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Thu, 10 Dec 2020 17:15:06 +0000 From: Tom Lendacky To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org Cc: Paolo Bonzini , Jim Mattson , Joerg Roedel , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Borislav Petkov , Ingo Molnar , Thomas Gleixner , Brijesh Singh Subject: [PATCH v5 32/34] KVM: SVM: Provide support for SEV-ES vCPU loading Date: Thu, 10 Dec 2020 11:10:07 -0600 Message-Id: <019390e9cb5e93cd73014fa5a040c17d42588733.1607620209.git.thomas.lendacky@amd.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: References: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Originating-IP: [165.204.77.1] X-ClientProxiedBy: CH2PR05CA0038.namprd05.prod.outlook.com (2603:10b6:610:38::15) To CY4PR12MB1352.namprd12.prod.outlook.com (2603:10b6:903:3a::13) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from tlendack-t1.amd.com (165.204.77.1) by CH2PR05CA0038.namprd05.prod.outlook.com (2603:10b6:610:38::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3654.5 via Frontend Transport; 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X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?HgCFU3HRQeOm/WSK434AVAhJCQQPV9PlHKohk2JfJj1Dud66j0DiIP3xZvXg?= =?us-ascii?Q?QKrcvbfmUOw2tvFBBnNdg1OPtAvcx4hnGC3A11iSd9FfmOEzV28+Sp/EyKZw?= =?us-ascii?Q?2HLCbK7XROlu3u2r2zI1lRQ50w8FQ0qUfWLKu2UiPEKSCdI1KXCGiNTDoL4y?= =?us-ascii?Q?XA7D3aOKHjIUQBUrn64rh3s/yRmE5BohHvCTvFM1HWIY+DD7HEOPqILj/Bmt?= =?us-ascii?Q?7aRMZaQ+mR9D5KAK+gBGiSEAe5SznhK1N+HV1MS763gsoTmNVXq4hXuLF7pu?= =?us-ascii?Q?IQsmm0PfKvgmJNmD6Djapn5xGufnJ2bG0ZYJhcOMobeClgG7jQ/1H4Ef7PTt?= =?us-ascii?Q?Z4TfnnjOFDXVrrfYFKmoXoQqGD8bWp4WWJOYdNU4sabOW+YKOrAqn2MvfR2i?= =?us-ascii?Q?qwumZkmcWQBm0sT2nBPF1KOICQGR7bgh4TpByZpTSCikLf1cWwPy38B62zcT?= =?us-ascii?Q?3fmXRGvQ1SbjzR7QaTi9OJopPGdRxXdIZwPeQucfC1h62jtGIFFsG9F4apYX?= =?us-ascii?Q?SVZxEGsjKKomMHIyPA+b4M8Y1a7Q365kQJoQJPWteQtTI2TMg5ydIDtZ4F7k?= =?us-ascii?Q?zEyPrDXEgr2Kis0zR4DF8DSoM7gD5d7LnqztvZK2k9gDDoBT3dkL7voj0POr?= =?us-ascii?Q?HwZAMvDZmRRi2hPTHOe9l9NkhwBcUJH27fCizZmR878t5skXP5/R05GFhk9c?= =?us-ascii?Q?W10Uf0J1N6ChQwlSeuhtzJfBGQJAgc9346lEOBkBpfVfBtcKcyWZbsUGG/qH?= =?us-ascii?Q?hUWWuRe0/h8ksBL61yKLeqHMrNM5L2/xFCMNOEVayVMwCNEyg2aKsu6nhMWv?= =?us-ascii?Q?qMSEIQM2fsE7ya4brtlT/txf2T7++0lYJtXVo8DgheyS04RhtwwgjlwE+n62?= =?us-ascii?Q?/d/bFblxAQCIM8k33RqQ4166xfrQNFzp+ELY6T7MeDDz+g3N5X3TfQQ5Xrzs?= =?us-ascii?Q?4SEZZdtpMl0FRtkN4Vh6/g5mHCjlwuXB+dlW/P4QPylrN+3YQ7g5XrBqG40q?= =?us-ascii?Q?jAan?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-AuthSource: CY4PR12MB1352.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Dec 2020 17:15:06.7913 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-Network-Message-Id: 28c59cef-20c4-4aa8-0fc8-08d89d2f2438 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 5vQFNENh+Xw/XGfJ5UUdwAGxCFFvfIHeF7sKKxoRAQlmpWsdg/Snrp6+ORwOL9X83pNXyaewoKhksOvAEsXG+g== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR1201MB0149 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tom Lendacky An SEV-ES vCPU requires additional VMCB vCPU load/put requirements. SEV-ES hardware will restore certain registers on VMEXIT, but not save them on VMRUN (see Table B-3 and Table B-4 of the AMD64 APM Volume 2), so make the following changes: General vCPU load changes: - During vCPU loading, perform a VMSAVE to the per-CPU SVM save area and save the current values of XCR0, XSS and PKRU to the per-CPU SVM save area as these registers will be restored on VMEXIT. General vCPU put changes: - Do not attempt to restore registers that SEV-ES hardware has already restored on VMEXIT. Signed-off-by: Tom Lendacky --- arch/x86/include/asm/svm.h | 10 ++++--- arch/x86/kvm/svm/sev.c | 54 ++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/svm/svm.c | 36 ++++++++++++++++--------- arch/x86/kvm/svm/svm.h | 22 +++++++++++----- arch/x86/kvm/x86.c | 3 ++- arch/x86/kvm/x86.h | 1 + 6 files changed, 103 insertions(+), 23 deletions(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index a57331de59e2..1c561945b426 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -234,7 +234,8 @@ struct vmcb_save_area { u8 cpl; u8 reserved_2[4]; u64 efer; - u8 reserved_3[112]; + u8 reserved_3[104]; + u64 xss; /* Valid for SEV-ES only */ u64 cr4; u64 cr3; u64 cr0; @@ -265,9 +266,12 @@ struct vmcb_save_area { /* * The following part of the save area is valid only for - * SEV-ES guests when referenced through the GHCB. + * SEV-ES guests when referenced through the GHCB or for + * saving to the host save area. */ - u8 reserved_7[104]; + u8 reserved_7[80]; + u32 pkru; + u8 reserved_7a[20]; u64 reserved_8; /* rax already available at 0x01f8 */ u64 rcx; u64 rdx; diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index e34d3a6dba80..225f18dbf522 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -18,12 +18,15 @@ #include #include +#include #include "x86.h" #include "svm.h" #include "cpuid.h" #include "trace.h" +#define __ex(x) __kvm_handle_fault_on_reboot(x) + static u8 sev_enc_bit; static int sev_flush_asids(void); static DECLARE_RWSEM(sev_deactivate_lock); @@ -1902,3 +1905,54 @@ void sev_es_create_vcpu(struct vcpu_svm *svm) GHCB_VERSION_MIN, sev_enc_bit)); } + +void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu) +{ + struct svm_cpu_data *sd = per_cpu(svm_data, cpu); + struct vmcb_save_area *hostsa; + unsigned int i; + + /* + * As an SEV-ES guest, hardware will restore the host state on VMEXIT, + * of which one step is to perform a VMLOAD. Since hardware does not + * perform a VMSAVE on VMRUN, the host savearea must be updated. + */ + asm volatile(__ex("vmsave") : : "a" (__sme_page_pa(sd->save_area)) : "memory"); + + /* + * Certain MSRs are restored on VMEXIT, only save ones that aren't + * restored. + */ + for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) { + if (host_save_user_msrs[i].sev_es_restored) + continue; + + rdmsrl(host_save_user_msrs[i].index, svm->host_user_msrs[i]); + } + + /* XCR0 is restored on VMEXIT, save the current host value */ + hostsa = (struct vmcb_save_area *)(page_address(sd->save_area) + 0x400); + hostsa->xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK); + + /* PKRU is restored on VMEXIT, save the curent host value */ + hostsa->pkru = read_pkru(); + + /* MSR_IA32_XSS is restored on VMEXIT, save the currnet host value */ + hostsa->xss = host_xss; +} + +void sev_es_vcpu_put(struct vcpu_svm *svm) +{ + unsigned int i; + + /* + * Certain MSRs are restored on VMEXIT and were saved with vmsave in + * sev_es_vcpu_load() above. Only restore ones that weren't. + */ + for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) { + if (host_save_user_msrs[i].sev_es_restored) + continue; + + wrmsrl(host_save_user_msrs[i].index, svm->host_user_msrs[i]); + } +} diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 46dd28cd1ea6..8fcee4cf4a62 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1418,15 +1418,20 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) vmcb_mark_all_dirty(svm->vmcb); } + if (sev_es_guest(svm->vcpu.kvm)) { + sev_es_vcpu_load(svm, cpu); + } else { #ifdef CONFIG_X86_64 - rdmsrl(MSR_GS_BASE, to_svm(vcpu)->host.gs_base); + rdmsrl(MSR_GS_BASE, to_svm(vcpu)->host.gs_base); #endif - savesegment(fs, svm->host.fs); - savesegment(gs, svm->host.gs); - svm->host.ldt = kvm_read_ldt(); + savesegment(fs, svm->host.fs); + savesegment(gs, svm->host.gs); + svm->host.ldt = kvm_read_ldt(); - for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) - rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]); + for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) + rdmsrl(host_save_user_msrs[i].index, + svm->host_user_msrs[i]); + } if (static_cpu_has(X86_FEATURE_TSCRATEMSR)) { u64 tsc_ratio = vcpu->arch.tsc_scaling_ratio; @@ -1454,19 +1459,24 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu) avic_vcpu_put(vcpu); ++vcpu->stat.host_state_reload; - kvm_load_ldt(svm->host.ldt); + if (sev_es_guest(svm->vcpu.kvm)) { + sev_es_vcpu_put(svm); + } else { + kvm_load_ldt(svm->host.ldt); #ifdef CONFIG_X86_64 - loadsegment(fs, svm->host.fs); - wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gsbase); - load_gs_index(svm->host.gs); + loadsegment(fs, svm->host.fs); + wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gsbase); + load_gs_index(svm->host.gs); #else #ifdef CONFIG_X86_32_LAZY_GS - loadsegment(gs, svm->host.gs); + loadsegment(gs, svm->host.gs); #endif #endif - for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) - wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]); + for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) + wrmsrl(host_save_user_msrs[i].index, + svm->host_user_msrs[i]); + } } static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 1cf959cfcbc8..657a4fc0e41f 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -23,15 +23,23 @@ #define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT) -static const u32 host_save_user_msrs[] = { +static const struct svm_host_save_msrs { + u32 index; /* Index of the MSR */ + bool sev_es_restored; /* True if MSR is restored on SEV-ES VMEXIT */ +} host_save_user_msrs[] = { #ifdef CONFIG_X86_64 - MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE, - MSR_FS_BASE, + { .index = MSR_STAR, .sev_es_restored = true }, + { .index = MSR_LSTAR, .sev_es_restored = true }, + { .index = MSR_CSTAR, .sev_es_restored = true }, + { .index = MSR_SYSCALL_MASK, .sev_es_restored = true }, + { .index = MSR_KERNEL_GS_BASE, .sev_es_restored = true }, + { .index = MSR_FS_BASE, .sev_es_restored = true }, #endif - MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, - MSR_TSC_AUX, + { .index = MSR_IA32_SYSENTER_CS, .sev_es_restored = true }, + { .index = MSR_IA32_SYSENTER_ESP, .sev_es_restored = true }, + { .index = MSR_IA32_SYSENTER_EIP, .sev_es_restored = true }, + { .index = MSR_TSC_AUX, .sev_es_restored = false }, }; - #define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs) #define MAX_DIRECT_ACCESS_MSRS 18 @@ -583,5 +591,7 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in); void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector); void sev_es_init_vmcb(struct vcpu_svm *svm); void sev_es_create_vcpu(struct vcpu_svm *svm); +void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu); +void sev_es_vcpu_put(struct vcpu_svm *svm); #endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4fd216b61a89..47cb63a2d079 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -197,7 +197,8 @@ EXPORT_SYMBOL_GPL(host_efer); bool __read_mostly allow_smaller_maxphyaddr = 0; EXPORT_SYMBOL_GPL(allow_smaller_maxphyaddr); -static u64 __read_mostly host_xss; +u64 __read_mostly host_xss; +EXPORT_SYMBOL_GPL(host_xss); u64 __read_mostly supported_xss; EXPORT_SYMBOL_GPL(supported_xss); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 0e8fe766a4c5..c5d737a0a828 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -278,6 +278,7 @@ fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu); extern u64 host_xcr0; extern u64 supported_xcr0; +extern u64 host_xss; extern u64 supported_xss; static inline bool kvm_mpx_supported(void) -- 2.28.0