From: Brijesh Singh <brijesh.singh@amd.com>
To: Peter Gonda <pgonda@google.com>
Cc: brijesh.singh@amd.com,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Joerg Roedel" <joro@8bytes.org>, "Borislav Petkov" <bp@suse.de>,
"Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
"x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 01/11] KVM: SVM: Add KVM_SEV SEND_START command
Date: Tue, 12 Nov 2019 16:27:25 -0600 [thread overview]
Message-ID: <4f509f43-a576-144d-efd4-ab0362f1d667@amd.com> (raw)
In-Reply-To: <CAMkAt6pzXrZw1TZgcX-G0wDNZBjf=1bQdErAJTxfzYQ2MJDZvw@mail.gmail.com>
On 11/12/19 12:35 PM, Peter Gonda wrote:
> On Wed, Jul 10, 2019 at 1:13 PM Singh, Brijesh <brijesh.singh@amd.com> wrote:
>> +static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
>> +{
>> + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
>> + void *amd_cert = NULL, *session_data = NULL;
>> + void *pdh_cert = NULL, *plat_cert = NULL;
>> + struct sev_data_send_start *data = NULL;
>> + struct kvm_sev_send_start params;
>> + int ret;
>> +
>> + if (!sev_guest(kvm))
>> + return -ENOTTY;
>> +
>> + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data,
>> + sizeof(struct kvm_sev_send_start)))
>> + return -EFAULT;
>> +
>> + data = kzalloc(sizeof(*data), GFP_KERNEL);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + /* userspace wants to query the session length */
>> + if (!params.session_len)
>> + goto cmd;
>> +
>> + if (!params.pdh_cert_uaddr || !params.pdh_cert_len ||
>> + !params.session_uaddr)
>> + return -EINVAL;
> I think pdh_cert is only required if the guest policy SEV bit is set.
> Can pdh_cert be optional?
We don't cache the policy information in kernel, having said so we can
try caching it during the LAUNCH_START to optimize this case. I have to
check with FW folks but I believe all those fields are required. IIRC,
When I passed NULL then SEND_START failed for me. But I double check it
and update you on this.
>
>> +
>> + /* copy the certificate blobs from userspace */
>> + pdh_cert = psp_copy_user_blob(params.pdh_cert_uaddr, params.pdh_cert_len);
>> + if (IS_ERR(pdh_cert)) {
>> + ret = PTR_ERR(pdh_cert);
>> + goto e_free;
>> + }
>> +
>> + data->pdh_cert_address = __psp_pa(pdh_cert);
>> + data->pdh_cert_len = params.pdh_cert_len;
>> +
>> + plat_cert = psp_copy_user_blob(params.plat_cert_uaddr, params.plat_cert_len);
>> + if (IS_ERR(plat_cert)) {
>> + ret = PTR_ERR(plat_cert);
>> + goto e_free_pdh;
>> + }
> I think plat_cert is also only required if the guest policy SEV bit is
> set. Can plat_cert also be optional?
Same as above, I believe its required.
>
>> +
>> + data->plat_cert_address = __psp_pa(plat_cert);
>> + data->plat_cert_len = params.plat_cert_len;
>> +
>> + amd_cert = psp_copy_user_blob(params.amd_cert_uaddr, params.amd_cert_len);
>> + if (IS_ERR(amd_cert)) {
>> + ret = PTR_ERR(amd_cert);
>> + goto e_free_plat_cert;
>> + }
> I think amd_cert is also only required if the guest policy SEV bit is
> set. Can amd_cert also be optional?
Same as above, I believe its required. I will double check it.
>> +
>> + data->amd_cert_address = __psp_pa(amd_cert);
>> + data->amd_cert_len = params.amd_cert_len;
>> +
>> + ret = -EINVAL;
>> + if (params.session_len > SEV_FW_BLOB_MAX_SIZE)
>> + goto e_free_amd_cert;
>> +
>> + ret = -ENOMEM;
>> + session_data = kmalloc(params.session_len, GFP_KERNEL);
>> + if (!session_data)
>> + goto e_free_amd_cert;
> This pattern of returning -EINVAL if a length is greater than
> SEV_FW_BLOB_MAX_SIZE and -ENOMEM if kmalloc fails is used at
> sev_launch_measure. And I think in your later patches you do similar,
> did you consider factoring this out into a helper function similar to
> psp_copy_user_blob?
Yes, we could factor out this check into a separate function. Let me see
what I can do in next iteration. thanks for the feedbacks.
-Brijesh
next prev parent reply other threads:[~2019-11-12 22:27 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-10 20:12 [PATCH v3 00/11] Add AMD SEV guest live migration support Singh, Brijesh
2019-07-10 20:13 ` [PATCH v3 01/11] KVM: SVM: Add KVM_SEV SEND_START command Singh, Brijesh
2019-08-22 10:08 ` Borislav Petkov
2019-08-22 13:23 ` Singh, Brijesh
2019-11-12 18:35 ` Peter Gonda
2019-11-12 22:27 ` Brijesh Singh [this message]
2019-11-14 19:27 ` Peter Gonda
2019-11-19 14:06 ` Brijesh Singh
2019-07-10 20:13 ` [PATCH v3 02/11] KVM: SVM: Add KVM_SEND_UPDATE_DATA command Singh, Brijesh
2019-08-22 12:02 ` Borislav Petkov
2019-08-22 13:27 ` Singh, Brijesh
2019-08-22 13:34 ` Borislav Petkov
2019-11-12 22:23 ` Peter Gonda
2019-07-10 20:13 ` [PATCH v3 03/11] KVM: SVM: Add KVM_SEV_SEND_FINISH command Singh, Brijesh
2019-08-26 13:29 ` Borislav Petkov
2019-07-10 20:13 ` [PATCH v3 04/11] KVM: SVM: Add support for KVM_SEV_RECEIVE_START command Singh, Brijesh
2019-07-10 20:13 ` [PATCH v3 05/11] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command Singh, Brijesh
2019-08-27 12:09 ` Borislav Petkov
2019-11-14 21:02 ` Peter Gonda
2019-07-10 20:13 ` [PATCH v3 06/11] KVM: SVM: Add KVM_SEV_RECEIVE_FINISH command Singh, Brijesh
2019-08-27 12:19 ` Borislav Petkov
2019-07-10 20:13 ` [PATCH v3 07/11] KVM: x86: Add AMD SEV specific Hypercall3 Singh, Brijesh
2019-07-10 20:13 ` [PATCH v3 08/11] KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall Singh, Brijesh
2019-07-21 20:57 ` David Rientjes
2019-07-22 17:12 ` Cfir Cohen
2019-07-23 15:31 ` Singh, Brijesh
2019-07-23 15:16 ` Singh, Brijesh
2019-11-25 19:07 ` Peter Gonda
2019-07-10 20:13 ` [PATCH v3 09/11] KVM: x86: Introduce KVM_GET_PAGE_ENC_BITMAP ioctl Singh, Brijesh
2019-08-29 16:26 ` Borislav Petkov
2019-08-29 16:41 ` Singh, Brijesh
2019-08-29 16:56 ` Borislav Petkov
2019-07-10 20:13 ` [PATCH v3 10/11] mm: x86: Invoke hypercall when page encryption status is changed Singh, Brijesh
2019-08-29 16:52 ` Borislav Petkov
2019-08-29 18:07 ` Borislav Petkov
2019-08-29 18:21 ` Thomas Gleixner
2019-08-29 18:32 ` Thomas Gleixner
2019-07-10 20:13 ` [PATCH v3 11/11] KVM: x86: Introduce KVM_SET_PAGE_ENC_BITMAP ioctl Singh, Brijesh
2019-11-15 1:22 ` Steve Rutherford
2019-11-15 1:39 ` Steve Rutherford
2019-07-12 15:52 ` [PATCH v3 00/11] Add AMD SEV guest live migration support Konrad Rzeszutek Wilk
2019-07-12 16:31 ` Singh, Brijesh
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