[XEN PATCH v5 07/13] x86/PV: guard svm specific functions with usinc_svm() check

[Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>]

From: Xenia Ragiadakou <burzalodowa@xxxxxxxxx>

Replace cpu_has_svm check with using_svm(), so that not only SVM support in CPU
is being checked at runtime, but also at build time we ensure the availability
of functions svm_load_segs() and svm_load_segs_prefetch().

Since SVM depends on HVM, it can be used alone.

Signed-off-by: Xenia Ragiadakou <burzalodowa@xxxxxxxxx>
Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
changes in v4:
 - changed patch subject line
 - adjusted call to using_svm(), as it has become an inline function
 - use #ifdef CONFIG_PV
 - description changed a bit for more clarity
 - added tag
changes in v3:
 - using_svm instead of IS_ENABLED(CONFIG_SVM)
 - updated description
---
 xen/arch/x86/domain.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index ccadfe0c9e..05cb9f7a4c 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1732,11 +1732,9 @@ static void load_segments(struct vcpu *n)
         if ( !(n->arch.flags & TF_kernel_mode) )
             SWAP(gsb, gss);
 
-#ifdef CONFIG_HVM
-        if ( cpu_has_svm && (uregs->fs | uregs->gs) <= 3 )
+        if ( using_svm() && (uregs->fs | uregs->gs) <= 3 )
             fs_gs_done = svm_load_segs(n->arch.pv.ldt_ents, LDT_VIRT_START(n),
                                        n->arch.pv.fs_base, gsb, gss);
-#endif
     }
 
     if ( !fs_gs_done )
@@ -2049,9 +2047,9 @@ static void __context_switch(void)
 
     write_ptbase(n);
 
-#if defined(CONFIG_PV) && defined(CONFIG_HVM)
+#ifdef CONFIG_PV
     /* Prefetch the VMCB if we expect to use it later in the context switch */
-    if ( cpu_has_svm && is_pv_64bit_domain(nd) && !is_idle_domain(nd) )
+    if ( using_svm() && is_pv_64bit_domain(nd) && !is_idle_domain(nd) )
         svm_load_segs_prefetch();
 #endif
 
-- 
2.25.1