From: Borislav Petkov <bp@alien8.de>
To: Brijesh Singh <brijesh.singh@amd.com>
Cc: 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, 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>,
Wanpeng Li <wanpengli@tencent.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>,
Michael Roth <michael.roth@amd.com>,
Vlastimil Babka <vbabka@suse.cz>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Andi Kleen <ak@linux.intel.com>,
tony.luck@intel.com, marcorr@google.com,
sathyanarayanan.kuppuswamy@linux.intel.com
Subject: Re: [PATCH Part1 v5 36/38] virt: Add SEV-SNP guest driver
Date: Mon, 6 Sep 2021 19:38:08 +0200 [thread overview]
Message-ID: <YTZSAB5H9EC2uk8z@zn.tnic> (raw)
In-Reply-To: <20210820151933.22401-37-brijesh.singh@amd.com>
On Fri, Aug 20, 2021 at 10:19:31AM -0500, Brijesh Singh wrote:
> +===================================================================
> +The Definitive SEV Guest API Documentation
> +===================================================================
> +
> +1. General description
> +======================
> +
> +The SEV API is a set of ioctls that are issued to by the guest or
issued to by?
Issued by the guest or hypervisor, you mean..
> +hypervisor to get or set certain aspect of the SEV virtual machine.
> +The ioctls belong to the following classes:
> +
> + - Hypervisor ioctls: These query and set global attributes which affect the
> + whole SEV firmware. These ioctl is used by platform provision tools.
"These ioctls are used ... "
> +
> + - Guest ioctls: These query and set attribute of the SEV virtual machine.
"... attributes... "
> +
> +2. API description
> +==================
> +
> +This section describes ioctls that can be used to query or set SEV guests.
> +For each ioctl, the following information is provided along with a
> +description:
> +
> + Technology:
> + which SEV techology provides this ioctl. sev, sev-es, sev-snp or all.
> +
> + Type:
> + hypervisor or guest. The ioctl can be used inside the guest or the
> + hypervisor.
> +
> + Parameters:
> + what parameters are accepted by the ioctl.
> +
> + Returns:
> + the return value. General error numbers (ENOMEM, EINVAL)
> + are not detailed, but errors with specific meanings are.
> +
> +The guest ioctl should be called to /dev/sev-guest device. The ioctl accepts
s/called to/issued on a file descriptor of the/
> +struct snp_user_guest_request. The input and output structure is specified
> +through the req_data and resp_data field respectively. If the ioctl fails
> +to execute due to the firmware error, then fw_err code will be set.
"... due to a ... "
> +
> +::
> + struct snp_user_guest_request {
So you said earlier:
> I followed the naming convension you recommended during the initial SEV driver
> developement. IIRC, the main reason for us having to add "user" in it because
> we wanted to distinguious that this structure is not exactly same as the what
> is defined in the SEV-SNP firmware spec.
but looking at the current variant in the code, the structure in the SNP spec is
Table 91. Layout of the CMDBUF_SNP_GUEST_REQUEST Structure
which corresponds to struct snp_guest_request_data so you can call this one:
struct snp_guest_request_ioctl
and then it is perfectly clear what is what.
> + /* Request and response structure address */
> + __u64 req_data;
> + __u64 resp_data;
> +
> + /* firmware error code on failure (see psp-sev.h) */
> + __u64 fw_err;
> + };
> +
> +2.1 SNP_GET_REPORT
> +------------------
> +
> +:Technology: sev-snp
> +:Type: guest ioctl
> +:Parameters (in): struct snp_report_req
> +:Returns (out): struct snp_report_resp on success, -negative on error
> +
> +The SNP_GET_REPORT ioctl can be used to query the attestation report from the
> +SEV-SNP firmware. The ioctl uses the SNP_GUEST_REQUEST (MSG_REPORT_REQ) command
> +provided by the SEV-SNP firmware to query the attestation report.
> +
> +On success, the snp_report_resp.data will contains the report. The report
"... will contain... "
> +format is described in the SEV-SNP specification. See the SEV-SNP specification
> +for further details.
"... which can be found at https://developer.amd.com/sev/."
assuming that URL will keep its validity in the foreseeable future.
> +static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
> +{
> + struct snp_guest_dev *snp_dev = to_snp_dev(file);
> + void __user *argp = (void __user *)arg;
> + struct snp_user_guest_request input;
> + int ret = -ENOTTY;
> +
> + if (copy_from_user(&input, argp, sizeof(input)))
> + return -EFAULT;
> +
> + mutex_lock(&snp_cmd_mutex);
> +
> + switch (ioctl) {
> + case SNP_GET_REPORT: {
> + ret = get_report(snp_dev, &input);
> + break;
> + }
No need for those {} brackets around the case.
> + default:
> + break;
> + }
> +
> + mutex_unlock(&snp_cmd_mutex);
> +
> + if (copy_to_user(argp, &input, sizeof(input)))
> + return -EFAULT;
> +
> + return ret;
> +}
> +
> +static void free_shared_pages(void *buf, size_t sz)
> +{
> + unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
> +
> + /* If fail to restore the encryption mask then leak it. */
> + if (set_memory_encrypted((unsigned long)buf, npages))
Hmm, this sounds like an abnormal condition about which we should at
least warn...
> + return;
> +
> + __free_pages(virt_to_page(buf), get_order(sz));
> +}
> +
> +static void *alloc_shared_pages(size_t sz)
> +{
> + unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
> + struct page *page;
> + int ret;
> +
> + page = alloc_pages(GFP_KERNEL_ACCOUNT, get_order(sz));
> + if (IS_ERR(page))
> + return NULL;
> +
> + ret = set_memory_decrypted((unsigned long)page_address(page), npages);
> + if (ret) {
> + __free_pages(page, get_order(sz));
> + return NULL;
> + }
> +
> + return page_address(page);
> +}
> +
> +static const struct file_operations snp_guest_fops = {
> + .owner = THIS_MODULE,
> + .unlocked_ioctl = snp_guest_ioctl,
> +};
> +
> +static int __init snp_guest_probe(struct platform_device *pdev)
> +{
> + struct snp_guest_platform_data *data;
> + struct device *dev = &pdev->dev;
> + struct snp_guest_dev *snp_dev;
> + struct miscdevice *misc;
> + int ret;
> +
> + if (!dev->platform_data)
> + return -ENODEV;
> +
> + data = (struct snp_guest_platform_data *)dev->platform_data;
> + vmpck_id = data->vmpck_id;
> +
> + snp_dev = devm_kzalloc(&pdev->dev, sizeof(struct snp_guest_dev), GFP_KERNEL);
> + if (!snp_dev)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, snp_dev);
> + snp_dev->dev = dev;
> +
> + snp_dev->crypto = init_crypto(snp_dev, data->vmpck, sizeof(data->vmpck));
> + if (!snp_dev->crypto)
> + return -EIO;
I guess you should put the crypto init...
> +
> + /* Allocate the shared page used for the request and response message. */
> + snp_dev->request = alloc_shared_pages(sizeof(struct snp_guest_msg));
> + if (IS_ERR(snp_dev->request)) {
> + ret = PTR_ERR(snp_dev->request);
> + goto e_free_crypto;
> + }
> +
> + snp_dev->response = alloc_shared_pages(sizeof(struct snp_guest_msg));
> + if (IS_ERR(snp_dev->response)) {
> + ret = PTR_ERR(snp_dev->response);
> + goto e_free_req;
> + }
... here, after the page allocation to save yourself all the setup work
if the shared pages allocation fails.
> +
> + misc = &snp_dev->misc;
> + misc->minor = MISC_DYNAMIC_MINOR;
> + misc->name = DEVICE_NAME;
> + misc->fops = &snp_guest_fops;
> +
> + return misc_register(misc);
> +
> +e_free_req:
> + free_shared_pages(snp_dev->request, sizeof(struct snp_guest_msg));
> +
> +e_free_crypto:
> + deinit_crypto(snp_dev->crypto);
> +
> + return ret;
> +}
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-09-06 17:38 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 15:18 [PATCH Part1 v5 00/38] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 01/38] x86/mm: Add sev_feature_enabled() helper Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 02/38] x86/sev: Shorten GHCB terminate macro names Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 03/38] x86/sev: Get rid of excessive use of defines Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 04/38] x86/head64: Carve out the guest encryption postprocessing into a helper Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 05/38] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 06/38] x86/sev: Save the negotiated GHCB version Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 07/38] x86/sev: Add support for hypervisor feature VMGEXIT Brijesh Singh
2021-08-23 9:47 ` Borislav Petkov
2021-08-23 18:25 ` Brijesh Singh
2021-08-23 18:34 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 08/38] x86/sev: Check SEV-SNP features support Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 09/38] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 10/38] x86/sev: Check the vmpl level Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 11/38] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2021-08-23 14:16 ` Borislav Petkov
2021-08-23 18:55 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 12/38] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 13/38] x86/sev: " Brijesh Singh
2021-08-23 17:35 ` Borislav Petkov
2021-08-23 18:56 ` Brijesh Singh
2021-08-23 19:45 ` [PATCH] x86/sev: Remove do_early_exception() forward declarations Borislav Petkov
2021-08-23 20:06 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 14/38] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 15/38] x86/kernel: Make the bss.decrypted section shared in RMP table Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 16/38] x86/kernel: Validate rom memory before accessing when SEV-SNP is active Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 17/38] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2021-08-25 11:06 ` Borislav Petkov
2021-08-25 13:54 ` Brijesh Singh
2021-08-25 14:00 ` Borislav Petkov
2021-08-27 17:09 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 18/38] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 19/38] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 20/38] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 21/38] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 22/38] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 23/38] x86/head/64: set up a startup %gs for stack protector Brijesh Singh
2021-08-25 14:29 ` Borislav Petkov
2021-08-25 15:18 ` Michael Roth
2021-08-25 16:29 ` Borislav Petkov
2021-08-27 13:38 ` Michael Roth
2021-08-31 8:03 ` Borislav Petkov
2021-08-31 23:30 ` Michael Roth
2021-08-25 15:07 ` Joerg Roedel
2021-08-25 17:07 ` Michael Roth
2021-08-20 15:19 ` [PATCH Part1 v5 24/38] x86/sev: move MSR-based VMGEXITs for CPUID to helper Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 25/38] KVM: x86: move lookup of indexed CPUID leafs " Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 26/38] x86/compressed/acpi: move EFI config table access to common code Brijesh Singh
2021-08-25 15:18 ` Borislav Petkov
2021-08-25 17:14 ` Michael Roth
2021-08-20 15:19 ` [PATCH Part1 v5 27/38] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 28/38] x86/compressed/64: enable SEV-SNP-validated CPUID in #VC handler Brijesh Singh
2021-08-25 19:19 ` Borislav Petkov
2021-08-27 16:46 ` Michael Roth
2021-08-31 10:04 ` Borislav Petkov
2021-09-01 1:03 ` Michael Roth
2021-09-02 10:53 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 29/38] x86/boot: add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2021-08-27 13:51 ` Borislav Petkov
2021-08-27 18:48 ` Michael Roth
2021-08-20 15:19 ` [PATCH Part1 v5 30/38] x86/compressed/64: store Confidential Computing blob address " Brijesh Singh
2021-08-27 14:15 ` Borislav Petkov
2021-08-27 19:09 ` Michael Roth
2021-08-31 10:26 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 31/38] x86/compressed/64: add identity mapping for Confidential Computing blob Brijesh Singh
2021-08-27 14:43 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 32/38] x86/sev: enable SEV-SNP-validated CPUID in #VC handlers Brijesh Singh
2021-08-27 15:18 ` Borislav Petkov
2021-08-27 15:47 ` Brijesh Singh
2021-08-27 16:56 ` Borislav Petkov
2021-08-27 18:39 ` Michael Roth
2021-08-27 18:32 ` Michael Roth
2021-08-30 16:03 ` Michael Roth
2021-08-31 16:22 ` Borislav Petkov
2021-09-01 1:16 ` Michael Roth
2021-09-02 11:05 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 33/38] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2021-08-27 17:44 ` Borislav Petkov
2021-08-27 18:07 ` Brijesh Singh
2021-08-27 18:13 ` Borislav Petkov
2021-08-27 18:27 ` Brijesh Singh
2021-08-27 18:38 ` Borislav Petkov
2021-08-27 19:57 ` Tom Lendacky
2021-08-27 20:17 ` Borislav Petkov
2021-08-27 20:31 ` Tom Lendacky
2021-08-20 15:19 ` [PATCH Part1 v5 34/38] x86/sev: Add snp_msg_seqno() helper Brijesh Singh
2021-08-27 18:41 ` Borislav Petkov
2021-08-30 15:07 ` Brijesh Singh
2021-09-02 11:26 ` Borislav Petkov
2021-09-02 15:27 ` Brijesh Singh
2021-08-31 20:46 ` Dov Murik
2021-08-31 21:13 ` Brijesh Singh
2021-09-09 14:54 ` Peter Gonda
2021-09-09 15:26 ` Brijesh Singh
2021-09-09 15:43 ` Peter Gonda
2021-09-09 16:17 ` Brijesh Singh
2021-09-09 16:21 ` Peter Gonda
2021-09-09 19:26 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 35/38] x86/sev: Register SNP guest request platform device Brijesh Singh
2021-08-31 11:37 ` Dov Murik
2021-08-31 16:03 ` Brijesh Singh
2021-09-02 16:40 ` Borislav Petkov
2021-09-02 19:58 ` Brijesh Singh
2021-09-03 8:15 ` Dov Murik
2021-09-03 12:08 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 36/38] virt: Add SEV-SNP guest driver Brijesh Singh
2021-09-06 17:38 ` Borislav Petkov [this message]
2021-09-07 13:35 ` Brijesh Singh
2021-09-08 13:44 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 37/38] virt: sevguest: Add support to derive key Brijesh Singh
2021-08-31 18:59 ` Dov Murik
2021-08-31 21:04 ` Brijesh Singh
2021-09-01 5:33 ` Dov Murik
2021-09-08 14:00 ` Borislav Petkov
2021-09-08 21:44 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 38/38] virt: sevguest: Add support to get extended report Brijesh Singh
2021-08-31 20:22 ` Dov Murik
2021-08-31 21:11 ` Brijesh Singh
2021-09-01 8:32 ` Dov Murik
2021-09-08 17:53 ` Borislav Petkov
2021-09-15 11:46 ` Brijesh Singh
2021-09-15 10:02 ` Dr. David Alan Gilbert
2021-09-15 11:53 ` Brijesh Singh
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