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Subject[PATCH 4.17 79/97] x86/KVM/VMX: Replace vmx_l1d_flush_always with vmx_l1d_flush_cond
Date
4.17-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
@@ -189,7 +189,7 @@ module_param(ple_window_max, uint, 0444)
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 */
@@ -263,10 +263,10 @@ 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;
}

@@ -9462,7 +9462,7 @@ 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

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