[Xen-changelog] [xen master] x86: skip further initialization for idle domains

[patchbot@xxxxxxx]

commit e5f317bda12a99d72e80f1fd639a53e36d377c44
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Jan 28 16:38:20 2015 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Jan 28 16:38:20 2015 +0100

    x86: skip further initialization for idle domains
    
    While in the end not really found necessary, early versions of the
    patches to follow pointed out that we needlessly set up paging for idle
    domains. Arranging for that to be skipped made me notice that we can at
    once skip vMCE setup for them. Leverage to adjustment to further
    re-arrange the way FPU setup gets skipped.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/domain.c |   19 +++++++++++--------
 xen/arch/x86/i387.c   |   10 +---------
 2 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 50b361b..cfe7945 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -427,12 +427,15 @@ int vcpu_initialise(struct vcpu *v)
     if ( rc )
         return rc;
 
-    paging_vcpu_init(v);
+    if ( !is_idle_domain(d) )
+    {
+        paging_vcpu_init(v);
 
-    if ( (rc = vcpu_init_fpu(v)) != 0 )
-        return rc;
+        if ( (rc = vcpu_init_fpu(v)) != 0 )
+            return rc;
 
-    vmce_init_vcpu(v);
+        vmce_init_vcpu(v);
+    }
 
     if ( has_hvm_container_domain(d) )
     {
@@ -559,12 +562,12 @@ int arch_domain_create(struct domain *d, unsigned int 
domcr_flags)
     HYPERVISOR_COMPAT_VIRT_START(d) =
         is_pv_domain(d) ? __HYPERVISOR_COMPAT_VIRT_START : ~0u;
 
-    if ( (rc = paging_domain_init(d, domcr_flags)) != 0 )
-        goto fail;
-    paging_initialised = 1;
-
     if ( !is_idle_domain(d) )
     {
+        if ( (rc = paging_domain_init(d, domcr_flags)) != 0 )
+            goto fail;
+        paging_initialised = 1;
+
         d->arch.cpuids = xmalloc_array(cpuid_input_t, MAX_CPUID_INPUT);
         rc = -ENOMEM;
         if ( d->arch.cpuids == NULL )
diff --git a/xen/arch/x86/i387.c b/xen/arch/x86/i387.c
index a372e0b..14f2a79 100644
--- a/xen/arch/x86/i387.c
+++ b/xen/arch/x86/i387.c
@@ -303,12 +303,8 @@ void save_fpu_enable(void)
 /* Initialize FPU's context save area */
 int vcpu_init_fpu(struct vcpu *v)
 {
-    int rc = 0;
+    int rc;
     
-    /* Idle domain doesn't have FPU state allocated */
-    if ( is_idle_vcpu(v) )
-        goto done;
-
     if ( (rc = xstate_alloc_save_area(v)) != 0 )
         return rc;
 
@@ -318,13 +314,9 @@ int vcpu_init_fpu(struct vcpu *v)
     {
         v->arch.fpu_ctxt = _xzalloc(sizeof(v->arch.xsave_area->fpu_sse), 16);
         if ( !v->arch.fpu_ctxt )
-        {
             rc = -ENOMEM;
-            goto done;
-        }
     }
 
-done:
     return rc;
 }
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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