[kvm-unit-tests,9/9] x86: Move 32-bit GDT and TSS to desc.c

Message ID	20211021114910.1347278-10-pbonzini@redhat.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> From: Paolo Bonzini <pbonzini@redhat.com> To: kvm@vger.kernel.org Cc: aaronlewis@google.com, jmattson@google.com, zxwang42@gmail.com, marcorr@google.com, seanjc@google.com, jroedel@suse.de, varad.gautam@suse.com Subject: [PATCH kvm-unit-tests 9/9] x86: Move 32-bit GDT and TSS to desc.c Date: Thu, 21 Oct 2021 07:49:10 -0400 Message-Id: <20211021114910.1347278-10-pbonzini@redhat.com> In-Reply-To: <20211021114910.1347278-1-pbonzini@redhat.com> References: <20211021114910.1347278-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	x86: Move IDT, GDT and TSS to C code \| expand [v3,kvm-unit-tests,0/8] x86: Move IDT, GDT and TSS to C code [kvm-unit-tests,1/9] x86: cleanup handling of 16-byte GDT descriptors [kvm-unit-tests,2/9] x86: fix call to set_gdt_entry [kvm-unit-tests,3/9] unify field names and definitions for GDT descriptors [kvm-unit-tests,4/9] replace tss_descr global with a function [kvm-unit-tests,5/9] x86: Move IDT to desc.c [kvm-unit-tests,6/9] x86: unify name of 32-bit and 64-bit GDT [kvm-unit-tests,7/9] x86: get rid of ring0stacktop [kvm-unit-tests,8/9] x86: Move 64-bit GDT and TSS to desc.c [kvm-unit-tests,9/9] x86: Move 32-bit GDT and TSS to desc.c

diff --git a/lib/x86/asm/setup.h b/lib/x86/asm/setup.h index e3c3bfb..4310132 100644 --- a/lib/x86/asm/setup.h +++ b/lib/x86/asm/setup.h @@ -1,6 +1,6 @@ #ifndef _X86_ASM_SETUP_H_ #define _X86_ASM_SETUP_H_ -unsigned long setup_tss(void); +unsigned long setup_tss(u8 *stacktop); #endif /* _X86_ASM_SETUP_H_ */ diff --git a/lib/x86/desc.c b/lib/x86/desc.c index c185c01..16b7256 100644 --- a/lib/x86/desc.c +++ b/lib/x86/desc.c @@ -14,8 +14,22 @@ struct descriptor_table_ptr idt_descr = { .base = (unsigned long)boot_idt, }; -#ifdef __x86_64__ +#ifndef __x86_64__ /* GDT, TSS and descriptors */ +gdt_entry_t gdt[TSS_MAIN / 8 + MAX_TEST_CPUS * 2] = { + { 0, 0, 0, .type_limit_flags = 0x0000}, /* 0x00 null */ + {0xffff, 0, 0, .type_limit_flags = 0xcf9b}, /* flat 32-bit code segment */ + {0xffff, 0, 0, .type_limit_flags = 0xcf93}, /* flat 32-bit data segment */ + {0xffff, 0, 0, .type_limit_flags = 0xcf1b}, /* flat 32-bit code segment, not present */ + { 0, 0, 0, .type_limit_flags = 0x0000}, /* TSS for task gates */ + {0xffff, 0, 0, .type_limit_flags = 0x8f9b}, /* 16-bit code segment */ + {0xffff, 0, 0, .type_limit_flags = 0x8f93}, /* 16-bit data segment */ + {0xffff, 0, 0, .type_limit_flags = 0xcffb}, /* 32-bit code segment (user) */ + {0xffff, 0, 0, .type_limit_flags = 0xcff3}, /* 32-bit data segment (user) */ +}; + +tss32_t tss[MAX_TEST_CPUS] = {0}; +#else gdt_entry_t gdt[TSS_MAIN / 8 + MAX_TEST_CPUS * 2] = { { 0, 0, 0, .type_limit_flags = 0x0000}, /* 0x00 null */ {0xffff, 0, 0, .type_limit_flags = 0xaf9b}, /* 0x08 64-bit code segment */ @@ -30,12 +44,12 @@ gdt_entry_t gdt[TSS_MAIN / 8 + MAX_TEST_CPUS * 2] = { }; tss64_t tss[MAX_TEST_CPUS] = {0}; +#endif struct descriptor_table_ptr gdt_descr = { .limit = sizeof(gdt) - 1, .base = (unsigned long)gdt, }; -#endif #ifndef __x86_64__ __attribute__((regparm(1))) @@ -365,7 +379,7 @@ void setup_tss32(void) { u16 desc_size = sizeof(tss32_t); - tss.cr3 = read_cr3(); + tss[0].cr3 = read_cr3(); tss_intr.cr3 = read_cr3(); tss_intr.ss0 = tss_intr.ss1 = tss_intr.ss2 = 0x10; tss_intr.esp = tss_intr.esp0 = tss_intr.esp1 = tss_intr.esp2 = @@ -401,7 +415,7 @@ void print_current_tss_info(void) printf("Unknown TSS %x\n", tr); else printf("TR=%x (%s) Main TSS back link %x. Intr TSS back link %x\n", - tr, tr ? "interrupt" : "main", tss.prev, tss_intr.prev); + tr, tr ? "interrupt" : "main", tss[0].prev, tss_intr.prev); } #else void set_intr_alt_stack(int e, void *addr) diff --git a/lib/x86/desc.h b/lib/x86/desc.h index ddfae04..b65539e 100644 --- a/lib/x86/desc.h +++ b/lib/x86/desc.h @@ -197,7 +197,7 @@ struct system_desc64 { extern idt_entry_t boot_idt[256]; #ifndef __x86_64__ -extern tss32_t tss; +extern tss32_t tss[]; extern tss32_t tss_intr; void set_gdt_task_gate(u16 tss_sel, u16 sel); void set_idt_task_gate(int vec, u16 sel); diff --git a/lib/x86/setup.c b/lib/x86/setup.c index ec005b5..9c4393f 100644 --- a/lib/x86/setup.c +++ b/lib/x86/setup.c @@ -104,7 +104,7 @@ void find_highmem(void) } /* Setup TSS for the current processor, and return TSS offset within GDT */ -unsigned long setup_tss(void) +unsigned long setup_tss(u8 *stacktop) { u32 id; tss64_t *tss_entry; @@ -122,6 +122,30 @@ unsigned long setup_tss(void) return TSS_MAIN + id * 16; } +#else +/* Setup TSS for the current processor, and return TSS offset within GDT */ +unsigned long setup_tss(u8 *stacktop) +{ + u32 id; + tss32_t *tss_entry; + + id = apic_id(); + + /* Runtime address of current TSS */ + tss_entry = &tss[id]; + + /* Update TSS */ + memset((void *)tss_entry, 0, sizeof(tss32_t)); + tss_entry->ss0 = KERNEL_DS; + + /* Update descriptors for TSS and percpu data segment. */ + set_gdt_entry(TSS_MAIN + id * 8, + (unsigned long)tss_entry, 0xffff, 0x89, 0); + set_gdt_entry(TSS_MAIN + MAX_TEST_CPUS * 8 + id * 8, + (unsigned long)stacktop - 4096, 0xfffff, 0x93, 0xc0); + + return TSS_MAIN + id * 8; +} #endif void setup_multiboot(struct mbi_bootinfo *bi) diff --git a/x86/cstart.S b/x86/cstart.S index e9100a4..2c0eec7 100644 --- a/x86/cstart.S +++ b/x86/cstart.S @@ -23,50 +23,6 @@ i = 0 i = i + 1 .endr -.globl gdt -gdt: - .quad 0 - .quad 0x00cf9b000000ffff // flat 32-bit code segment - .quad 0x00cf93000000ffff // flat 32-bit data segment - .quad 0x00cf1b000000ffff // flat 32-bit code segment, not present - .quad 0 // TSS for task gates - .quad 0x008f9b000000FFFF // 16-bit code segment - .quad 0x008f93000000FFFF // 16-bit data segment - .quad 0x00cffb000000ffff // 32-bit code segment (user) - .quad 0x00cff3000000ffff // 32-bit data segment (user) - .quad 0 // unused - - .quad 0 // 6 spare selectors - .quad 0 - .quad 0 - .quad 0 - .quad 0 - .quad 0 - -tss_descr: - .rept max_cpus - .quad 0x000089000000ffff // 32-bit avail tss - .endr -percpu_descr: - .rept max_cpus - .quad 0x00cf93000000ffff // 32-bit data segment for perCPU area - .endr -gdt_end: - -i = 0 -.globl tss -tss: - .rept max_cpus - .long 0 - .long 0 - .long 16 - .quad 0, 0 - .quad 0, 0, 0, 0, 0, 0, 0, 0 - .long 0, 0, 0 - i = i + 1 - .endr -tss_end: - .section .init .code32 @@ -78,21 +34,14 @@ mb_flags = 0x0 .long mb_magic, mb_flags, 0 - (mb_magic + mb_flags) mb_cmdline = 16 -.macro setup_percpu_area - lea -4096(%esp), %eax - - /* fill GS_BASE in the GDT, do not clobber %ebx (multiboot info) */ - mov (APIC_DEFAULT_PHYS_BASE + APIC_ID), %ecx - shr $24, %ecx - mov %ax, percpu_descr+2(,%ecx,8) - - shr $16, %eax - mov %al, percpu_descr+4(,%ecx,8) - mov %ah, percpu_descr+7(,%ecx,8) - - lea percpu_descr-gdt(,%ecx,8), %eax +.macro setup_tr_and_percpu + lidt idt_descr + push %esp + call setup_tss + addl $4, %esp + ltr %ax + add $(max_cpus * 8), %ax mov %ax, %gs - .endm .macro setup_segments @@ -109,7 +58,6 @@ start: lgdtl gdt_descr setup_segments mov $stacktop, %esp - setup_percpu_area push %ebx call setup_multiboot @@ -147,11 +95,10 @@ ap_start32: setup_segments mov $-4096, %esp lock xaddl %esp, smp_stacktop - setup_percpu_area + setup_tr_and_percpu call prepare_32 call reset_apic call save_id - call load_tss call enable_apic call enable_x2apic sti @@ -162,9 +109,9 @@ ap_start32: jmp 1b start32: + setup_tr_and_percpu call reset_apic call save_id - call load_tss call mask_pic_interrupts call enable_apic call ap_init @@ -177,26 +124,9 @@ start32: push %eax call exit -load_tss: - lidt idt_descr - mov $16, %eax - mov %ax, %ss - mov (APIC_DEFAULT_PHYS_BASE + APIC_ID), %eax - shr $24, %eax - mov %eax, %ebx - mov $((tss_end - tss) / max_cpus), %edx - imul %edx - add $tss, %eax - mov %ax, tss_descr+2(,%ebx,8) - shr $16, %eax - mov %al, tss_descr+4(,%ebx,8) - mov %ah, tss_descr+7(,%ebx,8) - lea tss_descr-gdt(,%ebx,8), %eax - ltr %ax - ret - ap_init: cld + sgdtl ap_gdt_descr // must be close to sipi_entry for real mode access to work lea sipi_entry, %esi xor %edi, %edi mov $(sipi_end - sipi_entry), %ecx @@ -220,11 +150,11 @@ sipi_entry: mov %cr0, %eax or $1, %eax mov %eax, %cr0 - lgdtl gdt_descr - sipi_entry + lgdtl ap_gdt_descr - sipi_entry ljmpl $8, $ap_start32 -gdt_descr: - .word gdt_end - gdt - 1 - .long gdt +ap_gdt_descr: + .word 0 + .long 0 sipi_end: diff --git a/x86/cstart64.S b/x86/cstart64.S index c6daa34..ddb83a0 100644 --- a/x86/cstart64.S +++ b/x86/cstart64.S @@ -68,6 +68,7 @@ MSR_GS_BASE = 0xc0000101 .macro load_tss lidtq idt_descr + movq %rsp, %rdi call setup_tss ltr %ax .endm diff --git a/x86/smap.c b/x86/smap.c index ac2c8d5..c6ddf38 100644 --- a/x86/smap.c +++ b/x86/smap.c @@ -20,7 +20,7 @@ void do_pf_tss(unsigned long error_code) save = test; #ifndef __x86_64__ - tss.eflags |= X86_EFLAGS_AC; + tss[0].eflags |= X86_EFLAGS_AC; #endif } diff --git a/x86/taskswitch.c b/x86/taskswitch.c index 1d6e6e2..0d31149 100644 --- a/x86/taskswitch.c +++ b/x86/taskswitch.c @@ -19,7 +19,7 @@ fault_handler(unsigned long error_code) print_current_tss_info(); printf("error code %lx\n", error_code); - tss.eip += 2; + tss[0].eip += 2; gdt[TSS_MAIN / 8].type &= ~DESC_BUSY; diff --git a/x86/umip.c b/x86/umip.c index 54f3884..55332f8 100644 --- a/x86/umip.c +++ b/x86/umip.c @@ -161,7 +161,7 @@ static noinline int do_ring3(void (*fn)(const char *), const char *arg) #ifdef __x86_64__ [sp0] "=m" (tss[0].rsp0), #else - [sp0] "=m" (tss.esp0), + [sp0] "=m" (tss[0].esp0), #endif : [user_ds] "i" (USER_DS), [user_cs] "i" (USER_CS),

[kvm-unit-tests,9/9] x86: Move 32-bit GDT and TSS to desc.c

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