145 lines
4.3 KiB
C
145 lines
4.3 KiB
C
/*
|
|
* Copyright (C) 2018 Intel Corporation. All rights reserved.
|
|
*
|
|
* SPDX-License-Identifier: BSD-3-Clause
|
|
*/
|
|
|
|
#ifndef GDT_H
|
|
#define GDT_H
|
|
|
|
/* GDT is defined in assembly so it can be used to switch modes before long mode
|
|
* is established.
|
|
* With 64-bit EFI this is not required since are already in long mode when EFI
|
|
* transfers control to the hypervisor. However, for any instantiation of the
|
|
* ACRN Hypervisor that requires a boot from reset the GDT will be
|
|
* used as mode transitions are being made to ultimately end up in long mode.
|
|
* For this reason we establish the GDT in assembly.
|
|
* This should not affect usage and convenience of interacting with the GDT in C
|
|
* as the complete definition of the GDT is driven by the defines in this file.
|
|
*
|
|
* Unless it proves to be not viable we will use a single GDT for all hypervisor
|
|
* CPUs, with space for per CPU LDT and TSS.
|
|
*/
|
|
|
|
/*
|
|
* Segment selectors in x86-64 and i386 are the same size, 8 bytes.
|
|
* Local Descriptor Table (LDT) selectors are 16 bytes on x86-64 instead of 8
|
|
* bytes.
|
|
* Task State Segment (TSS) selectors are 16 bytes on x86-64 instead of 8 bytes.
|
|
*/
|
|
#define X64_SEG_DESC_SIZE (0x8U) /* In long mode SEG Descriptors are 8 bytes */
|
|
#define X64_LDT_DESC_SIZE (0x10U)/* In long mode LDT Descriptors are 16 bytes */
|
|
#define X64_TSS_DESC_SIZE (0x10U)/* In long mode TSS Descriptors are 16 bytes */
|
|
|
|
/*****************************************************************************
|
|
*
|
|
* BEGIN: Definition of the GDT.
|
|
*
|
|
* NOTE:
|
|
* If you change the size of the GDT or rearrange the location of descriptors
|
|
* within the GDT you must change both the defines and the C structure header.
|
|
*
|
|
*****************************************************************************/
|
|
/* Number of global 8 byte segments descriptor(s) */
|
|
#define HOST_GDT_RING0_SEG_SELECTORS (0x3U) /* rsvd, code, data */
|
|
/* Offsets of global 8 byte segment descriptors */
|
|
#define HOST_GDT_RING0_RSVD_SEL (0x0000U)
|
|
#define HOST_GDT_RING0_CODE_SEL (0x0008U)
|
|
#define HOST_GDT_RING0_DATA_SEL (0x0010U)
|
|
/* Number of global 16 byte LDT descriptor(s) */
|
|
#define HOST_GDT_RING0_TSS_SELECTORS (0x1U)
|
|
/* One for each CPU in the hypervisor. */
|
|
|
|
/*****************************************************************************
|
|
*
|
|
* END: Definition of the GDT.
|
|
*
|
|
*****************************************************************************/
|
|
|
|
/* Offset to start of LDT Descriptors */
|
|
#define HOST_GDT_RING0_LDT_SEL \
|
|
(HOST_GDT_RING0_SEG_SELECTORS * X64_SEG_DESC_SIZE)
|
|
/* Offset to start of LDT Descriptors */
|
|
#define HOST_GDT_RING0_CPU_TSS_SEL (HOST_GDT_RING0_LDT_SEL)
|
|
/* Size of the GDT */
|
|
#define HOST_GDT_SIZE \
|
|
(HOST_GDT_RING0_CPU_TSS_SEL + \
|
|
(HOST_GDT_RING0_TSS_SELECTORS * X64_TSS_DESC_SIZE))
|
|
|
|
#ifndef ASSEMBLER
|
|
|
|
#include <types.h>
|
|
#include <asm/cpu.h>
|
|
|
|
#define TSS_AVAIL (9U)
|
|
|
|
/*
|
|
* Definition of 16 byte TSS and LDT selectors.
|
|
*/
|
|
struct tss_64_descriptor {
|
|
uint32_t low32_value;
|
|
uint32_t high32_value;
|
|
uint32_t base_addr_63_32;
|
|
uint32_t offset_12;
|
|
} __aligned(8);
|
|
|
|
/*****************************************************************************
|
|
*
|
|
* BEGIN: Definition of the GDT.
|
|
*
|
|
* NOTE:
|
|
* If you change the size of the GDT or rearrange the location of descriptors
|
|
* within the GDT you must change both the defines and the C structure header.
|
|
*
|
|
*****************************************************************************/
|
|
struct host_gdt {
|
|
uint64_t rsvd;
|
|
|
|
uint64_t code_segment_descriptor;
|
|
uint64_t data_segment_descriptor;
|
|
struct tss_64_descriptor host_gdt_tss_descriptors;
|
|
} __aligned(8);
|
|
|
|
/*****************************************************************************
|
|
*
|
|
* END: Definition of the GDT.
|
|
*
|
|
*****************************************************************************/
|
|
|
|
/*
|
|
* x86-64 Task State Segment (TSS) definition.
|
|
*/
|
|
struct tss_64 {
|
|
uint32_t rsvd1;
|
|
uint64_t rsp0;
|
|
uint64_t rsp1;
|
|
uint64_t rsp2;
|
|
uint32_t rsvd2;
|
|
uint32_t rsvd3;
|
|
uint64_t ist1;
|
|
uint64_t ist2;
|
|
uint64_t ist3;
|
|
uint64_t ist4;
|
|
uint64_t ist5;
|
|
uint64_t ist6;
|
|
uint64_t ist7;
|
|
uint32_t rsvd4;
|
|
uint32_t rsvd5;
|
|
uint16_t rsvd6;
|
|
uint16_t io_map_base_addr;
|
|
} __packed __aligned(16);
|
|
|
|
/*
|
|
* Definition of the GDT descriptor.
|
|
*/
|
|
struct host_gdt_descriptor {
|
|
uint16_t len;
|
|
struct host_gdt *gdt;
|
|
} __packed;
|
|
|
|
void load_gdtr_and_tr(void);
|
|
|
|
#endif /* end #ifndef ASSEMBLER */
|
|
|
|
#endif /* GDT_H */
|