From: Peter Zijlstra peterz@infradead.org

commit ddd07b750382adc2b78fdfbec47af8a6e0d8ef37 upstream.

CAT has happened, WBINDV is bad (even before CAT blowing away the entire cache on a multi-core platform wasn't nice), try not to use it ever.

Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Dave Hansen dave.hansen@intel.com Cc: Bin Yang bin.yang@intel.com Cc: Mark Gross mark.gross@intel.com Link: https://lkml.kernel.org/r/20180919085947.933674526@infradead.org Cc: stable@vger.kernel.org # 4.14.x: d2479a3: x86/pti: Fix boot problems from Global-bit setting Cc: stable@vger.kernel.org # 4.14.x Signed-off-by: Wen Yang wenyang@linux.alibaba.com --- arch/x86/mm/pageattr.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 101f3ad0d6ad..ab87da7a6043 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -239,26 +239,12 @@ static void cpa_flush_array(unsigned long *start, int numpages, int cache, int in_flags, struct page **pages) { unsigned int i, level; -#ifdef CONFIG_PREEMPT - /* - * Avoid wbinvd() because it causes latencies on all CPUs, - * regardless of any CPU isolation that may be in effect. - * - * This should be extended for CAT enabled systems independent of - * PREEMPT because wbinvd() does not respect the CAT partitions and - * this is exposed to unpriviledged users through the graphics - * subsystem. - */ - unsigned long do_wbinvd = 0; -#else - unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */ -#endif

BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);

- on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1); + flush_tlb_all();

- if (!cache || do_wbinvd) + if (!cache) return;

/*

On Tue, Jul 05, 2022 at 02:02:07PM +0800, Wen Yang wrote:

From: Peter Zijlstra peterz@infradead.org

commit ddd07b750382adc2b78fdfbec47af8a6e0d8ef37 upstream.

CAT has happened, WBINDV is bad (even before CAT blowing away the entire cache on a multi-core platform wasn't nice), try not to use it ever.

Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Dave Hansen dave.hansen@intel.com Cc: Bin Yang bin.yang@intel.com Cc: Mark Gross mark.gross@intel.com Link: https://lkml.kernel.org/r/20180919085947.933674526@infradead.org Cc: stable@vger.kernel.org # 4.19.x Signed-off-by: Wen Yang wenyang@linux.alibaba.com

---

arch/x86/mm/pageattr.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 101f3ad0d6ad..ab87da7a6043 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -239,26 +239,12 @@ static void cpa_flush_array(unsigned long *start, int numpages, int cache, int in_flags, struct page **pages) { unsigned int i, level; -#ifdef CONFIG_PREEMPT

• /*

• * Avoid wbinvd() because it causes latencies on all CPUs,
  

• * regardless of any CPU isolation that may be in effect.
  

• *
  

• * This should be extended for CAT enabled systems independent of
  

• * PREEMPT because wbinvd() does not respect the CAT partitions and
  

• * this is exposed to unpriviledged users through the graphics
  

• * subsystem.
  

• */
  

• unsigned long do_wbinvd = 0;

-#else

• unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */

-#endif BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);

• on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1);

• flush_tlb_all();

• if (!cache || do_wbinvd)

• if (!cache) return;

/* -- 2.19.1.6.gb485710b

As stated before, I am not allowed to accept this due to it being a requirement of a closed source kernel module. Please do not keep resending it hoping we will forget or I will have to add this to my email filters.

thanks,

greg k-h