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Subject: Re: [PATCH -next] kvm/svm: disable KCSAN for svm_vcpu_run()
From:   Qian Cai <cai@lca.pw>
In-Reply-To: <f02ca9b9-f0a6-dfb5-1ca0-32a12d4f56fb@redhat.com>
Date:   Fri, 17 Apr 2020 09:21:59 -0400
Cc:     Elver Marco <elver@google.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        kasan-dev <kasan-dev@googlegroups.com>, kvm@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>
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Message-Id: <1F15D565-D34D-41F5-B1C5-B9A04626EE97@lca.pw>
References: <20200415153709.1559-1-cai@lca.pw>
 <f02ca9b9-f0a6-dfb5-1ca0-32a12d4f56fb@redhat.com>
To:     "paul E. McKenney" <paulmck@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
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> On Apr 15, 2020, at 11:57 AM, Paolo Bonzini <pbonzini@redhat.com> =
wrote:
>=20
> On 15/04/20 17:37, Qian Cai wrote:
>> For some reasons, running a simple qemu-kvm command with KCSAN will
>> reset AMD hosts. It turns out svm_vcpu_run() could not be =
instrumented.
>> Disable it for now.
>>=20
>> # /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host
>> 	-smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2
>>=20
>> =3D=3D=3D console output =3D=3D=3D
>> Kernel 5.6.0-next-20200408+ on an x86_64
>>=20
>> hp-dl385g10-05 login:
>>=20
>> <...host reset...>
>>=20
>> HPE ProLiant System BIOS A40 v1.20 (03/09/2018)
>> (C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP
>> Early system initialization, please wait...
>>=20
>> Signed-off-by: Qian Cai <cai@lca.pw>
>> ---
>> arch/x86/kvm/svm/svm.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>=20
>> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
>> index 2be5bbae3a40..1fdb300e9337 100644
>> --- a/arch/x86/kvm/svm/svm.c
>> +++ b/arch/x86/kvm/svm/svm.c
>> @@ -3278,7 +3278,7 @@ static void svm_cancel_injection(struct =
kvm_vcpu *vcpu)
>>=20
>> bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
>>=20
>> -static void svm_vcpu_run(struct kvm_vcpu *vcpu)
>> +static __no_kcsan void svm_vcpu_run(struct kvm_vcpu *vcpu)
>> {
>> 	struct vcpu_svm *svm =3D to_svm(vcpu);
>>=20
>>=20
>=20
> I suppose you tested the patch to move cli/sti into the .S file.  =
Anyway:
>=20
> Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Paul, can you pick this up along with other KCSAN fixes?