From: Brijesh Singh <brijesh.singh@amd.com>
To: <x86@kernel.org>, <linux-kernel@vger.kernel.org>,
<kvm@vger.kernel.org>, <linux-efi@vger.kernel.org>,
<platform-driver-x86@vger.kernel.org>,
<linux-coco@lists.linux.dev>, <linux-mm@kvack.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
Tom Lendacky <thomas.lendacky@amd.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Ard Biesheuvel <ardb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
"Vitaly Kuznetsov" <vkuznets@redhat.com>,
Jim Mattson <jmattson@google.com>,
"Andy Lutomirski" <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
"Peter Zijlstra" <peterz@infradead.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Dov Murik <dovmurik@linux.ibm.com>,
Tobin Feldman-Fitzthum <tobin@ibm.com>,
Borislav Petkov <bp@alien8.de>,
Michael Roth <michael.roth@amd.com>,
Vlastimil Babka <vbabka@suse.cz>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Andi Kleen <ak@linux.intel.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
<tony.luck@intel.com>, <marcorr@google.com>,
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH v7 45/45] virt: sevguest: Add support to get extended report
Date: Wed, 10 Nov 2021 16:07:31 -0600 [thread overview]
Message-ID: <20211110220731.2396491-46-brijesh.singh@amd.com> (raw)
In-Reply-To: <20211110220731.2396491-1-brijesh.singh@amd.com>
Version 2 of GHCB specification defines Non-Automatic-Exit(NAE) to get
the extended guest report. It is similar to the SNP_GET_REPORT ioctl.
The main difference is related to the additional data that will be
returned. The additional data returned is a certificate blob that can
be used by the SNP guest user. The certificate blob layout is defined
in the GHCB specification. The driver simply treats the blob as a opaque
data and copies it to userspace.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
Documentation/virt/coco/sevguest.rst | 23 +++++++
drivers/virt/coco/sevguest/sevguest.c | 93 +++++++++++++++++++++++++++
include/uapi/linux/sev-guest.h | 13 ++++
3 files changed, 129 insertions(+)
diff --git a/Documentation/virt/coco/sevguest.rst b/Documentation/virt/coco/sevguest.rst
index 0bd9a65e0370..5217a9176fb9 100644
--- a/Documentation/virt/coco/sevguest.rst
+++ b/Documentation/virt/coco/sevguest.rst
@@ -86,6 +86,29 @@ on the various fields passed in the key derivation request.
On success, the snp_derived_key_resp.data will contains the derived key value. See
the SEV-SNP specification for further details.
+
+2.3 SNP_GET_EXT_REPORT
+----------------------
+:Technology: sev-snp
+:Type: guest ioctl
+:Parameters (in/out): struct snp_ext_report_req
+:Returns (out): struct snp_report_resp on success, -negative on error
+
+The SNP_GET_EXT_REPORT ioctl is similar to the SNP_GET_REPORT. The difference is
+related to the additional certificate data that is returned with the report.
+The certificate data returned is being provided by the hypervisor through the
+SNP_SET_EXT_CONFIG.
+
+The ioctl uses the SNP_GUEST_REQUEST (MSG_REPORT_REQ) command provided by the SEV-SNP
+firmware to get the attestation report.
+
+On success, the snp_ext_report_resp.data will contain the attestation report
+and snp_ext_report_req.certs_address will contain the certificate blob. If the
+length of the blob is smaller than expected then snp_ext_report_req.certs_len will
+be updated with the expected value.
+
+See GHCB specification for further detail on how to parse the certificate blob.
+
Reference
---------
diff --git a/drivers/virt/coco/sevguest/sevguest.c b/drivers/virt/coco/sevguest/sevguest.c
index bece6856573e..15e37f3a0bb1 100644
--- a/drivers/virt/coco/sevguest/sevguest.c
+++ b/drivers/virt/coco/sevguest/sevguest.c
@@ -41,6 +41,7 @@ struct snp_guest_dev {
struct device *dev;
struct miscdevice misc;
+ void *certs_data;
struct snp_guest_crypto *crypto;
struct snp_guest_msg *request, *response;
struct snp_secrets_page_layout *layout;
@@ -438,6 +439,88 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
return rc;
}
+static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
+{
+ struct snp_guest_crypto *crypto = snp_dev->crypto;
+ struct snp_ext_report_req req;
+ struct snp_report_resp *resp;
+ int ret, npages = 0, resp_len;
+
+ if (!arg->req_data || !arg->resp_data)
+ return -EINVAL;
+
+ /* Copy the request payload from userspace */
+ if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req)))
+ return -EFAULT;
+
+ /* Message version must be non-zero */
+ if (!req.data.msg_version)
+ return -EINVAL;
+
+ if (req.certs_len) {
+ if (req.certs_len > SEV_FW_BLOB_MAX_SIZE ||
+ !IS_ALIGNED(req.certs_len, PAGE_SIZE))
+ return -EINVAL;
+ }
+
+ if (req.certs_address && req.certs_len) {
+ if (!access_ok(req.certs_address, req.certs_len))
+ return -EFAULT;
+
+ /*
+ * Initialize the intermediate buffer with all zero's. This buffer
+ * is used in the guest request message to get the certs blob from
+ * the host. If host does not supply any certs in it, then copy
+ * zeros to indicate that certificate data was not provided.
+ */
+ memset(snp_dev->certs_data, 0, req.certs_len);
+
+ npages = req.certs_len >> PAGE_SHIFT;
+ }
+
+ /*
+ * The intermediate response buffer is used while decrypting the
+ * response payload. Make sure that it has enough space to cover the
+ * authtag.
+ */
+ resp_len = sizeof(resp->data) + crypto->a_len;
+ resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
+ if (!resp)
+ return -ENOMEM;
+
+ snp_dev->input.data_npages = npages;
+ ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, req.data.msg_version,
+ SNP_MSG_REPORT_REQ, &req.data.user_data,
+ sizeof(req.data.user_data), resp->data, resp_len, &arg->fw_err);
+
+ /* If certs length is invalid then copy the returned length */
+ if (arg->fw_err == SNP_GUEST_REQ_INVALID_LEN) {
+ req.certs_len = snp_dev->input.data_npages << PAGE_SHIFT;
+
+ if (copy_to_user((void __user *)arg->req_data, &req, sizeof(req)))
+ ret = -EFAULT;
+ }
+
+ if (ret)
+ goto e_free;
+
+ /* Copy the certificate data blob to userspace */
+ if (req.certs_address && req.certs_len &&
+ copy_to_user((void __user *)req.certs_address, snp_dev->certs_data,
+ req.certs_len)) {
+ ret = -EFAULT;
+ goto e_free;
+ }
+
+ /* Copy the response payload to userspace */
+ if (copy_to_user((void __user *)arg->resp_data, resp, sizeof(*resp)))
+ ret = -EFAULT;
+
+e_free:
+ kfree(resp);
+ return ret;
+}
+
static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
{
struct snp_guest_dev *snp_dev = to_snp_dev(file);
@@ -466,6 +549,9 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
case SNP_GET_DERIVED_KEY:
ret = get_derived_key(snp_dev, &input);
break;
+ case SNP_GET_EXT_REPORT:
+ ret = get_ext_report(snp_dev, &input);
+ break;
default:
break;
}
@@ -594,6 +680,10 @@ static int __init snp_guest_probe(struct platform_device *pdev)
if (!snp_dev->response)
goto e_fail;
+ snp_dev->certs_data = alloc_shared_pages(SEV_FW_BLOB_MAX_SIZE);
+ if (!snp_dev->certs_data)
+ goto e_fail;
+
ret = -EIO;
snp_dev->crypto = init_crypto(snp_dev, snp_dev->vmpck, VMPCK_KEY_LEN);
if (!snp_dev->crypto)
@@ -607,6 +697,7 @@ static int __init snp_guest_probe(struct platform_device *pdev)
/* initial the input address for guest request */
snp_dev->input.req_gpa = __pa(snp_dev->request);
snp_dev->input.resp_gpa = __pa(snp_dev->response);
+ snp_dev->input.data_gpa = __pa(snp_dev->certs_data);
ret = misc_register(misc);
if (ret)
@@ -617,6 +708,7 @@ static int __init snp_guest_probe(struct platform_device *pdev)
e_fail:
iounmap(layout);
+ free_shared_pages(snp_dev->certs_data, SEV_FW_BLOB_MAX_SIZE);
free_shared_pages(snp_dev->request, sizeof(struct snp_guest_msg));
free_shared_pages(snp_dev->response, sizeof(struct snp_guest_msg));
@@ -629,6 +721,7 @@ static int __exit snp_guest_remove(struct platform_device *pdev)
free_shared_pages(snp_dev->request, sizeof(struct snp_guest_msg));
free_shared_pages(snp_dev->response, sizeof(struct snp_guest_msg));
+ free_shared_pages(snp_dev->certs_data, SEV_FW_BLOB_MAX_SIZE);
deinit_crypto(snp_dev->crypto);
misc_deregister(&snp_dev->misc);
diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h
index f6d9c136ff4d..3f6a9d694a47 100644
--- a/include/uapi/linux/sev-guest.h
+++ b/include/uapi/linux/sev-guest.h
@@ -57,6 +57,16 @@ struct snp_derived_key_resp {
__u8 data[64];
};
+struct snp_ext_report_req {
+ struct snp_report_req data;
+
+ /* where to copy the certificate blob */
+ __u64 certs_address;
+
+ /* length of the certificate blob */
+ __u32 certs_len;
+};
+
#define SNP_GUEST_REQ_IOC_TYPE 'S'
/* Get SNP attestation report */
@@ -65,4 +75,7 @@ struct snp_derived_key_resp {
/* Get a derived key from the root */
#define SNP_GET_DERIVED_KEY _IOWR(SNP_GUEST_REQ_IOC_TYPE, 0x1, struct snp_guest_request_ioctl)
+/* Get SNP extended report as defined in the GHCB specification version 2. */
+#define SNP_GET_EXT_REPORT _IOWR(SNP_GUEST_REQ_IOC_TYPE, 0x2, struct snp_guest_request_ioctl)
+
#endif /* __UAPI_LINUX_SEV_GUEST_H_ */
--
2.25.1
next prev parent reply other threads:[~2021-11-10 22:09 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-10 22:06 [PATCH v7 00/45] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 01/45] x86/compressed/64: detect/setup SEV/SME features earlier in boot Brijesh Singh
2021-11-12 16:52 ` Borislav Petkov
2021-11-12 20:30 ` Michael Roth
2021-11-23 21:55 ` Venu Busireddy
2021-11-10 22:06 ` [PATCH v7 02/45] x86/sev: " Brijesh Singh
2021-11-15 19:12 ` Borislav Petkov
2021-11-15 20:17 ` Michael Roth
2021-11-17 13:11 ` Borislav Petkov
2021-12-06 23:47 ` Venu Busireddy
2021-11-10 22:06 ` [PATCH v7 03/45] x86/mm: Extend cc_attr to include AMD SEV-SNP Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 04/45] x86/sev: Shorten GHCB terminate macro names Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 05/45] x86/sev: Get rid of excessive use of defines Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 06/45] x86/head64: Carve out the guest encryption postprocessing into a helper Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 07/45] x86/sev: Remove do_early_exception() forward declarations Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 08/45] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 09/45] x86/sev: Save the negotiated GHCB version Brijesh Singh
2021-12-07 12:51 ` Tianyu Lan
2021-12-07 13:17 ` Borislav Petkov
2021-12-07 16:58 ` Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 10/45] x86/sev: Add support for hypervisor feature VMGEXIT Brijesh Singh
2021-12-02 17:52 ` Borislav Petkov
2021-12-06 15:15 ` Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 11/45] x86/sev: Check SEV-SNP features support Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 12/45] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2021-11-10 22:06 ` [PATCH v7 13/45] x86/sev: Check the vmpl level Brijesh Singh
2021-12-06 18:25 ` Borislav Petkov
2021-11-10 22:07 ` [PATCH v7 14/45] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2021-12-07 11:48 ` Borislav Petkov
2021-12-07 19:21 ` Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 15/45] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2021-11-15 14:05 ` Jörg Rödel
2021-11-10 22:07 ` [PATCH v7 16/45] x86/sev: " Brijesh Singh
2021-12-08 17:41 ` Borislav Petkov
2021-11-10 22:07 ` [PATCH v7 17/45] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 18/45] x86/kernel: Make the bss.decrypted section shared in RMP table Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 19/45] x86/kernel: Validate rom memory before accessing when SEV-SNP is active Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 20/45] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 21/45] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 22/45] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 23/45] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 24/45] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 25/45] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 26/45] x86/head: re-enable stack protection for 32/64-bit builds Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 27/45] x86/sev: move MSR-based VMGEXITs for CPUID to helper Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 28/45] KVM: x86: move lookup of indexed CPUID leafs " Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 29/45] x86/compressed/acpi: move EFI system table lookup " Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 30/45] x86/compressed/acpi: move EFI config " Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 31/45] x86/compressed/acpi: move EFI vendor " Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 32/45] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 33/45] KVM: SEV: Add documentation for SEV-SNP CPUID Enforcement Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 34/45] x86/compressed/64: add support for SEV-SNP CPUID table in #VC handlers Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 35/45] x86/boot: add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 36/45] x86/compressed: add SEV-SNP feature detection/setup Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 37/45] x86/compressed: use firmware-validated CPUID for SEV-SNP guests Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 38/45] x86/compressed/64: add identity mapping for Confidential Computing blob Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 39/45] x86/sev: add SEV-SNP feature detection/setup Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 40/45] x86/sev: use firmware-validated CPUID for SEV-SNP guests Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 41/45] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 42/45] x86/sev: Register SNP guest request platform device Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 43/45] virt: Add SEV-SNP guest driver Brijesh Singh
2021-11-10 22:27 ` Randy Dunlap
2021-11-11 19:27 ` Brijesh Singh
2021-11-11 22:57 ` Randy Dunlap
2021-11-17 23:34 ` Peter Gonda
2021-11-18 17:08 ` Peter Gonda
2021-11-18 17:32 ` Brijesh Singh
2021-11-19 16:16 ` Peter Gonda
2021-11-20 0:28 ` Brijesh Singh
2021-11-10 22:07 ` [PATCH v7 44/45] virt: sevguest: Add support to derive key Brijesh Singh
2021-11-18 16:43 ` Peter Gonda
2021-11-18 17:43 ` Brijesh Singh
2021-11-10 22:07 ` Brijesh Singh [this message]
2021-11-15 15:56 ` [PATCH v7 00/45] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Venu Busireddy
2021-11-15 16:02 ` Brijesh Singh
2021-11-15 16:37 ` Venu Busireddy
2021-11-15 16:45 ` Brijesh Singh
2021-11-15 16:55 ` Venu Busireddy
2021-11-16 15:45 ` Venu Busireddy
2021-11-16 16:03 ` Brijesh Singh
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