[-next] kvm/svm: disable KCSAN for svm_vcpu_run()
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Message ID 20200415153709.1559-1-cai@lca.pw
State New
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  • [-next] kvm/svm: disable KCSAN for svm_vcpu_run()
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Commit Message

Qian Cai April 15, 2020, 3:37 p.m. UTC
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.

 # /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host
	-smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2

=== console output ===
Kernel 5.6.0-next-20200408+ on an x86_64

hp-dl385g10-05 login:

<...host reset...>

HPE ProLiant System BIOS A40 v1.20 (03/09/2018)
(C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP
Early system initialization, please wait...

Signed-off-by: Qian Cai <cai@lca.pw>
---
 arch/x86/kvm/svm/svm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Paolo Bonzini April 15, 2020, 3:57 p.m. UTC | #1
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.
> 
>  # /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host
> 	-smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2
> 
> === console output ===
> Kernel 5.6.0-next-20200408+ on an x86_64
> 
> hp-dl385g10-05 login:
> 
> <...host reset...>
> 
> HPE ProLiant System BIOS A40 v1.20 (03/09/2018)
> (C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP
> Early system initialization, please wait...
> 
> Signed-off-by: Qian Cai <cai@lca.pw>
> ---
>  arch/x86/kvm/svm/svm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 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)
>  
>  bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
>  
> -static void svm_vcpu_run(struct kvm_vcpu *vcpu)
> +static __no_kcsan void svm_vcpu_run(struct kvm_vcpu *vcpu)
>  {
>  	struct vcpu_svm *svm = to_svm(vcpu);
>  
> 

I suppose you tested the patch to move cli/sti into the .S file.  Anyway:

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Thanks,

Paolo
Qian Cai April 15, 2020, 4:30 p.m. UTC | #2
> On Apr 15, 2020, at 11:57 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> 
> 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.
>> 
>> # /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host
>> 	-smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2
>> 
>> === console output ===
>> Kernel 5.6.0-next-20200408+ on an x86_64
>> 
>> hp-dl385g10-05 login:
>> 
>> <...host reset...>
>> 
>> HPE ProLiant System BIOS A40 v1.20 (03/09/2018)
>> (C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP
>> Early system initialization, please wait...
>> 
>> Signed-off-by: Qian Cai <cai@lca.pw>
>> ---
>> arch/x86/kvm/svm/svm.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> 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)
>> 
>> bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
>> 
>> -static void svm_vcpu_run(struct kvm_vcpu *vcpu)
>> +static __no_kcsan void svm_vcpu_run(struct kvm_vcpu *vcpu)
>> {
>> 	struct vcpu_svm *svm = to_svm(vcpu);
>> 
>> 
> 
> I suppose you tested the patch to move cli/sti into the .S file.  Anyway:

Yes, tested that without any luck.
Qian Cai April 17, 2020, 1:21 p.m. UTC | #3
> On Apr 15, 2020, at 11:57 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> 
> 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.
>> 
>> # /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host
>> 	-smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2
>> 
>> === console output ===
>> Kernel 5.6.0-next-20200408+ on an x86_64
>> 
>> hp-dl385g10-05 login:
>> 
>> <...host reset...>
>> 
>> HPE ProLiant System BIOS A40 v1.20 (03/09/2018)
>> (C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP
>> Early system initialization, please wait...
>> 
>> Signed-off-by: Qian Cai <cai@lca.pw>
>> ---
>> arch/x86/kvm/svm/svm.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> 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)
>> 
>> bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
>> 
>> -static void svm_vcpu_run(struct kvm_vcpu *vcpu)
>> +static __no_kcsan void svm_vcpu_run(struct kvm_vcpu *vcpu)
>> {
>> 	struct vcpu_svm *svm = to_svm(vcpu);
>> 
>> 
> 
> I suppose you tested the patch to move cli/sti into the .S file.  Anyway:
> 
> Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Paul, can you pick this up along with other KCSAN fixes?
Paul E. McKenney April 17, 2020, 3:17 p.m. UTC | #4
On Fri, Apr 17, 2020 at 09:21:59AM -0400, Qian Cai wrote:
> 
> 
> > On Apr 15, 2020, at 11:57 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> > 
> > 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.
> >> 
> >> # /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host
> >> 	-smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2
> >> 
> >> === console output ===
> >> Kernel 5.6.0-next-20200408+ on an x86_64
> >> 
> >> hp-dl385g10-05 login:
> >> 
> >> <...host reset...>
> >> 
> >> HPE ProLiant System BIOS A40 v1.20 (03/09/2018)
> >> (C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP
> >> Early system initialization, please wait...
> >> 
> >> Signed-off-by: Qian Cai <cai@lca.pw>
> >> ---
> >> arch/x86/kvm/svm/svm.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >> 
> >> 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)
> >> 
> >> bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
> >> 
> >> -static void svm_vcpu_run(struct kvm_vcpu *vcpu)
> >> +static __no_kcsan void svm_vcpu_run(struct kvm_vcpu *vcpu)
> >> {
> >> 	struct vcpu_svm *svm = to_svm(vcpu);
> >> 
> >> 
> > 
> > I suppose you tested the patch to move cli/sti into the .S file.  Anyway:
> > 
> > Acked-by: Paolo Bonzini <pbonzini@redhat.com>
> 
> Paul, can you pick this up along with other KCSAN fixes?

Queued and pushed, thank you both!

							Thanx, Paul

Patch
diff mbox series

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)
 
 bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
 
-static void svm_vcpu_run(struct kvm_vcpu *vcpu)
+static __no_kcsan void svm_vcpu_run(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);