File xsa439-1.patch of Package xen.32199
# Commit 1c18d73774533a55ba9d1cbee8bdace03efdb5e7
# Date 2023-09-18 16:43:01 +0100
# Author Andrew Cooper <andrew.cooper3@citrix.com>
# Committer Andrew Cooper <andrew.cooper3@citrix.com>
x86/spec-ctrl: Fix confusion between SPEC_CTRL_EXIT_TO_XEN{,_IST}
c/s 3fffaf9c13e9 ("x86/entry: Avoid using alternatives in NMI/#MC paths")
dropped the only user, leaving behind the (incorrect) implication that Xen had
split exit paths.
Delete the unused SPEC_CTRL_EXIT_TO_XEN and rename SPEC_CTRL_EXIT_TO_XEN_IST
to SPEC_CTRL_EXIT_TO_XEN for consistency.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/include/asm-x86/spec_ctrl_asm.h
+++ b/xen/include/asm-x86/spec_ctrl_asm.h
@@ -71,7 +71,6 @@
* - SPEC_CTRL_ENTRY_FROM_PV
* - SPEC_CTRL_ENTRY_FROM_INTR
* - SPEC_CTRL_ENTRY_FROM_INTR_IST
- * - SPEC_CTRL_EXIT_TO_XEN_IST
* - SPEC_CTRL_EXIT_TO_XEN
* - SPEC_CTRL_EXIT_TO_PV
*
@@ -275,11 +274,6 @@
ALTERNATIVE "", __stringify(DO_SPEC_CTRL_ENTRY maybexen=1), \
X86_FEATURE_SC_MSR_PV
-/* Use when exiting to Xen context. */
-#define SPEC_CTRL_EXIT_TO_XEN \
- ALTERNATIVE "", \
- DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_SC_MSR_PV
-
/* Use when exiting to PV guest context. */
#define SPEC_CTRL_EXIT_TO_PV \
ALTERNATIVE "", \
@@ -346,8 +340,8 @@ UNLIKELY_DISPATCH_LABEL(\@_serialise):
UNLIKELY_END(\@_serialise)
.endm
-/* Use when exiting to Xen in IST context. */
-.macro SPEC_CTRL_EXIT_TO_XEN_IST
+/* Use when exiting to Xen context. */
+.macro SPEC_CTRL_EXIT_TO_XEN
/*
* Requires %rbx=stack_end
* Clobbers %rax, %rcx, %rdx
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -571,7 +571,7 @@ UNLIKELY_START(ne, exit_cr3)
UNLIKELY_END(exit_cr3)
/* WARNING! `ret`, `call *`, `jmp *` not safe beyond this point. */
- SPEC_CTRL_EXIT_TO_XEN_IST /* Req: %rbx=end, Clob: acd */
+ SPEC_CTRL_EXIT_TO_XEN /* Req: %rbx=end, Clob: acd */
RESTORE_ALL adj=8
iretq