lkml.org 
[lkml]   [2018]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 082/104] x86/KVM/VMX: Replace vmx_l1d_flush_always with vmx_l1d_flush_cond
    Date
    4.14-stable review patch.  If anyone has any objections, please let me know.

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

    From: Nicolai Stange <nstange@suse.de>

    commit 427362a142441f08051369db6fbe7f61c73b3dca upstream

    The vmx_l1d_flush_always static key is only ever evaluated if
    vmx_l1d_should_flush is enabled. In that case however, there are only two
    L1d flushing modes possible: "always" and "conditional".

    The "conditional" mode's implementation tends to require more sophisticated
    logic than the "always" mode.

    Avoid inverted logic by replacing the 'vmx_l1d_flush_always' static key
    with a 'vmx_l1d_flush_cond' one.

    There is no change in functionality.

    Signed-off-by: Nicolai Stange <nstange@suse.de>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    arch/x86/kvm/vmx.c | 10 +++++-----
    1 file changed, 5 insertions(+), 5 deletions(-)

    --- a/arch/x86/kvm/vmx.c
    +++ b/arch/x86/kvm/vmx.c
    @@ -192,7 +192,7 @@ module_param(ple_window_max, int, S_IRUG
    extern const ulong vmx_return;

    static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush);
    -static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_always);
    +static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_cond);
    static DEFINE_MUTEX(vmx_l1d_flush_mutex);

    /* Storage for pre module init parameter parsing */
    @@ -266,10 +266,10 @@ static int vmx_setup_l1d_flush(enum vmx_
    else
    static_branch_disable(&vmx_l1d_should_flush);

    - if (l1tf == VMENTER_L1D_FLUSH_ALWAYS)
    - static_branch_enable(&vmx_l1d_flush_always);
    + if (l1tf == VMENTER_L1D_FLUSH_COND)
    + static_branch_enable(&vmx_l1d_flush_cond);
    else
    - static_branch_disable(&vmx_l1d_flush_always);
    + static_branch_disable(&vmx_l1d_flush_cond);
    return 0;
    }

    @@ -9167,7 +9167,7 @@ static void vmx_l1d_flush(struct kvm_vcp
    * This code is only executed when the the flush mode is 'cond' or
    * 'always'
    */
    - if (!static_branch_unlikely(&vmx_l1d_flush_always)) {
    + if (static_branch_likely(&vmx_l1d_flush_cond)) {
    /*
    * Clear the flush bit, it gets set again either from
    * vcpu_run() or from one of the unsafe VMEXIT

    \
     
     \ /
      Last update: 2018-08-14 19:43    [W:2.492 / U:0.416 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site