[XEN][PATCH 2/5] x86: hvm: compat: introduce vcpu_is_hcall_compat() helper

[Grygorii Strashko <grygorii_strashko@xxxxxxxx>]

From: Grygorii Strashko <grygorii_strashko@xxxxxxxx>

Introduce vcpu_is_hcall_compat() helper and use it instead of direct access
to struct vcpu->hcall_compat field in preparation for making HVM COMPAT
code optional.

Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
---
 xen/arch/x86/hvm/hvm.c       | 9 +++++----
 xen/arch/x86/hvm/hypercall.c | 6 +++---
 xen/arch/x86/hypercall.c     | 6 +-----
 xen/common/kernel.c          | 2 +-
 xen/include/xen/sched.h      | 9 +++++++++
 5 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 0c60faa39d7b..2e47a71714fd 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3500,7 +3500,7 @@ unsigned int copy_to_user_hvm(void *to, const void *from, 
unsigned int len)
 {
     int rc;
 
-    if ( current->hcall_compat && is_compat_arg_xlat_range(to, len) )
+    if ( vcpu_is_hcall_compat(current) && is_compat_arg_xlat_range(to, len) )
     {
         memcpy(to, from, len);
         return 0;
@@ -3514,7 +3514,7 @@ unsigned int clear_user_hvm(void *to, unsigned int len)
 {
     int rc;
 
-    if ( current->hcall_compat && is_compat_arg_xlat_range(to, len) )
+    if ( vcpu_is_hcall_compat(current) && is_compat_arg_xlat_range(to, len) )
     {
         memset(to, 0x00, len);
         return 0;
@@ -3529,7 +3529,7 @@ unsigned int copy_from_user_hvm(void *to, const void 
*from, unsigned int len)
 {
     int rc;
 
-    if ( current->hcall_compat && is_compat_arg_xlat_range(from, len) )
+    if ( vcpu_is_hcall_compat(current) && is_compat_arg_xlat_range(from, len) )
     {
         memcpy(to, from, len);
         return 0;
@@ -5214,7 +5214,8 @@ long do_hvm_op(unsigned long op, 
XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
 
     case HVMOP_altp2m:
-        rc = current->hcall_compat ? compat_altp2m_op(arg) : do_altp2m_op(arg);
+        rc = vcpu_is_hcall_compat(current) ? compat_altp2m_op(arg)
+                                           : do_altp2m_op(arg);
         break;
 
     default:
diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
index b254b3e2f7d6..549e25445e67 100644
--- a/xen/arch/x86/hvm/hypercall.c
+++ b/xen/arch/x86/hvm/hypercall.c
@@ -29,7 +29,7 @@ long hvm_memory_op(unsigned long cmd, 
XEN_GUEST_HANDLE_PARAM(void) arg)
         return -ENOSYS;
     }
 
-    if ( !current->hcall_compat )
+    if ( !vcpu_is_hcall_compat(current) )
         rc = do_memory_op(cmd, arg);
     else
         rc = compat_memory_op(cmd, arg);
@@ -57,7 +57,7 @@ long hvm_grant_table_op(
         return -ENOSYS;
     }
 
-    if ( !current->hcall_compat )
+    if ( !vcpu_is_hcall_compat(current) )
         return do_grant_table_op(cmd, uop, count);
     else
         return compat_grant_table_op(cmd, uop, count);
@@ -96,7 +96,7 @@ long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         return -ENOSYS;
     }
 
-    if ( !curr->hcall_compat )
+    if ( !vcpu_is_hcall_compat(curr) )
         return do_physdev_op(cmd, arg);
     else
         return compat_physdev_op(cmd, arg);
diff --git a/xen/arch/x86/hypercall.c b/xen/arch/x86/hypercall.c
index dc0a90ca0915..3a1a363d8648 100644
--- a/xen/arch/x86/hypercall.c
+++ b/xen/arch/x86/hypercall.c
@@ -53,11 +53,7 @@ unsigned long hypercall_create_continuation(
 
         regs->rax = op;
 
-#ifdef CONFIG_COMPAT
-        if ( !curr->hcall_compat )
-#else
-        if ( true )
-#endif
+        if ( !vcpu_is_hcall_compat(curr) )
         {
             for ( i = 0; *p != '\0'; i++ )
             {
diff --git a/xen/common/kernel.c b/xen/common/kernel.c
index e6979352e100..99be0fbb9d90 100644
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -615,7 +615,7 @@ long do_xen_version(int cmd, XEN_GUEST_HANDLE_PARAM(void) 
arg)
         const struct vcpu *curr = current;
 
 #ifdef CONFIG_COMPAT
-        if ( curr->hcall_compat )
+        if ( vcpu_is_hcall_compat(curr) )
         {
             compat_platform_parameters_t params = {
                 .virt_start = is_pv_vcpu(curr)
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 02bdc256ce37..e3ce427f0bd9 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -311,6 +311,15 @@ struct vcpu
 #endif
 };
 
+static inline bool vcpu_is_hcall_compat(const struct vcpu *v)
+{
+#ifdef CONFIG_COMPAT
+    return v->hcall_compat;
+#else
+    return false;
+#endif /* CONFIG_COMPAT */
+}
+
 struct sched_unit {
     struct domain         *domain;
     struct vcpu           *vcpu_list;
-- 
2.34.1