diff options
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
-rw-r--r-- | arch/x86/kernel/cpu/common.c | 92 |
1 files changed, 82 insertions, 10 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c5d6f17d9b9d..35ad8480c464 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -23,6 +23,7 @@ #include <linux/syscore_ops.h> #include <linux/pgtable.h> +#include <asm/cmdline.h> #include <asm/stackprotector.h> #include <asm/perf_event.h> #include <asm/mmu_context.h> @@ -359,7 +360,7 @@ void native_write_cr0(unsigned long val) unsigned long bits_missing = 0; set_register: - asm volatile("mov %0,%%cr0": "+r" (val), "+m" (__force_order)); + asm volatile("mov %0,%%cr0": "+r" (val) : : "memory"); if (static_branch_likely(&cr_pinning)) { if (unlikely((val & X86_CR0_WP) != X86_CR0_WP)) { @@ -378,7 +379,7 @@ void native_write_cr4(unsigned long val) unsigned long bits_changed = 0; set_register: - asm volatile("mov %0,%%cr4": "+r" (val), "+m" (cr4_pinned_bits)); + asm volatile("mov %0,%%cr4": "+r" (val) : : "memory"); if (static_branch_likely(&cr_pinning)) { if (unlikely((val & cr4_pinned_mask) != cr4_pinned_bits)) { @@ -1221,6 +1222,59 @@ static void detect_nopl(void) } /* + * We parse cpu parameters early because fpu__init_system() is executed + * before parse_early_param(). + */ +static void __init cpu_parse_early_param(void) +{ + char arg[128]; + char *argptr = arg; + int arglen, res, bit; + +#ifdef CONFIG_X86_32 + if (cmdline_find_option_bool(boot_command_line, "no387")) +#ifdef CONFIG_MATH_EMULATION + setup_clear_cpu_cap(X86_FEATURE_FPU); +#else + pr_err("Option 'no387' required CONFIG_MATH_EMULATION enabled.\n"); +#endif + + if (cmdline_find_option_bool(boot_command_line, "nofxsr")) + setup_clear_cpu_cap(X86_FEATURE_FXSR); +#endif + + if (cmdline_find_option_bool(boot_command_line, "noxsave")) + setup_clear_cpu_cap(X86_FEATURE_XSAVE); + + if (cmdline_find_option_bool(boot_command_line, "noxsaveopt")) + setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); + + if (cmdline_find_option_bool(boot_command_line, "noxsaves")) + setup_clear_cpu_cap(X86_FEATURE_XSAVES); + + arglen = cmdline_find_option(boot_command_line, "clearcpuid", arg, sizeof(arg)); + if (arglen <= 0) + return; + + pr_info("Clearing CPUID bits:"); + do { + res = get_option(&argptr, &bit); + if (res == 0 || res == 3) + break; + + /* If the argument was too long, the last bit may be cut off */ + if (res == 1 && arglen >= sizeof(arg)) + break; + + if (bit >= 0 && bit < NCAPINTS * 32) { + pr_cont(" " X86_CAP_FMT, x86_cap_flag(bit)); + setup_clear_cpu_cap(bit); + } + } while (res == 2); + pr_cont("\n"); +} + +/* * Do minimum CPU detection early. * Fields really needed: vendor, cpuid_level, family, model, mask, * cache alignment. @@ -1255,6 +1309,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) get_cpu_cap(c); get_cpu_address_sizes(c); setup_force_cpu_cap(X86_FEATURE_CPUID); + cpu_parse_early_param(); if (this_cpu->c_early_init) this_cpu->c_early_init(c); @@ -1413,15 +1468,7 @@ static void generic_identify(struct cpuinfo_x86 *c) * ESPFIX issue, we can change this. */ #ifdef CONFIG_X86_32 -# ifdef CONFIG_PARAVIRT_XXL - do { - extern void native_iret(void); - if (pv_ops.cpu.iret == native_iret) - set_cpu_bug(c, X86_BUG_ESPFIX); - } while (0); -# else set_cpu_bug(c, X86_BUG_ESPFIX); -# endif #endif } @@ -1829,6 +1876,8 @@ static inline void tss_setup_ist(struct tss_struct *tss) tss->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(NMI); tss->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(DB); tss->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(MCE); + /* Only mapped when SEV-ES is active */ + tss->x86_tss.ist[IST_INDEX_VC] = __this_cpu_ist_top_va(VC); } #else /* CONFIG_X86_64 */ @@ -1861,6 +1910,29 @@ static inline void tss_setup_io_bitmap(struct tss_struct *tss) } /* + * Setup everything needed to handle exceptions from the IDT, including the IST + * exceptions which use paranoid_entry(). + */ +void cpu_init_exception_handling(void) +{ + struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw); + int cpu = raw_smp_processor_id(); + + /* paranoid_entry() gets the CPU number from the GDT */ + setup_getcpu(cpu); + + /* IST vectors need TSS to be set up. */ + tss_setup_ist(tss); + tss_setup_io_bitmap(tss); + set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss); + + load_TR_desc(); + + /* Finally load the IDT */ + load_current_idt(); +} + +/* * cpu_init() initializes state that is per-CPU. Some data is already * initialized (naturally) in the bootstrap process, such as the GDT * and IDT. We reload them nevertheless, this function acts as a |