Re: [PATCH v13 01/12] KVM: SVM: Add KVM_SEV SEND_START command
On 15/04/21 17:53, Ashish Kalra wrote:
From: Brijesh Singh
The command is used to create an outgoing SEV guest encryption context.
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: "H. Peter Anvin"
Cc: Paolo Bonzini
Cc: Joerg Roedel
Cc: Borislav Petkov
Cc: Tom Lendacky
Cc: x...@kernel.org
Cc: k...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Steve Rutherford
Reviewed-by: Venu Busireddy
Signed-off-by: Brijesh Singh
Signed-off-by: Ashish Kalra
---
.../virt/kvm/amd-memory-encryption.rst| 27
arch/x86/kvm/svm/sev.c| 125 ++
include/linux/psp-sev.h | 8 +-
include/uapi/linux/kvm.h | 12 ++
4 files changed, 168 insertions(+), 4 deletions(-)
diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst
b/Documentation/virt/kvm/amd-memory-encryption.rst
index 469a6308765b..ac799dd7a618 100644
--- a/Documentation/virt/kvm/amd-memory-encryption.rst
+++ b/Documentation/virt/kvm/amd-memory-encryption.rst
@@ -284,6 +284,33 @@ Returns: 0 on success, -negative on error
__u32 len;
};
+10. KVM_SEV_SEND_START
+--
+
+The KVM_SEV_SEND_START command can be used by the hypervisor to create an
+outgoing guest encryption context.
+
+Parameters (in): struct kvm_sev_send_start
+
+Returns: 0 on success, -negative on error
+
+::
+struct kvm_sev_send_start {
+__u32 policy; /* guest policy */
+
+__u64 pdh_cert_uaddr; /* platform Diffie-Hellman
certificate */
+__u32 pdh_cert_len;
+
+__u64 plat_certs_uaddr;/* platform certificate chain */
+__u32 plat_certs_len;
+
+__u64 amd_certs_uaddr;/* AMD certificate */
+__u32 amd_certs_len;
+
+__u64 session_uaddr; /* Guest session information */
+__u32 session_len;
+};
+
References
==
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 874ea309279f..2b65900c05d6 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1110,6 +1110,128 @@ static int sev_get_attestation_report(struct kvm *kvm,
struct kvm_sev_cmd *argp)
return ret;
}
+/* Userspace wants to query session length. */
+static int
+__sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd
*argp,
+ struct kvm_sev_send_start *params)
+{
+ struct kvm_sev_info *sev = _kvm_svm(kvm)->sev_info;
+ struct sev_data_send_start *data;
+ int ret;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
+ if (data == NULL)
+ return -ENOMEM;
+
+ data->handle = sev->handle;
+ ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, data, >error);
This is missing an "if (ret < 0)" (and this time I'm pretty sure it's
indeed the case :)), otherwise you miss for example the EBADF return
code if the SEV file descriptor is closed or reused. Same for
KVM_SEND_UPDATE_DATA. Also, the length==0 case is not documented.
Paolo
+ params->session_len = data->session_len;
+ if (copy_to_user((void __user *)(uintptr_t)argp->data, params,
+ sizeof(struct kvm_sev_send_start)))
+ ret = -EFAULT;
+
+ kfree(data);
+ return ret;
+}
+
+static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+ struct kvm_sev_info *sev = _kvm_svm(kvm)->sev_info;
+ struct sev_data_send_start *data;
+ struct kvm_sev_send_start params;
+ void *amd_certs, *session_data;
+ void *pdh_cert, *plat_certs;
+ int ret;
+
+ if (!sev_guest(kvm))
+ return -ENOTTY;
+
+ if (copy_from_user(, (void __user *)(uintptr_t)argp->data,
+ sizeof(struct kvm_sev_send_start)))
+ return -EFAULT;
+
+ /* if session_len is zero, userspace wants to query the session length
*/
+ if (!params.session_len)
+ return __sev_send_start_query_session_length(kvm, argp,
+ );
+
+ /* some sanity checks */
+ if (!params.pdh_cert_uaddr || !params.pdh_cert_len ||
+ !params.session_uaddr || params.session_len > SEV_FW_BLOB_MAX_SIZE)
+ return -EINVAL;
+
+ /* allocate the memory to hold the session data blob */
+ session_data = kmalloc(params.session_len, GFP_KERNEL_ACCOUNT);
+ if (!session_data)
+ return -ENOMEM;
+
+ /* 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_session;
+ }
+
+ plat_certs = psp_copy_user_blob(params.plat_certs_uaddr,
+
[PATCH v13 01/12] KVM: SVM: Add KVM_SEV SEND_START command
From: Brijesh Singh
The command is used to create an outgoing SEV guest encryption context.
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: "H. Peter Anvin"
Cc: Paolo Bonzini
Cc: Joerg Roedel
Cc: Borislav Petkov
Cc: Tom Lendacky
Cc: x...@kernel.org
Cc: k...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Steve Rutherford
Reviewed-by: Venu Busireddy
Signed-off-by: Brijesh Singh
Signed-off-by: Ashish Kalra
---
.../virt/kvm/amd-memory-encryption.rst| 27
arch/x86/kvm/svm/sev.c| 125 ++
include/linux/psp-sev.h | 8 +-
include/uapi/linux/kvm.h | 12 ++
4 files changed, 168 insertions(+), 4 deletions(-)
diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst
b/Documentation/virt/kvm/amd-memory-encryption.rst
index 469a6308765b..ac799dd7a618 100644
--- a/Documentation/virt/kvm/amd-memory-encryption.rst
+++ b/Documentation/virt/kvm/amd-memory-encryption.rst
@@ -284,6 +284,33 @@ Returns: 0 on success, -negative on error
__u32 len;
};
+10. KVM_SEV_SEND_START
+--
+
+The KVM_SEV_SEND_START command can be used by the hypervisor to create an
+outgoing guest encryption context.
+
+Parameters (in): struct kvm_sev_send_start
+
+Returns: 0 on success, -negative on error
+
+::
+struct kvm_sev_send_start {
+__u32 policy; /* guest policy */
+
+__u64 pdh_cert_uaddr; /* platform Diffie-Hellman
certificate */
+__u32 pdh_cert_len;
+
+__u64 plat_certs_uaddr;/* platform certificate chain */
+__u32 plat_certs_len;
+
+__u64 amd_certs_uaddr;/* AMD certificate */
+__u32 amd_certs_len;
+
+__u64 session_uaddr; /* Guest session information */
+__u32 session_len;
+};
+
References
==
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 874ea309279f..2b65900c05d6 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1110,6 +1110,128 @@ static int sev_get_attestation_report(struct kvm *kvm,
struct kvm_sev_cmd *argp)
return ret;
}
+/* Userspace wants to query session length. */
+static int
+__sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd
*argp,
+ struct kvm_sev_send_start *params)
+{
+ struct kvm_sev_info *sev = _kvm_svm(kvm)->sev_info;
+ struct sev_data_send_start *data;
+ int ret;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
+ if (data == NULL)
+ return -ENOMEM;
+
+ data->handle = sev->handle;
+ ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, data, >error);
+
+ params->session_len = data->session_len;
+ if (copy_to_user((void __user *)(uintptr_t)argp->data, params,
+ sizeof(struct kvm_sev_send_start)))
+ ret = -EFAULT;
+
+ kfree(data);
+ return ret;
+}
+
+static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+ struct kvm_sev_info *sev = _kvm_svm(kvm)->sev_info;
+ struct sev_data_send_start *data;
+ struct kvm_sev_send_start params;
+ void *amd_certs, *session_data;
+ void *pdh_cert, *plat_certs;
+ int ret;
+
+ if (!sev_guest(kvm))
+ return -ENOTTY;
+
+ if (copy_from_user(, (void __user *)(uintptr_t)argp->data,
+ sizeof(struct kvm_sev_send_start)))
+ return -EFAULT;
+
+ /* if session_len is zero, userspace wants to query the session length
*/
+ if (!params.session_len)
+ return __sev_send_start_query_session_length(kvm, argp,
+ );
+
+ /* some sanity checks */
+ if (!params.pdh_cert_uaddr || !params.pdh_cert_len ||
+ !params.session_uaddr || params.session_len > SEV_FW_BLOB_MAX_SIZE)
+ return -EINVAL;
+
+ /* allocate the memory to hold the session data blob */
+ session_data = kmalloc(params.session_len, GFP_KERNEL_ACCOUNT);
+ if (!session_data)
+ return -ENOMEM;
+
+ /* 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_session;
+ }
+
+ plat_certs = psp_copy_user_blob(params.plat_certs_uaddr,
+ params.plat_certs_len);
+ if (IS_ERR(plat_certs)) {
+ ret = PTR_ERR(plat_certs);
+ goto e_free_pdh;
+ }
+
+ amd_certs = psp_copy_user_blob(params.amd_certs_uaddr,
+ params.amd_certs_len);
+ if (IS_ERR(amd_certs)) {
+ ret =
