Patch "X86/nVMX: Properly set spec_ctrl and pred_cmd before merging MSRs" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

X86/nVMX: Properly set spec_ctrl and pred_cmd before merging MSRs

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-nvmx-properly-set-spec_ctrl-and-pred_cmd-before-merging-msrs.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: KarimAllah Ahmed <[email protected]>
Date: Sat, 10 Feb 2018 23:39:25 +0000
Subject: X86/nVMX: Properly set spec_ctrl and pred_cmd before merging MSRs
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From: KarimAllah Ahmed <[email protected]>

commit 206587a9fb764d71f035dc7f6d3b6488f5d5b304 upstream.

These two variables should check whether SPEC_CTRL and PRED_CMD are supposed to be passed through to L2 guests or not. While msr_write_intercepted_l01 would return 'true' if it is not passed through.

So just invert the result of msr_write_intercepted_l01 to implement the correct semantics.

---
 arch/x86/kvm/vmx.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -10220,8 +10220,8 @@ static inline bool nested_vmx_merge_msr_
 	 *    updated to reflect this when L1 (or its L2s) actually write to
 	 *    the MSR.
 	 */
-	bool pred_cmd = msr_write_intercepted_l01(vcpu, MSR_IA32_PRED_CMD);
-	bool spec_ctrl = msr_write_intercepted_l01(vcpu, MSR_IA32_SPEC_CTRL);
+	bool pred_cmd = !msr_write_intercepted_l01(vcpu, MSR_IA32_PRED_CMD);
+	bool spec_ctrl = !msr_write_intercepted_l01(vcpu, MSR_IA32_SPEC_CTRL);
 
 	if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
 	    !pred_cmd && !spec_ctrl)

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/kvm-nvmx-set-the-cpu_based_use_msr_bitmaps-if-we-have-a-valid-l02-msr-bitmap.patch queue-4.15/x86-nvmx-properly-set-spec_ctrl-and-pred_cmd-before-merging-msrs.patch queue-4.15/x86-speculation-update-speculation-control-microcode-blacklist.patch queue-4.15/kvm-x86-reduce-retpoline-performance-impact-in-slot_handle_level_range-by-always-inlining-iterator-helper-methods.patch queue-4.15/revert-x86-speculation-simplify-indirect_branch_prediction_barrier.patch