diff options
Diffstat (limited to 'arch/x86/kvm/svm/sev.c')
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 1093 |
1 files changed, 659 insertions, 434 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 943bd074a5d3..f59c65abe3cf 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -26,6 +26,7 @@ #include <asm/fpu/xcr.h> #include <asm/fpu/xstate.h> #include <asm/debugreg.h> +#include <asm/msr.h> #include <asm/sev.h> #include "mmu.h" @@ -36,7 +37,6 @@ #include "trace.h" #define GHCB_VERSION_MAX 2ULL -#define GHCB_VERSION_DEFAULT 2ULL #define GHCB_VERSION_MIN 1ULL #define GHCB_HV_FT_SUPPORTED (GHCB_HV_FT_SNP | GHCB_HV_FT_SNP_AP_CREATION) @@ -58,24 +58,31 @@ static bool sev_es_debug_swap_enabled = true; module_param_named(debug_swap, sev_es_debug_swap_enabled, bool, 0444); static u64 sev_supported_vmsa_features; +static unsigned int nr_ciphertext_hiding_asids; +module_param_named(ciphertext_hiding_asids, nr_ciphertext_hiding_asids, uint, 0444); + #define AP_RESET_HOLD_NONE 0 #define AP_RESET_HOLD_NAE_EVENT 1 #define AP_RESET_HOLD_MSR_PROTO 2 -/* As defined by SEV-SNP Firmware ABI, under "Guest Policy". */ -#define SNP_POLICY_MASK_API_MINOR GENMASK_ULL(7, 0) -#define SNP_POLICY_MASK_API_MAJOR GENMASK_ULL(15, 8) -#define SNP_POLICY_MASK_SMT BIT_ULL(16) -#define SNP_POLICY_MASK_RSVD_MBO BIT_ULL(17) -#define SNP_POLICY_MASK_DEBUG BIT_ULL(19) -#define SNP_POLICY_MASK_SINGLE_SOCKET BIT_ULL(20) - -#define SNP_POLICY_MASK_VALID (SNP_POLICY_MASK_API_MINOR | \ - SNP_POLICY_MASK_API_MAJOR | \ - SNP_POLICY_MASK_SMT | \ - SNP_POLICY_MASK_RSVD_MBO | \ - SNP_POLICY_MASK_DEBUG | \ - SNP_POLICY_MASK_SINGLE_SOCKET) +/* + * SEV-SNP policy bits that can be supported by KVM. These include policy bits + * that have implementation support within KVM or policy bits that do not + * require implementation support within KVM to enforce the policy. + */ +#define KVM_SNP_POLICY_MASK_VALID (SNP_POLICY_MASK_API_MINOR | \ + SNP_POLICY_MASK_API_MAJOR | \ + SNP_POLICY_MASK_SMT | \ + SNP_POLICY_MASK_RSVD_MBO | \ + SNP_POLICY_MASK_DEBUG | \ + SNP_POLICY_MASK_SINGLE_SOCKET | \ + SNP_POLICY_MASK_CXL_ALLOW | \ + SNP_POLICY_MASK_MEM_AES_256_XTS | \ + SNP_POLICY_MASK_RAPL_DIS | \ + SNP_POLICY_MASK_CIPHERTEXT_HIDING_DRAM | \ + SNP_POLICY_MASK_PAGE_SWAP_DISABLE) + +static u64 snp_supported_policy_bits __ro_after_init; #define INITIAL_VMSA_GPA 0xFFFFFFFFF000 @@ -84,6 +91,10 @@ static DECLARE_RWSEM(sev_deactivate_lock); static DEFINE_MUTEX(sev_bitmap_lock); unsigned int max_sev_asid; static unsigned int min_sev_asid; +static unsigned int max_sev_es_asid; +static unsigned int min_sev_es_asid; +static unsigned int max_snp_asid; +static unsigned int min_snp_asid; static unsigned long sev_me_mask; static unsigned int nr_asids; static unsigned long *sev_asid_bitmap; @@ -116,6 +127,7 @@ static int sev_flush_asids(unsigned int min_asid, unsigned int max_asid) */ down_write(&sev_deactivate_lock); + /* SNP firmware requires use of WBINVD for ASID recycling. */ wbinvd_on_all_cpus(); if (sev_snp_enabled) @@ -140,11 +152,19 @@ static inline bool is_mirroring_enc_context(struct kvm *kvm) static bool sev_vcpu_has_debug_swap(struct vcpu_svm *svm) { struct kvm_vcpu *vcpu = &svm->vcpu; - struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm); return sev->vmsa_features & SVM_SEV_FEAT_DEBUG_SWAP; } +static bool snp_is_secure_tsc_enabled(struct kvm *kvm) +{ + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); + + return (sev->vmsa_features & SVM_SEV_FEAT_SECURE_TSC) && + !WARN_ON_ONCE(!sev_snp_guest(kvm)); +} + /* Must be called with the sev_bitmap_lock held */ static bool __sev_recycle_asids(unsigned int min_asid, unsigned int max_asid) { @@ -171,20 +191,34 @@ static void sev_misc_cg_uncharge(struct kvm_sev_info *sev) misc_cg_uncharge(type, sev->misc_cg, 1); } -static int sev_asid_new(struct kvm_sev_info *sev) +static int sev_asid_new(struct kvm_sev_info *sev, unsigned long vm_type) { /* * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid. * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1. - * Note: min ASID can end up larger than the max if basic SEV support is - * effectively disabled by disallowing use of ASIDs for SEV guests. */ - unsigned int min_asid = sev->es_active ? 1 : min_sev_asid; - unsigned int max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid; - unsigned int asid; + unsigned int min_asid, max_asid, asid; bool retry = true; int ret; + if (vm_type == KVM_X86_SNP_VM) { + min_asid = min_snp_asid; + max_asid = max_snp_asid; + } else if (sev->es_active) { + min_asid = min_sev_es_asid; + max_asid = max_sev_es_asid; + } else { + min_asid = min_sev_asid; + max_asid = max_sev_asid; + } + + /* + * The min ASID can end up larger than the max if basic SEV support is + * effectively disabled by disallowing use of ASIDs for SEV guests. + * Similarly for SEV-ES guests the min ASID can end up larger than the + * max when ciphertext hiding is enabled, effectively disabling SEV-ES + * support. + */ if (min_asid > max_asid) return -ENOTTY; @@ -226,9 +260,7 @@ e_uncharge: static unsigned int sev_get_asid(struct kvm *kvm) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; - - return sev->asid; + return to_kvm_sev_info(kvm)->asid; } static void sev_asid_free(struct kvm_sev_info *sev) @@ -403,9 +435,10 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp, struct kvm_sev_init *data, unsigned long vm_type) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_platform_init_args init_args = {0}; bool es_active = vm_type != KVM_X86_SEV_VM; + bool snp_active = vm_type == KVM_X86_SNP_VM; u64 valid_vmsa_features = es_active ? sev_supported_vmsa_features : 0; int ret; @@ -415,12 +448,26 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp, if (data->flags) return -EINVAL; + if (!snp_active) + valid_vmsa_features &= ~SVM_SEV_FEAT_SECURE_TSC; + if (data->vmsa_features & ~valid_vmsa_features) return -EINVAL; if (data->ghcb_version > GHCB_VERSION_MAX || (!es_active && data->ghcb_version)) return -EINVAL; + /* + * KVM supports the full range of mandatory features defined by version + * 2 of the GHCB protocol, so default to that for SEV-ES guests created + * via KVM_SEV_INIT2 (KVM_SEV_INIT forces version 1). + */ + if (es_active && !data->ghcb_version) + data->ghcb_version = 2; + + if (snp_active && data->ghcb_version < 2) + return -EINVAL; + if (unlikely(sev->active)) return -EINVAL; @@ -429,28 +476,25 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp, sev->vmsa_features = data->vmsa_features; sev->ghcb_version = data->ghcb_version; - /* - * Currently KVM supports the full range of mandatory features defined - * by version 2 of the GHCB protocol, so default to that for SEV-ES - * guests created via KVM_SEV_INIT2. - */ - if (sev->es_active && !sev->ghcb_version) - sev->ghcb_version = GHCB_VERSION_DEFAULT; - - if (vm_type == KVM_X86_SNP_VM) + if (snp_active) sev->vmsa_features |= SVM_SEV_FEAT_SNP_ACTIVE; - ret = sev_asid_new(sev); + ret = sev_asid_new(sev, vm_type); if (ret) goto e_no_asid; init_args.probe = false; ret = sev_platform_init(&init_args); if (ret) - goto e_free; + goto e_free_asid; + + if (!zalloc_cpumask_var(&sev->have_run_cpus, GFP_KERNEL_ACCOUNT)) { + ret = -ENOMEM; + goto e_free_asid; + } /* This needs to happen after SEV/SNP firmware initialization. */ - if (vm_type == KVM_X86_SNP_VM) { + if (snp_active) { ret = snp_guest_req_init(kvm); if (ret) goto e_free; @@ -465,6 +509,8 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp, return 0; e_free: + free_cpumask_var(sev->have_run_cpus); +e_free_asid: argp->error = init_args.error; sev_asid_free(sev); sev->asid = 0; @@ -500,10 +546,9 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) static int sev_guest_init2(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct kvm_sev_init data; - if (!sev->need_init) + if (!to_kvm_sev_info(kvm)->need_init) return -EINVAL; if (kvm->arch.vm_type != KVM_X86_SEV_VM && @@ -543,14 +588,14 @@ static int __sev_issue_cmd(int fd, int id, void *data, int *error) static int sev_issue_cmd(struct kvm *kvm, int id, void *data, int *error) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); return __sev_issue_cmd(sev->fd, id, data, error); } static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_data_launch_start start; struct kvm_sev_launch_start params; void *dh_blob, *session_blob; @@ -610,6 +655,7 @@ static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) goto e_free_session; } + sev->policy = params.policy; sev->handle = start.handle; sev->fd = argp->sev_fd; @@ -622,9 +668,9 @@ e_free_dh: static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr, unsigned long ulen, unsigned long *n, - int write) + unsigned int flags) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); unsigned long npages, size; int npinned; unsigned long locked, lock_limit; @@ -663,7 +709,7 @@ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr, return ERR_PTR(-ENOMEM); /* Pin the user virtual address. */ - npinned = pin_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages); + npinned = pin_user_pages_fast(uaddr, npages, flags, pages); if (npinned != npages) { pr_err("SEV: Failure locking %lu pages.\n", npages); ret = -ENOMEM; @@ -686,11 +732,9 @@ err: static void sev_unpin_memory(struct kvm *kvm, struct page **pages, unsigned long npages) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; - unpin_user_pages(pages, npages); kvfree(pages); - sev->pages_locked -= npages; + to_kvm_sev_info(kvm)->pages_locked -= npages; } static void sev_clflush_pages(struct page *pages[], unsigned long npages) @@ -710,6 +754,29 @@ static void sev_clflush_pages(struct page *pages[], unsigned long npages) } } +static void sev_writeback_caches(struct kvm *kvm) +{ + /* + * Ensure that all dirty guest tagged cache entries are written back + * before releasing the pages back to the system for use. CLFLUSH will + * not do this without SME_COHERENT, and flushing many cache lines + * individually is slower than blasting WBINVD for large VMs, so issue + * WBNOINVD (or WBINVD if the "no invalidate" variant is unsupported) + * on CPUs that have done VMRUN, i.e. may have dirtied data using the + * VM's ASID. + * + * For simplicity, never remove CPUs from the bitmap. Ideally, KVM + * would clear the mask when flushing caches, but doing so requires + * serializing multiple calls and having responding CPUs (to the IPI) + * mark themselves as still running if they are running (or about to + * run) a vCPU for the VM. + * + * Note, the caller is responsible for ensuring correctness if the mask + * can be modified, e.g. if a CPU could be doing VMRUN. + */ + wbnoinvd_on_cpus_mask(to_kvm_sev_info(kvm)->have_run_cpus); +} + static unsigned long get_num_contig_pages(unsigned long idx, struct page **inpages, unsigned long npages) { @@ -734,7 +801,6 @@ static unsigned long get_num_contig_pages(unsigned long idx, static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) { unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i; - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct kvm_sev_launch_update_data params; struct sev_data_launch_update_data data; struct page **inpages; @@ -751,7 +817,7 @@ static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) vaddr_end = vaddr + size; /* Lock the user memory. */ - inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1); + inpages = sev_pin_memory(kvm, vaddr, size, &npages, FOLL_WRITE); if (IS_ERR(inpages)) return PTR_ERR(inpages); @@ -762,7 +828,7 @@ static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) sev_clflush_pages(inpages, npages); data.reserved = 0; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; for (i = 0; vaddr < vaddr_end; vaddr = next_vaddr, i += pages) { int offset, len; @@ -802,7 +868,7 @@ e_unpin: static int sev_es_sync_vmsa(struct vcpu_svm *svm) { struct kvm_vcpu *vcpu = &svm->vcpu; - struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm); struct sev_es_save_area *save = svm->sev_es.vmsa; struct xregs_state *xsave; const u8 *s; @@ -972,7 +1038,6 @@ static int sev_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp) { void __user *measure = u64_to_user_ptr(argp->data); - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_launch_measure data; struct kvm_sev_launch_measure params; void __user *p = NULL; @@ -1005,7 +1070,7 @@ static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp) } cmd: - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_MEASURE, &data, &argp->error); /* @@ -1033,19 +1098,17 @@ e_free_blob: static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_launch_finish data; if (!sev_guest(kvm)) return -ENOTTY; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; return sev_issue_cmd(kvm, SEV_CMD_LAUNCH_FINISH, &data, &argp->error); } static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct kvm_sev_guest_status params; struct sev_data_guest_status data; int ret; @@ -1055,7 +1118,7 @@ static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp) memset(&data, 0, sizeof(data)); - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_GUEST_STATUS, &data, &argp->error); if (ret) return ret; @@ -1074,11 +1137,10 @@ static int __sev_issue_dbg_cmd(struct kvm *kvm, unsigned long src, unsigned long dst, int size, int *error, bool enc) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_dbg data; data.reserved = 0; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; data.dst_addr = dst; data.src_addr = src; data.len = size; @@ -1250,7 +1312,7 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec) if (IS_ERR(src_p)) return PTR_ERR(src_p); - dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, 1); + dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, FOLL_WRITE); if (IS_ERR(dst_p)) { sev_unpin_memory(kvm, src_p, n); return PTR_ERR(dst_p); @@ -1302,7 +1364,6 @@ err: static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_launch_secret data; struct kvm_sev_launch_secret params; struct page **pages; @@ -1316,7 +1377,7 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params))) return -EFAULT; - pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 1); + pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, FOLL_WRITE); if (IS_ERR(pages)) return PTR_ERR(pages); @@ -1358,7 +1419,7 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) data.hdr_address = __psp_pa(hdr); data.hdr_len = params.hdr_len; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_SECRET, &data, &argp->error); kfree(hdr); @@ -1378,7 +1439,6 @@ e_unpin_memory: static int sev_get_attestation_report(struct kvm *kvm, struct kvm_sev_cmd *argp) { void __user *report = u64_to_user_ptr(argp->data); - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_attestation_report data; struct kvm_sev_attestation_report params; void __user *p; @@ -1411,7 +1471,7 @@ static int sev_get_attestation_report(struct kvm *kvm, struct kvm_sev_cmd *argp) memcpy(data.mnonce, params.mnonce, sizeof(params.mnonce)); } cmd: - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_ATTESTATION_REPORT, &data, &argp->error); /* * If we query the session length, FW responded with expected data. @@ -1441,12 +1501,11 @@ static int __sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp, struct kvm_sev_send_start *params) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_send_start data; int ret; memset(&data, 0, sizeof(data)); - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error); params->session_len = data.session_len; @@ -1459,7 +1518,6 @@ __sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp, static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_send_start data; struct kvm_sev_send_start params; void *amd_certs, *session_data; @@ -1520,7 +1578,7 @@ static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp) data.amd_certs_len = params.amd_certs_len; data.session_address = __psp_pa(session_data); data.session_len = params.session_len; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error); @@ -1552,12 +1610,11 @@ static int __sev_send_update_data_query_lengths(struct kvm *kvm, struct kvm_sev_cmd *argp, struct kvm_sev_send_update_data *params) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_send_update_data data; int ret; memset(&data, 0, sizeof(data)); - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error); params->hdr_len = data.hdr_len; @@ -1572,7 +1629,6 @@ __sev_send_update_data_query_lengths(struct kvm *kvm, struct kvm_sev_cmd *argp, static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_send_update_data data; struct kvm_sev_send_update_data params; void *hdr, *trans_data; @@ -1608,11 +1664,11 @@ static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) /* allocate memory for header and transport buffer */ ret = -ENOMEM; - hdr = kzalloc(params.hdr_len, GFP_KERNEL_ACCOUNT); + hdr = kzalloc(params.hdr_len, GFP_KERNEL); if (!hdr) goto e_unpin; - trans_data = kzalloc(params.trans_len, GFP_KERNEL_ACCOUNT); + trans_data = kzalloc(params.trans_len, GFP_KERNEL); if (!trans_data) goto e_free_hdr; @@ -1626,7 +1682,7 @@ static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset; data.guest_address |= sev_me_mask; data.guest_len = params.guest_len; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error); @@ -1657,31 +1713,29 @@ e_unpin: static int sev_send_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_send_finish data; if (!sev_guest(kvm)) return -ENOTTY; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; return sev_issue_cmd(kvm, SEV_CMD_SEND_FINISH, &data, &argp->error); } static int sev_send_cancel(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_send_cancel data; if (!sev_guest(kvm)) return -ENOTTY; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; return sev_issue_cmd(kvm, SEV_CMD_SEND_CANCEL, &data, &argp->error); } static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_data_receive_start start; struct kvm_sev_receive_start params; int *error = &argp->error; @@ -1755,7 +1809,6 @@ e_free_pdh: static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct kvm_sev_receive_update_data params; struct sev_data_receive_update_data data; void *hdr = NULL, *trans = NULL; @@ -1798,7 +1851,7 @@ static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) /* Pin guest memory */ guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK, - PAGE_SIZE, &n, 1); + PAGE_SIZE, &n, FOLL_WRITE); if (IS_ERR(guest_page)) { ret = PTR_ERR(guest_page); goto e_free_trans; @@ -1815,7 +1868,7 @@ static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset; data.guest_address |= sev_me_mask; data.guest_len = params.guest_len; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, &data, &argp->error); @@ -1832,13 +1885,12 @@ e_free_hdr: static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct sev_data_receive_finish data; if (!sev_guest(kvm)) return -ENOTTY; - data.handle = sev->handle; + data.handle = to_kvm_sev_info(kvm)->handle; return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error); } @@ -1858,8 +1910,8 @@ static bool is_cmd_allowed_from_mirror(u32 cmd_id) static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm) { - struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info; - struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info; + struct kvm_sev_info *dst_sev = to_kvm_sev_info(dst_kvm); + struct kvm_sev_info *src_sev = to_kvm_sev_info(src_kvm); int r = -EBUSY; if (dst_kvm == src_kvm) @@ -1893,8 +1945,8 @@ release_dst: static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm) { - struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info; - struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info; + struct kvm_sev_info *dst_sev = to_kvm_sev_info(dst_kvm); + struct kvm_sev_info *src_sev = to_kvm_sev_info(src_kvm); mutex_unlock(&dst_kvm->lock); mutex_unlock(&src_kvm->lock); @@ -1902,74 +1954,10 @@ static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm) atomic_set_release(&src_sev->migration_in_progress, 0); } -/* vCPU mutex subclasses. */ -enum sev_migration_role { - SEV_MIGRATION_SOURCE = 0, - SEV_MIGRATION_TARGET, - SEV_NR_MIGRATION_ROLES, -}; - -static int sev_lock_vcpus_for_migration(struct kvm *kvm, - enum sev_migration_role role) -{ - struct kvm_vcpu *vcpu; - unsigned long i, j; - - kvm_for_each_vcpu(i, vcpu, kvm) { - if (mutex_lock_killable_nested(&vcpu->mutex, role)) - goto out_unlock; - -#ifdef CONFIG_PROVE_LOCKING - if (!i) - /* - * Reset the role to one that avoids colliding with - * the role used for the first vcpu mutex. - */ - role = SEV_NR_MIGRATION_ROLES; - else - mutex_release(&vcpu->mutex.dep_map, _THIS_IP_); -#endif - } - - return 0; - -out_unlock: - - kvm_for_each_vcpu(j, vcpu, kvm) { - if (i == j) - break; - -#ifdef CONFIG_PROVE_LOCKING - if (j) - mutex_acquire(&vcpu->mutex.dep_map, role, 0, _THIS_IP_); -#endif - - mutex_unlock(&vcpu->mutex); - } - return -EINTR; -} - -static void sev_unlock_vcpus_for_migration(struct kvm *kvm) -{ - struct kvm_vcpu *vcpu; - unsigned long i; - bool first = true; - - kvm_for_each_vcpu(i, vcpu, kvm) { - if (first) - first = false; - else - mutex_acquire(&vcpu->mutex.dep_map, - SEV_NR_MIGRATION_ROLES, 0, _THIS_IP_); - - mutex_unlock(&vcpu->mutex); - } -} - static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm) { - struct kvm_sev_info *dst = &to_kvm_svm(dst_kvm)->sev_info; - struct kvm_sev_info *src = &to_kvm_svm(src_kvm)->sev_info; + struct kvm_sev_info *dst = to_kvm_sev_info(dst_kvm); + struct kvm_sev_info *src = to_kvm_sev_info(src_kvm); struct kvm_vcpu *dst_vcpu, *src_vcpu; struct vcpu_svm *dst_svm, *src_svm; struct kvm_sev_info *mirror; @@ -2009,8 +1997,7 @@ static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm) * and add the new mirror to the list. */ if (is_mirroring_enc_context(dst_kvm)) { - struct kvm_sev_info *owner_sev_info = - &to_kvm_svm(dst->enc_context_owner)->sev_info; + struct kvm_sev_info *owner_sev_info = to_kvm_sev_info(dst->enc_context_owner); list_del(&src->mirror_entry); list_add_tail(&dst->mirror_entry, &owner_sev_info->mirror_vms); @@ -2019,7 +2006,7 @@ static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm) kvm_for_each_vcpu(i, dst_vcpu, dst_kvm) { dst_svm = to_svm(dst_vcpu); - sev_init_vmcb(dst_svm); + sev_init_vmcb(dst_svm, false); if (!dst->es_active) continue; @@ -2053,6 +2040,10 @@ static int sev_check_source_vcpus(struct kvm *dst, struct kvm *src) struct kvm_vcpu *src_vcpu; unsigned long i; + if (src->created_vcpus != atomic_read(&src->online_vcpus) || + dst->created_vcpus != atomic_read(&dst->online_vcpus)) + return -EBUSY; + if (!sev_es_guest(src)) return 0; @@ -2069,7 +2060,7 @@ static int sev_check_source_vcpus(struct kvm *dst, struct kvm *src) int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd) { - struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *dst_sev = to_kvm_sev_info(kvm); struct kvm_sev_info *src_sev, *cg_cleanup_sev; CLASS(fd, f)(source_fd); struct kvm *source_kvm; @@ -2093,7 +2084,7 @@ int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd) goto out_unlock; } - src_sev = &to_kvm_svm(source_kvm)->sev_info; + src_sev = to_kvm_sev_info(source_kvm); dst_sev->misc_cg = get_current_misc_cg(); cg_cleanup_sev = dst_sev; @@ -2104,10 +2095,10 @@ int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd) charged = true; } - ret = sev_lock_vcpus_for_migration(kvm, SEV_MIGRATION_SOURCE); + ret = kvm_lock_all_vcpus(kvm); if (ret) goto out_dst_cgroup; - ret = sev_lock_vcpus_for_migration(source_kvm, SEV_MIGRATION_TARGET); + ret = kvm_lock_all_vcpus(source_kvm); if (ret) goto out_dst_vcpu; @@ -2115,15 +2106,26 @@ int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd) if (ret) goto out_source_vcpu; + /* + * Allocate a new have_run_cpus for the destination, i.e. don't copy + * the set of CPUs from the source. If a CPU was used to run a vCPU in + * the source VM but is never used for the destination VM, then the CPU + * can only have cached memory that was accessible to the source VM. + */ + if (!zalloc_cpumask_var(&dst_sev->have_run_cpus, GFP_KERNEL_ACCOUNT)) { + ret = -ENOMEM; + goto out_source_vcpu; + } + sev_migrate_from(kvm, source_kvm); kvm_vm_dead(source_kvm); cg_cleanup_sev = src_sev; ret = 0; out_source_vcpu: - sev_unlock_vcpus_for_migration(source_kvm); + kvm_unlock_all_vcpus(source_kvm); out_dst_vcpu: - sev_unlock_vcpus_for_migration(kvm); + kvm_unlock_all_vcpus(kvm); out_dst_cgroup: /* Operates on the source on success, on the destination on failure. */ if (charged) @@ -2145,6 +2147,10 @@ int sev_dev_get_attr(u32 group, u64 attr, u64 *val) *val = sev_supported_vmsa_features; return 0; + case KVM_X86_SNP_POLICY_BITS: + *val = snp_supported_policy_bits; + return 0; + default: return -ENXIO; } @@ -2181,7 +2187,7 @@ static void *snp_context_create(struct kvm *kvm, struct kvm_sev_cmd *argp) static int snp_bind_asid(struct kvm *kvm, int *error) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_data_snp_activate data = {0}; data.gctx_paddr = __psp_pa(sev->snp_context); @@ -2191,7 +2197,7 @@ static int snp_bind_asid(struct kvm *kvm, int *error) static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_data_snp_launch_start start = {0}; struct kvm_sev_snp_launch_start params; int rc; @@ -2209,16 +2215,19 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) if (params.flags) return -EINVAL; - if (params.policy & ~SNP_POLICY_MASK_VALID) + if (params.policy & ~snp_supported_policy_bits) return -EINVAL; /* Check for policy bits that must be set */ - if (!(params.policy & SNP_POLICY_MASK_RSVD_MBO) || - !(params.policy & SNP_POLICY_MASK_SMT)) + if (!(params.policy & SNP_POLICY_MASK_RSVD_MBO)) return -EINVAL; - if (params.policy & SNP_POLICY_MASK_SINGLE_SOCKET) - return -EINVAL; + if (snp_is_secure_tsc_enabled(kvm)) { + if (WARN_ON_ONCE(!kvm->arch.default_tsc_khz)) + return -EINVAL; + + start.desired_tsc_khz = kvm->arch.default_tsc_khz; + } sev->snp_context = snp_context_create(kvm, argp); if (!sev->snp_context) @@ -2226,6 +2235,7 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) start.gctx_paddr = __psp_pa(sev->snp_context); start.policy = params.policy; + memcpy(start.gosvw, params.gosvw, sizeof(params.gosvw)); rc = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_START, &start, &argp->error); if (rc) { @@ -2234,6 +2244,7 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) goto e_free_context; } + sev->policy = params.policy; sev->fd = argp->sev_fd; rc = snp_bind_asid(kvm, &argp->error); if (rc) { @@ -2260,7 +2271,7 @@ static int sev_gmem_post_populate(struct kvm *kvm, gfn_t gfn_start, kvm_pfn_t pf void __user *src, int order, void *opaque) { struct sev_gmem_populate_args *sev_populate_args = opaque; - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); int n_private = 0, ret, i; int npages = (1 << order); gfn_t gfn; @@ -2350,7 +2361,7 @@ err: static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_gmem_populate_args sev_populate_args = {0}; struct kvm_sev_snp_launch_update params; struct kvm_memory_slot *memslot; @@ -2367,7 +2378,7 @@ static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp) pr_debug("%s: GFN start 0x%llx length 0x%llx type %d flags %d\n", __func__, params.gfn_start, params.len, params.type, params.flags); - if (!PAGE_ALIGNED(params.len) || params.flags || + if (!params.len || !PAGE_ALIGNED(params.len) || params.flags || (params.type != KVM_SEV_SNP_PAGE_TYPE_NORMAL && params.type != KVM_SEV_SNP_PAGE_TYPE_ZERO && params.type != KVM_SEV_SNP_PAGE_TYPE_UNMEASURED && @@ -2399,7 +2410,7 @@ static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp) mutex_lock(&kvm->slots_lock); memslot = gfn_to_memslot(kvm, params.gfn_start); - if (!kvm_slot_can_be_private(memslot)) { + if (!kvm_slot_has_gmem(memslot)) { ret = -EINVAL; goto out; } @@ -2434,7 +2445,7 @@ out: static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_data_snp_launch_update data = {}; struct kvm_vcpu *vcpu; unsigned long i; @@ -2482,7 +2493,7 @@ static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) static int snp_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct kvm_sev_snp_launch_finish params; struct sev_data_snp_launch_finish *data; void *id_block = NULL, *id_auth = NULL; @@ -2677,7 +2688,7 @@ out: int sev_mem_enc_register_region(struct kvm *kvm, struct kvm_enc_region *range) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct enc_region *region; int ret = 0; @@ -2696,7 +2707,8 @@ int sev_mem_enc_register_region(struct kvm *kvm, return -ENOMEM; mutex_lock(&kvm->lock); - region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages, 1); + region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages, + FOLL_WRITE | FOLL_LONGTERM); if (IS_ERR(region->pages)) { ret = PTR_ERR(region->pages); mutex_unlock(&kvm->lock); @@ -2729,7 +2741,7 @@ e_free: static struct enc_region * find_enc_region(struct kvm *kvm, struct kvm_enc_region *range) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct list_head *head = &sev->regions_list; struct enc_region *i; @@ -2773,12 +2785,7 @@ int sev_mem_enc_unregister_region(struct kvm *kvm, goto failed; } - /* - * Ensure that all guest tagged cache entries are flushed before - * releasing the pages back to the system for use. CLFLUSH will - * not do this, so issue a WBINVD. - */ - wbinvd_on_all_cpus(); + sev_writeback_caches(kvm); __unregister_enc_region_locked(kvm, region); @@ -2820,13 +2827,18 @@ int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd) goto e_unlock; } + mirror_sev = to_kvm_sev_info(kvm); + if (!zalloc_cpumask_var(&mirror_sev->have_run_cpus, GFP_KERNEL_ACCOUNT)) { + ret = -ENOMEM; + goto e_unlock; + } + /* * The mirror kvm holds an enc_context_owner ref so its asid can't * disappear until we're done with it */ - source_sev = &to_kvm_svm(source_kvm)->sev_info; + source_sev = to_kvm_sev_info(source_kvm); kvm_get_kvm(source_kvm); - mirror_sev = &to_kvm_svm(kvm)->sev_info; list_add_tail(&mirror_sev->mirror_entry, &source_sev->mirror_vms); /* Set enc_context_owner and copy its encryption context over */ @@ -2854,7 +2866,7 @@ e_unlock: static int snp_decommission_context(struct kvm *kvm) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct sev_data_snp_addr data = {}; int ret; @@ -2879,7 +2891,7 @@ static int snp_decommission_context(struct kvm *kvm) void sev_vm_destroy(struct kvm *kvm) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); struct list_head *head = &sev->regions_list; struct list_head *pos, *q; @@ -2888,7 +2900,13 @@ void sev_vm_destroy(struct kvm *kvm) WARN_ON(!list_empty(&sev->mirror_vms)); - /* If this is a mirror_kvm release the enc_context_owner and skip sev cleanup */ + free_cpumask_var(sev->have_run_cpus); + + /* + * If this is a mirror VM, remove it from the owner's list of a mirrors + * and skip ASID cleanup (the ASID is tied to the lifetime of the owner). + * Note, mirror VMs don't support registering encrypted regions. + */ if (is_mirroring_enc_context(kvm)) { struct kvm *owner_kvm = sev->enc_context_owner; @@ -2899,12 +2917,6 @@ void sev_vm_destroy(struct kvm *kvm) return; } - /* - * Ensure that all guest tagged cache entries are flushed before - * releasing the pages back to the system for use. CLFLUSH will - * not do this, so issue a WBINVD. - */ - wbinvd_on_all_cpus(); /* * if userspace was terminated before unregistering the memory regions @@ -2950,9 +2962,37 @@ void __init sev_set_cpu_caps(void) } } +static bool is_sev_snp_initialized(void) +{ + struct sev_user_data_snp_status *status; + struct sev_data_snp_addr buf; + bool initialized = false; + int ret, error = 0; + + status = snp_alloc_firmware_page(GFP_KERNEL | __GFP_ZERO); + if (!status) + return false; + + buf.address = __psp_pa(status); + ret = sev_do_cmd(SEV_CMD_SNP_PLATFORM_STATUS, &buf, &error); + if (ret) { + pr_err("SEV: SNP_PLATFORM_STATUS failed ret=%d, fw_error=%d (%#x)\n", + ret, error, error); + goto out; + } + + initialized = !!status->state; + +out: + snp_free_firmware_page(status); + + return initialized; +} + void __init sev_hardware_setup(void) { unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count; + struct sev_platform_init_args init_args = {0}; bool sev_snp_supported = false; bool sev_es_supported = false; bool sev_supported = false; @@ -2972,6 +3012,16 @@ void __init sev_hardware_setup(void) WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_FLUSHBYASID))) goto out; + /* + * The kernel's initcall infrastructure lacks the ability to express + * dependencies between initcalls, whereas the modules infrastructure + * automatically handles dependencies via symbol loading. Ensure the + * PSP SEV driver is initialized before proceeding if KVM is built-in, + * as the dependency isn't handled by the initcall infrastructure. + */ + if (IS_BUILTIN(CONFIG_KVM_AMD) && sev_module_init()) + goto out; + /* Retrieve SEV CPUID information */ cpuid(0x8000001f, &eax, &ebx, &ecx, &edx); @@ -3037,12 +3087,48 @@ void __init sev_hardware_setup(void) if (min_sev_asid == 1) goto out; + min_sev_es_asid = min_snp_asid = 1; + max_sev_es_asid = max_snp_asid = min_sev_asid - 1; + sev_es_asid_count = min_sev_asid - 1; WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count)); sev_es_supported = true; sev_snp_supported = sev_snp_enabled && cc_platform_has(CC_ATTR_HOST_SEV_SNP); out: + if (sev_enabled) { + init_args.probe = true; + + if (sev_is_snp_ciphertext_hiding_supported()) + init_args.max_snp_asid = min(nr_ciphertext_hiding_asids, + min_sev_asid - 1); + + if (sev_platform_init(&init_args)) + sev_supported = sev_es_supported = sev_snp_supported = false; + else if (sev_snp_supported) + sev_snp_supported = is_sev_snp_initialized(); + + if (sev_snp_supported) { + snp_supported_policy_bits = sev_get_snp_policy_bits() & + KVM_SNP_POLICY_MASK_VALID; + nr_ciphertext_hiding_asids = init_args.max_snp_asid; + } + + /* + * If ciphertext hiding is enabled, the joint SEV-ES/SEV-SNP + * ASID range is partitioned into separate SEV-ES and SEV-SNP + * ASID ranges, with the SEV-SNP range being [1..max_snp_asid] + * and the SEV-ES range being (max_snp_asid..max_sev_es_asid]. + * Note, SEV-ES may effectively be disabled if all ASIDs from + * the joint range are assigned to SEV-SNP. + */ + if (nr_ciphertext_hiding_asids) { + max_snp_asid = nr_ciphertext_hiding_asids; + min_sev_es_asid = max_snp_asid + 1; + pr_info("SEV-SNP ciphertext hiding enabled\n"); + } + } + if (boot_cpu_has(X86_FEATURE_SEV)) pr_info("SEV %s (ASIDs %u - %u)\n", sev_supported ? min_sev_asid <= max_sev_asid ? "enabled" : @@ -3051,12 +3137,14 @@ out: min_sev_asid, max_sev_asid); if (boot_cpu_has(X86_FEATURE_SEV_ES)) pr_info("SEV-ES %s (ASIDs %u - %u)\n", - sev_es_supported ? "enabled" : "disabled", - min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1); + sev_es_supported ? min_sev_es_asid <= max_sev_es_asid ? "enabled" : + "unusable" : + "disabled", + min_sev_es_asid, max_sev_es_asid); if (boot_cpu_has(X86_FEATURE_SEV_SNP)) pr_info("SEV-SNP %s (ASIDs %u - %u)\n", - sev_snp_supported ? "enabled" : "disabled", - min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1); + str_enabled_disabled(sev_snp_supported), + min_snp_asid, max_snp_asid); sev_enabled = sev_supported; sev_es_enabled = sev_es_supported; @@ -3069,6 +3157,9 @@ out: sev_supported_vmsa_features = 0; if (sev_es_debug_swap_enabled) sev_supported_vmsa_features |= SVM_SEV_FEAT_DEBUG_SWAP; + + if (sev_snp_enabled && tsc_khz && cpu_feature_enabled(X86_FEATURE_SNP_SECURE_TSC)) + sev_supported_vmsa_features |= SVM_SEV_FEAT_SECURE_TSC; } void sev_hardware_unsetup(void) @@ -3084,6 +3175,8 @@ void sev_hardware_unsetup(void) misc_cg_set_capacity(MISC_CG_RES_SEV, 0); misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0); + + sev_platform_shutdown(); } int sev_cpu_init(struct svm_cpu_data *sd) @@ -3126,30 +3219,29 @@ static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va) /* * VM Page Flush takes a host virtual address and a guest ASID. Fall - * back to WBINVD if this faults so as not to make any problems worse - * by leaving stale encrypted data in the cache. + * back to full writeback of caches if this faults so as not to make + * any problems worse by leaving stale encrypted data in the cache. */ - if (WARN_ON_ONCE(wrmsrl_safe(MSR_AMD64_VM_PAGE_FLUSH, addr | asid))) - goto do_wbinvd; + if (WARN_ON_ONCE(wrmsrq_safe(MSR_AMD64_VM_PAGE_FLUSH, addr | asid))) + goto do_sev_writeback_caches; return; -do_wbinvd: - wbinvd_on_all_cpus(); +do_sev_writeback_caches: + sev_writeback_caches(vcpu->kvm); } void sev_guest_memory_reclaimed(struct kvm *kvm) { /* * With SNP+gmem, private/encrypted memory is unreachable via the - * hva-based mmu notifiers, so these events are only actually - * pertaining to shared pages where there is no need to perform - * the WBINVD to flush associated caches. + * hva-based mmu notifiers, i.e. these events are explicitly scoped to + * shared pages, where there's no need to flush caches. */ if (!sev_guest(kvm) || sev_snp_guest(kvm)) return; - wbinvd_on_all_cpus(); + sev_writeback_caches(kvm); } void sev_free_vcpu(struct kvm_vcpu *vcpu) @@ -3183,9 +3275,14 @@ skip_vmsa_free: kvfree(svm->sev_es.ghcb_sa); } +static u64 kvm_get_cached_sw_exit_code(struct vmcb_control_area *control) +{ + return (((u64)control->exit_code_hi) << 32) | control->exit_code; +} + static void dump_ghcb(struct vcpu_svm *svm) { - struct ghcb *ghcb = svm->sev_es.ghcb; + struct vmcb_control_area *control = &svm->vmcb->control; unsigned int nbits; /* Re-use the dump_invalid_vmcb module parameter */ @@ -3194,18 +3291,24 @@ static void dump_ghcb(struct vcpu_svm *svm) return; } - nbits = sizeof(ghcb->save.valid_bitmap) * 8; + nbits = sizeof(svm->sev_es.valid_bitmap) * 8; - pr_err("GHCB (GPA=%016llx):\n", svm->vmcb->control.ghcb_gpa); + /* + * Print KVM's snapshot of the GHCB values that were (unsuccessfully) + * used to handle the exit. If the guest has since modified the GHCB + * itself, dumping the raw GHCB won't help debug why KVM was unable to + * handle the VMGEXIT that KVM observed. + */ + pr_err("GHCB (GPA=%016llx) snapshot:\n", svm->vmcb->control.ghcb_gpa); pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_code", - ghcb->save.sw_exit_code, ghcb_sw_exit_code_is_valid(ghcb)); + kvm_get_cached_sw_exit_code(control), kvm_ghcb_sw_exit_code_is_valid(svm)); pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_1", - ghcb->save.sw_exit_info_1, ghcb_sw_exit_info_1_is_valid(ghcb)); + control->exit_info_1, kvm_ghcb_sw_exit_info_1_is_valid(svm)); pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_2", - ghcb->save.sw_exit_info_2, ghcb_sw_exit_info_2_is_valid(ghcb)); + control->exit_info_2, kvm_ghcb_sw_exit_info_2_is_valid(svm)); pr_err("%-20s%016llx is_valid: %u\n", "sw_scratch", - ghcb->save.sw_scratch, ghcb_sw_scratch_is_valid(ghcb)); - pr_err("%-20s%*pb\n", "valid_bitmap", nbits, ghcb->save.valid_bitmap); + svm->sev_es.sw_scratch, kvm_ghcb_sw_scratch_is_valid(svm)); + pr_err("%-20s%*pb\n", "valid_bitmap", nbits, svm->sev_es.valid_bitmap); } static void sev_es_sync_to_ghcb(struct vcpu_svm *svm) @@ -3251,36 +3354,32 @@ static void sev_es_sync_from_ghcb(struct vcpu_svm *svm) BUILD_BUG_ON(sizeof(svm->sev_es.valid_bitmap) != sizeof(ghcb->save.valid_bitmap)); memcpy(&svm->sev_es.valid_bitmap, &ghcb->save.valid_bitmap, sizeof(ghcb->save.valid_bitmap)); - vcpu->arch.regs[VCPU_REGS_RAX] = kvm_ghcb_get_rax_if_valid(svm, ghcb); - vcpu->arch.regs[VCPU_REGS_RBX] = kvm_ghcb_get_rbx_if_valid(svm, ghcb); - vcpu->arch.regs[VCPU_REGS_RCX] = kvm_ghcb_get_rcx_if_valid(svm, ghcb); - vcpu->arch.regs[VCPU_REGS_RDX] = kvm_ghcb_get_rdx_if_valid(svm, ghcb); - vcpu->arch.regs[VCPU_REGS_RSI] = kvm_ghcb_get_rsi_if_valid(svm, ghcb); + vcpu->arch.regs[VCPU_REGS_RAX] = kvm_ghcb_get_rax_if_valid(svm); + vcpu->arch.regs[VCPU_REGS_RBX] = kvm_ghcb_get_rbx_if_valid(svm); + vcpu->arch.regs[VCPU_REGS_RCX] = kvm_ghcb_get_rcx_if_valid(svm); + vcpu->arch.regs[VCPU_REGS_RDX] = kvm_ghcb_get_rdx_if_valid(svm); + vcpu->arch.regs[VCPU_REGS_RSI] = kvm_ghcb_get_rsi_if_valid(svm); - svm->vmcb->save.cpl = kvm_ghcb_get_cpl_if_valid(svm, ghcb); + svm->vmcb->save.cpl = kvm_ghcb_get_cpl_if_valid(svm); - if (kvm_ghcb_xcr0_is_valid(svm)) { - vcpu->arch.xcr0 = ghcb_get_xcr0(ghcb); - kvm_update_cpuid_runtime(vcpu); - } + if (kvm_ghcb_xcr0_is_valid(svm)) + __kvm_set_xcr(vcpu, 0, kvm_ghcb_get_xcr0(svm)); + + if (kvm_ghcb_xss_is_valid(svm)) + __kvm_emulate_msr_write(vcpu, MSR_IA32_XSS, kvm_ghcb_get_xss(svm)); /* Copy the GHCB exit information into the VMCB fields */ - exit_code = ghcb_get_sw_exit_code(ghcb); + exit_code = kvm_ghcb_get_sw_exit_code(svm); control->exit_code = lower_32_bits(exit_code); control->exit_code_hi = upper_32_bits(exit_code); - control->exit_info_1 = ghcb_get_sw_exit_info_1(ghcb); - control->exit_info_2 = ghcb_get_sw_exit_info_2(ghcb); - svm->sev_es.sw_scratch = kvm_ghcb_get_sw_scratch_if_valid(svm, ghcb); + control->exit_info_1 = kvm_ghcb_get_sw_exit_info_1(svm); + control->exit_info_2 = kvm_ghcb_get_sw_exit_info_2(svm); + svm->sev_es.sw_scratch = kvm_ghcb_get_sw_scratch_if_valid(svm); /* Clear the valid entries fields */ memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap)); } -static u64 kvm_ghcb_get_sw_exit_code(struct vmcb_control_area *control) -{ - return (((u64)control->exit_code_hi) << 32) | control->exit_code; -} - static int sev_es_validate_vmgexit(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; @@ -3292,7 +3391,7 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm) * Retrieve the exit code now even though it may not be marked valid * as it could help with debugging. */ - exit_code = kvm_ghcb_get_sw_exit_code(control); + exit_code = kvm_get_cached_sw_exit_code(control); /* Only GHCB Usage code 0 is supported */ if (svm->sev_es.ghcb->ghcb_usage) { @@ -3420,8 +3519,7 @@ vmgexit_err: dump_ghcb(svm); } - ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, reason); + svm_vmgexit_bad_input(svm, reason); /* Resume the guest to "return" the error code. */ return 1; @@ -3462,10 +3560,28 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm) svm->sev_es.ghcb = NULL; } -void pre_sev_run(struct vcpu_svm *svm, int cpu) +int pre_sev_run(struct vcpu_svm *svm, int cpu) { struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu); - unsigned int asid = sev_get_asid(svm->vcpu.kvm); + struct kvm *kvm = svm->vcpu.kvm; + unsigned int asid = sev_get_asid(kvm); + + /* + * Reject KVM_RUN if userspace attempts to run the vCPU with an invalid + * VMSA, e.g. if userspace forces the vCPU to be RUNNABLE after an SNP + * AP Destroy event. + */ + if (sev_es_guest(kvm) && !VALID_PAGE(svm->vmcb->control.vmsa_pa)) + return -EINVAL; + + /* + * To optimize cache flushes when memory is reclaimed from an SEV VM, + * track physical CPUs that enter the guest for SEV VMs and thus can + * have encrypted, dirty data in the cache, and flush caches only for + * CPUs that have entered the guest. + */ + if (!cpumask_test_cpu(cpu, to_kvm_sev_info(kvm)->have_run_cpus)) + cpumask_set_cpu(cpu, to_kvm_sev_info(kvm)->have_run_cpus); /* Assign the asid allocated with this SEV guest */ svm->asid = asid; @@ -3478,11 +3594,12 @@ void pre_sev_run(struct vcpu_svm *svm, int cpu) */ if (sd->sev_vmcbs[asid] == svm->vmcb && svm->vcpu.arch.last_vmentry_cpu == cpu) - return; + return 0; sd->sev_vmcbs[asid] = svm->vmcb; svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID; vmcb_mark_dirty(svm->vmcb, VMCB_ASID); + return 0; } #define GHCB_SCRATCH_AREA_LIMIT (16ULL * PAGE_SIZE) @@ -3564,8 +3681,7 @@ static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len) return 0; e_scratch: - ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_SCRATCH_AREA); + svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_SCRATCH_AREA); return 1; } @@ -3627,13 +3743,20 @@ static int snp_begin_psc_msr(struct vcpu_svm *svm, u64 ghcb_msr) return 1; /* resume guest */ } - if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) { + if (!user_exit_on_hypercall(vcpu->kvm, KVM_HC_MAP_GPA_RANGE)) { set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR); return 1; /* resume guest */ } vcpu->run->exit_reason = KVM_EXIT_HYPERCALL; vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE; + /* + * In principle this should have been -KVM_ENOSYS, but userspace (QEMU <=9.2) + * assumed that vcpu->run->hypercall.ret is never changed by KVM and thus that + * it was always zero on KVM_EXIT_HYPERCALL. Since KVM is now overwriting + * vcpu->run->hypercall.ret, ensuring that it is zero to not break QEMU. + */ + vcpu->run->hypercall.ret = 0; vcpu->run->hypercall.args[0] = gpa; vcpu->run->hypercall.args[1] = 1; vcpu->run->hypercall.args[2] = (op == SNP_PAGE_STATE_PRIVATE) @@ -3658,7 +3781,14 @@ static void snp_complete_psc(struct vcpu_svm *svm, u64 psc_ret) svm->sev_es.psc_inflight = 0; svm->sev_es.psc_idx = 0; svm->sev_es.psc_2m = false; - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, psc_ret); + + /* + * PSC requests always get a "no action" response in SW_EXITINFO1, with + * a PSC-specific return code in SW_EXITINFO2 that provides the "real" + * return code. E.g. if the PSC request was interrupted, the need to + * retry is communicated via SW_EXITINFO2, not SW_EXITINFO1. + */ + svm_vmgexit_no_action(svm, psc_ret); } static void __snp_complete_one_psc(struct vcpu_svm *svm) @@ -3710,7 +3840,7 @@ static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc) bool huge; u64 gfn; - if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) { + if (!user_exit_on_hypercall(vcpu->kvm, KVM_HC_MAP_GPA_RANGE)) { snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC); return 1; } @@ -3797,6 +3927,13 @@ next_range: case VMGEXIT_PSC_OP_SHARED: vcpu->run->exit_reason = KVM_EXIT_HYPERCALL; vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE; + /* + * In principle this should have been -KVM_ENOSYS, but userspace (QEMU <=9.2) + * assumed that vcpu->run->hypercall.ret is never changed by KVM and thus that + * it was always zero on KVM_EXIT_HYPERCALL. Since KVM is now overwriting + * vcpu->run->hypercall.ret, ensuring that it is zero to not break QEMU. + */ + vcpu->run->hypercall.ret = 0; vcpu->run->hypercall.args[0] = gfn_to_gpa(gfn); vcpu->run->hypercall.args[1] = npages; vcpu->run->hypercall.args[2] = entry_start.operation == VMGEXIT_PSC_OP_PRIVATE @@ -3820,113 +3957,90 @@ next_range: goto next_range; } - unreachable(); + BUG(); } -static int __sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu) +/* + * Invoked as part of svm_vcpu_reset() processing of an init event. + */ +static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + struct kvm_memory_slot *slot; + struct page *page; + kvm_pfn_t pfn; + gfn_t gfn; + + guard(mutex)(&svm->sev_es.snp_vmsa_mutex); + + if (!svm->sev_es.snp_ap_waiting_for_reset) + return; - WARN_ON(!mutex_is_locked(&svm->sev_es.snp_vmsa_mutex)); + svm->sev_es.snp_ap_waiting_for_reset = false; /* Mark the vCPU as offline and not runnable */ vcpu->arch.pv.pv_unhalted = false; - vcpu->arch.mp_state = KVM_MP_STATE_HALTED; + kvm_set_mp_state(vcpu, KVM_MP_STATE_HALTED); /* Clear use of the VMSA */ svm->vmcb->control.vmsa_pa = INVALID_PAGE; - if (VALID_PAGE(svm->sev_es.snp_vmsa_gpa)) { - gfn_t gfn = gpa_to_gfn(svm->sev_es.snp_vmsa_gpa); - struct kvm_memory_slot *slot; - struct page *page; - kvm_pfn_t pfn; - - slot = gfn_to_memslot(vcpu->kvm, gfn); - if (!slot) - return -EINVAL; - - /* - * The new VMSA will be private memory guest memory, so - * retrieve the PFN from the gmem backend. - */ - if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, &page, NULL)) - return -EINVAL; - - /* - * From this point forward, the VMSA will always be a - * guest-mapped page rather than the initial one allocated - * by KVM in svm->sev_es.vmsa. In theory, svm->sev_es.vmsa - * could be free'd and cleaned up here, but that involves - * cleanups like wbinvd_on_all_cpus() which would ideally - * be handled during teardown rather than guest boot. - * Deferring that also allows the existing logic for SEV-ES - * VMSAs to be re-used with minimal SNP-specific changes. - */ - svm->sev_es.snp_has_guest_vmsa = true; - - /* Use the new VMSA */ - svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn); - - /* Mark the vCPU as runnable */ - vcpu->arch.pv.pv_unhalted = false; - vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; - - svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; - - /* - * gmem pages aren't currently migratable, but if this ever - * changes then care should be taken to ensure - * svm->sev_es.vmsa is pinned through some other means. - */ - kvm_release_page_clean(page); - } - /* * When replacing the VMSA during SEV-SNP AP creation, * mark the VMCB dirty so that full state is always reloaded. */ vmcb_mark_all_dirty(svm->vmcb); - return 0; -} + if (!VALID_PAGE(svm->sev_es.snp_vmsa_gpa)) + return; -/* - * Invoked as part of svm_vcpu_reset() processing of an init event. - */ -void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) -{ - struct vcpu_svm *svm = to_svm(vcpu); - int ret; + gfn = gpa_to_gfn(svm->sev_es.snp_vmsa_gpa); + svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; - if (!sev_snp_guest(vcpu->kvm)) + slot = gfn_to_memslot(vcpu->kvm, gfn); + if (!slot) return; - mutex_lock(&svm->sev_es.snp_vmsa_mutex); + /* + * The new VMSA will be private memory guest memory, so retrieve the + * PFN from the gmem backend. + */ + if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, &page, NULL)) + return; - if (!svm->sev_es.snp_ap_waiting_for_reset) - goto unlock; + /* + * From this point forward, the VMSA will always be a guest-mapped page + * rather than the initial one allocated by KVM in svm->sev_es.vmsa. In + * theory, svm->sev_es.vmsa could be free'd and cleaned up here, but + * that involves cleanups like flushing caches, which would ideally be + * handled during teardown rather than guest boot. Deferring that also + * allows the existing logic for SEV-ES VMSAs to be re-used with + * minimal SNP-specific changes. + */ + svm->sev_es.snp_has_guest_vmsa = true; - svm->sev_es.snp_ap_waiting_for_reset = false; + /* Use the new VMSA */ + svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn); - ret = __sev_snp_update_protected_guest_state(vcpu); - if (ret) - vcpu_unimpl(vcpu, "snp: AP state update on init failed\n"); + /* Mark the vCPU as runnable */ + kvm_set_mp_state(vcpu, KVM_MP_STATE_RUNNABLE); -unlock: - mutex_unlock(&svm->sev_es.snp_vmsa_mutex); + /* + * gmem pages aren't currently migratable, but if this ever changes + * then care should be taken to ensure svm->sev_es.vmsa is pinned + * through some other means. + */ + kvm_release_page_clean(page); } static int sev_snp_ap_creation(struct vcpu_svm *svm) { - struct kvm_sev_info *sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(svm->vcpu.kvm); struct kvm_vcpu *vcpu = &svm->vcpu; struct kvm_vcpu *target_vcpu; struct vcpu_svm *target_svm; unsigned int request; unsigned int apic_id; - bool kick; - int ret; request = lower_32_bits(svm->vmcb->control.exit_info_1); apic_id = upper_32_bits(svm->vmcb->control.exit_info_1); @@ -3939,47 +4053,23 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm) return -EINVAL; } - ret = 0; - target_svm = to_svm(target_vcpu); - /* - * The target vCPU is valid, so the vCPU will be kicked unless the - * request is for CREATE_ON_INIT. For any errors at this stage, the - * kick will place the vCPU in an non-runnable state. - */ - kick = true; - - mutex_lock(&target_svm->sev_es.snp_vmsa_mutex); - - target_svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; - target_svm->sev_es.snp_ap_waiting_for_reset = true; - - /* Interrupt injection mode shouldn't change for AP creation */ - if (request < SVM_VMGEXIT_AP_DESTROY) { - u64 sev_features; - - sev_features = vcpu->arch.regs[VCPU_REGS_RAX]; - sev_features ^= sev->vmsa_features; - - if (sev_features & SVM_SEV_FEAT_INT_INJ_MODES) { - vcpu_unimpl(vcpu, "vmgexit: invalid AP injection mode [%#lx] from guest\n", - vcpu->arch.regs[VCPU_REGS_RAX]); - ret = -EINVAL; - goto out; - } - } + guard(mutex)(&target_svm->sev_es.snp_vmsa_mutex); switch (request) { case SVM_VMGEXIT_AP_CREATE_ON_INIT: - kick = false; - fallthrough; case SVM_VMGEXIT_AP_CREATE: + if (vcpu->arch.regs[VCPU_REGS_RAX] != sev->vmsa_features) { + vcpu_unimpl(vcpu, "vmgexit: mismatched AP sev_features [%#lx] != [%#llx] from guest\n", + vcpu->arch.regs[VCPU_REGS_RAX], sev->vmsa_features); + return -EINVAL; + } + if (!page_address_valid(vcpu, svm->vmcb->control.exit_info_2)) { vcpu_unimpl(vcpu, "vmgexit: invalid AP VMSA address [%#llx] from guest\n", svm->vmcb->control.exit_info_2); - ret = -EINVAL; - goto out; + return -EINVAL; } /* @@ -3993,30 +4083,30 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm) vcpu_unimpl(vcpu, "vmgexit: AP VMSA address [%llx] from guest is unsafe as it is 2M aligned\n", svm->vmcb->control.exit_info_2); - ret = -EINVAL; - goto out; + return -EINVAL; } target_svm->sev_es.snp_vmsa_gpa = svm->vmcb->control.exit_info_2; break; case SVM_VMGEXIT_AP_DESTROY: + target_svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; break; default: vcpu_unimpl(vcpu, "vmgexit: invalid AP creation request [%#x] from guest\n", request); - ret = -EINVAL; - break; + return -EINVAL; } -out: - if (kick) { - kvm_make_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, target_vcpu); - kvm_vcpu_kick(target_vcpu); - } + target_svm->sev_es.snp_ap_waiting_for_reset = true; - mutex_unlock(&target_svm->sev_es.snp_vmsa_mutex); + /* + * Unless Creation is deferred until INIT, signal the vCPU to update + * its state. + */ + if (request != SVM_VMGEXIT_AP_CREATE_ON_INIT) + kvm_make_request_and_kick(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, target_vcpu); - return ret; + return 0; } static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa) @@ -4055,7 +4145,8 @@ static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_ goto out_unlock; } - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, SNP_GUEST_ERR(0, fw_err)); + /* No action is requested *from KVM* if there was a firmware error. */ + svm_vmgexit_no_action(svm, SNP_GUEST_ERR(0, fw_err)); ret = 1; /* resume guest */ @@ -4111,8 +4202,7 @@ static int snp_handle_ext_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t r return snp_handle_guest_req(svm, req_gpa, resp_gpa); request_invalid: - ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT); + svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT); return 1; /* resume guest */ } @@ -4120,7 +4210,7 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; struct kvm_vcpu *vcpu = &svm->vcpu; - struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm); u64 ghcb_info; int ret = 1; @@ -4304,10 +4394,9 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) if (ret) return ret; - ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 0); - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 0); + svm_vmgexit_success(svm, 0); - exit_code = kvm_ghcb_get_sw_exit_code(control); + exit_code = kvm_get_cached_sw_exit_code(control); switch (exit_code) { case SVM_VMGEXIT_MMIO_READ: ret = setup_vmgexit_scratch(svm, true, control->exit_info_2); @@ -4340,7 +4429,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) ret = kvm_emulate_ap_reset_hold(vcpu); break; case SVM_VMGEXIT_AP_JUMP_TABLE: { - struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm); switch (control->exit_info_1) { case 0: @@ -4349,21 +4438,19 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) break; case 1: /* Get AP jump table address */ - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, sev->ap_jump_table); + svm_vmgexit_success(svm, sev->ap_jump_table); break; default: pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n", control->exit_info_1); - ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT); + svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT); } ret = 1; break; } case SVM_VMGEXIT_HV_FEATURES: - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_HV_FT_SUPPORTED); - + svm_vmgexit_success(svm, GHCB_HV_FT_SUPPORTED); ret = 1; break; case SVM_VMGEXIT_TERM_REQUEST: @@ -4384,8 +4471,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) case SVM_VMGEXIT_AP_CREATION: ret = sev_snp_ap_creation(svm); if (ret) { - ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT); + svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT); } ret = 1; @@ -4430,35 +4516,36 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in) count, in); } -static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm) +void sev_es_recalc_msr_intercepts(struct kvm_vcpu *vcpu) { - struct kvm_vcpu *vcpu = &svm->vcpu; + /* Clear intercepts on MSRs that are context switched by hardware. */ + svm_disable_intercept_for_msr(vcpu, MSR_AMD64_SEV_ES_GHCB, MSR_TYPE_RW); + svm_disable_intercept_for_msr(vcpu, MSR_EFER, MSR_TYPE_RW); + svm_disable_intercept_for_msr(vcpu, MSR_IA32_CR_PAT, MSR_TYPE_RW); - if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) { - bool v_tsc_aux = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) || - guest_cpuid_has(vcpu, X86_FEATURE_RDPID); + if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) + svm_set_intercept_for_msr(vcpu, MSR_TSC_AUX, MSR_TYPE_RW, + !guest_cpu_cap_has(vcpu, X86_FEATURE_RDTSCP) && + !guest_cpu_cap_has(vcpu, X86_FEATURE_RDPID)); - set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux); - } + svm_set_intercept_for_msr(vcpu, MSR_AMD64_GUEST_TSC_FREQ, MSR_TYPE_R, + !snp_is_secure_tsc_enabled(vcpu->kvm)); /* * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if * the host/guest supports its use. * - * guest_can_use() checks a number of requirements on the host/guest to - * ensure that MSR_IA32_XSS is available, but it might report true even - * if X86_FEATURE_XSAVES isn't configured in the guest to ensure host - * MSR_IA32_XSS is always properly restored. For SEV-ES, it is better - * to further check that the guest CPUID actually supports - * X86_FEATURE_XSAVES so that accesses to MSR_IA32_XSS by misbehaved - * guests will still get intercepted and caught in the normal - * kvm_emulate_rdmsr()/kvm_emulated_wrmsr() paths. + * KVM treats the guest as being capable of using XSAVES even if XSAVES + * isn't enabled in guest CPUID as there is no intercept for XSAVES, + * i.e. the guest can use XSAVES/XRSTOR to read/write XSS if XSAVE is + * exposed to the guest and XSAVES is supported in hardware. Condition + * full XSS passthrough on the guest being able to use XSAVES *and* + * XSAVES being exposed to the guest so that KVM can at least honor + * guest CPUID for RDMSR and WRMSR. */ - if (guest_can_use(vcpu, X86_FEATURE_XSAVES) && - guest_cpuid_has(vcpu, X86_FEATURE_XSAVES)) - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 1, 1); - else - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 0, 0); + svm_set_intercept_for_msr(vcpu, MSR_IA32_XSS, MSR_TYPE_RW, + !guest_cpu_cap_has(vcpu, X86_FEATURE_XSAVES) || + !guest_cpuid_has(vcpu, X86_FEATURE_XSAVES)); } void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm) @@ -4470,15 +4557,12 @@ void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm) best = kvm_find_cpuid_entry(vcpu, 0x8000001F); if (best) vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f)); - - if (sev_es_guest(svm->vcpu.kvm)) - sev_es_vcpu_after_set_cpuid(svm); } -static void sev_es_init_vmcb(struct vcpu_svm *svm) +static void sev_es_init_vmcb(struct vcpu_svm *svm, bool init_event) { + struct kvm_sev_info *sev = to_kvm_sev_info(svm->vcpu.kvm); struct vmcb *vmcb = svm->vmcb01.ptr; - struct kvm_vcpu *vcpu = &svm->vcpu; svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE; @@ -4489,8 +4573,16 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm) * the VMSA will be NULL if this vCPU is the destination for intrahost * migration, and will be copied later. */ - if (svm->sev_es.vmsa && !svm->sev_es.snp_has_guest_vmsa) - svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa); + if (!svm->sev_es.snp_has_guest_vmsa) { + if (svm->sev_es.vmsa) + svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa); + else + svm->vmcb->control.vmsa_pa = INVALID_PAGE; + } + + if (cpu_feature_enabled(X86_FEATURE_ALLOWED_SEV_FEATURES)) + svm->vmcb->control.allowed_sev_features = sev->vmsa_features | + VMCB_ALLOWED_SEV_FEATURES_VALID; /* Can't intercept CR register access, HV can't modify CR registers */ svm_clr_intercept(svm, INTERCEPT_CR0_READ); @@ -4529,13 +4621,20 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm) /* Can't intercept XSETBV, HV can't modify XCR0 directly */ svm_clr_intercept(svm, INTERCEPT_XSETBV); - /* Clear intercepts on selected MSRs */ - set_msr_interception(vcpu, svm->msrpm, MSR_EFER, 1, 1); - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_CR_PAT, 1, 1); + /* + * Set the GHCB MSR value as per the GHCB specification when emulating + * vCPU RESET for an SEV-ES guest. + */ + if (!init_event) + set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version, + GHCB_VERSION_MIN, + sev_enc_bit)); } -void sev_init_vmcb(struct vcpu_svm *svm) +void sev_init_vmcb(struct vcpu_svm *svm, bool init_event) { + struct kvm_vcpu *vcpu = &svm->vcpu; + svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE; clr_exception_intercept(svm, UD_VECTOR); @@ -4545,28 +4644,42 @@ void sev_init_vmcb(struct vcpu_svm *svm) */ clr_exception_intercept(svm, GP_VECTOR); - if (sev_es_guest(svm->vcpu.kvm)) - sev_es_init_vmcb(svm); + if (init_event && sev_snp_guest(vcpu->kvm)) + sev_snp_init_protected_guest_state(vcpu); + + if (sev_es_guest(vcpu->kvm)) + sev_es_init_vmcb(svm, init_event); } -void sev_es_vcpu_reset(struct vcpu_svm *svm) +int sev_vcpu_create(struct kvm_vcpu *vcpu) { - struct kvm_vcpu *vcpu = &svm->vcpu; - struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; + struct vcpu_svm *svm = to_svm(vcpu); + struct page *vmsa_page; + + mutex_init(&svm->sev_es.snp_vmsa_mutex); + + if (!sev_es_guest(vcpu->kvm)) + return 0; /* - * Set the GHCB MSR value as per the GHCB specification when emulating - * vCPU RESET for an SEV-ES guest. + * SEV-ES guests require a separate (from the VMCB) VMSA page used to + * contain the encrypted register state of the guest. */ - set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version, - GHCB_VERSION_MIN, - sev_enc_bit)); + vmsa_page = snp_safe_alloc_page(); + if (!vmsa_page) + return -ENOMEM; - mutex_init(&svm->sev_es.snp_vmsa_mutex); + svm->sev_es.vmsa = page_address(vmsa_page); + + vcpu->arch.guest_tsc_protected = snp_is_secure_tsc_enabled(vcpu->kvm); + + return 0; } void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_area *hostsa) { + struct kvm *kvm = svm->vcpu.kvm; + /* * All host state for SEV-ES guests is categorized into three swap types * based on how it is handled by hardware during a world switch: @@ -4590,19 +4703,37 @@ void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_are /* * If DebugSwap is enabled, debug registers are loaded but NOT saved by - * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU both - * saves and loads debug registers (Type-A). + * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU does + * not save or load debug registers. Sadly, KVM can't prevent SNP + * guests from lying about DebugSwap on secondary vCPUs, i.e. the + * SEV_FEATURES provided at "AP Create" isn't guaranteed to match what + * the guest has actually enabled (or not!) in the VMSA. + * + * If DebugSwap is *possible*, save the masks so that they're restored + * if the guest enables DebugSwap. But for the DRs themselves, do NOT + * rely on the CPU to restore the host values; KVM will restore them as + * needed in common code, via hw_breakpoint_restore(). Note, KVM does + * NOT support virtualizing Breakpoint Extensions, i.e. the mask MSRs + * don't need to be restored per se, KVM just needs to ensure they are + * loaded with the correct values *if* the CPU writes the MSRs. */ - if (sev_vcpu_has_debug_swap(svm)) { - hostsa->dr0 = native_get_debugreg(0); - hostsa->dr1 = native_get_debugreg(1); - hostsa->dr2 = native_get_debugreg(2); - hostsa->dr3 = native_get_debugreg(3); + if (sev_vcpu_has_debug_swap(svm) || + (sev_snp_guest(kvm) && cpu_feature_enabled(X86_FEATURE_DEBUG_SWAP))) { hostsa->dr0_addr_mask = amd_get_dr_addr_mask(0); hostsa->dr1_addr_mask = amd_get_dr_addr_mask(1); hostsa->dr2_addr_mask = amd_get_dr_addr_mask(2); hostsa->dr3_addr_mask = amd_get_dr_addr_mask(3); } + + /* + * TSC_AUX is always virtualized for SEV-ES guests when the feature is + * available, i.e. TSC_AUX is loaded on #VMEXIT from the host save area. + * Set the save area to the current hardware value, i.e. the current + * user return value, so that the correct value is restored on #VMEXIT. + */ + if (cpu_feature_enabled(X86_FEATURE_V_TSC_AUX) && + !WARN_ON_ONCE(tsc_aux_uret_slot < 0)) + hostsa->tsc_aux = kvm_get_user_return_msr(tsc_aux_uret_slot); } void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector) @@ -4622,7 +4753,7 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector) * Return from an AP Reset Hold VMGEXIT, where the guest will * set the CS and RIP. Set SW_EXIT_INFO_2 to a non-zero value. */ - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1); + svm_vmgexit_success(svm, 1); break; case AP_RESET_HOLD_MSR_PROTO: /* @@ -4700,7 +4831,7 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code) } slot = gfn_to_memslot(kvm, gfn); - if (!kvm_slot_can_be_private(slot)) { + if (!kvm_slot_has_gmem(slot)) { pr_warn_ratelimited("SEV: Unexpected RMP fault, non-private slot for GPA 0x%llx\n", gpa); return; @@ -4820,7 +4951,7 @@ static bool is_large_rmp_possible(struct kvm *kvm, kvm_pfn_t pfn, int order) int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order) { - struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_info *sev = to_kvm_sev_info(kvm); kvm_pfn_t pfn_aligned; gfn_t gfn_aligned; int level, rc; @@ -4910,7 +5041,7 @@ void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end) /* * SEV-ES avoids host/guest cache coherency issues through - * WBINVD hooks issued via MMU notifiers during run-time, and + * WBNOINVD hooks issued via MMU notifiers during run-time, and * KVM's VM destroy path at shutdown. Those MMU notifier events * don't cover gmem since there is no requirement to map pages * to a HVA in order to use them for a running guest. While the @@ -4928,7 +5059,7 @@ next_pfn: } } -int sev_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn) +int sev_gmem_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn, bool is_private) { int level, rc; bool assigned; @@ -4942,3 +5073,97 @@ int sev_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn) return level; } + +struct vmcb_save_area *sev_decrypt_vmsa(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + struct vmcb_save_area *vmsa; + struct kvm_sev_info *sev; + int error = 0; + int ret; + + if (!sev_es_guest(vcpu->kvm)) + return NULL; + + /* + * If the VMSA has not yet been encrypted, return a pointer to the + * current un-encrypted VMSA. + */ + if (!vcpu->arch.guest_state_protected) + return (struct vmcb_save_area *)svm->sev_es.vmsa; + + sev = to_kvm_sev_info(vcpu->kvm); + + /* Check if the SEV policy allows debugging */ + if (sev_snp_guest(vcpu->kvm)) { + if (!(sev->policy & SNP_POLICY_MASK_DEBUG)) + return NULL; + } else { + if (sev->policy & SEV_POLICY_MASK_NODBG) + return NULL; + } + + if (sev_snp_guest(vcpu->kvm)) { + struct sev_data_snp_dbg dbg = {0}; + + vmsa = snp_alloc_firmware_page(__GFP_ZERO); + if (!vmsa) + return NULL; + + dbg.gctx_paddr = __psp_pa(sev->snp_context); + dbg.src_addr = svm->vmcb->control.vmsa_pa; + dbg.dst_addr = __psp_pa(vmsa); + + ret = sev_do_cmd(SEV_CMD_SNP_DBG_DECRYPT, &dbg, &error); + + /* + * Return the target page to a hypervisor page no matter what. + * If this fails, the page can't be used, so leak it and don't + * try to use it. + */ + if (snp_page_reclaim(vcpu->kvm, PHYS_PFN(__pa(vmsa)))) + return NULL; + + if (ret) { + pr_err("SEV: SNP_DBG_DECRYPT failed ret=%d, fw_error=%d (%#x)\n", + ret, error, error); + free_page((unsigned long)vmsa); + + return NULL; + } + } else { + struct sev_data_dbg dbg = {0}; + struct page *vmsa_page; + + vmsa_page = alloc_page(GFP_KERNEL); + if (!vmsa_page) + return NULL; + + vmsa = page_address(vmsa_page); + + dbg.handle = sev->handle; + dbg.src_addr = svm->vmcb->control.vmsa_pa; + dbg.dst_addr = __psp_pa(vmsa); + dbg.len = PAGE_SIZE; + + ret = sev_do_cmd(SEV_CMD_DBG_DECRYPT, &dbg, &error); + if (ret) { + pr_err("SEV: SEV_CMD_DBG_DECRYPT failed ret=%d, fw_error=%d (0x%x)\n", + ret, error, error); + __free_page(vmsa_page); + + return NULL; + } + } + + return vmsa; +} + +void sev_free_decrypted_vmsa(struct kvm_vcpu *vcpu, struct vmcb_save_area *vmsa) +{ + /* If the VMSA has not yet been encrypted, nothing was allocated */ + if (!vcpu->arch.guest_state_protected || !vmsa) + return; + + free_page((unsigned long)vmsa); +} |