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x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond'

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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: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nicolai Stange 2018-07-21 22:25:00 +02:00 committed by Greg Kroah-Hartman
parent 698ac1bc17
commit 936f566260
1 changed files with 5 additions and 5 deletions
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10
arch/x86/kvm/vmx.c
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@ -190,7 +190,7 @@ module_param(ple_window_max, int, S_IRUGO);
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 */
@ -264,10 +264,10 @@ static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf)
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;
}
@ -8666,7 +8666,7 @@ static void vmx_l1d_flush(struct kvm_vcpu *vcpu)
* 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