[v6,01/11] x86/hypervisor: make hypervisor_ap_setup return an error code

Commit Message

Wei Liu Jan. 31, 2020, 5:49 p.m. UTC

We want to be able to handle AP setup error in the upper layer.

Signed-off-by: Wei Liu <[e-mail]>
---
v6:
1. Change map_vcpuinfo as well
2. Make code shorter
---
 xen/arch/x86/guest/hypervisor.c        |  6 ++++--
 xen/arch/x86/guest/xen/xen.c           | 24 +++++++++++++++---------
 xen/include/asm-x86/guest/hypervisor.h |  6 +++---
 3 files changed, 22 insertions(+), 14 deletions(-)

Comments

Jan Beulich Feb. 3, 2020, 12:56 p.m. UTC | #1

On 31.01.2020 18:49, Wei Liu wrote:
> We want to be able to handle AP setup error in the upper layer.
> 
> Signed-off-by: Wei Liu <[e-mail]>
> ---
> v6:
> 1. Change map_vcpuinfo as well

And by implication then ...

> @@ -257,11 +257,17 @@ static void __init setup(void)
>      init_evtchn();
>  }
>  
> -static void ap_setup(void)
> +static int ap_setup(void)
>  {
> +    int rc;
> +
>      set_vcpu_id();
> -    map_vcpuinfo();
> -    init_evtchn();
> +    rc = map_vcpuinfo();
> +
> +    if ( !rc )
> +        init_evtchn();

... init_evtchn() as well?

Jan

Wei Liu Feb. 3, 2020, 1:58 p.m. UTC | #2

On Mon, Feb 03, 2020 at 01:56:48PM +0100, Jan Beulich wrote:
> On 31.01.2020 18:49, Wei Liu wrote:
> > We want to be able to handle AP setup error in the upper layer.
> > 
> > Signed-off-by: Wei Liu <[e-mail]>
> > ---
> > v6:
> > 1. Change map_vcpuinfo as well
> 
> And by implication then ...
> 
> > @@ -257,11 +257,17 @@ static void __init setup(void)
> >      init_evtchn();
> >  }
> >  
> > -static void ap_setup(void)
> > +static int ap_setup(void)
> >  {
> > +    int rc;
> > +
> >      set_vcpu_id();
> > -    map_vcpuinfo();
> > -    init_evtchn();
> > +    rc = map_vcpuinfo();
> > +
> > +    if ( !rc )
> > +        init_evtchn();
> 
> ... init_evtchn() as well?

OK. I can change that too.

Wei.

> 
> Jan

Patch

diff --git a/xen/arch/x86/guest/hypervisor.c b/xen/arch/x86/guest/hypervisor.c
index 4f27b98740..e72c92ffdf 100644
--- a/xen/arch/x86/guest/hypervisor.c
+++ b/xen/arch/x86/guest/hypervisor.c
@@ -52,10 +52,12 @@  void __init hypervisor_setup(void)
         ops->setup();
 }
 
-void hypervisor_ap_setup(void)
+int hypervisor_ap_setup(void)
 {
     if ( ops && ops->ap_setup )
-        ops->ap_setup();
+        return ops->ap_setup();
+
+    return 0;
 }
 
 void hypervisor_resume(void)
diff --git a/xen/arch/x86/guest/xen/xen.c b/xen/arch/x86/guest/xen/xen.c
index 6dbc5f953f..d50f86bae7 100644
--- a/xen/arch/x86/guest/xen/xen.c
+++ b/xen/arch/x86/guest/xen/xen.c
@@ -113,16 +113,16 @@  static int map_vcpuinfo(void)
     info.mfn = virt_to_mfn(&vcpu_info[vcpu]);
     info.offset = (unsigned long)&vcpu_info[vcpu] & ~PAGE_MASK;
     rc = xen_hypercall_vcpu_op(VCPUOP_register_vcpu_info, vcpu, &info);
-    if ( rc )
-    {
-        BUG_ON(vcpu >= XEN_LEGACY_MAX_VCPUS);
-        this_cpu(vcpu_info) = &XEN_shared_info->vcpu_info[vcpu];
-    }
-    else
+    if ( !rc )
     {
         this_cpu(vcpu_info) = &vcpu_info[vcpu];
         set_bit(vcpu, vcpu_info_mapped);
     }
+    else if ( vcpu < XEN_LEGACY_MAX_VCPUS )
+    {
+        rc = 0;
+        this_cpu(vcpu_info) = &XEN_shared_info->vcpu_info[vcpu];
+    }
 
     return rc;
 }
@@ -257,11 +257,17 @@  static void __init setup(void)
     init_evtchn();
 }
 
-static void ap_setup(void)
+static int ap_setup(void)
 {
+    int rc;
+
     set_vcpu_id();
-    map_vcpuinfo();
-    init_evtchn();
+    rc = map_vcpuinfo();
+
+    if ( !rc )
+        init_evtchn();
+
+    return rc;
 }
 
 int xg_alloc_unused_page(mfn_t *mfn)
diff --git a/xen/include/asm-x86/guest/hypervisor.h b/xen/include/asm-x86/guest/hypervisor.h
index 392f4b90ae..b503854c5b 100644
--- a/xen/include/asm-x86/guest/hypervisor.h
+++ b/xen/include/asm-x86/guest/hypervisor.h
@@ -25,7 +25,7 @@  struct hypervisor_ops {
     /* Main setup routine */
     void (*setup)(void);
     /* AP setup */
-    void (*ap_setup)(void);
+    int (*ap_setup)(void);
     /* Resume from suspension */
     void (*resume)(void);
 };
@@ -34,7 +34,7 @@  struct hypervisor_ops {
 
 const char *hypervisor_probe(void);
 void hypervisor_setup(void);
-void hypervisor_ap_setup(void);
+int hypervisor_ap_setup(void);
 void hypervisor_resume(void);
 
 #else
@@ -44,7 +44,7 @@  void hypervisor_resume(void);
 
 static inline const char *hypervisor_probe(void) { return NULL; }
 static inline void hypervisor_setup(void) { ASSERT_UNREACHABLE(); }
-static inline void hypervisor_ap_setup(void) { ASSERT_UNREACHABLE(); }
+static inline int hypervisor_ap_setup(void) { ASSERT_UNREACHABLE(); return 0; }
 static inline void hypervisor_resume(void) { ASSERT_UNREACHABLE(); }
 
 #endif  /* CONFIG_GUEST */