diff options
Diffstat (limited to 'arch/x86/kvm/svm/sev.c')
-rw-r--r-- | arch/x86/kvm/svm/sev.c | 915 |
1 files changed, 876 insertions, 39 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 566f4d18185b..9858d5ae9ddd 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -14,10 +14,20 @@ #include <linux/psp-sev.h> #include <linux/pagemap.h> #include <linux/swap.h> +#include <linux/processor.h> +#include <linux/trace_events.h> +#include <asm/fpu/internal.h> + +#include <asm/trapnr.h> #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); static DEFINE_MUTEX(sev_bitmap_lock); @@ -25,7 +35,6 @@ unsigned int max_sev_asid; static unsigned int min_sev_asid; static unsigned long *sev_asid_bitmap; static unsigned long *sev_reclaim_asid_bitmap; -#define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT) struct enc_region { struct list_head list; @@ -57,19 +66,19 @@ static int sev_flush_asids(void) } /* Must be called with the sev_bitmap_lock held */ -static bool __sev_recycle_asids(void) +static bool __sev_recycle_asids(int min_asid, int max_asid) { int pos; /* Check if there are any ASIDs to reclaim before performing a flush */ - pos = find_next_bit(sev_reclaim_asid_bitmap, - max_sev_asid, min_sev_asid - 1); - if (pos >= max_sev_asid) + pos = find_next_bit(sev_reclaim_asid_bitmap, max_sev_asid, min_asid); + if (pos >= max_asid) return false; if (sev_flush_asids()) return false; + /* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */ bitmap_xor(sev_asid_bitmap, sev_asid_bitmap, sev_reclaim_asid_bitmap, max_sev_asid); bitmap_zero(sev_reclaim_asid_bitmap, max_sev_asid); @@ -77,20 +86,23 @@ static bool __sev_recycle_asids(void) return true; } -static int sev_asid_new(void) +static int sev_asid_new(struct kvm_sev_info *sev) { + int pos, min_asid, max_asid; bool retry = true; - int pos; mutex_lock(&sev_bitmap_lock); /* - * SEV-enabled guest must use asid from min_sev_asid to max_sev_asid. + * 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. */ + min_asid = sev->es_active ? 0 : min_sev_asid - 1; + max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid; again: - pos = find_next_zero_bit(sev_asid_bitmap, max_sev_asid, min_sev_asid - 1); - if (pos >= max_sev_asid) { - if (retry && __sev_recycle_asids()) { + pos = find_next_zero_bit(sev_asid_bitmap, max_sev_asid, min_asid); + if (pos >= max_asid) { + if (retry && __sev_recycle_asids(min_asid, max_asid)) { retry = false; goto again; } @@ -172,7 +184,7 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) if (unlikely(sev->active)) return ret; - asid = sev_asid_new(); + asid = sev_asid_new(sev); if (asid < 0) return ret; @@ -191,6 +203,16 @@ e_free: return ret; } +static int sev_es_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + if (!sev_es) + return -ENOTTY; + + to_kvm_svm(kvm)->sev_info.es_active = true; + + return sev_guest_init(kvm, argp); +} + static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error) { struct sev_data_activate *data; @@ -490,6 +512,96 @@ e_free: return ret; } +static int sev_es_sync_vmsa(struct vcpu_svm *svm) +{ + struct vmcb_save_area *save = &svm->vmcb->save; + + /* Check some debug related fields before encrypting the VMSA */ + if (svm->vcpu.guest_debug || (save->dr7 & ~DR7_FIXED_1)) + return -EINVAL; + + /* Sync registgers */ + save->rax = svm->vcpu.arch.regs[VCPU_REGS_RAX]; + save->rbx = svm->vcpu.arch.regs[VCPU_REGS_RBX]; + save->rcx = svm->vcpu.arch.regs[VCPU_REGS_RCX]; + save->rdx = svm->vcpu.arch.regs[VCPU_REGS_RDX]; + save->rsp = svm->vcpu.arch.regs[VCPU_REGS_RSP]; + save->rbp = svm->vcpu.arch.regs[VCPU_REGS_RBP]; + save->rsi = svm->vcpu.arch.regs[VCPU_REGS_RSI]; + save->rdi = svm->vcpu.arch.regs[VCPU_REGS_RDI]; +#ifdef CONFIG_X86_64 + save->r8 = svm->vcpu.arch.regs[VCPU_REGS_R8]; + save->r9 = svm->vcpu.arch.regs[VCPU_REGS_R9]; + save->r10 = svm->vcpu.arch.regs[VCPU_REGS_R10]; + save->r11 = svm->vcpu.arch.regs[VCPU_REGS_R11]; + save->r12 = svm->vcpu.arch.regs[VCPU_REGS_R12]; + save->r13 = svm->vcpu.arch.regs[VCPU_REGS_R13]; + save->r14 = svm->vcpu.arch.regs[VCPU_REGS_R14]; + save->r15 = svm->vcpu.arch.regs[VCPU_REGS_R15]; +#endif + save->rip = svm->vcpu.arch.regs[VCPU_REGS_RIP]; + + /* Sync some non-GPR registers before encrypting */ + save->xcr0 = svm->vcpu.arch.xcr0; + save->pkru = svm->vcpu.arch.pkru; + save->xss = svm->vcpu.arch.ia32_xss; + + /* + * SEV-ES will use a VMSA that is pointed to by the VMCB, not + * the traditional VMSA that is part of the VMCB. Copy the + * traditional VMSA as it has been built so far (in prep + * for LAUNCH_UPDATE_VMSA) to be the initial SEV-ES state. + */ + memcpy(svm->vmsa, save, sizeof(*save)); + + return 0; +} + +static int sev_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct sev_data_launch_update_vmsa *vmsa; + int i, ret; + + if (!sev_es_guest(kvm)) + return -ENOTTY; + + vmsa = kzalloc(sizeof(*vmsa), GFP_KERNEL); + if (!vmsa) + return -ENOMEM; + + for (i = 0; i < kvm->created_vcpus; i++) { + struct vcpu_svm *svm = to_svm(kvm->vcpus[i]); + + /* Perform some pre-encryption checks against the VMSA */ + ret = sev_es_sync_vmsa(svm); + if (ret) + goto e_free; + + /* + * The LAUNCH_UPDATE_VMSA command will perform in-place + * encryption of the VMSA memory content (i.e it will write + * the same memory region with the guest's key), so invalidate + * it first. + */ + clflush_cache_range(svm->vmsa, PAGE_SIZE); + + vmsa->handle = sev->handle; + vmsa->address = __sme_pa(svm->vmsa); + vmsa->len = PAGE_SIZE; + ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_VMSA, vmsa, + &argp->error); + if (ret) + goto e_free; + + svm->vcpu.arch.guest_state_protected = true; + } + +e_free: + kfree(vmsa); + return ret; +} + static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp) { void __user *measure = (void __user *)(uintptr_t)argp->data; @@ -932,7 +1044,7 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp) struct kvm_sev_cmd sev_cmd; int r; - if (!svm_sev_enabled()) + if (!svm_sev_enabled() || !sev) return -ENOTTY; if (!argp) @@ -947,12 +1059,18 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp) case KVM_SEV_INIT: r = sev_guest_init(kvm, &sev_cmd); break; + case KVM_SEV_ES_INIT: + r = sev_es_guest_init(kvm, &sev_cmd); + break; case KVM_SEV_LAUNCH_START: r = sev_launch_start(kvm, &sev_cmd); break; case KVM_SEV_LAUNCH_UPDATE_DATA: r = sev_launch_update_data(kvm, &sev_cmd); break; + case KVM_SEV_LAUNCH_UPDATE_VMSA: + r = sev_launch_update_vmsa(kvm, &sev_cmd); + break; case KVM_SEV_LAUNCH_MEASURE: r = sev_launch_measure(kvm, &sev_cmd); break; @@ -1125,49 +1243,61 @@ void sev_vm_destroy(struct kvm *kvm) sev_asid_free(sev->asid); } -int __init sev_hardware_setup(void) +void __init sev_hardware_setup(void) { - struct sev_user_data_status *status; - int rc; + unsigned int eax, ebx, ecx, edx; + bool sev_es_supported = false; + bool sev_supported = false; + + /* Does the CPU support SEV? */ + if (!boot_cpu_has(X86_FEATURE_SEV)) + goto out; + + /* Retrieve SEV CPUID information */ + cpuid(0x8000001f, &eax, &ebx, &ecx, &edx); + + /* Set encryption bit location for SEV-ES guests */ + sev_enc_bit = ebx & 0x3f; /* Maximum number of encrypted guests supported simultaneously */ - max_sev_asid = cpuid_ecx(0x8000001F); + max_sev_asid = ecx; if (!svm_sev_enabled()) - return 1; + goto out; /* Minimum ASID value that should be used for SEV guest */ - min_sev_asid = cpuid_edx(0x8000001F); + min_sev_asid = edx; /* Initialize SEV ASID bitmaps */ sev_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL); if (!sev_asid_bitmap) - return 1; + goto out; sev_reclaim_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL); if (!sev_reclaim_asid_bitmap) - return 1; + goto out; - status = kmalloc(sizeof(*status), GFP_KERNEL); - if (!status) - return 1; + pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1); + sev_supported = true; - /* - * Check SEV platform status. - * - * PLATFORM_STATUS can be called in any state, if we failed to query - * the PLATFORM status then either PSP firmware does not support SEV - * feature or SEV firmware is dead. - */ - rc = sev_platform_status(status, NULL); - if (rc) - goto err; + /* SEV-ES support requested? */ + if (!sev_es) + goto out; - pr_info("SEV supported\n"); + /* Does the CPU support SEV-ES? */ + if (!boot_cpu_has(X86_FEATURE_SEV_ES)) + goto out; -err: - kfree(status); - return rc; + /* Has the system been allocated ASIDs for SEV-ES? */ + if (min_sev_asid == 1) + goto out; + + pr_info("SEV-ES supported: %u ASIDs\n", min_sev_asid - 1); + sev_es_supported = true; + +out: + sev = sev_supported; + sev_es = sev_es_supported; } void sev_hardware_teardown(void) @@ -1181,13 +1311,329 @@ void sev_hardware_teardown(void) sev_flush_asids(); } +/* + * Pages used by hardware to hold guest encrypted state must be flushed before + * returning them to the system. + */ +static void sev_flush_guest_memory(struct vcpu_svm *svm, void *va, + unsigned long len) +{ + /* + * If hardware enforced cache coherency for encrypted mappings of the + * same physical page is supported, nothing to do. + */ + if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) + return; + + /* + * If the VM Page Flush MSR is supported, use it to flush the page + * (using the page virtual address and the guest ASID). + */ + if (boot_cpu_has(X86_FEATURE_VM_PAGE_FLUSH)) { + struct kvm_sev_info *sev; + unsigned long va_start; + u64 start, stop; + + /* Align start and stop to page boundaries. */ + va_start = (unsigned long)va; + start = (u64)va_start & PAGE_MASK; + stop = PAGE_ALIGN((u64)va_start + len); + + if (start < stop) { + sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info; + + while (start < stop) { + wrmsrl(MSR_AMD64_VM_PAGE_FLUSH, + start | sev->asid); + + start += PAGE_SIZE; + } + + return; + } + + WARN(1, "Address overflow, using WBINVD\n"); + } + + /* + * Hardware should always have one of the above features, + * but if not, use WBINVD and issue a warning. + */ + WARN_ONCE(1, "Using WBINVD to flush guest memory\n"); + wbinvd_on_all_cpus(); +} + +void sev_free_vcpu(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm; + + if (!sev_es_guest(vcpu->kvm)) + return; + + svm = to_svm(vcpu); + + if (vcpu->arch.guest_state_protected) + sev_flush_guest_memory(svm, svm->vmsa, PAGE_SIZE); + __free_page(virt_to_page(svm->vmsa)); + + if (svm->ghcb_sa_free) + kfree(svm->ghcb_sa); +} + +static void dump_ghcb(struct vcpu_svm *svm) +{ + struct ghcb *ghcb = svm->ghcb; + unsigned int nbits; + + /* Re-use the dump_invalid_vmcb module parameter */ + if (!dump_invalid_vmcb) { + pr_warn_ratelimited("set kvm_amd.dump_invalid_vmcb=1 to dump internal KVM state.\n"); + return; + } + + nbits = sizeof(ghcb->save.valid_bitmap) * 8; + + pr_err("GHCB (GPA=%016llx):\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)); + 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)); + 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)); + 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); +} + +static void sev_es_sync_to_ghcb(struct vcpu_svm *svm) +{ + struct kvm_vcpu *vcpu = &svm->vcpu; + struct ghcb *ghcb = svm->ghcb; + + /* + * The GHCB protocol so far allows for the following data + * to be returned: + * GPRs RAX, RBX, RCX, RDX + * + * Copy their values to the GHCB if they are dirty. + */ + if (kvm_register_is_dirty(vcpu, VCPU_REGS_RAX)) + ghcb_set_rax(ghcb, vcpu->arch.regs[VCPU_REGS_RAX]); + if (kvm_register_is_dirty(vcpu, VCPU_REGS_RBX)) + ghcb_set_rbx(ghcb, vcpu->arch.regs[VCPU_REGS_RBX]); + if (kvm_register_is_dirty(vcpu, VCPU_REGS_RCX)) + ghcb_set_rcx(ghcb, vcpu->arch.regs[VCPU_REGS_RCX]); + if (kvm_register_is_dirty(vcpu, VCPU_REGS_RDX)) + ghcb_set_rdx(ghcb, vcpu->arch.regs[VCPU_REGS_RDX]); +} + +static void sev_es_sync_from_ghcb(struct vcpu_svm *svm) +{ + struct vmcb_control_area *control = &svm->vmcb->control; + struct kvm_vcpu *vcpu = &svm->vcpu; + struct ghcb *ghcb = svm->ghcb; + u64 exit_code; + + /* + * The GHCB protocol so far allows for the following data + * to be supplied: + * GPRs RAX, RBX, RCX, RDX + * XCR0 + * CPL + * + * VMMCALL allows the guest to provide extra registers. KVM also + * expects RSI for hypercalls, so include that, too. + * + * Copy their values to the appropriate location if supplied. + */ + memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs)); + + vcpu->arch.regs[VCPU_REGS_RAX] = ghcb_get_rax_if_valid(ghcb); + vcpu->arch.regs[VCPU_REGS_RBX] = ghcb_get_rbx_if_valid(ghcb); + vcpu->arch.regs[VCPU_REGS_RCX] = ghcb_get_rcx_if_valid(ghcb); + vcpu->arch.regs[VCPU_REGS_RDX] = ghcb_get_rdx_if_valid(ghcb); + vcpu->arch.regs[VCPU_REGS_RSI] = ghcb_get_rsi_if_valid(ghcb); + + svm->vmcb->save.cpl = ghcb_get_cpl_if_valid(ghcb); + + if (ghcb_xcr0_is_valid(ghcb)) { + vcpu->arch.xcr0 = ghcb_get_xcr0(ghcb); + kvm_update_cpuid_runtime(vcpu); + } + + /* Copy the GHCB exit information into the VMCB fields */ + exit_code = ghcb_get_sw_exit_code(ghcb); + 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); + + /* Clear the valid entries fields */ + memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap)); +} + +static int sev_es_validate_vmgexit(struct vcpu_svm *svm) +{ + struct kvm_vcpu *vcpu; + struct ghcb *ghcb; + u64 exit_code = 0; + + ghcb = svm->ghcb; + + /* Only GHCB Usage code 0 is supported */ + if (ghcb->ghcb_usage) + goto vmgexit_err; + + /* + * Retrieve the exit code now even though is may not be marked valid + * as it could help with debugging. + */ + exit_code = ghcb_get_sw_exit_code(ghcb); + + if (!ghcb_sw_exit_code_is_valid(ghcb) || + !ghcb_sw_exit_info_1_is_valid(ghcb) || + !ghcb_sw_exit_info_2_is_valid(ghcb)) + goto vmgexit_err; + + switch (ghcb_get_sw_exit_code(ghcb)) { + case SVM_EXIT_READ_DR7: + break; + case SVM_EXIT_WRITE_DR7: + if (!ghcb_rax_is_valid(ghcb)) + goto vmgexit_err; + break; + case SVM_EXIT_RDTSC: + break; + case SVM_EXIT_RDPMC: + if (!ghcb_rcx_is_valid(ghcb)) + goto vmgexit_err; + break; + case SVM_EXIT_CPUID: + if (!ghcb_rax_is_valid(ghcb) || + !ghcb_rcx_is_valid(ghcb)) + goto vmgexit_err; + if (ghcb_get_rax(ghcb) == 0xd) + if (!ghcb_xcr0_is_valid(ghcb)) + goto vmgexit_err; + break; + case SVM_EXIT_INVD: + break; + case SVM_EXIT_IOIO: + if (ghcb_get_sw_exit_info_1(ghcb) & SVM_IOIO_STR_MASK) { + if (!ghcb_sw_scratch_is_valid(ghcb)) + goto vmgexit_err; + } else { + if (!(ghcb_get_sw_exit_info_1(ghcb) & SVM_IOIO_TYPE_MASK)) + if (!ghcb_rax_is_valid(ghcb)) + goto vmgexit_err; + } + break; + case SVM_EXIT_MSR: + if (!ghcb_rcx_is_valid(ghcb)) + goto vmgexit_err; + if (ghcb_get_sw_exit_info_1(ghcb)) { + if (!ghcb_rax_is_valid(ghcb) || + !ghcb_rdx_is_valid(ghcb)) + goto vmgexit_err; + } + break; + case SVM_EXIT_VMMCALL: + if (!ghcb_rax_is_valid(ghcb) || + !ghcb_cpl_is_valid(ghcb)) + goto vmgexit_err; + break; + case SVM_EXIT_RDTSCP: + break; + case SVM_EXIT_WBINVD: + break; + case SVM_EXIT_MONITOR: + if (!ghcb_rax_is_valid(ghcb) || + !ghcb_rcx_is_valid(ghcb) || + !ghcb_rdx_is_valid(ghcb)) + goto vmgexit_err; + break; + case SVM_EXIT_MWAIT: + if (!ghcb_rax_is_valid(ghcb) || + !ghcb_rcx_is_valid(ghcb)) + goto vmgexit_err; + break; + case SVM_VMGEXIT_MMIO_READ: + case SVM_VMGEXIT_MMIO_WRITE: + if (!ghcb_sw_scratch_is_valid(ghcb)) + goto vmgexit_err; + break; + case SVM_VMGEXIT_NMI_COMPLETE: + case SVM_VMGEXIT_AP_JUMP_TABLE: + case SVM_VMGEXIT_UNSUPPORTED_EVENT: + break; + default: + goto vmgexit_err; + } + + return 0; + +vmgexit_err: + vcpu = &svm->vcpu; + + if (ghcb->ghcb_usage) { + vcpu_unimpl(vcpu, "vmgexit: ghcb usage %#x is not valid\n", + ghcb->ghcb_usage); + } else { + vcpu_unimpl(vcpu, "vmgexit: exit reason %#llx is not valid\n", + exit_code); + dump_ghcb(svm); + } + + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON; + vcpu->run->internal.ndata = 2; + vcpu->run->internal.data[0] = exit_code; + vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu; + + return -EINVAL; +} + +static void pre_sev_es_run(struct vcpu_svm *svm) +{ + if (!svm->ghcb) + return; + + if (svm->ghcb_sa_free) { + /* + * The scratch area lives outside the GHCB, so there is a + * buffer that, depending on the operation performed, may + * need to be synced, then freed. + */ + if (svm->ghcb_sa_sync) { + kvm_write_guest(svm->vcpu.kvm, + ghcb_get_sw_scratch(svm->ghcb), + svm->ghcb_sa, svm->ghcb_sa_len); + svm->ghcb_sa_sync = false; + } + + kfree(svm->ghcb_sa); + svm->ghcb_sa = NULL; + svm->ghcb_sa_free = false; + } + + trace_kvm_vmgexit_exit(svm->vcpu.vcpu_id, svm->ghcb); + + sev_es_sync_to_ghcb(svm); + + kvm_vcpu_unmap(&svm->vcpu, &svm->ghcb_map, true); + svm->ghcb = NULL; +} + void pre_sev_run(struct vcpu_svm *svm, int cpu) { struct svm_cpu_data *sd = per_cpu(svm_data, cpu); int asid = sev_get_asid(svm->vcpu.kvm); + /* Perform any SEV-ES pre-run actions */ + pre_sev_es_run(svm); + /* Assign the asid allocated with this SEV guest */ - svm->vmcb->control.asid = asid; + svm->asid = asid; /* * Flush guest TLB: @@ -1203,3 +1649,394 @@ void pre_sev_run(struct vcpu_svm *svm, int cpu) svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID; vmcb_mark_dirty(svm->vmcb, VMCB_ASID); } + +#define GHCB_SCRATCH_AREA_LIMIT (16ULL * PAGE_SIZE) +static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len) +{ + struct vmcb_control_area *control = &svm->vmcb->control; + struct ghcb *ghcb = svm->ghcb; + u64 ghcb_scratch_beg, ghcb_scratch_end; + u64 scratch_gpa_beg, scratch_gpa_end; + void *scratch_va; + + scratch_gpa_beg = ghcb_get_sw_scratch(ghcb); + if (!scratch_gpa_beg) { + pr_err("vmgexit: scratch gpa not provided\n"); + return false; + } + + scratch_gpa_end = scratch_gpa_beg + len; + if (scratch_gpa_end < scratch_gpa_beg) { + pr_err("vmgexit: scratch length (%#llx) not valid for scratch address (%#llx)\n", + len, scratch_gpa_beg); + return false; + } + + if ((scratch_gpa_beg & PAGE_MASK) == control->ghcb_gpa) { + /* Scratch area begins within GHCB */ + ghcb_scratch_beg = control->ghcb_gpa + + offsetof(struct ghcb, shared_buffer); + ghcb_scratch_end = control->ghcb_gpa + + offsetof(struct ghcb, reserved_1); + + /* + * If the scratch area begins within the GHCB, it must be + * completely contained in the GHCB shared buffer area. + */ + if (scratch_gpa_beg < ghcb_scratch_beg || + scratch_gpa_end > ghcb_scratch_end) { + pr_err("vmgexit: scratch area is outside of GHCB shared buffer area (%#llx - %#llx)\n", + scratch_gpa_beg, scratch_gpa_end); + return false; + } + + scratch_va = (void *)svm->ghcb; + scratch_va += (scratch_gpa_beg - control->ghcb_gpa); + } else { + /* + * The guest memory must be read into a kernel buffer, so + * limit the size + */ + if (len > GHCB_SCRATCH_AREA_LIMIT) { + pr_err("vmgexit: scratch area exceeds KVM limits (%#llx requested, %#llx limit)\n", + len, GHCB_SCRATCH_AREA_LIMIT); + return false; + } + scratch_va = kzalloc(len, GFP_KERNEL); + if (!scratch_va) + return false; + + if (kvm_read_guest(svm->vcpu.kvm, scratch_gpa_beg, scratch_va, len)) { + /* Unable to copy scratch area from guest */ + pr_err("vmgexit: kvm_read_guest for scratch area failed\n"); + + kfree(scratch_va); + return false; + } + + /* + * The scratch area is outside the GHCB. The operation will + * dictate whether the buffer needs to be synced before running + * the vCPU next time (i.e. a read was requested so the data + * must be written back to the guest memory). + */ + svm->ghcb_sa_sync = sync; + svm->ghcb_sa_free = true; + } + + svm->ghcb_sa = scratch_va; + svm->ghcb_sa_len = len; + + return true; +} + +static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask, + unsigned int pos) +{ + svm->vmcb->control.ghcb_gpa &= ~(mask << pos); + svm->vmcb->control.ghcb_gpa |= (value & mask) << pos; +} + +static u64 get_ghcb_msr_bits(struct vcpu_svm *svm, u64 mask, unsigned int pos) +{ + return (svm->vmcb->control.ghcb_gpa >> pos) & mask; +} + +static void set_ghcb_msr(struct vcpu_svm *svm, u64 value) +{ + svm->vmcb->control.ghcb_gpa = value; +} + +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; + u64 ghcb_info; + int ret = 1; + + ghcb_info = control->ghcb_gpa & GHCB_MSR_INFO_MASK; + + trace_kvm_vmgexit_msr_protocol_enter(svm->vcpu.vcpu_id, + control->ghcb_gpa); + + switch (ghcb_info) { + case GHCB_MSR_SEV_INFO_REQ: + set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX, + GHCB_VERSION_MIN, + sev_enc_bit)); + break; + case GHCB_MSR_CPUID_REQ: { + u64 cpuid_fn, cpuid_reg, cpuid_value; + + cpuid_fn = get_ghcb_msr_bits(svm, + GHCB_MSR_CPUID_FUNC_MASK, + GHCB_MSR_CPUID_FUNC_POS); + + /* Initialize the registers needed by the CPUID intercept */ + vcpu->arch.regs[VCPU_REGS_RAX] = cpuid_fn; + vcpu->arch.regs[VCPU_REGS_RCX] = 0; + + ret = svm_invoke_exit_handler(svm, SVM_EXIT_CPUID); + if (!ret) { + ret = -EINVAL; + break; + } + + cpuid_reg = get_ghcb_msr_bits(svm, + GHCB_MSR_CPUID_REG_MASK, + GHCB_MSR_CPUID_REG_POS); + if (cpuid_reg == 0) + cpuid_value = vcpu->arch.regs[VCPU_REGS_RAX]; + else if (cpuid_reg == 1) + cpuid_value = vcpu->arch.regs[VCPU_REGS_RBX]; + else if (cpuid_reg == 2) + cpuid_value = vcpu->arch.regs[VCPU_REGS_RCX]; + else + cpuid_value = vcpu->arch.regs[VCPU_REGS_RDX]; + + set_ghcb_msr_bits(svm, cpuid_value, + GHCB_MSR_CPUID_VALUE_MASK, + GHCB_MSR_CPUID_VALUE_POS); + + set_ghcb_msr_bits(svm, GHCB_MSR_CPUID_RESP, + GHCB_MSR_INFO_MASK, + GHCB_MSR_INFO_POS); + break; + } + case GHCB_MSR_TERM_REQ: { + u64 reason_set, reason_code; + + reason_set = get_ghcb_msr_bits(svm, + GHCB_MSR_TERM_REASON_SET_MASK, + GHCB_MSR_TERM_REASON_SET_POS); + reason_code = get_ghcb_msr_bits(svm, + GHCB_MSR_TERM_REASON_MASK, + GHCB_MSR_TERM_REASON_POS); + pr_info("SEV-ES guest requested termination: %#llx:%#llx\n", + reason_set, reason_code); + fallthrough; + } + default: + ret = -EINVAL; + } + + trace_kvm_vmgexit_msr_protocol_exit(svm->vcpu.vcpu_id, + control->ghcb_gpa, ret); + + return ret; +} + +int sev_handle_vmgexit(struct vcpu_svm *svm) +{ + struct vmcb_control_area *control = &svm->vmcb->control; + u64 ghcb_gpa, exit_code; + struct ghcb *ghcb; + int ret; + + /* Validate the GHCB */ + ghcb_gpa = control->ghcb_gpa; + if (ghcb_gpa & GHCB_MSR_INFO_MASK) + return sev_handle_vmgexit_msr_protocol(svm); + + if (!ghcb_gpa) { + vcpu_unimpl(&svm->vcpu, "vmgexit: GHCB gpa is not set\n"); + return -EINVAL; + } + + if (kvm_vcpu_map(&svm->vcpu, ghcb_gpa >> PAGE_SHIFT, &svm->ghcb_map)) { + /* Unable to map GHCB from guest */ + vcpu_unimpl(&svm->vcpu, "vmgexit: error mapping GHCB [%#llx] from guest\n", + ghcb_gpa); + return -EINVAL; + } + + svm->ghcb = svm->ghcb_map.hva; + ghcb = svm->ghcb_map.hva; + + trace_kvm_vmgexit_enter(svm->vcpu.vcpu_id, ghcb); + + exit_code = ghcb_get_sw_exit_code(ghcb); + + ret = sev_es_validate_vmgexit(svm); + if (ret) + return ret; + + sev_es_sync_from_ghcb(svm); + ghcb_set_sw_exit_info_1(ghcb, 0); + ghcb_set_sw_exit_info_2(ghcb, 0); + + ret = -EINVAL; + switch (exit_code) { + case SVM_VMGEXIT_MMIO_READ: + if (!setup_vmgexit_scratch(svm, true, control->exit_info_2)) + break; + + ret = kvm_sev_es_mmio_read(&svm->vcpu, + control->exit_info_1, + control->exit_info_2, + svm->ghcb_sa); + break; + case SVM_VMGEXIT_MMIO_WRITE: + if (!setup_vmgexit_scratch(svm, false, control->exit_info_2)) + break; + + ret = kvm_sev_es_mmio_write(&svm->vcpu, + control->exit_info_1, + control->exit_info_2, + svm->ghcb_sa); + break; + case SVM_VMGEXIT_NMI_COMPLETE: + ret = svm_invoke_exit_handler(svm, SVM_EXIT_IRET); + break; + case SVM_VMGEXIT_AP_JUMP_TABLE: { + struct kvm_sev_info *sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info; + + switch (control->exit_info_1) { + case 0: + /* Set AP jump table address */ + sev->ap_jump_table = control->exit_info_2; + break; + case 1: + /* Get AP jump table address */ + ghcb_set_sw_exit_info_2(ghcb, 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(ghcb, 1); + ghcb_set_sw_exit_info_2(ghcb, + X86_TRAP_UD | + SVM_EVTINJ_TYPE_EXEPT | + SVM_EVTINJ_VALID); + } + + ret = 1; + break; + } + case SVM_VMGEXIT_UNSUPPORTED_EVENT: + vcpu_unimpl(&svm->vcpu, + "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n", + control->exit_info_1, control->exit_info_2); + break; + default: + ret = svm_invoke_exit_handler(svm, exit_code); + } + + return ret; +} + +int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in) +{ + if (!setup_vmgexit_scratch(svm, in, svm->vmcb->control.exit_info_2)) + return -EINVAL; + + return kvm_sev_es_string_io(&svm->vcpu, size, port, + svm->ghcb_sa, svm->ghcb_sa_len, in); +} + +void sev_es_init_vmcb(struct vcpu_svm *svm) +{ + struct kvm_vcpu *vcpu = &svm->vcpu; + + svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE; + svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK; + + /* + * An SEV-ES guest requires a VMSA area that is a separate from the + * VMCB page. Do not include the encryption mask on the VMSA physical + * address since hardware will access it using the guest key. + */ + svm->vmcb->control.vmsa_pa = __pa(svm->vmsa); + + /* Can't intercept CR register access, HV can't modify CR registers */ + svm_clr_intercept(svm, INTERCEPT_CR0_READ); + svm_clr_intercept(svm, INTERCEPT_CR4_READ); + svm_clr_intercept(svm, INTERCEPT_CR8_READ); + svm_clr_intercept(svm, INTERCEPT_CR0_WRITE); + svm_clr_intercept(svm, INTERCEPT_CR4_WRITE); + svm_clr_intercept(svm, INTERCEPT_CR8_WRITE); + + svm_clr_intercept(svm, INTERCEPT_SELECTIVE_CR0); + + /* Track EFER/CR register changes */ + svm_set_intercept(svm, TRAP_EFER_WRITE); + svm_set_intercept(svm, TRAP_CR0_WRITE); + svm_set_intercept(svm, TRAP_CR4_WRITE); + svm_set_intercept(svm, TRAP_CR8_WRITE); + + /* No support for enable_vmware_backdoor */ + clr_exception_intercept(svm, GP_VECTOR); + + /* 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_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHFROMIP, 1, 1); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHTOIP, 1, 1); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTFROMIP, 1, 1); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTTOIP, 1, 1); +} + +void sev_es_create_vcpu(struct vcpu_svm *svm) +{ + /* + * Set the GHCB MSR value as per the GHCB specification when creating + * a vCPU for an SEV-ES guest. + */ + set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX, + 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]); + } +} |