[tip:x86/pti] X86/nVMX: Properly set spec_ctrl and pred_cmd before merging MSRs

tip-bot for KarimAllah Ahmed
2018-02-11T12:10:21Z

Commit-ID: fb5b90b795c76e9c10c520fcdb7fe0d7b8334833
Gitweb: https://git.kernel.org/tip/fb5b90b795c76e9c10c520fcdb7fe0d7b8334833
Author: KarimAllah Ahmed <karahmed@amazon.de>
AuthorDate: Sat, 10 Feb 2018 23:39:25 +0000
Committer: Ingo Molnar <mingo@kernel.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@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: dave.hansen@intel.com
Cc: kvm@vger.kernel.org
Cc: sironi@amazon.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@kernel.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)