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Shutemov" , Andi Kleen , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH Part1 v5 33/38] x86/sev: Provide support for SNP guest request NAEs Message-ID: References: <20210820151933.22401-1-brijesh.singh@amd.com> <20210820151933.22401-34-brijesh.singh@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210820151933.22401-34-brijesh.singh@amd.com> Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=alien8.de header.s=dkim header.b=CnZ7xUnX; dmarc=pass (policy=none) header.from=alien8.de; spf=pass (imf04.hostedemail.com: domain of bp@alien8.de designates 5.9.137.197 as permitted sender) smtp.mailfrom=bp@alien8.de X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: F1BCB50000A4 X-Stat-Signature: zi4dbwmho6t9c9k7ag1ki7rfjntn7dc9 X-HE-Tag: 1630086217-951086 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Aug 20, 2021 at 10:19:28AM -0500, Brijesh Singh wrote: > +int snp_issue_guest_request(int type, struct snp_guest_request_data *input, unsigned long *fw_err) > +{ > + struct ghcb_state state; > + unsigned long id, flags; > + struct ghcb *ghcb; > + int ret; > + > + if (!sev_feature_enabled(SEV_SNP)) > + return -ENODEV; > + > + local_irq_save(flags); > + > + ghcb = __sev_get_ghcb(&state); > + if (!ghcb) { > + ret = -EIO; > + goto e_restore_irq; > + } > + > + vc_ghcb_invalidate(ghcb); > + > + if (type == GUEST_REQUEST) { > + id = SVM_VMGEXIT_GUEST_REQUEST; > + } else if (type == EXT_GUEST_REQUEST) { > + id = SVM_VMGEXIT_EXT_GUEST_REQUEST; > + ghcb_set_rax(ghcb, input->data_gpa); > + ghcb_set_rbx(ghcb, input->data_npages); Hmmm, now I'm not sure. We did enum psc_op where you simply pass in the op directly to the hardware because the enum uses the same numbers as the actual command. But here that @type thing is simply used to translate to the SVM_VMGEXIT thing. So maybe you don't need it here and you can hand in the exit_code directly: int snp_issue_guest_request(u64 exit_code, struct snp_guest_request_data *input, unsigned long *fw_err) which you then pass in directly to... > + } else { > + ret = -EINVAL; > + goto e_put; > + } > + > + ret = sev_es_ghcb_hv_call(ghcb, NULL, id, input->req_gpa, input->resp_gpa); ... this guy here: ret = sev_es_ghcb_hv_call(ghcb, NULL, exit_code, input->req_gpa, input->resp_gpa); > + if (ret) > + goto e_put; > + > + if (ghcb->save.sw_exit_info_2) { > + /* Number of expected pages are returned in RBX */ > + if (id == EXT_GUEST_REQUEST && > + ghcb->save.sw_exit_info_2 == SNP_GUEST_REQ_INVALID_LEN) > + input->data_npages = ghcb_get_rbx(ghcb); > + > + if (fw_err) > + *fw_err = ghcb->save.sw_exit_info_2; > + > + ret = -EIO; > + } > + > +e_put: > + __sev_put_ghcb(&state); > +e_restore_irq: > + local_irq_restore(flags); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(snp_issue_guest_request); > diff --git a/include/linux/sev-guest.h b/include/linux/sev-guest.h Why is this a separate header in the include/linux/ namespace? Is SNP available on something which is !x86, all of a sudden? > new file mode 100644 > index 000000000000..24dd17507789 > --- /dev/null > +++ b/include/linux/sev-guest.h > @@ -0,0 +1,48 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * AMD Secure Encrypted Virtualization (SEV) guest driver interface > + * > + * Copyright (C) 2021 Advanced Micro Devices, Inc. > + * > + * Author: Brijesh Singh > + * > + */ > + > +#ifndef __LINUX_SEV_GUEST_H_ > +#define __LINUX_SEV_GUEST_H_ > + > +#include > + > +enum vmgexit_type { > + GUEST_REQUEST, > + EXT_GUEST_REQUEST, > + > + GUEST_REQUEST_MAX > +}; > + > +/* > + * The error code when the data_npages is too small. The error code > + * is defined in the GHCB specification. > + */ > +#define SNP_GUEST_REQ_INVALID_LEN 0x100000000ULL so basically BIT_ULL(32) > + > +struct snp_guest_request_data { "snp_req_data" I guess is shorter. And having "guest" in there is probably not needed because snp is always guest-related anyway. > + unsigned long req_gpa; > + unsigned long resp_gpa; > + unsigned long data_gpa; > + unsigned int data_npages; > +}; > + > +#ifdef CONFIG_AMD_MEM_ENCRYPT > +int snp_issue_guest_request(int vmgexit_type, struct snp_guest_request_data *input, > + unsigned long *fw_err); > +#else > + > +static inline int snp_issue_guest_request(int type, struct snp_guest_request_data *input, > + unsigned long *fw_err) > +{ > + return -ENODEV; > +} > + > +#endif /* CONFIG_AMD_MEM_ENCRYPT */ > +#endif /* __LINUX_SEV_GUEST_H__ */ > -- > 2.17.1 > -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette