;
>      else
> 

Looks good to me.

Reviewed-by: Don Slutz <dslutz@verizon.com>

   -Don Slutz