/* * VMware Detection code. * * Copyright (C) 2008, VMware, Inc. * Author : Alok N Kataria * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #undef pr_fmt #define pr_fmt(fmt) "vmware: " fmt #define CPUID_VMWARE_INFO_LEAF 0x40000000 #define CPUID_VMWARE_FEATURES_LEAF 0x40000010 #define CPUID_VMWARE_FEATURES_ECX_VMMCALL BIT(0) #define CPUID_VMWARE_FEATURES_ECX_VMCALL BIT(1) #define VMWARE_HYPERVISOR_MAGIC 0x564D5868 #define VMWARE_CMD_GETVERSION 10 #define VMWARE_CMD_GETHZ 45 #define VMWARE_CMD_GETVCPU_INFO 68 #define VMWARE_CMD_LEGACY_X2APIC 3 #define VMWARE_CMD_VCPU_RESERVED 31 #define VMWARE_CMD_STEALCLOCK 91 #define STEALCLOCK_NOT_AVAILABLE (-1) #define STEALCLOCK_DISABLED 0 #define STEALCLOCK_ENABLED 1 #define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \ __asm__("inl (%%dx), %%eax" : \ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ "a"(VMWARE_HYPERVISOR_MAGIC), \ "c"(VMWARE_CMD_##cmd), \ "d"(VMWARE_HYPERVISOR_PORT), "b"(UINT_MAX) : \ "memory") #define VMWARE_VMCALL(cmd, eax, ebx, ecx, edx) \ __asm__("vmcall" : \ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ "a"(VMWARE_HYPERVISOR_MAGIC), \ "c"(VMWARE_CMD_##cmd), \ "d"(0), "b"(UINT_MAX) : \ "memory") #define VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx) \ __asm__("vmmcall" : \ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ "a"(VMWARE_HYPERVISOR_MAGIC), \ "c"(VMWARE_CMD_##cmd), \ "d"(0), "b"(UINT_MAX) : \ "memory") #define VMWARE_CMD(cmd, eax, ebx, ecx, edx) do { \ switch (vmware_hypercall_mode) { \ case CPUID_VMWARE_FEATURES_ECX_VMCALL: \ VMWARE_VMCALL(cmd, eax, ebx, ecx, edx); \ break; \ case CPUID_VMWARE_FEATURES_ECX_VMMCALL: \ VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx); \ break; \ default: \ VMWARE_PORT(cmd, eax, ebx, ecx, edx); \ break; \ } \ } while (0) struct vmware_steal_time { union { uint64_t clock; /* stolen time counter in units of vtsc */ struct { /* only for little-endian */ uint32_t clock_low; uint32_t clock_high; }; }; uint64_t reserved[7]; }; static unsigned long vmware_tsc_khz __ro_after_init; static u8 vmware_hypercall_mode __ro_after_init; static inline int __vmware_platform(void) { uint32_t eax, ebx, ecx, edx; VMWARE_CMD(GETVERSION, eax, ebx, ecx, edx); return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC; } static unsigned long vmware_get_tsc_khz(void) { return vmware_tsc_khz; } #ifdef CONFIG_PARAVIRT static struct cyc2ns_data vmware_cyc2ns __ro_after_init; static bool vmw_sched_clock __initdata = true; static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64); static bool has_steal_clock; static bool steal_acc __initdata = true; /* steal time accounting */ static __init int setup_vmw_sched_clock(char *s) { vmw_sched_clock = false; return 0; } early_param("no-vmw-sched-clock", setup_vmw_sched_clock); static __init int parse_no_stealacc(char *arg) { steal_acc = false; return 0; } early_param("no-steal-acc", parse_no_stealacc); static noinstr u64 vmware_sched_clock(void) { unsigned long long ns; ns = mul_u64_u32_shr(rdtsc(), vmware_cyc2ns.cyc2ns_mul, vmware_cyc2ns.cyc2ns_shift); ns -= vmware_cyc2ns.cyc2ns_offset; return ns; } static void __init vmware_cyc2ns_setup(void) { struct cyc2ns_data *d = &vmware_cyc2ns; unsigned long long tsc_now = rdtsc(); clocks_calc_mult_shift(&d->cyc2ns_mul, &d->cyc2ns_shift, vmware_tsc_khz, NSEC_PER_MSEC, 0); d->cyc2ns_offset = mul_u64_u32_shr(tsc_now, d->cyc2ns_mul, d->cyc2ns_shift); pr_info("using clock offset of %llu ns\n", d->cyc2ns_offset); } static int vmware_cmd_stealclock(uint32_t arg1, uint32_t arg2) { uint32_t result, info; asm volatile (VMWARE_HYPERCALL : "=a"(result), "=c"(info) : "a"(VMWARE_HYPERVISOR_MAGIC), "b"(0), "c"(VMWARE_CMD_STEALCLOCK), "d"(0), "S"(arg1), "D"(arg2) : "memory"); return result; } static bool stealclock_enable(phys_addr_t pa) { return vmware_cmd_stealclock(upper_32_bits(pa), lower_32_bits(pa)) == STEALCLOCK_ENABLED; } static int __stealclock_disable(void) { return vmware_cmd_stealclock(0, 1); } static void stealclock_disable(void) { __stealclock_disable(); } static bool vmware_is_stealclock_available(void) { return __stealclock_disable() != STEALCLOCK_NOT_AVAILABLE; } /** * vmware_steal_clock() - read the per-cpu steal clock * @cpu: the cpu number whose steal clock we want to read * * The function reads the steal clock if we are on a 64-bit system, otherwise * reads it in parts, checking that the high part didn't change in the * meantime. * * Return: * The steal clock reading in ns. */ static uint64_t vmware_steal_clock(int cpu) { struct vmware_steal_time *steal = &per_cpu(vmw_steal_time, cpu); uint64_t clock; if (IS_ENABLED(CONFIG_64BIT)) clock = READ_ONCE(steal->clock); else { uint32_t initial_high, low, high; do { initial_high = READ_ONCE(steal->clock_high); /* Do not reorder initial_high and high readings */ virt_rmb(); low = READ_ONCE(steal->clock_low); /* Keep low reading in between */ virt_rmb(); high = READ_ONCE(steal->clock_high); } while (initial_high != high); clock = ((uint64_t)high << 32) | low; } return mul_u64_u32_shr(clock, vmware_cyc2ns.cyc2ns_mul, vmware_cyc2ns.cyc2ns_shift); } static void vmware_register_steal_time(void) { int cpu = smp_processor_id(); struct vmware_steal_time *st = &per_cpu(vmw_steal_time, cpu); if (!has_steal_clock) return; if (!stealclock_enable(slow_virt_to_phys(st))) { has_steal_clock = false; return; } pr_info("vmware-stealtime: cpu %d, pa %llx\n", cpu, (unsigned long long) slow_virt_to_phys(st)); } static void vmware_disable_steal_time(void) { if (!has_steal_clock) return; stealclock_disable(); } static void vmware_guest_cpu_init(void) { if (has_steal_clock) vmware_register_steal_time(); } static void vmware_pv_guest_cpu_reboot(void *unused) { vmware_disable_steal_time(); } static int vmware_pv_reboot_notify(struct notifier_block *nb, unsigned long code, void *unused) { if (code == SYS_RESTART) on_each_cpu(vmware_pv_guest_cpu_reboot, NULL, 1); return NOTIFY_DONE; } static struct notifier_block vmware_pv_reboot_nb = { .notifier_call = vmware_pv_reboot_notify, }; #ifdef CONFIG_SMP static void __init vmware_smp_prepare_boot_cpu(void) { vmware_guest_cpu_init(); native_smp_prepare_boot_cpu(); } static int vmware_cpu_online(unsigned int cpu) { local_irq_disable(); vmware_guest_cpu_init(); local_irq_enable(); return 0; } static int vmware_cpu_down_prepare(unsigned int cpu) { local_irq_disable(); vmware_disable_steal_time(); local_irq_enable(); return 0; } #endif static __init int activate_jump_labels(void) { if (has_steal_clock) { static_key_slow_inc(¶virt_steal_enabled); if (steal_acc) static_key_slow_inc(¶virt_steal_rq_enabled); } return 0; } arch_initcall(activate_jump_labels); static void __init vmware_paravirt_ops_setup(void) { pv_info.name = "VMware hypervisor"; pv_ops.cpu.io_delay = paravirt_nop; if (vmware_tsc_khz == 0) return; vmware_cyc2ns_setup(); if (vmw_sched_clock) paravirt_set_sched_clock(vmware_sched_clock); if (vmware_is_stealclock_available()) { has_steal_clock = true; static_call_update(pv_steal_clock, vmware_steal_clock); /* We use reboot notifier only to disable steal clock */ register_reboot_notifier(&vmware_pv_reboot_nb); #ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = vmware_smp_prepare_boot_cpu; if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/vmware:online", vmware_cpu_online, vmware_cpu_down_prepare) < 0) pr_err("vmware_guest: Failed to install cpu hotplug callbacks\n"); #else vmware_guest_cpu_init(); #endif } } #else #define vmware_paravirt_ops_setup() do {} while (0) #endif /* * VMware hypervisor takes care of exporting a reliable TSC to the guest. * Still, due to timing difference when running on virtual cpus, the TSC can * be marked as unstable in some cases. For example, the TSC sync check at * bootup can fail due to a marginal offset between vcpus' TSCs (though the * TSCs do not drift from each other). Also, the ACPI PM timer clocksource * is not suitable as a watchdog when running on a hypervisor because the * kernel may miss a wrap of the counter if the vcpu is descheduled for a * long time. To skip these checks at runtime we set these capability bits, * so that the kernel could just trust the hypervisor with providing a * reliable virtual TSC that is suitable for timekeeping. */ static void __init vmware_set_capabilities(void) { setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC); setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE); if (vmware_tsc_khz) setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ); if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMCALL) setup_force_cpu_cap(X86_FEATURE_VMCALL); else if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMMCALL) setup_force_cpu_cap(X86_FEATURE_VMW_VMMCALL); } static void __init vmware_platform_setup(void) { uint32_t eax, ebx, ecx, edx; uint64_t lpj, tsc_khz; VMWARE_CMD(GETHZ, eax, ebx, ecx, edx); if (ebx != UINT_MAX) { lpj = tsc_khz = eax | (((uint64_t)ebx) << 32); do_div(tsc_khz, 1000); WARN_ON(tsc_khz >> 32); pr_info("TSC freq read from hypervisor : %lu.%03lu MHz\n", (unsigned long) tsc_khz / 1000, (unsigned long) tsc_khz % 1000); if (!preset_lpj) { do_div(lpj, HZ); preset_lpj = lpj; } vmware_tsc_khz = tsc_khz; x86_platform.calibrate_tsc = vmware_get_tsc_khz; x86_platform.calibrate_cpu = vmware_get_tsc_khz; #ifdef CONFIG_X86_LOCAL_APIC /* Skip lapic calibration since we know the bus frequency. */ lapic_timer_period = ecx / HZ; pr_info("Host bus clock speed read from hypervisor : %u Hz\n", ecx); #endif } else { pr_warn("Failed to get TSC freq from the hypervisor\n"); } vmware_paravirt_ops_setup(); #ifdef CONFIG_X86_IO_APIC no_timer_check = 1; #endif vmware_set_capabilities(); } static u8 __init vmware_select_hypercall(void) { int eax, ebx, ecx, edx; cpuid(CPUID_VMWARE_FEATURES_LEAF, &eax, &ebx, &ecx, &edx); return (ecx & (CPUID_VMWARE_FEATURES_ECX_VMMCALL | CPUID_VMWARE_FEATURES_ECX_VMCALL)); } /* * While checking the dmi string information, just checking the product * serial key should be enough, as this will always have a VMware * specific string when running under VMware hypervisor. * If !boot_cpu_has(X86_FEATURE_HYPERVISOR), vmware_hypercall_mode * intentionally defaults to 0. */ static uint32_t __init vmware_platform(void) { if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) { unsigned int eax; unsigned int hyper_vendor_id[3]; cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0], &hyper_vendor_id[1], &hyper_vendor_id[2]); if (!memcmp(hyper_vendor_id, "VMwareVMware", 12)) { if (eax >= CPUID_VMWARE_FEATURES_LEAF) vmware_hypercall_mode = vmware_select_hypercall(); pr_info("hypercall mode: 0x%02x\n", (unsigned int) vmware_hypercall_mode); return CPUID_VMWARE_INFO_LEAF; } } else if (dmi_available && dmi_name_in_serial("VMware") && __vmware_platform()) return 1; return 0; } /* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */ static bool __init vmware_legacy_x2apic_available(void) { uint32_t eax, ebx, ecx, edx; VMWARE_CMD(GETVCPU_INFO, eax, ebx, ecx, edx); return !(eax & BIT(VMWARE_CMD_VCPU_RESERVED)) && (eax & BIT(VMWARE_CMD_LEGACY_X2APIC)); } #ifdef CONFIG_AMD_MEM_ENCRYPT static void vmware_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs) { /* Copy VMWARE specific Hypercall parameters to the GHCB */ ghcb_set_rip(ghcb, regs->ip); ghcb_set_rbx(ghcb, regs->bx); ghcb_set_rcx(ghcb, regs->cx); ghcb_set_rdx(ghcb, regs->dx); ghcb_set_rsi(ghcb, regs->si); ghcb_set_rdi(ghcb, regs->di); ghcb_set_rbp(ghcb, regs->bp); } static bool vmware_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs) { if (!(ghcb_rbx_is_valid(ghcb) && ghcb_rcx_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb) && ghcb_rsi_is_valid(ghcb) && ghcb_rdi_is_valid(ghcb) && ghcb_rbp_is_valid(ghcb))) return false; regs->bx = ghcb_get_rbx(ghcb); regs->cx = ghcb_get_rcx(ghcb); regs->dx = ghcb_get_rdx(ghcb); regs->si = ghcb_get_rsi(ghcb); regs->di = ghcb_get_rdi(ghcb); regs->bp = ghcb_get_rbp(ghcb); return true; } #endif const __initconst struct hypervisor_x86 x86_hyper_vmware = { .name = "VMware", .detect = vmware_platform, .type = X86_HYPER_VMWARE, .init.init_platform = vmware_platform_setup, .init.x2apic_available = vmware_legacy_x2apic_available, #ifdef CONFIG_AMD_MEM_ENCRYPT .runtime.sev_es_hcall_prepare = vmware_sev_es_hcall_prepare, .runtime.sev_es_hcall_finish = vmware_sev_es_hcall_finish, #endif };