[Xen-changelog] [xen staging] VMX: don't unconditionally set the tsc_scaling.setup hook

[patchbot@xxxxxxx]

commit 2e20a71404d5bff0b6a0bb604c89c2192c38755a
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Jul 19 09:35:43 2018 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Jul 19 09:35:43 2018 +0200

    VMX: don't unconditionally set the tsc_scaling.setup hook
    
    Instead of checking hvm_tsc_scaling_supported inside the hook function,
    install the hook only when setting state such that said predicate
    becomes true.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vmx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 12e0ee5c4e..df3408bdde 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1282,7 +1282,7 @@ static void vmx_handle_cd(struct vcpu *v, unsigned long 
value)
 
 static void vmx_setup_tsc_scaling(struct vcpu *v)
 {
-    if ( !hvm_tsc_scaling_supported || v->domain->arch.vtsc )
+    if ( v->domain->arch.vtsc )
         return;
 
     vmx_vmcs_enter(v);
@@ -2345,7 +2345,6 @@ static struct hvm_function_table __initdata 
vmx_function_table = {
     .altp2m_vcpu_emulate_vmfunc = vmx_vcpu_emulate_vmfunc,
     .tsc_scaling = {
         .max_ratio = VMX_TSC_MULTIPLIER_MAX,
-        .setup     = vmx_setup_tsc_scaling,
     },
 };
 
@@ -2485,7 +2484,10 @@ const struct hvm_function_table * __init start_vmx(void)
     }
 
     if ( cpu_has_vmx_tsc_scaling )
+    {
         vmx_function_table.tsc_scaling.ratio_frac_bits = 48;
+        vmx_function_table.tsc_scaling.setup = vmx_setup_tsc_scaling;
+    }
 
     if ( cpu_has_mpx && cpu_has_vmx_mpx )
     {
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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