diff mbox series

[57/65] x86/setup: Read CR4 earlier in __start_xen()

Message ID 20211126123446.32324-58-andrew.cooper3@citrix.com (mailing list archive)
State New, archived
Headers show
Series x86: Support for CET Indirect Branch Tracking | expand

Commit Message

Andrew Cooper Nov. 26, 2021, 12:34 p.m. UTC 
This is necessary for read_cr4() to function correctly.  Move the EFER caching
at the same time.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Wei Liu <wl@xen.org>
---
 xen/arch/x86/setup.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Jan Beulich Dec. 3, 2021, 12:58 p.m. UTC | #1 
On 26.11.2021 13:34, Andrew Cooper wrote:
> This is necessary for read_cr4() to function correctly.  Move the EFER caching
> at the same time.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff mbox series

Patch

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 9bd42a55f94b..141957c9f6a5 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -872,6 +872,9 @@  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();
 
@@ -918,9 +921,6 @@  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;