[xen stable-4.15] x86/setup: Read CR4 earlier in __start_xen()

[patchbot@xxxxxxx]

commit 473f7cb1a1a0299ebbc243e52d407a990936f79a
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon Nov 1 10:19:57 2021 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Fri Mar 25 17:10:38 2022 +0000

    x86/setup: Read CR4 earlier in __start_xen()
    
    This is necessary for read_cr4() to function correctly.  Move the EFER 
caching
    at the same time.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    (cherry picked from commit 9851bc4939101828d2ad7634b93c0d9ccaef5b7e)
---
 xen/arch/x86/setup.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index b1f96f71b6..467dcfc4cf 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -870,6 +870,9 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     /* Full exception support from here on in. */
 
+    rdmsrl(MSR_EFER, this_cpu(efer));
+    asm volatile ( "mov %%cr4,%0" : "=r" (get_cpu_info()->cr4) );
+
     /* Enable NMIs.  Our loader (e.g. Tboot) may have left them disabled. */
     enable_nmis();
 
@@ -916,9 +919,6 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     parse_video_info();
 
-    rdmsrl(MSR_EFER, this_cpu(efer));
-    asm volatile ( "mov %%cr4,%0" : "=r" (get_cpu_info()->cr4) );
-
     /* We initialise the serial devices very early so we can get debugging. */
     ns16550.io_base = 0x3f8;
     ns16550.irq     = 4;
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.15