[PATCH Altp2m cleanup v6] Cleaning up altp2m code

[PATCH Altp2m cleanup v6] Cleaning up altp2m code

[Paul Lai]

Altp2m cleanup work

The altp2m clean work is motivated by the following URLs:
   https://lists.xenproject.org/archives/html/xen-devel/2015-07/msg04323.html

Most of the work has been:
Lots of white space, indentation, and other coding style preference
corrections.
Lots of function return type corrections (and checking).
Better sanity checking of values before processing in do_altp2m_op().
Using 'bool' instead of 'bool_t' for stronger checking.

Paul Lai (1):
  altp2m cleanup work.

 xen/arch/x86/hvm/hvm.c        | 47 ++++++++++++++++++++-----------------------
 xen/include/asm-x86/hvm/hvm.h | 26 +++++++++++++++++++-----
 2 files changed, 43 insertions(+), 30 deletions(-)

-- 
2.7.4


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[PATCH Altp2m cleanup v6] altp2m cleanup work.

[Paul Lai]

Indent goto labels by one space.
Inline (header) altp2m functions.
In do_altp2m_op(), during the sanity check of the passed command,
return -ENONSYS if not a valid command.
In do_altp2m_op(), when evaluating a command, ASSERT_UNREACHABLE()
if the command is not recognizable.  The sanity check above should
have triggered the return of -ENOSYS.

Changes since last version:

Fixing fall through in switch statement above ASSERT_UNREACHABLE() (in
do_altp2m_op()).
Make hvm_funcs.altp2m_supported "bool" instead of "bool_t".
Make hvm_altp2m_supported() and altp2m_vcpu_emulate_ve() return
bool (rather than return void()).

Signed-off-by: Paul Lai <paul.c.lai@intel.com>
---
 xen/arch/x86/hvm/hvm.c        | 47 ++++++++++++++++++++-----------------------
 xen/include/asm-x86/hvm/hvm.h | 26 +++++++++++++++++++-----
 2 files changed, 43 insertions(+), 30 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 7bad845..3a4ea56 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1959,11 +1959,11 @@ int hvm_hap_nested_page_fault(paddr_t gpa, unsigned long gla,
      * Otherwise, this is an error condition. */
     rc = fall_through;
 
-out_put_gfn:
+ out_put_gfn:
     __put_gfn(p2m, gfn);
     if ( ap2m_active )
         __put_gfn(hostp2m, gfn);
-out:
+ out:
     /* All of these are delayed until we exit, since we might 
      * sleep on event ring wait queues, and we must not hold
      * locks in such circumstance */
@@ -5308,12 +5308,25 @@ static int do_altp2m_op(
         return -EFAULT;
 
     if ( a.pad1 || a.pad2 ||
-         (a.version != HVMOP_ALTP2M_INTERFACE_VERSION) ||
-         (a.cmd < HVMOP_altp2m_get_domain_state) ||
-         (a.cmd > HVMOP_altp2m_change_gfn) )
+        (a.version != HVMOP_ALTP2M_INTERFACE_VERSION) )
         return -EINVAL;
 
-    d = (a.cmd != HVMOP_altp2m_vcpu_enable_notify) ?
+    switch ( a.cmd )
+    {
+    case HVMOP_altp2m_get_domain_state:
+    case HVMOP_altp2m_set_domain_state:
+    case HVMOP_altp2m_vcpu_enable_notify:
+    case HVMOP_altp2m_create_p2m:
+    case HVMOP_altp2m_destroy_p2m:
+    case HVMOP_altp2m_switch_p2m:
+    case HVMOP_altp2m_set_mem_access:
+    case HVMOP_altp2m_change_gfn:
+        break;
+    default:
+        return -ENOSYS;
+    }
+
+    d = ( a.cmd != HVMOP_altp2m_vcpu_enable_notify ) ?
         rcu_lock_domain_by_any_id(a.domain) : rcu_lock_current_domain();
 
     if ( d == NULL )
@@ -5430,6 +5443,9 @@ static int do_altp2m_op(
             rc = p2m_change_altp2m_gfn(d, a.u.change_gfn.view,
                     _gfn(a.u.change_gfn.old_gfn),
                     _gfn(a.u.change_gfn.new_gfn));
+        break;
+    default:
+        ASSERT_UNREACHABLE();
     }
 
  out:
@@ -5954,25 +5970,6 @@ void hvm_toggle_singlestep(struct vcpu *v)
     v->arch.hvm_vcpu.single_step = !v->arch.hvm_vcpu.single_step;
 }
 
-void altp2m_vcpu_update_p2m(struct vcpu *v)
-{
-    if ( hvm_funcs.altp2m_vcpu_update_p2m )
-        hvm_funcs.altp2m_vcpu_update_p2m(v);
-}
-
-void altp2m_vcpu_update_vmfunc_ve(struct vcpu *v)
-{
-    if ( hvm_funcs.altp2m_vcpu_update_vmfunc_ve )
-        hvm_funcs.altp2m_vcpu_update_vmfunc_ve(v);
-}
-
-bool_t altp2m_vcpu_emulate_ve(struct vcpu *v)
-{
-    if ( hvm_funcs.altp2m_vcpu_emulate_ve )
-        return hvm_funcs.altp2m_vcpu_emulate_ve(v);
-    return 0;
-}
-
 int hvm_set_mode(struct vcpu *v, int mode)
 {
 
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 81b60d5..b1be6bd 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -100,7 +100,7 @@ struct hvm_function_table {
     bool_t pvh_supported;
 
     /* Necessary hardware support for alternate p2m's? */
-    bool_t altp2m_supported;
+    bool altp2m_supported;
 
     /* Indicate HAP capabilities. */
     unsigned int hap_capabilities;
@@ -593,19 +593,35 @@ static inline bool_t hvm_is_singlestep_supported(void)
 }
 
 /* returns true if hardware supports alternate p2m's */
-static inline bool_t hvm_altp2m_supported(void)
+static inline bool hvm_altp2m_supported(void)
 {
     return hvm_funcs.altp2m_supported;
 }
 
 /* updates the current hardware p2m */
-void altp2m_vcpu_update_p2m(struct vcpu *v);
+static inline void altp2m_vcpu_update_p2m(struct vcpu *v)
+{
+    if ( hvm_funcs.altp2m_vcpu_update_p2m )
+        hvm_funcs.altp2m_vcpu_update_p2m(v);
+}
 
 /* updates VMCS fields related to VMFUNC and #VE */
-void altp2m_vcpu_update_vmfunc_ve(struct vcpu *v);
+static inline void altp2m_vcpu_update_vmfunc_ve(struct vcpu *v)
+{
+    if ( hvm_funcs.altp2m_vcpu_update_vmfunc_ve )
+        hvm_funcs.altp2m_vcpu_update_vmfunc_ve(v);
+}
 
 /* emulates #VE */
-bool_t altp2m_vcpu_emulate_ve(struct vcpu *v);
+static inline bool altp2m_vcpu_emulate_ve(struct vcpu *v)
+{
+    if ( hvm_funcs.altp2m_vcpu_emulate_ve )
+    {
+        hvm_funcs.altp2m_vcpu_emulate_ve(v);
+        return true;
+    }
+    return false;
+}
 
 /* Check CR4/EFER values */
 const char *hvm_efer_valid(const struct vcpu *v, uint64_t value,
-- 
2.7.4


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Re: [PATCH Altp2m cleanup v6] altp2m cleanup work.

[Jan Beulich]

>>> On 26.09.16 at 19:52, <paul.c.lai@intel.com> wrote:
> Indent goto labels by one space.
> Inline (header) altp2m functions.
> In do_altp2m_op(), during the sanity check of the passed command,
> return -ENONSYS if not a valid command.
> In do_altp2m_op(), when evaluating a command, ASSERT_UNREACHABLE()
> if the command is not recognizable.  The sanity check above should
> have triggered the return of -ENOSYS.
> 
> Changes since last version:
> 
> Fixing fall through in switch statement above ASSERT_UNREACHABLE() (in
> do_altp2m_op()).
> Make hvm_funcs.altp2m_supported "bool" instead of "bool_t".
> Make hvm_altp2m_supported() and altp2m_vcpu_emulate_ve() return
> bool (rather than return void()).

This changes section belongs ...

> Signed-off-by: Paul Lai <paul.c.lai@intel.com>
> ---

... here, as it shouldn't end up in the commit message.

> @@ -5308,12 +5308,25 @@ static int do_altp2m_op(
>          return -EFAULT;
>  
>      if ( a.pad1 || a.pad2 ||
> -         (a.version != HVMOP_ALTP2M_INTERFACE_VERSION) ||
> -         (a.cmd < HVMOP_altp2m_get_domain_state) ||
> -         (a.cmd > HVMOP_altp2m_change_gfn) )
> +        (a.version != HVMOP_ALTP2M_INTERFACE_VERSION) )
>          return -EINVAL;
>  
> -    d = (a.cmd != HVMOP_altp2m_vcpu_enable_notify) ?
> +    switch ( a.cmd )
> +    {
> +    case HVMOP_altp2m_get_domain_state:
> +    case HVMOP_altp2m_set_domain_state:
> +    case HVMOP_altp2m_vcpu_enable_notify:
> +    case HVMOP_altp2m_create_p2m:
> +    case HVMOP_altp2m_destroy_p2m:
> +    case HVMOP_altp2m_switch_p2m:
> +    case HVMOP_altp2m_set_mem_access:
> +    case HVMOP_altp2m_change_gfn:
> +        break;
> +    default:
> +        return -ENOSYS;

Quite recently a patch went in to eliminate such bogus -ENOSYS
instances. Please use -EOPNOTSUPP instead.

With that corrected,
Acked-by: Jan Beulich <jbeulich@suse.com>

Jan


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