linux-kernel - [PATCH 04/14] KVM: x86: nSVM: don't copy pause related settings

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 14 Sep 2021 18:48:15 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Borislav Petkov <bp@...en8.de>, Bandan Das <bsd@...hat.com>,
        linux-kernel@...r.kernel.org (open list),
        Joerg Roedel <joro@...tes.org>, Ingo Molnar <mingo@...hat.com>,
        Wei Huang <wei.huang2@....com>,
        Sean Christopherson <seanjc@...gle.com>,
        linux-kselftest@...r.kernel.org (open list:KERNEL SELFTEST FRAMEWORK),
        Maxim Levitsky <mlevitsk@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Jim Mattson <jmattson@...gle.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Shuah Khan <shuah@...nel.org>,
        Wanpeng Li <wanpengli@...cent.com>
Subject: [PATCH 04/14] KVM: x86: nSVM: don't copy pause related settings

According to the SDM, the CPU never modifies these settings.
It loads them on VM entry and updates an internal copy instead.

Also don't load them from the vmcb12 as we don't expose these
features to the nested guest yet.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kvm/svm/nested.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 2545d0c61985..476e01f98035 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -551,9 +551,6 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm)
 	svm->vmcb->control.event_inj           = svm->nested.ctl.event_inj;
 	svm->vmcb->control.event_inj_err       = svm->nested.ctl.event_inj_err;
 
-	svm->vmcb->control.pause_filter_count  = svm->nested.ctl.pause_filter_count;
-	svm->vmcb->control.pause_filter_thresh = svm->nested.ctl.pause_filter_thresh;
-
 	nested_svm_transition_tlb_flush(vcpu);
 
 	/* Enter Guest-Mode */
@@ -808,11 +805,6 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	vmcb12->control.event_inj         = svm->nested.ctl.event_inj;
 	vmcb12->control.event_inj_err     = svm->nested.ctl.event_inj_err;
 
-	vmcb12->control.pause_filter_count =
-		svm->vmcb->control.pause_filter_count;
-	vmcb12->control.pause_filter_thresh =
-		svm->vmcb->control.pause_filter_thresh;
-
 	nested_svm_copy_common_state(svm->nested.vmcb02.ptr, svm->vmcb01.ptr);
 
 	svm_switch_vmcb(svm, &svm->vmcb01);
-- 
2.26.3