linux-kernel - [PATCH RESEND 05/30] KVM: x86: nSVM: expose clean bit support to the guest

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20220207155447.840194-6-mlevitsk@redhat.com>
Date:   Mon,  7 Feb 2022 17:54:22 +0200
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Tony Luck <tony.luck@...el.com>,
        "Chang S. Bae" <chang.seok.bae@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Wanpeng Li <wanpengli@...cent.com>,
        Ingo Molnar <mingo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        linux-kernel@...r.kernel.org,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        intel-gvt-dev@...ts.freedesktop.org,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Joerg Roedel <joro@...tes.org>,
        Sean Christopherson <seanjc@...gle.com>,
        David Airlie <airlied@...ux.ie>,
        Zhi Wang <zhi.a.wang@...el.com>,
        Brijesh Singh <brijesh.singh@....com>,
        Jim Mattson <jmattson@...gle.com>, x86@...nel.org,
        Daniel Vetter <daniel@...ll.ch>,
        Borislav Petkov <bp@...en8.de>,
        Zhenyu Wang <zhenyuw@...ux.intel.com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH RESEND 05/30] KVM: x86: nSVM: expose clean bit support to the guest

KVM already honours few clean bits thus it makes sense
to let the nested guest know about it.

Note that KVM also doesn't check if the hardware supports
clean bits, and therefore nested KVM was
already setting clean bits and L0 KVM
was already honouring them.


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

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 71bfa52121622..8013be9edf27c 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4663,6 +4663,7 @@ static __init void svm_set_cpu_caps(void)
 	/* CPUID 0x80000001 and 0x8000000A (SVM features) */
 	if (nested) {
 		kvm_cpu_cap_set(X86_FEATURE_SVM);
+		kvm_cpu_cap_set(X86_FEATURE_VMCBCLEAN);
 
 		if (nrips)
 			kvm_cpu_cap_set(X86_FEATURE_NRIPS);
-- 
2.26.3