diff options
Diffstat (limited to 'arch/x86/kernel/cpu/vmware.c')
| -rw-r--r-- | arch/x86/kernel/cpu/vmware.c | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c new file mode 100644 index 000000000..924571fe5 --- /dev/null +++ b/arch/x86/kernel/cpu/vmware.c @@ -0,0 +1,525 @@ +/* + * VMware Detection code. + * + * Copyright (C) 2008, VMware, Inc. + * Author : Alok N Kataria <akataria@vmware.com> + * + * 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 <linux/dmi.h> +#include <linux/init.h> +#include <linux/export.h> +#include <linux/clocksource.h> +#include <linux/cpu.h> +#include <linux/reboot.h> +#include <asm/div64.h> +#include <asm/x86_init.h> +#include <asm/hypervisor.h> +#include <asm/timer.h> +#include <asm/apic.h> +#include <asm/vmware.h> +#include <asm/svm.h> + +#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 unsigned long long notrace 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) + pv_ops.time.sched_clock = vmware_sched_clock; + + if (vmware_is_stealclock_available()) { + has_steal_clock = true; + pv_ops.time.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_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 & (1 << VMWARE_CMD_VCPU_RESERVED)) == 0 && + (eax & (1 << VMWARE_CMD_LEGACY_X2APIC)) != 0; +} + +#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->save.rbx; + regs->cx = ghcb->save.rcx; + regs->dx = ghcb->save.rdx; + regs->si = ghcb->save.rsi; + regs->di = ghcb->save.rdi; + regs->bp = ghcb->save.rbp; + + 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 +}; |