x86/spec-ctrl: Fill in whitepaper URL

... now that we a link available.

Fixes: 9deaf2d932f0 ("x86/spec-ctrl: Enable Zen2 chickenbit")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index 070060d90b0f08f4d0cd94859924200759c6ef48..1ddb55cbe520940bd10f255e42a4b1b4fc111809 100644 (file)
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -828,7 +828,7 @@ void amd_set_legacy_ssbd(bool enable)
  * On Zen2 we offer this chicken (bit) on the altar of Speculation.
  *
  * Refer to the AMD Branch Type Confusion whitepaper:
- * https://XXX
+ * https://www.amd.com/system/files/documents/technical-guidance-for-mitigating-branch-type-confusion.pdf
  *
  * Setting this unnamed bit supposedly causes prediction information on
  * non-branch instructions to be ignored.  It is to be set unilaterally in