Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v10 24/26] KVM: s390: device attrs to enable/disable AP
 interpretation
To:     Tony Krowiak <akrowiak@linux.ibm.com>,
        Tony Krowiak <akrowiak@linux.vnet.ibm.com>,
        linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org
Cc:     freude@de.ibm.com, schwidefsky@de.ibm.com,
        heiko.carstens@de.ibm.com, borntraeger@de.ibm.com,
        cohuck@redhat.com, kwankhede@nvidia.com,
        bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com,
        alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com,
        alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com,
        jjherne@linux.vnet.ibm.com, thuth@redhat.com,
        pasic@linux.vnet.ibm.com, berrange@redhat.com,
        fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com,
        frankja@linux.ibm.com
References: <1536781396-13601-1-git-send-email-akrowiak@linux.vnet.ibm.com>
 <1536781396-13601-25-git-send-email-akrowiak@linux.vnet.ibm.com>
 <9263b698-1827-1b7f-28bf-75b44657dea2@redhat.com>
 <18a21cda-1da9-3bfb-7b34-80415b5457f9@linux.ibm.com>
From:   David Hildenbrand <david@redhat.com>
Openpgp: preference=signencrypt
Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata=
 xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ
 dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL
 QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp
 XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK
 Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9
 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt
 WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc
 UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv
 jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb
 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk
 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI
 BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG
 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj
 xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3
 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob
 s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM
 m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez
 MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK
 z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh
 dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E
 UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq
 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga
 uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid
 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X
 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+
 xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC
 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb
 hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC
 u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS
 gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg
 rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl
 BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl
 KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ
 NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo
 YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5
 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy
 qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl
 C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV
 W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV
 TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx
 +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl
 SE+xAvmumFBY
Organization: Red Hat GmbH
Message-ID: <172560fb-2c54-ea43-3401-f108cf2a0595@redhat.com>
Date:   Mon, 24 Sep 2018 13:23:42 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.0
MIME-Version: 1.0
In-Reply-To: <18a21cda-1da9-3bfb-7b34-80415b5457f9@linux.ibm.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 22/09/2018 01:40, Tony Krowiak wrote:
> On 09/17/2018 04:51 AM, David Hildenbrand wrote:
>> Am 12.09.18 um 21:43 schrieb Tony Krowiak:
>>> From: Tony Krowiak <akrowiak@linux.ibm.com>
>>>
>>> Introduces two new VM crypto device attributes (KVM_S390_VM_CRYPTO)
>>> to enable or disable AP instruction interpretation from userspace
>>> via the KVM_SET_DEVICE_ATTR ioctl:
>>>
>>> * The KVM_S390_VM_CRYPTO_ENABLE_APIE attribute enables hardware
>>>    interpretation of AP instructions executed on the guest.
>>>
>>> * The KVM_S390_VM_CRYPTO_DISABLE_APIE attribute disables hardware
>>>    interpretation of AP instructions executed on the guest. In this
>>>    case the instructions will be intercepted and pass through to
>>>    the guest.
>>>
>>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
>>> ---
>>>   arch/s390/include/asm/kvm_host.h |    1 +
>>>   arch/s390/include/uapi/asm/kvm.h |    2 ++
>>>   arch/s390/kvm/kvm-s390.c         |   27 +++++++++++++++++++++++----
>>>   3 files changed, 26 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>>> index b32bd1b..36d3531 100644
>>> --- a/arch/s390/include/asm/kvm_host.h
>>> +++ b/arch/s390/include/asm/kvm_host.h
>>> @@ -719,6 +719,7 @@ struct kvm_s390_crypto {
>>>   	__u32 crycbd;
>>>   	__u8 aes_kw;
>>>   	__u8 dea_kw;
>>> +	__u8 apie;
>>>   };
>>>   
>>>   #define APCB0_MASK_SIZE 1
>>> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
>>> index 8c23afc..a8dbd90 100644
>>> --- a/arch/s390/include/uapi/asm/kvm.h
>>> +++ b/arch/s390/include/uapi/asm/kvm.h
>>> @@ -161,6 +161,8 @@ struct kvm_s390_vm_cpu_subfunc {
>>>   #define KVM_S390_VM_CRYPTO_ENABLE_DEA_KW	1
>>>   #define KVM_S390_VM_CRYPTO_DISABLE_AES_KW	2
>>>   #define KVM_S390_VM_CRYPTO_DISABLE_DEA_KW	3
>>> +#define KVM_S390_VM_CRYPTO_ENABLE_APIE		4
>>> +#define KVM_S390_VM_CRYPTO_DISABLE_APIE		5
>>>   
>>>   /* kvm attributes for migration mode */
>>>   #define KVM_S390_VM_MIGRATION_STOP	0
>>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>>> index 2cdd980..286c2e0 100644
>>> --- a/arch/s390/kvm/kvm-s390.c
>>> +++ b/arch/s390/kvm/kvm-s390.c
>>> @@ -856,12 +856,11 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm)
>>>   
>>>   static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
>>>   {
>>> -	if (!test_kvm_facility(kvm, 76))
>>> -		return -EINVAL;
>>> -
>>>   	mutex_lock(&kvm->lock);
>>>   	switch (attr->attr) {
>>>   	case KVM_S390_VM_CRYPTO_ENABLE_AES_KW:
>>> +		if (!test_kvm_facility(kvm, 76))
>>> +			return -EINVAL;
>>>   		get_random_bytes(
>>>   			kvm->arch.crypto.crycb->aes_wrapping_key_mask,
>>>   			sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask));
>>> @@ -869,6 +868,8 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
>>>   		VM_EVENT(kvm, 3, "%s", "ENABLE: AES keywrapping support");
>>>   		break;
>>>   	case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW:
>>> +		if (!test_kvm_facility(kvm, 76))
>>> +			return -EINVAL;
>>>   		get_random_bytes(
>>>   			kvm->arch.crypto.crycb->dea_wrapping_key_mask,
>>>   			sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask));
>>> @@ -876,17 +877,31 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
>>>   		VM_EVENT(kvm, 3, "%s", "ENABLE: DEA keywrapping support");
>>>   		break;
>>>   	case KVM_S390_VM_CRYPTO_DISABLE_AES_KW:
>>> +		if (!test_kvm_facility(kvm, 76))
>>> +			return -EINVAL;
>>>   		kvm->arch.crypto.aes_kw = 0;
>>>   		memset(kvm->arch.crypto.crycb->aes_wrapping_key_mask, 0,
>>>   			sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask));
>>>   		VM_EVENT(kvm, 3, "%s", "DISABLE: AES keywrapping support");
>>>   		break;
>>>   	case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW:
>>> +		if (!test_kvm_facility(kvm, 76))
>>> +			return -EINVAL;
>>>   		kvm->arch.crypto.dea_kw = 0;
>>>   		memset(kvm->arch.crypto.crycb->dea_wrapping_key_mask, 0,
>>>   			sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask));
>>>   		VM_EVENT(kvm, 3, "%s", "DISABLE: DEA keywrapping support");
>>>   		break;
>>> +	case KVM_S390_VM_CRYPTO_ENABLE_APIE:
>>> +		if (!ap_instructions_available()) {
>>> +			mutex_unlock(&kvm->lock);
>>> +			return -EOPNOTSUPP;
>>> +		}
>>> +		kvm->arch.crypto.apie = 1;
>>> +		break;
>>> +	case KVM_S390_VM_CRYPTO_DISABLE_APIE:
>>> +		kvm->arch.crypto.apie = 0;
>>> +		break;
>>>   	default:
>>>   		mutex_unlock(&kvm->lock);
>>>   		return -ENXIO;
>>> @@ -1493,6 +1508,8 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
>>>   		case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW:
>>>   		case KVM_S390_VM_CRYPTO_DISABLE_AES_KW:
>>>   		case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW:
>>> +		case KVM_S390_VM_CRYPTO_ENABLE_APIE:
>>> +		case KVM_S390_VM_CRYPTO_DISABLE_APIE:
>>
>> As also replied to the QEMU series, could we indicate
>> KVM_S390_VM_CRYPTO_ENABLE_APIE (and maybe
>> KVM_S390_VM_CRYPTO_DISABLE_APIE) only with ap_instructions_available(),
>> so we can avoid the additional KVM_S390_VM_CPU_FEAT_AP?
>>
>> KVM_S390_VM_CPU_FEAT_AP is right now completely unused in KVM otherwise
>> (never checked, we only care about apie).
> 
> After much discussion with Halil and a few exchanges with you, we
> decided to go ahead and accept your suggestion to get rid of 
> KVM_S390_VM_CPU_FEAT and keep the VM device attributes to enable/disable
> apie.
> 
> To that end, I responded to patches 03/26, 11/26 and 25/26 with fixup!
> patches that show the KVM/kernel changes that will be necessary to get
> rid of KVM_S390_VM_CPU_FEAT and use apie to control ECA.28. I did that
> to generate discussion in v10 rather than waiting until v11 for
> comments. I make no guarantees that those fixup! patches will
> successfully apply should you have a v10 branch generated from this
> patch series you want to update.
> 

Will you also fixup this patch to expose KVM_S390_VM_CRYPTO_ENABLE_APIE
only if supported by HW? (ap_instructions_available)

-- 

Thanks,

David / dhildenb