lkml.org 
[lkml]   [2018]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.9 15/65] x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
    Date
    4.9-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Juergen Gross <jgross@suse.com>

    commit 71c208dd54ab971036d83ff6d9837bae4976e623 upstream.

    Older Xen versions (4.5 and before) might have problems migrating pv
    guests with MSR_IA32_SPEC_CTRL having a non-zero value. So before
    suspending zero that MSR and restore it after being resumed.

    Signed-off-by: Juergen Gross <jgross@suse.com>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Reviewed-by: Jan Beulich <jbeulich@suse.com>
    Cc: stable@vger.kernel.org
    Cc: xen-devel@lists.xenproject.org
    Cc: boris.ostrovsky@oracle.com
    Link: https://lkml.kernel.org/r/20180226140818.4849-1-jgross@suse.com
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    arch/x86/xen/suspend.c | 16 ++++++++++++++++
    1 file changed, 16 insertions(+)

    --- a/arch/x86/xen/suspend.c
    +++ b/arch/x86/xen/suspend.c
    @@ -1,11 +1,14 @@
    #include <linux/types.h>
    #include <linux/tick.h>
    +#include <linux/percpu-defs.h>

    #include <xen/xen.h>
    #include <xen/interface/xen.h>
    #include <xen/grant_table.h>
    #include <xen/events.h>

    +#include <asm/cpufeatures.h>
    +#include <asm/msr-index.h>
    #include <asm/xen/hypercall.h>
    #include <asm/xen/page.h>
    #include <asm/fixmap.h>
    @@ -68,6 +71,8 @@ static void xen_pv_post_suspend(int susp
    xen_mm_unpin_all();
    }

    +static DEFINE_PER_CPU(u64, spec_ctrl);
    +
    void xen_arch_pre_suspend(void)
    {
    if (xen_pv_domain())
    @@ -84,6 +89,9 @@ void xen_arch_post_suspend(int cancelled

    static void xen_vcpu_notify_restore(void *data)
    {
    + if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL))
    + wrmsrl(MSR_IA32_SPEC_CTRL, this_cpu_read(spec_ctrl));
    +
    /* Boot processor notified via generic timekeeping_resume() */
    if (smp_processor_id() == 0)
    return;
    @@ -93,7 +101,15 @@ static void xen_vcpu_notify_restore(void

    static void xen_vcpu_notify_suspend(void *data)
    {
    + u64 tmp;
    +
    tick_suspend_local();
    +
    + if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL)) {
    + rdmsrl(MSR_IA32_SPEC_CTRL, tmp);
    + this_cpu_write(spec_ctrl, tmp);
    + wrmsrl(MSR_IA32_SPEC_CTRL, 0);
    + }
    }

    void xen_arch_resume(void)

    \
     
     \ /
      Last update: 2018-03-10 01:41    [W:4.089 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site