[xen stable-4.15] x86/tsx: Move has_rtm_always_abort to an outer scope

[patchbot@xxxxxxx]

commit 8ae80402a20e6469f6497367b313f1f3a3f4d1b6
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed Jun 23 21:53:58 2021 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue Feb 8 18:04:52 2022 +0000

    x86/tsx: Move has_rtm_always_abort to an outer scope
    
    We are about to introduce a second path which needs to conditionally force 
the
    presence of RTM_ALWAYS_ABORT.
    
    No functional change.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    (cherry picked from commit 4116139131e93b4f075e5442e3c1b424280f6f1f)
---
 xen/arch/x86/tsx.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/xen/arch/x86/tsx.c b/xen/arch/x86/tsx.c
index 88adf08c49..c3b8a7ec00 100644
--- a/xen/arch/x86/tsx.c
+++ b/xen/arch/x86/tsx.c
@@ -42,6 +42,7 @@ void tsx_init(void)
     if ( unlikely(cpu_has_tsx_ctrl < 0) )
     {
         uint64_t caps = 0;
+        bool has_rtm_always_abort;
 
         if ( boot_cpu_data.cpuid_level >= 7 )
             boot_cpu_data.x86_capability[cpufeat_word(X86_FEATURE_ARCH_CAPS)]
@@ -51,6 +52,7 @@ void tsx_init(void)
             rdmsrl(MSR_ARCH_CAPABILITIES, caps);
 
         cpu_has_tsx_ctrl = !!(caps & ARCH_CAPS_TSX_CTRL);
+        has_rtm_always_abort = cpu_has_rtm_always_abort;
 
         if ( cpu_has_tsx_force_abort )
         {
@@ -67,11 +69,7 @@ void tsx_init(void)
              * RTM_ALWAYS_ABORT enumerates the new functionality, but is also
              * read as zero if TSX_FORCE_ABORT.ENABLE_RTM has been set before
              * we run.
-             *
-             * Undo this behaviour in Xen's view of the world.
              */
-            bool has_rtm_always_abort = cpu_has_rtm_always_abort;
-
             if ( !has_rtm_always_abort )
             {
                 uint64_t val;
@@ -82,15 +80,6 @@ void tsx_init(void)
                     has_rtm_always_abort = true;
             }
 
-            /*
-             * Always force RTM_ALWAYS_ABORT, even if it currently visible.
-             * If the user explicitly opts to enable TSX, we'll set
-             * TSX_FORCE_ABORT.ENABLE_RTM and cause RTM_ALWAYS_ABORT to be
-             * hidden from the general CPUID scan later.
-             */
-            if ( has_rtm_always_abort )
-                setup_force_cpu_cap(X86_FEATURE_RTM_ALWAYS_ABORT);
-
             /*
              * If no explicit tsx= option is provided, pick a default.
              *
@@ -108,9 +97,18 @@ void tsx_init(void)
              * With RTM_ALWAYS_ABORT, disable TSX.
              */
             if ( opt_tsx < 0 )
-                opt_tsx = !cpu_has_rtm_always_abort;
+                opt_tsx = !has_rtm_always_abort;
         }
 
+        /*
+         * Always force RTM_ALWAYS_ABORT, even if it currently visible.  If
+         * the user explicitly opts to enable TSX, we'll set the appropriate
+         * RTM_ENABLE bit and cause RTM_ALWAYS_ABORT to be hidden from the
+         * general CPUID scan later.
+         */
+        if ( has_rtm_always_abort )
+            setup_force_cpu_cap(X86_FEATURE_RTM_ALWAYS_ABORT);
+
         /*
          * The TSX features (HLE/RTM) are handled specially.  They both
          * enumerate features but, on certain parts, have mechanisms to be
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.15