linux-kernel - [tip:x86/pti] X86/nVMX: Properly set spec_ctrl and pred

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Date:   Sun, 11 Feb 2018 04:10:21 -0800
From:   tip-bot for KarimAllah Ahmed <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, karahmed@...zon.de,
        dwmw@...zon.co.uk, dave.hansen@...ux.intel.com,
        torvalds@...ux-foundation.org, arjan@...ux.intel.com,
        tglx@...utronix.de, bp@...en8.de, pbonzini@...hat.com,
        dan.j.williams@...el.com, mingo@...nel.org, hpa@...or.com,
        jmattson@...gle.com, rkrcmar@...hat.com, dwmw2@...radead.org,
        gregkh@...uxfoundation.org, luto@...nel.org, jpoimboe@...hat.com,
        peterz@...radead.org
Subject: [tip:x86/pti] X86/nVMX: Properly set spec_ctrl and pred_cmd before
 merging MSRs

Commit-ID:  fb5b90b795c76e9c10c520fcdb7fe0d7b8334833
Gitweb:     https://git.kernel.org/tip/fb5b90b795c76e9c10c520fcdb7fe0d7b8334833
Author:     KarimAllah Ahmed <karahmed@...zon.de>
AuthorDate: Sat, 10 Feb 2018 23:39:25 +0000
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Sun, 11 Feb 2018 11:24:16 +0100

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

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.

Signed-off-by: KarimAllah Ahmed <karahmed@...zon.de>
Signed-off-by: David Woodhouse <dwmw@...zon.co.uk>
Reviewed-by: Jim Mattson <jmattson@...gle.com>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Arjan van de Ven <arjan@...ux.intel.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dan Williams <dan.j.williams@...el.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: David Woodhouse <dwmw2@...radead.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: arjan.van.de.ven@...el.com
Cc: dave.hansen@...el.com
Cc: kvm@...r.kernel.org
Cc: sironi@...zon.de
Fixes: 086e7d4118cc ("KVM: VMX: Allow direct access to MSR_IA32_SPEC_CTRL")
Link: http://lkml.kernel.org/r/1518305967-31356-5-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kvm/vmx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index bee4c49..599179b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10219,8 +10219,8 @@ static inline bool nested_vmx_merge_msr_bitmap(struct kvm_vcpu *vcpu,
 	 *    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)