ACK: [SRU][Bionic][PATCH 1/1] x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths

[Kleber Souza]

On 08/14/18 22:14, Joseph Salisbury wrote:
> From: Juergen Gross <jgross at suse.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1777338
> 
> Commit:
> 
>   1f50ddb4f418 ("x86/speculation: Handle HT correctly on AMD")
> 
> ... added speculative_store_bypass_ht_init() to the per-CPU initialization sequence.
> 
> speculative_store_bypass_ht_init() needs to be called on each CPU for
> PV guests, too.
> 
> Reported-by: Brian Woods <brian.woods at amd.com>
> Tested-by: Brian Woods <brian.woods at amd.com>
> Signed-off-by: Juergen Gross <jgross at suse.com>
> Cc: <stable at vger.kernel.org>
> Cc: Linus Torvalds <torvalds at linux-foundation.org>
> Cc: Peter Zijlstra <peterz at infradead.org>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: boris.ostrovsky at oracle.com
> Cc: xen-devel at lists.xenproject.org
> Fixes: 1f50ddb4f4189243c05926b842dc1a0332195f31 ("x86/speculation: Handle HT correctly on AMD")
> Link: https://lore.kernel.org/lkml/20180621084331.21228-1-jgross@suse.com
> Signed-off-by: Ingo Molnar <mingo at kernel.org>
> (cherry picked from commit 74899d92e66663dc7671a8017b3146dcd4735f3b)
> Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>

Clean cherry-pick, specific to Xen and tested by the bug reporter.

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

> ---
>  arch/x86/xen/smp_pv.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
> index c0c756c..db6d90e 100644
> --- a/arch/x86/xen/smp_pv.c
> +++ b/arch/x86/xen/smp_pv.c
> @@ -32,6 +32,7 @@
>  #include <xen/interface/vcpu.h>
>  #include <xen/interface/xenpmu.h>
>  
> +#include <asm/spec-ctrl.h>
>  #include <asm/xen/interface.h>
>  #include <asm/xen/hypercall.h>
>  
> @@ -70,6 +71,8 @@ static void cpu_bringup(void)
>  	cpu_data(cpu).x86_max_cores = 1;
>  	set_cpu_sibling_map(cpu);
>  
> +	speculative_store_bypass_ht_init();
> +
>  	xen_setup_cpu_clockevents();
>  
>  	notify_cpu_starting(cpu);
> @@ -250,6 +253,8 @@ static void __init xen_pv_smp_prepare_cpus(unsigned int max_cpus)
>  	}
>  	set_cpu_sibling_map(0);
>  
> +	speculative_store_bypass_ht_init();
> +
>  	xen_pmu_init(0);
>  
>  	if (xen_smp_intr_init(0) || xen_smp_intr_init_pv(0))
>