@@ -2584,7 +2584,7 @@ pages) must also be specified via the tbuf_size parameter.
### tsx
= <bool>
- Applicability: x86
+ Applicability: x86 with CONFIG_INTEL active
Default: false on parts vulnerable to TAA, true otherwise
Controls for the use of Transactional Synchronization eXtensions.
@@ -67,7 +67,7 @@ obj-y += srat.o
obj-y += string.o
obj-y += time.o
obj-y += traps.o
-obj-y += tsx.o
+obj-$(CONFIG_INTEL) += tsx.o
obj-y += usercopy.o
obj-y += x86_emulate.o
obj-$(CONFIG_TBOOT) += tboot.o
@@ -503,9 +503,15 @@ static inline uint8_t get_cpu_family(uint32_t raw, uint8_t *model,
return fam;
}
+#ifdef CONFIG_INTEL
extern int8_t opt_tsx;
extern bool rtm_disabled;
void tsx_init(void);
+#else
+#define opt_tsx 0 /* explicitly indicate TSX is off */
+#define rtm_disabled false /* RTM was not force-disabled */
+static inline void tsx_init(void) {}
+#endif
void update_mcu_opt_ctrl(void);
void set_in_mcu_opt_ctrl(uint32_t mask, uint32_t val);
@@ -116,8 +116,10 @@ static int __init cf_check parse_spec_ctrl(const char *s)
if ( opt_pv_l1tf_domu < 0 )
opt_pv_l1tf_domu = 0;
+#ifdef CONFIG_INTEL
if ( opt_tsx == -1 )
opt_tsx = -3;
+#endif
disable_common:
opt_rsb_pv = false;
@@ -2264,6 +2266,7 @@ void __init init_speculation_mitigations(void)
* plausibly value TSX higher than Hyperthreading...), disable TSX to
* mitigate TAA.
*/
+#ifdef CONFIG_INTEL
if ( opt_tsx == -1 && cpu_has_bug_taa && cpu_has_tsx_ctrl &&
((hw_smt_enabled && opt_smt) ||
!boot_cpu_has(X86_FEATURE_SC_VERW_IDLE)) )
@@ -2271,6 +2274,7 @@ void __init init_speculation_mitigations(void)
opt_tsx = 0;
tsx_init();
}
+#endif
/*
* On some SRBDS-affected hardware, it may be safe to relax srb-lock by
Transactional Synchronization Extensions are supported on certain Intel's CPUs only, hence can be put under CONFIG_INTEL build option. The whole TSX support, even if supported by CPU, may need to be disabled via options, by microcode or through spec-ctrl, depending on a set of specific conditions. To make sure nothing gets accidentally runtime-broken all modifications of global TSX configuration variables is secured by #ifdef's, while variables themselves redefined to 0, so that ones can't mistakenly be written to. Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com> CC: Andrew Cooper <andrew.cooper3@citrix.com> CC: Jan Beulich <jbeulich@suse.com> --- changes in v2: - updated command line doc - updated patch description - make tsx_init() stub one line --- docs/misc/xen-command-line.pandoc | 2 +- xen/arch/x86/Makefile | 2 +- xen/arch/x86/include/asm/processor.h | 6 ++++++ xen/arch/x86/spec_ctrl.c | 4 ++++ 4 files changed, 12 insertions(+), 2 deletions(-)