From nobody Sun Oct 12 16:22:43 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=randomman.co.uk ARC-Seal: i=1; a=rsa-sha256; t=1749828799; cv=none; d=zohomail.com; s=zohoarc; b=U6eMyZN7mYQM2r1sHTbFpfo6LgtcVNF4ZFAGbeMrJezLV8O/3TAkGvjParYSOuRY5Itlx0wsbzDjnZFPTyLNXTCVxdcO58yds0VUgHmxZCRGKQN70Tz7nawTX9whwyeOIOn8CFH+rnghdWKaSQyzKAiSDezuHYAQgp4/c0XKiHk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1749828799; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=r4CjSD1iXLbvUkWWVMkRfYc/xRNXuzjLMs/YY76+C2Q=; b=CueTVO4NEnhiHfRIEGC0UioP8w0fY4qGlLKQsBprRj0L+IyL+wnOXUXpt6q2vgWZHHIAsYCExK/zWkilYS1zIDIpObFtbH6JEJh+wytQA2alkKTV0DT7HyT9aF67LsGheGydPg1kQY6sG4od88aPNTsuKfB++Ol+ch7G4vPK6Yg= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1749828799918761.0492826085684; Fri, 13 Jun 2025 08:33:19 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uQ6Om-00030n-U5; Fri, 13 Jun 2025 11:32:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uQ6Om-00030W-6j for qemu-devel@nongnu.org; Fri, 13 Jun 2025 11:32:56 -0400 Received: from smtp-out-60.livemail.co.uk ([213.171.216.60] helo=dkim.livemail.co.uk) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uQ6Oi-0005WZ-SO for qemu-devel@nongnu.org; Fri, 13 Jun 2025 11:32:55 -0400 Received: from smtp.livemail.co.uk (unknown [10.44.132.84]) by dkim.livemail.co.uk (Postfix) with ESMTPS id A7A86401DA; Fri, 13 Jun 2025 16:32:50 +0100 (BST) Received: from localhost.localdomain (unknown [145.40.191.116]) (Authenticated sender: roy.hopkins@randomman.co.uk) by smtp.livemail.co.uk (Postfix) with ESMTPSA id 1256DA0232; Fri, 13 Jun 2025 16:32:46 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=randomman.co.uk; s=livemail2; t=1749828770; bh=HsR51g/RYvSxr0PjCbXbzIbeC0wc9IOog+RU+6oMGhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TRwjekyiidGuq8/k5AXU3Vdcj3ybQmAYKrwmoDStRNDRjeQkqa3iLPqnymSIdhQbl /DxUJ4D/cStckJIP64r7LdospqzchjTvnt4fWYywu0vP2LLOyLJHWmm24Lfv+mw3Gx Xuj29l5fjdj8niqjOhAfQsCNnHfclLooITfNCw5g= From: Roy Hopkins To: qemu-devel@nongnu.org Cc: Roy Hopkins , Paolo Bonzini , "Daniel P . Berrange" , Stefano Garzarella , Marcelo Tosatti , "Michael S . Tsirkin" , Cornelia Huck , Marcel Apfelbaum , Sergio Lopez , Eduardo Habkost , Alistair Francis , Peter Xu , David Hildenbrand , Igor Mammedov , Tom Lendacky , Michael Roth , Ani Sinha , Gerd Hoffman , Pankaj Gupta , Joerg Roedel Subject: [PATCH v8 16/16] sev: Provide sev_features flags from IGVM VMSA to KVM_SEV_INIT2 Date: Fri, 13 Jun 2025 16:32:26 +0100 Message-ID: X-Mailer: git-send-email 2.43.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=213.171.216.60; envelope-from=roy.hopkins@randomman.co.uk; helo=dkim.livemail.co.uk X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @randomman.co.uk) X-ZM-MESSAGEID: 1749828801909116600 Content-Type: text/plain; charset="utf-8" IGVM files can contain an initial VMSA that should be applied to each vcpu as part of the initial guest state. The sev_features flags are provided as part of the VMSA structure. However, KVM only allows sev_features to be set during initialization and not as the guest is being prepared for launch. This patch queries KVM for the supported set of sev_features flags and processes the VP context entries in the IGVM file during kvm_init to determine any sev_features flags set in the IGVM file. These are then provided in the call to KVM_SEV_INIT2 to ensure the guest state matches that specified in the IGVM file. The igvm process() function is modified to allow a partial processing of the file during initialization, with on the IGVM_VHT_VP_CONTEXT fields being processed. This means the function is called twice, firstly to extract the sev_features then secondly to actually configure the guest. Signed-off-by: Roy Hopkins Acked-by: Michael S. Tsirkin Acked-by: Stefano Garzarella Acked-by: Gerd Hoffman Tested-by: Stefano Garzarella Reviewed-by: Liam Merwick --- backends/igvm.c | 17 +++- backends/igvm.h | 2 +- hw/i386/pc_piix.c | 2 +- hw/i386/pc_q35.c | 2 +- include/system/igvm-cfg.h | 5 +- target/i386/sev.c | 161 +++++++++++++++++++++++++++++++++----- 6 files changed, 163 insertions(+), 26 deletions(-) diff --git a/backends/igvm.c b/backends/igvm.c index 034f504716..9853ba941e 100644 --- a/backends/igvm.c +++ b/backends/igvm.c @@ -869,7 +869,7 @@ static IgvmHandle qigvm_file_init(char *filename, Error= **errp) } =20 int qigvm_process_file(IgvmCfg *cfg, ConfidentialGuestSupport *cgs, - Error **errp) + bool onlyVpContext, Error **errp) { int32_t header_count; QIgvmParameterData *parameter; @@ -913,11 +913,22 @@ int qigvm_process_file(IgvmCfg *cfg, ConfidentialGues= tSupport *cgs, ctx.current_header_index++) { IgvmVariableHeaderType type =3D igvm_get_header_type( ctx.file, IGVM_HEADER_SECTION_DIRECTIVE, ctx.current_header_in= dex); - if (qigvm_handler(&ctx, type, errp) < 0) { - goto cleanup_parameters; + if (!onlyVpContext || (type =3D=3D IGVM_VHT_VP_CONTEXT)) { + if (qigvm_handler(&ctx, type, errp) < 0) { + goto cleanup_parameters; + } } } =20 + /* + * If only processing the VP context then we don't need to process + * any more of the file. + */ + if (onlyVpContext) { + retval =3D 0; + goto cleanup_parameters; + } + header_count =3D igvm_header_count(ctx.file, IGVM_HEADER_SECTION_INITIALIZATION); if (header_count < 0) { diff --git a/backends/igvm.h b/backends/igvm.h index db02ea9165..a4abab043a 100644 --- a/backends/igvm.h +++ b/backends/igvm.h @@ -17,6 +17,6 @@ #include "qapi/error.h" =20 int qigvm_process_file(IgvmCfg *igvm, ConfidentialGuestSupport *cgs, - Error **errp); + bool onlyVpContext, Error **errp); =20 #endif diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 3184ea1b37..a3285fbc64 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -371,7 +371,7 @@ static void pc_init1(MachineState *machine, const char = *pci_type) /* Apply guest state from IGVM if supplied */ if (x86ms->igvm) { if (IGVM_CFG_GET_CLASS(x86ms->igvm) - ->process(x86ms->igvm, machine->cgs, &error_fatal) < 0) { + ->process(x86ms->igvm, machine->cgs, false, &error_fatal) = < 0) { g_assert_not_reached(); } } diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index 6990e1c669..cf871cfdad 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -330,7 +330,7 @@ static void pc_q35_init(MachineState *machine) /* Apply guest state from IGVM if supplied */ if (x86ms->igvm) { if (IGVM_CFG_GET_CLASS(x86ms->igvm) - ->process(x86ms->igvm, machine->cgs, &error_fatal) < 0) { + ->process(x86ms->igvm, machine->cgs, false, &error_fatal) = < 0) { g_assert_not_reached(); } } diff --git a/include/system/igvm-cfg.h b/include/system/igvm-cfg.h index 321b3196f0..944f23a814 100644 --- a/include/system/igvm-cfg.h +++ b/include/system/igvm-cfg.h @@ -31,11 +31,14 @@ typedef struct IgvmCfgClass { /* * If an IGVM filename has been specified then process the IGVM file. * Performs a no-op if no filename has been specified. + * If onlyVpContext is true then only the IGVM_VHT_VP_CONTEXT entries + * in the IGVM file will be processed, allowing information about the + * CPU state to be determined before processing the entire file. * * Returns 0 for ok and -1 on error. */ int (*process)(IgvmCfg *cfg, ConfidentialGuestSupport *cgs, - Error **errp); + bool onlyVpContext, Error **errp); =20 } IgvmCfgClass; =20 diff --git a/target/i386/sev.c b/target/i386/sev.c index 2798fe1c38..df55a25a67 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -118,6 +118,8 @@ struct SevCommonState { uint32_t cbitpos; uint32_t reduced_phys_bits; bool kernel_hashes; + uint64_t sev_features; + uint64_t supported_sev_features; =20 /* runtime state */ uint8_t api_major; @@ -485,7 +487,40 @@ static void sev_apply_cpu_context(CPUState *cpu) } } =20 -static int check_vmsa_supported(hwaddr gpa, const struct sev_es_save_area = *vmsa, +static int check_sev_features(SevCommonState *sev_common, uint64_t sev_fea= tures, + Error **errp) +{ + /* + * Ensure SEV_FEATURES is configured for correct SEV hardware and that + * the requested features are supported. If SEV-SNP is enabled then + * that feature must be enabled, otherwise it must be cleared. + */ + if (sev_snp_enabled() && !(sev_features & SVM_SEV_FEAT_SNP_ACTIVE)) { + error_setg( + errp, + "%s: SEV_SNP is enabled but is not enabled in VMSA sev_feature= s", + __func__); + return -1; + } else if (!sev_snp_enabled() && + (sev_features & SVM_SEV_FEAT_SNP_ACTIVE)) { + error_setg( + errp, + "%s: SEV_SNP is not enabled but is enabled in VMSA sev_feature= s", + __func__); + return -1; + } + if (sev_features & ~sev_common->supported_sev_features) { + error_setg(errp, + "%s: VMSA contains unsupported sev_features: %lX, " + "supported features: %lX", + __func__, sev_features, sev_common->supported_sev_featu= res); + return -1; + } + return 0; +} + +static int check_vmsa_supported(SevCommonState *sev_common, hwaddr gpa, + const struct sev_es_save_area *vmsa, Error **errp) { struct sev_es_save_area vmsa_check; @@ -551,24 +586,10 @@ static int check_vmsa_supported(hwaddr gpa, const str= uct sev_es_save_area *vmsa, vmsa_check.x87_fcw =3D 0; vmsa_check.mxcsr =3D 0; =20 - if (sev_snp_enabled()) { - if (vmsa_check.sev_features !=3D SVM_SEV_FEAT_SNP_ACTIVE) { - error_setg(errp, - "%s: sev_features in the VMSA contains an unsupport= ed " - "value. For SEV-SNP, sev_features must be set to %x= .", - __func__, SVM_SEV_FEAT_SNP_ACTIVE); - return -1; - } - vmsa_check.sev_features =3D 0; - } else { - if (vmsa_check.sev_features !=3D 0) { - error_setg(errp, - "%s: sev_features in the VMSA contains an unsupport= ed " - "value. For SEV-ES and SEV, sev_features must be " - "set to 0.", __func__); - return -1; - } + if (check_sev_features(sev_common, vmsa_check.sev_features, errp) < 0)= { + return -1; } + vmsa_check.sev_features =3D 0; =20 if (!buffer_is_zero(&vmsa_check, sizeof(vmsa_check))) { error_setg(errp, @@ -1722,6 +1743,39 @@ static int sev_snp_kvm_type(X86ConfidentialGuest *cg) return KVM_X86_SNP_VM; } =20 +static int sev_init_supported_features(ConfidentialGuestSupport *cgs, + SevCommonState *sev_common, Error *= *errp) +{ + X86ConfidentialGuestClass *x86_klass =3D + X86_CONFIDENTIAL_GUEST_GET_CLASS(cgs); + /* + * Older kernels do not support query or setting of sev_features. In t= his + * case the set of supported features must be zero to match the settin= gs + * in the kernel. + */ + if (x86_klass->kvm_type(X86_CONFIDENTIAL_GUEST(sev_common)) =3D=3D + KVM_X86_DEFAULT_VM) { + sev_common->supported_sev_features =3D 0; + return 0; + } + + /* Query KVM for the supported set of sev_features */ + struct kvm_device_attr attr =3D { + .group =3D KVM_X86_GRP_SEV, + .attr =3D KVM_X86_SEV_VMSA_FEATURES, + .addr =3D (unsigned long)&sev_common->supported_sev_features, + }; + if (kvm_ioctl(kvm_state, KVM_GET_DEVICE_ATTR, &attr) < 0) { + error_setg(errp, "%s: failed to query supported sev_features", + __func__); + return -1; + } + if (sev_snp_enabled()) { + sev_common->supported_sev_features |=3D SVM_SEV_FEAT_SNP_ACTIVE; + } + return 0; +} + static int sev_common_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) { char *devname; @@ -1802,6 +1856,10 @@ static int sev_common_kvm_init(ConfidentialGuestSupp= ort *cgs, Error **errp) } } =20 + if (sev_init_supported_features(cgs, sev_common, errp) < 0) { + return -1; + } + trace_kvm_sev_init(); switch (x86_klass->kvm_type(X86_CONFIDENTIAL_GUEST(sev_common))) { case KVM_X86_DEFAULT_VM: @@ -1813,6 +1871,40 @@ static int sev_common_kvm_init(ConfidentialGuestSupp= ort *cgs, Error **errp) case KVM_X86_SEV_ES_VM: case KVM_X86_SNP_VM: { struct kvm_sev_init args =3D { 0 }; + MachineState *machine =3D MACHINE(qdev_get_machine()); + X86MachineState *x86machine =3D X86_MACHINE(qdev_get_machine()); + + /* + * If configuration is provided via an IGVM file then the IGVM file + * might contain configuration of the initial vcpu context. For SEV + * the vcpu context includes the sev_features which should be appl= ied + * to the vcpu. + * + * KVM does not synchronize sev_features from CPU state. Instead it + * requires sev_features to be provided as part of this initializa= tion + * call which is subsequently automatically applied to the VMSA of + * each vcpu. + * + * The IGVM file is normally processed after initialization. There= fore + * we need to pre-process it here to extract sev_features in order= to + * provide it to KVM_SEV_INIT2. Each cgs_* function that is called= by + * the IGVM processor detects this pre-process by observing the st= ate + * as SEV_STATE_UNINIT. + */ + if (x86machine->igvm) { + if (IGVM_CFG_GET_CLASS(x86machine->igvm) + ->process(x86machine->igvm, machine->cgs, true, errp) = =3D=3D + -1) { + return -1; + } + /* + * KVM maintains a bitmask of allowed sev_features. This does = not + * include SVM_SEV_FEAT_SNP_ACTIVE which is set accordingly by= KVM + * itself. Therefore we need to clear this flag. + */ + args.vmsa_features =3D sev_common->sev_features & + ~SVM_SEV_FEAT_SNP_ACTIVE; + } =20 ret =3D sev_ioctl(sev_common->sev_fd, KVM_SEV_INIT2, &args, &fw_er= ror); break; @@ -2417,6 +2509,24 @@ static int cgs_set_guest_state(hwaddr gpa, uint8_t *= ptr, uint64_t len, SevCommonState *sev_common =3D SEV_COMMON(MACHINE(qdev_get_machine())-= >cgs); SevCommonStateClass *klass =3D SEV_COMMON_GET_CLASS(sev_common); =20 + if (sev_common->state =3D=3D SEV_STATE_UNINIT) { + /* Pre-processing of IGVM file called from sev_common_kvm_init() */ + if ((cpu_index =3D=3D 0) && (memory_type =3D=3D CGS_PAGE_TYPE_VMSA= )) { + const struct sev_es_save_area *sa =3D + (const struct sev_es_save_area *)ptr; + if (len < sizeof(*sa)) { + error_setg(errp, "%s: invalid VMSA length encountered", + __func__); + return -1; + } + if (check_sev_features(sev_common, sa->sev_features, errp) < 0= ) { + return -1; + } + sev_common->sev_features =3D sa->sev_features; + } + return 0; + } + if (!sev_enabled()) { error_setg(errp, "%s: attempt to configure guest memory, but SEV " "is not enabled", __func__); @@ -2436,7 +2546,8 @@ static int cgs_set_guest_state(hwaddr gpa, uint8_t *p= tr, uint64_t len, __func__); return -1; } - if (check_vmsa_supported(gpa, (const struct sev_es_save_area *)ptr, + if (check_vmsa_supported(sev_common, gpa, + (const struct sev_es_save_area *)ptr, errp) < 0) { return -1; } @@ -2493,6 +2604,12 @@ static int cgs_get_mem_map_entry(int index, struct e820_entry *table; int num_entries; =20 + SevCommonState *sev_common =3D SEV_COMMON(MACHINE(qdev_get_machine())-= >cgs); + if (sev_common->state =3D=3D SEV_STATE_UNINIT) { + /* Pre-processing of IGVM file called from sev_common_kvm_init() */ + return 1; + } + num_entries =3D e820_get_table(&table); if ((index < 0) || (index >=3D num_entries)) { return 1; @@ -2524,6 +2641,12 @@ static int cgs_set_guest_policy(ConfidentialGuestPol= icyType policy_type, uint32_t policy_data1_size, void *policy_d= ata2, uint32_t policy_data2_size, Error **errp) { + SevCommonState *sev_common =3D SEV_COMMON(MACHINE(qdev_get_machine())-= >cgs); + if (sev_common->state =3D=3D SEV_STATE_UNINIT) { + /* Pre-processing of IGVM file called from sev_common_kvm_init() */ + return 0; + } + if (policy_type !=3D GUEST_POLICY_SEV) { error_setg(errp, "%s: Invalid guest policy type provided for SEV: = %d", __func__, policy_type); --=20 2.43.0