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>,
<brijesh.ksingh@gmail.com>, <tony.luck@intel.com>,
<marcorr@google.com>,
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH v10 44/45] virt: sevguest: Add support to get extended report
Date: Wed, 9 Feb 2022 12:10:38 -0600 [thread overview]
Message-ID: <20220209181039.1262882-45-brijesh.singh@amd.com> (raw)
In-Reply-To: <20220209181039.1262882-1-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, 127 insertions(+), 2 deletions(-)
diff --git a/Documentation/virt/coco/sevguest.rst b/Documentation/virt/coco/sevguest.rst
index ae2e76f59435..0f352056572d 100644
--- a/Documentation/virt/coco/sevguest.rst
+++ b/Documentation/virt/coco/sevguest.rst
@@ -95,6 +95,29 @@ on the various fields passed in the key derivation request.
On success, the snp_derived_key_resp.data 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 2062f94fdc38..b840cf426f38 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;
@@ -431,6 +432,83 @@ 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 = {0};
+ struct snp_report_resp *resp;
+ int ret, npages = 0, resp_len;
+
+ lockdep_assert_held(&snp_cmd_mutex);
+
+ if (!arg->req_data || !arg->resp_data)
+ return -EINVAL;
+
+ if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req)))
+ return -EFAULT;
+
+ 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 zeros. 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, arg->msg_version,
+ SNP_MSG_REPORT_REQ, &req.data,
+ sizeof(req.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;
+
+ 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;
+ }
+
+ 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);
@@ -463,6 +541,9 @@ 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;
}
@@ -590,10 +671,14 @@ static int __init snp_guest_probe(struct platform_device *pdev)
if (!snp_dev->response)
goto e_free_request;
+ snp_dev->certs_data = alloc_shared_pages(SEV_FW_BLOB_MAX_SIZE);
+ if (!snp_dev->certs_data)
+ goto e_free_response;
+
ret = -EIO;
snp_dev->crypto = init_crypto(snp_dev, snp_dev->vmpck, VMPCK_KEY_LEN);
if (!snp_dev->crypto)
- goto e_free_response;
+ goto e_free_cert_data;
misc = &snp_dev->misc;
misc->minor = MISC_DYNAMIC_MINOR;
@@ -603,14 +688,17 @@ 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)
- goto e_free_response;
+ goto e_free_cert_data;
dev_info(dev, "Initialized SNP guest driver (using vmpck_id %d)\n", vmpck_id);
return 0;
+e_free_cert_data:
+ free_shared_pages(snp_dev->certs_data, SEV_FW_BLOB_MAX_SIZE);
e_free_response:
free_shared_pages(snp_dev->response, sizeof(struct snp_guest_msg));
e_free_request:
@@ -624,6 +712,7 @@ static int __exit snp_guest_remove(struct platform_device *pdev)
{
struct snp_guest_dev *snp_dev = platform_get_drvdata(pdev);
+ free_shared_pages(snp_dev->certs_data, SEV_FW_BLOB_MAX_SIZE);
free_shared_pages(snp_dev->response, sizeof(struct snp_guest_msg));
free_shared_pages(snp_dev->request, sizeof(struct snp_guest_msg));
deinit_crypto(snp_dev->crypto);
diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h
index 598367f12064..256aaeff7e65 100644
--- a/include/uapi/linux/sev-guest.h
+++ b/include/uapi/linux/sev-guest.h
@@ -56,6 +56,16 @@ struct snp_guest_request_ioctl {
__u64 fw_err;
};
+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 */
@@ -64,4 +74,7 @@ struct snp_guest_request_ioctl {
/* 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:[~2022-02-09 18:13 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-09 18:09 [PATCH v10 00/45] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2022-02-09 18:09 ` [PATCH v10 01/45] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2022-02-09 18:09 ` [PATCH v10 02/45] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2022-02-09 18:09 ` [PATCH v10 03/45] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2022-02-09 18:09 ` [PATCH v10 04/45] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2022-02-09 18:09 ` [PATCH v10 05/45] x86/boot: Introduce helpers for MSR reads/writes Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 06/45] x86/boot: Use MSR read/write helpers instead of inline assembly Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 07/45] x86/compressed/64: Detect/setup SEV/SME features earlier in boot Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 08/45] x86/sev: " Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 09/45] x86/mm: Extend cc_attr to include AMD SEV-SNP Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 10/45] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 11/45] x86/sev: Save the negotiated GHCB version Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 12/45] x86/sev: Check SEV-SNP features support Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 13/45] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 14/45] x86/sev: Check the vmpl level Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 15/45] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 16/45] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 17/45] x86/sev: " Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 18/45] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 19/45] x86/kernel: Make the .bss..decrypted section shared in RMP table Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 20/45] x86/kernel: Validate ROM memory before accessing when SEV-SNP is active Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 21/45] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2022-02-10 16:48 ` Borislav Petkov
2022-02-11 14:55 ` Borislav Petkov
2022-02-11 17:27 ` Brijesh Singh
2022-02-13 12:15 ` Borislav Petkov
2022-02-13 14:50 ` Tom Lendacky
2022-02-13 17:21 ` Borislav Petkov
2022-02-15 12:43 ` Kirill A. Shutemov
2022-02-15 12:54 ` Borislav Petkov
2022-02-15 13:15 ` Kirill A. Shutemov
2022-02-15 14:41 ` Borislav Petkov
2022-02-16 13:32 ` Borislav Petkov
2022-02-09 18:10 ` [PATCH v10 22/45] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 23/45] x86/head/64: Re-enable stack protection Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 24/45] x86/compressed/acpi: Move EFI detection to helper Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 25/45] x86/compressed/acpi: Move EFI system table lookup " Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 26/45] x86/compressed/acpi: Move EFI config " Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 27/45] x86/compressed/acpi: Move EFI vendor " Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 28/45] x86/compressed/acpi: Move EFI kexec handling into common code Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 29/45] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 30/45] KVM: x86: Move lookup of indexed CPUID leafs to helper Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 31/45] x86/sev: Move MSR-based VMGEXITs for CPUID " Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 32/45] x86/compressed/64: Add support for SEV-SNP CPUID table in #VC handlers Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 33/45] x86/boot: Add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 34/45] x86/compressed: Add SEV-SNP feature detection/setup Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 35/45] x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guests Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 36/45] x86/compressed: Export and rename add_identity_map() Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 37/45] x86/compressed/64: Add identity mapping for Confidential Computing blob Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 38/45] x86/sev: Add SEV-SNP feature detection/setup Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 39/45] x86/sev: Use firmware-validated CPUID for SEV-SNP guests Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 40/45] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 41/45] x86/sev: Register SEV-SNP guest request platform device Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 42/45] virt: Add SEV-SNP guest driver Brijesh Singh
2022-02-09 18:10 ` [PATCH v10 43/45] virt: sevguest: Add support to derive key Brijesh Singh
2022-02-09 18:10 ` Brijesh Singh [this message]
2022-02-09 18:10 ` [PATCH v10 45/45] virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement Brijesh Singh
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