linux-kernel - [RFC PATCH 18/18] KVM: x86: Enable module parameter for MBEC

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Message-ID: <20250313203702.575156-19-jon@nutanix.com>
Date: Thu, 13 Mar 2025 13:36:57 -0700
From: Jon Kohler <jon@...anix.com>
To: seanjc@...gle.com, pbonzini@...hat.com, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        x86@...nel.org, hpa@...or.com, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc: Jon Kohler <jon@...anix.com>
Subject: [RFC PATCH 18/18] KVM: x86: Enable module parameter for MBEC

Enable 'enable_pt_guest_exec_control', which will allow user space to
control enablement of Intel MBEC by advertising secondary exec control
bit 22 to a given vCPU.

Signed-off-by: Jon Kohler <jon@...anix.com>

---
 arch/x86/kvm/x86.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4b2fbb9088ea..607ed2142ce8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -197,7 +197,7 @@ module_param(eager_page_split, bool, 0644);
 static bool __read_mostly mitigate_smt_rsb;
 module_param(mitigate_smt_rsb, bool, 0444);
 
-bool __read_mostly enable_pt_guest_exec_control;
+bool __read_mostly enable_pt_guest_exec_control = true;
 EXPORT_SYMBOL_GPL(enable_pt_guest_exec_control);
 module_param(enable_pt_guest_exec_control, bool, 0444);
 
-- 
2.43.0