[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC PATCH v2 7/7] x86/boot: Do not use trampoline for no-real-mode boot paths
From: David Woodhouse <dwmw@xxxxxxxxxxxx> Where booted from EFI or with no-real-mode, there is no need to stomp on low memory with the 16-boot code. Instead, just go straight to trampoline_protmode_entry() at its physical location within the Xen image. For now, the boot code (including the EFI loader path) still determines what the trampoline_phys address should be. The trampoline is actually relocated for that address and copied into low memory, from a relocate_trampoline() call made from __start_xen(). For subsequent AP startup and wakeup, the 32-bit trampoline can't trivially be used in-place as that region isn't mapped. So copy it down to low memory too, having relocated it (again) to work from there. Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx> --- xen/arch/x86/acpi/power.c | 6 +-- xen/arch/x86/boot/head.S | 67 ++++++++++++++++------------------ xen/arch/x86/boot/trampoline.S | 30 +++++++++++---- xen/arch/x86/cpu/common.c | 2 +- xen/arch/x86/cpu/intel.c | 2 +- xen/arch/x86/efi/efi-boot.h | 31 ++-------------- xen/arch/x86/mm.c | 2 +- xen/arch/x86/setup.c | 43 ++++++++++++++++++++-- xen/arch/x86/smpboot.c | 6 +-- xen/arch/x86/tboot.c | 6 +-- xen/arch/x86/x86_64/mm.c | 2 +- xen/include/asm-x86/acpi.h | 2 +- xen/include/asm-x86/config.h | 10 ++--- 13 files changed, 117 insertions(+), 92 deletions(-) diff --git a/xen/arch/x86/acpi/power.c b/xen/arch/x86/acpi/power.c index a704c7c340..a1ce8acb21 100644 --- a/xen/arch/x86/acpi/power.c +++ b/xen/arch/x86/acpi/power.c @@ -152,9 +152,9 @@ static void acpi_sleep_prepare(u32 state) return; if ( acpi_sinfo.vector_width == 32 ) - *(uint32_t *)wakeup_vector_va = bootsym_phys(wakeup_start); + *(uint32_t *)wakeup_vector_va = trampsym_phys(wakeup_start); else - *(uint64_t *)wakeup_vector_va = bootsym_phys(wakeup_start); + *(uint64_t *)wakeup_vector_va = trampsym_phys(wakeup_start); } static void acpi_sleep_post(u32 state) {} @@ -388,7 +388,7 @@ static void tboot_sleep(u8 sleep_state) g_tboot_shared->acpi_sinfo.wakeup_vector = acpi_sinfo.wakeup_vector; g_tboot_shared->acpi_sinfo.vector_width = acpi_sinfo.vector_width; g_tboot_shared->acpi_sinfo.kernel_s3_resume_vector = - bootsym_phys(wakeup_start); + trampsym_phys(wakeup_start); switch ( sleep_state ) { diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S index 7d6c8d3292..c23eeb3aa4 100644 --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -696,16 +696,23 @@ trampoline_setup: lea __PAGE_HYPERVISOR+sym_esi(l1_identmap),%edi mov %edi,sym_fs(l2_bootmap) - /* Apply relocations to bootstrap trampoline. */ - mov sym_fs(trampoline_phys),%edx - mov $sym_offs(__trampoline_rel_start),%edi -1: - mov %fs:(%edi),%eax - add %edx,%fs:(%edi,%eax) - add $4,%edi - cmp $sym_offs(__trampoline_rel_stop),%edi - jb 1b + /* Do not parse command line on EFI platform here. */ + cmpb $0,sym_fs(efi_platform) + jnz 1f + /* Bail if there is no command line to parse. */ + mov sym_fs(multiboot_ptr),%ebx + testl $MBI_CMDLINE,MB_flags(%ebx) + jz 1f + + lea sym_esi(early_boot_opts),%eax + push %eax + pushl MB_cmdline(%ebx) + call cmdline_parse_early + +1: + /* Apply relocations to 32-bit trampoline for execution in place. */ + lea sym_esi(perm_trampoline_start),%edx mov $sym_offs(__trampoline32_rel_start),%edi 1: mov %fs:(%edi),%eax @@ -714,6 +721,21 @@ trampoline_setup: cmp $sym_offs(__trampoline32_rel_stop),%edi jb 1b + cmp $0,sym_esi(skip_realmode) + jz .Ldo_realmode + + /* Go directly to trampoline_protmode_entry at its physical address */ + lea trampoline_protmode_entry-__XEN_VIRT_START(%esi),%eax + pushl $BOOT_CS32 + push %eax + + /* EBX == 0 indicates we are the BP (Boot Processor). */ + xor %ebx,%ebx + retl + +.Ldo_realmode: + /* Apply relocations to 16-bit boot code. */ + mov sym_fs(trampoline_phys),%edx mov $sym_offs(__bootsym_rel_start),%edi 1: mov %fs:(%edi),%eax @@ -743,35 +765,12 @@ trampoline_setup: cmp $sym_offs(__bootdatasym_rel_stop),%edi jb 1b - /* Do not parse command line on EFI platform here. */ - cmpb $0,sym_fs(efi_platform) - jnz 1f - - /* Bail if there is no command line to parse. */ - mov sym_fs(multiboot_ptr),%ebx - testl $MBI_CMDLINE,MB_flags(%ebx) - jz 1f - - lea sym_esi(early_boot_opts),%eax - push %eax - pushl MB_cmdline(%ebx) - call cmdline_parse_early - -1: /* Switch to low-memory stack which lives at the end of trampoline region. */ mov sym_fs(trampoline_phys),%edi lea TRAMPOLINE_SPACE+TRAMPOLINE_STACK_SPACE(%edi),%esp - cmpb $0, sym_fs(skip_realmode) - jz 1f - /* If no-real-mode, jump straight to trampoline_protmode_entry */ - lea trampoline_protmode_entry-boot_trampoline_start(%edi),%eax - /* EBX == 0 indicates we are the BP (Boot Processor). */ - xor %ebx,%ebx - jmp 2f -1: + /* Go via 16-bit code in trampoline_boot_cpu_entry */ lea trampoline_boot_cpu_entry-boot_trampoline_start(%edi),%eax -2: pushl $BOOT_CS32 push %eax @@ -794,8 +793,6 @@ cmdline_parse_early: reloc: #include "reloc.S" -ENTRY(boot_trampoline_start) #include "trampoline.S" -ENTRY(boot_trampoline_end) #include "x86_64.S" diff --git a/xen/arch/x86/boot/trampoline.S b/xen/arch/x86/boot/trampoline.S index fdfee2edb1..1ce815e0da 100644 --- a/xen/arch/x86/boot/trampoline.S +++ b/xen/arch/x86/boot/trampoline.S @@ -60,7 +60,7 @@ GLOBAL(bootdata_start) .popsection #undef trampsym -#define trampsym(s) ((s)-boot_trampoline_start) +#define trampsym(s) ((s)-perm_trampoline_start) #define trampsym_rel(sym, off, opnd...) \ trampsym(sym),##opnd; \ @@ -70,7 +70,7 @@ GLOBAL(bootdata_start) .popsection #undef tramp32sym -#define tramp32sym(s) ((s)-boot_trampoline_start) +#define tramp32sym(s) ((s)-perm_trampoline_start) #define tramp32sym_rel(sym, off, opnd...) \ tramp32sym(sym),##opnd; \ @@ -83,6 +83,7 @@ GLOBAL(bootdata_start) .code16 +ENTRY(perm_trampoline_start) GLOBAL(trampoline_realmode_entry) mov %cs,%ax mov %ax,%ds @@ -90,7 +91,7 @@ GLOBAL(trampoline_realmode_entry) cld cli lidt trampsym(idt_48) - lgdt trampsym(gdt_48) + lgdtl trampsym(gdt_48) mov $1,%bl # EBX != 0 indicates we are an AP xor %ax, %ax inc %ax @@ -230,11 +231,23 @@ start64: /* The first page of trampoline is permanent, the rest boot-time only. */ /* Reuse the boot trampoline on the 1st trampoline page as stack for wakeup. */ - .equ wakeup_stack, boot_trampoline_start + PAGE_SIZE + .equ wakeup_stack, perm_trampoline_start + PAGE_SIZE .global wakeup_stack +ENTRY(perm_trampoline_end) + /* From here on early boot only. */ +ENTRY(boot_trampoline_start) + + .word 0 +boot16_idt: + .word 0, 0, 0 # base = limit = 0 + .word 0 +boot16_gdt: + .word 7*8-1 + .long tramp32sym_rel(trampoline_gdt,4) + .code32 trampoline_boot_cpu_entry: /* Load pseudo-real-mode segments. */ @@ -298,8 +311,8 @@ trampoline_boot_cpu_entry: cli /* Reset GDT and IDT. Some BIOSes clobber GDTR. */ - lidt bootsym(idt_48) - lgdt bootsym(gdt_48) + lidt bootsym(boot16_idt) # XXX + lgdtl bootsym(boot16_gdt) /* Enter protected mode, and flush insn queue. */ xor %ax,%ax @@ -337,7 +350,8 @@ trampoline_boot_cpu_entry: xor %ebx,%ebx /* Jump to the common bootstrap entry point. */ - jmp trampoline_protmode_entry + mov $tramp32sym_rel(trampoline_protmode_entry,4,%eax) + jmp *%eax #include "video.h" @@ -373,6 +387,8 @@ rm_idt: .word 256*4-1, 0, 0 #include "video.S" #endif +ENTRY(boot_trampoline_end) + .pushsection .data.boot16, "aw", @progbits GLOBAL(bootdata_end) .popsection diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c index 1d21ff9467..b268e010c5 100644 --- a/xen/arch/x86/cpu/common.c +++ b/xen/arch/x86/cpu/common.c @@ -408,7 +408,7 @@ static void generic_identify(struct cpuinfo_x86 *c) &c->x86_capability[cpufeat_word(X86_FEATURE_LAHF_LM)], &c->x86_capability[cpufeat_word(X86_FEATURE_SYSCALL)]); if (c == &boot_cpu_data) - bootsym(cpuid_ext_features) = + trampsym(cpuid_ext_features) = c->x86_capability[cpufeat_word(X86_FEATURE_NX)]; if (c->extended_cpuid_level >= 0x80000004) diff --git a/xen/arch/x86/cpu/intel.c b/xen/arch/x86/cpu/intel.c index 8e23ed6379..e7f794a601 100644 --- a/xen/arch/x86/cpu/intel.c +++ b/xen/arch/x86/cpu/intel.c @@ -240,7 +240,7 @@ static void early_init_intel(struct cpuinfo_x86 *c) MSR_IA32_MISC_ENABLE_XD_DISABLE); if (disable) { wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable & ~disable); - bootsym(trampoline_misc_enable_off) |= disable; + trampsym(trampoline_misc_enable_off) |= disable; } if (disable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h index f6f435a4c5..ecec334d60 100644 --- a/xen/arch/x86/efi/efi-boot.h +++ b/xen/arch/x86/efi/efi-boot.h @@ -98,29 +98,6 @@ static void __init efi_arch_relocate_image(unsigned long delta) } } -extern const s32 __trampoline_rel_start[], __trampoline_rel_stop[]; -extern const s32 __trampoline32_rel_start[], __trampoline32_rel_stop[]; - -static void __init relocate_trampoline(unsigned long phys) -{ - const s32 *trampoline_ptr; - - trampoline_phys = phys; - - if ( !efi_enabled(EFI_LOADER) ) - return; - - /* Apply relocations to trampoline. */ - for ( trampoline_ptr = __trampoline_rel_start; - trampoline_ptr < __trampoline_rel_stop; - ++trampoline_ptr ) - *(u32 *)(*trampoline_ptr + (long)trampoline_ptr) += phys; - for ( trampoline_ptr = __trampoline32_rel_start; - trampoline_ptr < __trampoline32_rel_stop; - ++trampoline_ptr ) - *(u32 *)(*trampoline_ptr + (long)trampoline_ptr) += phys; -} - static void __init place_string(u32 *addr, const char *s) { char *alloc = NULL; @@ -223,7 +200,7 @@ static void __init efi_arch_pre_exit_boot(void) { if ( !cfg.addr ) blexit(L"No memory for trampoline"); - relocate_trampoline(cfg.addr); + trampoline_phys = cfg.addr; } } @@ -232,7 +209,6 @@ static void __init noreturn efi_arch_post_exit_boot(void) u64 cr4 = XEN_MINIMAL_CR4 & ~X86_CR4_PGE, efer; efi_arch_relocate_image(__XEN_VIRT_START - xen_phys_start); - memcpy((void *)trampoline_phys, boot_trampoline_start, cfg.size); /* Set system registers and transfer control. */ asm volatile("pushq $0\n\tpopfq"); @@ -565,14 +541,14 @@ static void __init efi_arch_memory_setup(void) cfg.addr = 0x100000; if ( efi_enabled(EFI_LOADER) ) - cfg.size = boot_trampoline_end - boot_trampoline_start; + cfg.size = perm_trampoline_end - perm_trampoline_start; else cfg.size = TRAMPOLINE_SPACE + TRAMPOLINE_STACK_SPACE; status = efi_bs->AllocatePages(AllocateMaxAddress, EfiLoaderData, PFN_UP(cfg.size), &cfg.addr); if ( status == EFI_SUCCESS ) - relocate_trampoline(cfg.addr); + trampoline_phys = cfg.addr; else { cfg.addr = 0; @@ -664,7 +640,6 @@ static void __init efi_arch_load_addr_check(EFI_LOADED_IMAGE *loaded_image) blexit(L"Xen must be loaded below 4Gb."); if ( xen_phys_start & ((1 << L2_PAGETABLE_SHIFT) - 1) ) blexit(L"Xen must be loaded at a 2Mb boundary."); - trampoline_xen_phys_start = xen_phys_start; } static bool __init efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable) diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 7a2e188916..17a55b4b8a 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -314,7 +314,7 @@ void __init arch_init_memory(void) */ BUG_ON(pvh_boot && trampoline_phys != 0x1000); for ( i = 0; - i < (pvh_boot ? (1 + PFN_UP(boot_trampoline_end - boot_trampoline_start)) + i < (pvh_boot ? (1 + PFN_UP(perm_trampoline_end - perm_trampoline_start)) : 0x100); i++ ) share_xen_page_with_guest(mfn_to_page(_mfn(i)), dom_io, SHARE_rw); diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c index 4dd4c4161c..b255242561 100644 --- a/xen/arch/x86/setup.c +++ b/xen/arch/x86/setup.c @@ -675,6 +675,42 @@ static int copy_bios_e820(struct e820entry *map, unsigned int limit) return n; } +extern const s32 __trampoline_rel_start[], __trampoline_rel_stop[]; +extern const s32 __trampoline32_rel_start[], __trampoline32_rel_stop[]; + +static void __init relocate_trampoline(unsigned long phys) +{ + const s32 *trampoline_ptr; + uint32_t tramp32_delta = 0; + + /* Apply relocations to trampoline. */ + for ( trampoline_ptr = __trampoline_rel_start; + trampoline_ptr < __trampoline_rel_stop; + ++trampoline_ptr ) + *(u32 *)(*trampoline_ptr + (long)trampoline_ptr) += phys; + + tramp32_delta = phys; + if (!efi_enabled(EFI_LOADER)) { + /* + * The non-EFI boot code uses the 32-bit trampoline in place + * so will have relocated it to the physical address of + * perm_trampoline_start already. Undo that as it needs to + * run from low memory for AP startup, because the Xen + * physical address range won't be mapped. + */ + tramp32_delta -= trampoline_xen_phys_start; + tramp32_delta -= (unsigned long)(perm_trampoline_start - __XEN_VIRT_START); + } + for ( trampoline_ptr = __trampoline32_rel_start; + trampoline_ptr < __trampoline32_rel_stop; + ++trampoline_ptr ) + *(u32 *)(*trampoline_ptr + (long)trampoline_ptr) += tramp32_delta; + trampoline_xen_phys_start = xen_phys_start; + + memcpy(trampsym(perm_trampoline_start), perm_trampoline_start, + perm_trampoline_end - perm_trampoline_start); +} + void __init noreturn __start_xen(unsigned long mbi_p) { char *memmap_type = NULL; @@ -1047,7 +1083,6 @@ void __init noreturn __start_xen(unsigned long mbi_p) /* Select relocation address. */ e = end - reloc_size; xen_phys_start = e; - bootsym(trampoline_xen_phys_start) = e; /* * Perform relocation to new physical address. @@ -1479,6 +1514,8 @@ void __init noreturn __start_xen(unsigned long mbi_p) else end_boot_allocator(); + relocate_trampoline(trampoline_phys); + system_state = SYS_STATE_boot; /* * No calls involving ACPI code should go between the setting of @@ -1838,8 +1875,8 @@ int __hwdom_init xen_in_range(unsigned long mfn) if ( !xen_regions[0].s ) { /* S3 resume code (and other real mode trampoline code) */ - xen_regions[region_s3].s = bootsym_phys(boot_trampoline_start); - xen_regions[region_s3].e = bootsym_phys(boot_trampoline_end); + xen_regions[region_s3].s = trampsym_phys(perm_trampoline_start); + xen_regions[region_s3].e = trampsym_phys(perm_trampoline_end); /* * This needs to remain in sync with the uses of the same symbols in diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c index 7e76cc3d68..02d97a1aa3 100644 --- a/xen/arch/x86/smpboot.c +++ b/xen/arch/x86/smpboot.c @@ -48,7 +48,7 @@ #include <mach_wakecpu.h> #include <smpboot_hooks.h> -#define setup_trampoline() (bootsym_phys(trampoline_realmode_entry)) +#define setup_trampoline() (trampsym_phys(trampoline_realmode_entry)) unsigned long __read_mostly trampoline_phys; @@ -600,7 +600,7 @@ static int do_boot_cpu(int apicid, int cpu) { boot_error = 1; smp_mb(); - if ( bootsym(trampoline_cpu_started) == 0xA5 ) + if ( trampsym(trampoline_cpu_started) == 0xA5 ) /* trampoline started but...? */ printk("Stuck ??\n"); else @@ -616,7 +616,7 @@ static int do_boot_cpu(int apicid, int cpu) } /* mark "stuck" area as not stuck */ - bootsym(trampoline_cpu_started) = 0; + trampsym(trampoline_cpu_started) = 0; smp_mb(); smpboot_restore_warm_reset_vector(); diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c index 9e3d9c4c69..006f0678a6 100644 --- a/xen/arch/x86/tboot.c +++ b/xen/arch/x86/tboot.c @@ -369,9 +369,9 @@ void tboot_shutdown(uint32_t shutdown_type) */ g_tboot_shared->num_mac_regions = 3; /* S3 resume code (and other real mode trampoline code) */ - g_tboot_shared->mac_regions[0].start = bootsym_phys(boot_trampoline_start); - g_tboot_shared->mac_regions[0].size = bootsym_phys(boot_trampoline_end) - - bootsym_phys(boot_trampoline_start); + g_tboot_shared->mac_regions[0].start = trampsym_phys(perm_trampoline_start); + g_tboot_shared->mac_regions[0].size = trampsym_phys(perm_trampoline_end) - + trampsym_phys(perm_trampoline_start); /* hypervisor .text + .rodata */ g_tboot_shared->mac_regions[1].start = (uint64_t)__pa(&_stext); g_tboot_shared->mac_regions[1].size = __pa(&__2M_rodata_end) - diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c index ffe8ba2086..dbbbc64beb 100644 --- a/xen/arch/x86/x86_64/mm.c +++ b/xen/arch/x86/x86_64/mm.c @@ -697,7 +697,7 @@ void __init zap_low_mappings(void) /* Replace with mapping of the boot trampoline only. */ map_pages_to_xen(trampoline_phys, maddr_to_mfn(trampoline_phys), - PFN_UP(boot_trampoline_end - boot_trampoline_start), + PFN_UP(perm_trampoline_end - perm_trampoline_start), __PAGE_HYPERVISOR); } diff --git a/xen/include/asm-x86/acpi.h b/xen/include/asm-x86/acpi.h index c138def1bd..dffe02a363 100644 --- a/xen/include/asm-x86/acpi.h +++ b/xen/include/asm-x86/acpi.h @@ -110,7 +110,7 @@ extern int acpi_scan_nodes(u64 start, u64 end); #ifdef CONFIG_ACPI_SLEEP extern struct acpi_sleep_info acpi_sinfo; -#define acpi_video_flags bootsym(video_flags) +#define acpi_video_flags trampsym(video_flags) struct xenpf_enter_acpi_sleep; extern int acpi_enter_sleep(struct xenpf_enter_acpi_sleep *sleep); extern int acpi_enter_state(u32 state); diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h index 9b7ed50825..dbd7cb255a 100644 --- a/xen/include/asm-x86/config.h +++ b/xen/include/asm-x86/config.h @@ -90,12 +90,12 @@ #ifndef __ASSEMBLY__ extern unsigned long trampoline_phys; -#define bootsym_phys(sym) \ - (((unsigned long)&(sym)-(unsigned long)&boot_trampoline_start)+trampoline_phys) -#define bootsym(sym) \ +#define trampsym_phys(sym) \ + (((unsigned long)&(sym)-(unsigned long)&perm_trampoline_start)+trampoline_phys) +#define trampsym(sym) \ (*RELOC_HIDE((typeof(&(sym)))__va(__pa(&(sym))), \ - trampoline_phys-__pa(boot_trampoline_start))) -extern char boot_trampoline_start[], boot_trampoline_end[]; + trampoline_phys-__pa(perm_trampoline_start))) +extern char perm_trampoline_start[], perm_trampoline_end[]; extern char trampoline_realmode_entry[]; extern unsigned int trampoline_xen_phys_start; extern unsigned char trampoline_cpu_started; -- 2.17.2 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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