From: Brijesh Singh <brijesh.singh@xxxxxxx> The KVM_SNP_INIT command is used by the hypervisor to initialize the SEV-SNP platform context. In a typical workflow, this command should be the first command issued. When creating SEV-SNP guest, the VMM must use this command instead of the KVM_SEV_INIT or KVM_SEV_ES_INIT. The flags value must be zero, it will be extended in future SNP support to communicate the optional features (such as restricted INT injection etc). Co-developed-by: Pavan Kumar Paluri <papaluri@xxxxxxx> Signed-off-by: Pavan Kumar Paluri <papaluri@xxxxxxx> Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> --- .../virt/kvm/x86/amd-memory-encryption.rst | 27 +++++++++++++ arch/x86/include/asm/svm.h | 1 + arch/x86/kvm/svm/sev.c | 39 ++++++++++++++++++- arch/x86/kvm/svm/svm.h | 4 ++ include/uapi/linux/kvm.h | 13 +++++++ 5 files changed, 83 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst b/Documentation/virt/kvm/x86/amd-memory-encryption.rst index 995780088eb2..b1a19c9a577a 100644 --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst @@ -434,6 +434,33 @@ issued by the hypervisor to make the guest ready for execution. Returns: 0 on success, -negative on error +18. KVM_SNP_INIT +---------------- + +The KVM_SNP_INIT command can be used by the hypervisor to initialize SEV-SNP +context. In a typical workflow, this command should be the first command issued. + +Parameters (in/out): struct kvm_snp_init + +Returns: 0 on success, -negative on error + +:: + + struct kvm_snp_init { + __u64 flags; + }; + +The flags bitmap is defined as:: + + /* enable the restricted injection */ + #define KVM_SEV_SNP_RESTRICTED_INJET (1<<0) + + /* enable the restricted injection timer */ + #define KVM_SEV_SNP_RESTRICTED_TIMER_INJET (1<<1) + +If the specified flags is not supported then return -EOPNOTSUPP, and the supported +flags are returned. + References ========== diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 19bf955b67e0..a901f1daaefc 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -289,6 +289,7 @@ static_assert((X2AVIC_MAX_PHYSICAL_ID & AVIC_PHYSICAL_MAX_INDEX_MASK) == X2AVIC_ #define AVIC_HPA_MASK ~((0xFFFULL << 52) | 0xFFF) #define SVM_SEV_FEAT_DEBUG_SWAP BIT(5) +#define SVM_SEV_FEAT_SNP_ACTIVE BIT(0) struct vmcb_seg { u16 selector; diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 4eefc168ebb3..0cd2a850cb45 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -251,6 +251,25 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) sev_decommission(handle); } +static int verify_snp_init_flags(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + struct kvm_snp_init params; + int ret = 0; + + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, sizeof(params))) + return -EFAULT; + + if (params.flags & ~SEV_SNP_SUPPORTED_FLAGS) + ret = -EOPNOTSUPP; + + params.flags = SEV_SNP_SUPPORTED_FLAGS; + + if (copy_to_user((void __user *)(uintptr_t)argp->data, ¶ms, sizeof(params))) + ret = -EFAULT; + + return ret; +} + static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) { struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; @@ -264,12 +283,19 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) return ret; sev->active = true; - sev->es_active = argp->id == KVM_SEV_ES_INIT; + sev->es_active = (argp->id == KVM_SEV_ES_INIT || argp->id == KVM_SEV_SNP_INIT); + sev->snp_active = argp->id == KVM_SEV_SNP_INIT; asid = sev_asid_new(sev); if (asid < 0) goto e_no_asid; sev->asid = asid; + if (sev->snp_active) { + ret = verify_snp_init_flags(kvm, argp); + if (ret) + goto e_free; + } + ret = sev_platform_init(&argp->error); if (ret) goto e_free; @@ -285,6 +311,7 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) sev_asid_free(sev); sev->asid = 0; e_no_asid: + sev->snp_active = false; sev->es_active = false; sev->active = false; return ret; @@ -623,6 +650,10 @@ static int sev_es_sync_vmsa(struct vcpu_svm *svm) if (sev_es_debug_swap_enabled) save->sev_features |= SVM_SEV_FEAT_DEBUG_SWAP; + /* Enable the SEV-SNP feature */ + if (sev_snp_guest(svm->vcpu.kvm)) + save->sev_features |= SVM_SEV_FEAT_SNP_ACTIVE; + pr_debug("Virtual Machine Save Area (VMSA):\n"); print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, save, sizeof(*save), false); @@ -1881,6 +1912,12 @@ int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp) } switch (sev_cmd.id) { + case KVM_SEV_SNP_INIT: + if (!sev_snp_enabled) { + r = -ENOTTY; + goto out; + } + fallthrough; case KVM_SEV_ES_INIT: if (!sev_es_enabled) { r = -ENOTTY; diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 635430fa641b..71f56bee0b90 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -76,6 +76,9 @@ enum { /* TPR and CR2 are always written before VMRUN */ #define VMCB_ALWAYS_DIRTY_MASK ((1U << VMCB_INTR) | (1U << VMCB_CR2)) +/* Supported init feature flags */ +#define SEV_SNP_SUPPORTED_FLAGS 0x0 + struct kvm_sev_info { bool active; /* SEV enabled guest */ bool es_active; /* SEV-ES enabled guest */ @@ -91,6 +94,7 @@ struct kvm_sev_info { struct list_head mirror_entry; /* Use as a list entry of mirrors */ struct misc_cg *misc_cg; /* For misc cgroup accounting */ atomic_t migration_in_progress; + u64 snp_init_flags; }; struct kvm_svm { diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 65fc983af840..a98a77f4fc4c 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1962,6 +1962,9 @@ enum sev_cmd_id { /* Guest Migration Extension */ KVM_SEV_SEND_CANCEL, + /* SNP specific commands */ + KVM_SEV_SNP_INIT, + KVM_SEV_NR_MAX, }; @@ -2058,6 +2061,16 @@ struct kvm_sev_receive_update_data { __u32 trans_len; }; +/* enable the restricted injection */ +#define KVM_SEV_SNP_RESTRICTED_INJET (1 << 0) + +/* enable the restricted injection timer */ +#define KVM_SEV_SNP_RESTRICTED_TIMER_INJET (1 << 1) + +struct kvm_snp_init { + __u64 flags; +}; + #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) #define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1) #define KVM_DEV_ASSIGN_MASK_INTX (1 << 2) -- 2.25.1