From patchwork Wed Jul 7 18:36:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brijesh Singh X-Patchwork-Id: 12363757 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,SPF_HELO_NONE, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07CCCC11F6B for ; Wed, 7 Jul 2021 18:38:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9D46960C41 for ; Wed, 7 Jul 2021 18:38:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D46960C41 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amd.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8CACE6B0092; Wed, 7 Jul 2021 14:38:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8A1E26B0093; Wed, 7 Jul 2021 14:38:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 631C86B009E; Wed, 7 Jul 2021 14:38:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0180.hostedemail.com [216.40.44.180]) by kanga.kvack.org (Postfix) with ESMTP id 363536B0092 for ; Wed, 7 Jul 2021 14:38:34 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 95ABD23E70 for ; Wed, 7 Jul 2021 18:38:33 +0000 (UTC) X-FDA: 78336652506.12.7B7BB05 Received: from NAM10-MW2-obe.outbound.protection.outlook.com (mail-mw2nam10on2067.outbound.protection.outlook.com [40.107.94.67]) by imf01.hostedemail.com (Postfix) with ESMTP id 2CA635005F47 for ; Wed, 7 Jul 2021 18:38:25 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=R2P8y68her4iiVyZSQVAwUcnHqTe82EBzQCLNBvr65wLReScNgFnx8Nf4jSxoY75E7XiOHDGHt8U3wmkQK38n6jdhmjHryeb8fq7HT6TwG0felNYh7IR+98vTEg1LaZ93IkdTnzw0vAEzzqaCbQQEv2Vd6vmFYuy0OcjU5LEYarBLDvl/29CGiIrjgoS23slK9c0UBnJXUpvxwlnDBn439X0Aw3KR4MXLabp5s66v7OlfxWOTeg4hlSTLXBOU2vR6nZ8AishTBtNEvZnBApTmWzlpQywRzvH/1ZvFdwL18eoUHjaegb4VDZrg2GNAv4wRxXevNhHZAlOUnjsnxWHzQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=uy11knPYsrGP2DMI5bbBN/Qbj/rYf+mI8hBeoLJFHrM=; b=QcGJ3LIVVaVWcPVvbSczP8IJxiq7Auf+mPQN390vUdMrMLg1jO3giNRG4Hr32J3U2TtQpp/VMqXne9BLrUHcuwHhWWsQ8mgGjTxfKPdbsyUP1mMblsSFb4nIHkkQi8PsJv6hvgKV9anQx9XRkWUlgT/ub2nGPMeISYPFvlnF8x/pbCyHO+ezHSvHptf5eg0lhXrY+RKlsQSzRFHGhRwlAWAcIZDgECnHj25KM0t9M4Hq9ZvT9yLKfFXIJbSIqGMT1rqQk4OZTab7RZDElMdiqjP4pqVtARf0yKkSeThwG3aEXqlY6UT3K4h1J+g3tx7CjPNe88t7WuPLh7t83E+ItA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=uy11knPYsrGP2DMI5bbBN/Qbj/rYf+mI8hBeoLJFHrM=; b=y9mOV1DKmqJuNmWs1XsaGanDTqonk/1xglE5mUf4zXuxaXYTg221pblnsCDwJLEQiOHUVF5CLAkeQsk3jPlycNU8sWUcu0agNIvP3yQcVz1qpsjFDKGmBrySZC2htucDZMoFpFExjYhSI2uFywcXDi3iSeJNO6VVqQGJknsoeQA= Received: from BYAPR12MB2711.namprd12.prod.outlook.com (2603:10b6:a03:63::10) by BY5PR12MB4099.namprd12.prod.outlook.com (2603:10b6:a03:20f::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4308.20; Wed, 7 Jul 2021 18:38:20 +0000 Received: from BYAPR12MB2711.namprd12.prod.outlook.com ([fe80::40e3:aade:9549:4bed]) by BYAPR12MB2711.namprd12.prod.outlook.com ([fe80::40e3:aade:9549:4bed%7]) with mapi id 15.20.4287.033; Wed, 7 Jul 2021 18:38:20 +0000 From: Brijesh Singh 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, linux-crypto@vger.kernel.org Cc: Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Borislav Petkov , Michael Roth , Vlastimil Babka , tony.luck@intel.com, npmccallum@redhat.com, brijesh.ksingh@gmail.com, Brijesh Singh Subject: [PATCH Part2 RFC v4 33/40] KVM: SVM: Add support to handle MSR based Page State Change VMGEXIT Date: Wed, 7 Jul 2021 13:36:09 -0500 Message-Id: <20210707183616.5620-34-brijesh.singh@amd.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210707183616.5620-1-brijesh.singh@amd.com> References: <20210707183616.5620-1-brijesh.singh@amd.com> X-ClientProxiedBy: SN6PR04CA0078.namprd04.prod.outlook.com (2603:10b6:805:f2::19) To BYAPR12MB2711.namprd12.prod.outlook.com (2603:10b6:a03:63::10) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from sbrijesh-desktop.amd.com (165.204.77.1) by SN6PR04CA0078.namprd04.prod.outlook.com (2603:10b6:805:f2::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4308.20 via Frontend Transport; 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dkim=pass header.d=amd.com header.s=selector1 header.b=y9mOV1DK; dmarc=pass (policy=quarantine) header.from=amd.com; spf=pass (imf01.hostedemail.com: domain of brijesh.singh@amd.com designates 40.107.94.67 as permitted sender) smtp.mailfrom=brijesh.singh@amd.com X-Stat-Signature: cpuyg6pu34urmsx5yubt31qwsdyd6q6t X-Rspamd-Queue-Id: 2CA635005F47 X-Rspamd-Server: rspam01 X-HE-Tag: 1625683105-428086 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: SEV-SNP VMs can ask the hypervisor to change the page state in the RMP table to be private or shared using the Page State Change MSR protocol as defined in the GHCB specification. Before changing the page state in the RMP entry, we lookup the page in the TDP to make sure that there is a valid mapping for it. If the mapping exist then try to find a workable page level between the TDP and RMP for the page. If the page is not mapped in the TDP, then create a fault such that it gets mapped before we change the page state in the RMP entry. Signed-off-by: Brijesh Singh --- arch/x86/include/asm/sev-common.h | 3 + arch/x86/kvm/svm/sev.c | 141 ++++++++++++++++++++++++++++++ 2 files changed, 144 insertions(+) diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h index 6990d5a9d73c..2561413cb316 100644 --- a/arch/x86/include/asm/sev-common.h +++ b/arch/x86/include/asm/sev-common.h @@ -81,6 +81,9 @@ #define GHCB_MSR_PSC_RESP 0x015 #define GHCB_MSR_PSC_ERROR_POS 32 +#define GHCB_MSR_PSC_ERROR_MASK GENMASK_ULL(31, 0) +#define GHCB_MSR_PSC_RSVD_POS 12 +#define GHCB_MSR_PSC_RSVD_MASK GENMASK_ULL(19, 0) #define GHCB_MSR_PSC_RESP_VAL(val) ((val) >> GHCB_MSR_PSC_ERROR_POS) /* GHCB Hypervisor Feature Request */ diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 3af5d1ad41bf..68d275b2a660 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -28,6 +28,7 @@ #include "svm_ops.h" #include "cpuid.h" #include "trace.h" +#include "mmu.h" #define __ex(x) __kvm_handle_fault_on_reboot(x) @@ -2843,6 +2844,127 @@ static void set_ghcb_msr(struct vcpu_svm *svm, u64 value) svm->vmcb->control.ghcb_gpa = value; } +static int snp_rmptable_psmash(struct kvm_vcpu *vcpu, kvm_pfn_t pfn) +{ + pfn = pfn & ~(KVM_PAGES_PER_HPAGE(PG_LEVEL_2M) - 1); + + return psmash(pfn_to_page(pfn)); +} + +static int snp_make_page_shared(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_pfn_t pfn, int level) +{ + struct rmpupdate val; + int rc, rmp_level; + struct rmpentry *e; + + e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &rmp_level); + if (!e) + return -EINVAL; + + if (!rmpentry_assigned(e)) + return 0; + + /* Log if the entry is validated */ + if (rmpentry_validated(e)) + pr_warn_ratelimited("Remove RMP entry for a validated gpa 0x%llx\n", gpa); + + /* + * Is the page part of an existing 2M RMP entry ? Split the 2MB into multiple + * of 4K-page before making the memory shared. + */ + if ((level == PG_LEVEL_4K) && (rmp_level == PG_LEVEL_2M)) { + rc = snp_rmptable_psmash(vcpu, pfn); + if (rc) + return rc; + } + + memset(&val, 0, sizeof(val)); + val.pagesize = X86_TO_RMP_PG_LEVEL(level); + return rmpupdate(pfn_to_page(pfn), &val); +} + +static int snp_make_page_private(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_pfn_t pfn, int level) +{ + struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; + struct rmpupdate val; + struct rmpentry *e; + int rmp_level; + + e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &rmp_level); + if (!e) + return -EINVAL; + + /* Log if the entry is validated */ + if (rmpentry_validated(e)) + pr_warn_ratelimited("Asked to make a pre-validated gpa %llx private\n", gpa); + + memset(&val, 0, sizeof(val)); + val.gpa = gpa; + val.asid = sev->asid; + val.pagesize = X86_TO_RMP_PG_LEVEL(level); + val.assigned = true; + + return rmpupdate(pfn_to_page(pfn), &val); +} + +static int __snp_handle_psc(struct kvm_vcpu *vcpu, int op, gpa_t gpa, int level) +{ + struct kvm *kvm = vcpu->kvm; + int rc, tdp_level; + kvm_pfn_t pfn; + gpa_t gpa_end; + + gpa_end = gpa + page_level_size(level); + + while (gpa < gpa_end) { + /* + * Get the pfn and level for the gpa from the nested page table. + * + * If the TDP walk failed, then its safe to say that we don't have a valid + * mapping for the gpa in the nested page table. Create a fault to map the + * page is nested page table. + */ + if (!kvm_mmu_get_tdp_walk(vcpu, gpa, &pfn, &tdp_level)) { + pfn = kvm_mmu_map_tdp_page(vcpu, gpa, PFERR_USER_MASK, level); + if (is_error_noslot_pfn(pfn)) + goto out; + + if (!kvm_mmu_get_tdp_walk(vcpu, gpa, &pfn, &tdp_level)) + goto out; + } + + /* Adjust the level so that we don't go higher than the backing page level */ + level = min_t(size_t, level, tdp_level); + + write_lock(&kvm->mmu_lock); + + switch (op) { + case SNP_PAGE_STATE_SHARED: + rc = snp_make_page_shared(vcpu, gpa, pfn, level); + break; + case SNP_PAGE_STATE_PRIVATE: + rc = snp_make_page_private(vcpu, gpa, pfn, level); + break; + default: + rc = -EINVAL; + break; + } + + write_unlock(&kvm->mmu_lock); + + if (rc) { + pr_err_ratelimited("Error op %d gpa %llx pfn %llx level %d rc %d\n", + op, gpa, pfn, level, rc); + goto out; + } + + gpa = gpa + page_level_size(level); + } + +out: + return rc; +} + static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; @@ -2941,6 +3063,25 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) GHCB_MSR_INFO_POS); break; } + case GHCB_MSR_PSC_REQ: { + gfn_t gfn; + int ret; + u8 op; + + gfn = get_ghcb_msr_bits(svm, GHCB_MSR_PSC_GFN_MASK, GHCB_MSR_PSC_GFN_POS); + op = get_ghcb_msr_bits(svm, GHCB_MSR_PSC_OP_MASK, GHCB_MSR_PSC_OP_POS); + + ret = __snp_handle_psc(vcpu, op, gfn_to_gpa(gfn), PG_LEVEL_4K); + + /* If failed to change the state then spec requires to return all F's */ + if (ret) + ret = -1; + + set_ghcb_msr_bits(svm, ret, GHCB_MSR_PSC_ERROR_MASK, GHCB_MSR_PSC_ERROR_POS); + set_ghcb_msr_bits(svm, 0, GHCB_MSR_PSC_RSVD_MASK, GHCB_MSR_PSC_RSVD_POS); + set_ghcb_msr_bits(svm, GHCB_MSR_PSC_RESP, GHCB_MSR_INFO_MASK, GHCB_MSR_INFO_POS); + break; + } case GHCB_MSR_TERM_REQ: { u64 reason_set, reason_code;