From: "H. Peter Anvin (Intel)" <hpa@xxxxxxxxx> Add a header file for FRED prototypes and definitions. Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx> Tested-by: Shan Kang <shan.kang@xxxxxxxxx> Signed-off-by: Xin Li <xin3.li@xxxxxxxxx> --- Changes since v6: * Replace pt_regs csx flags prefix FRED_CSL_ with FRED_CSX_. --- arch/x86/include/asm/fred.h | 106 ++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 arch/x86/include/asm/fred.h diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h new file mode 100644 index 000000000000..b59397411ab9 --- /dev/null +++ b/arch/x86/include/asm/fred.h @@ -0,0 +1,106 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * arch/x86/include/asm/fred.h + * + * Macros for Flexible Return and Event Delivery (FRED) + */ + +#ifndef ASM_X86_FRED_H +#define ASM_X86_FRED_H + +#ifdef CONFIG_X86_FRED + +#include <linux/const.h> +#include <asm/asm.h> + +/* + * FRED return instructions + * + * Replace with "ERETS"/"ERETU" once binutils support FRED return instructions. + * The binutils version supporting FRED instructions is still TBD, and will + * update once we have it. + */ +#define ERETS _ASM_BYTES(0xf2,0x0f,0x01,0xca) +#define ERETU _ASM_BYTES(0xf3,0x0f,0x01,0xca) + +/* + * RSP is aligned to a 64-byte boundary before used to push a new stack frame + */ +#define FRED_STACK_FRAME_RSP_MASK _AT(unsigned long, (~0x3f)) + +/* + * Event stack level macro for the FRED_STKLVLS MSR. + * Usage example: FRED_STKLVL(X86_TRAP_DF, 3) + * Multiple values can be ORd together. + */ +#define FRED_STKLVL(v,l) (_AT(unsigned long, l) << (2*(v))) + +/* FRED_CONFIG MSR */ +#define FRED_CONFIG_CSL_MASK 0x3 +#define FRED_CONFIG_REDZONE_AMOUNT 1 /* measured in 64-byte cache lines */ +#define FRED_CONFIG_REDZONE (_AT(unsigned long, FRED_CONFIG_REDZONE_AMOUNT) << 6) +#define FRED_CONFIG_INT_STKLVL(l) (_AT(unsigned long, l) << 9) +#define FRED_CONFIG_ENTRYPOINT(p) _AT(unsigned long, (p)) + +/* FRED event type and vector bit width and counts */ +#define FRED_EVENT_TYPE_BITS 3 /* only 3 bits used in FRED 3.0 */ +#define FRED_EVENT_TYPE_COUNT _BITUL(FRED_EVENT_TYPE_BITS) +#define FRED_EVENT_VECTOR_BITS 8 +#define FRED_EVENT_VECTOR_COUNT _BITUL(FRED_EVENT_VECTOR_BITS) + +/* FRED EVENT_TYPE_OTHER vector numbers */ +#define FRED_SYSCALL 1 +#define FRED_SYSENTER 2 + +/* Flags above the CS selector (regs->csx) */ +#define FRED_CSX_ENABLE_NMI _BITUL(28) +#define FRED_CSX_ALLOW_SINGLE_STEP _BITUL(25) +#define FRED_CSX_INTERRUPT_SHADOW _BITUL(24) + +#ifndef __ASSEMBLY__ + +#include <linux/kernel.h> +#include <asm/ptrace.h> + +/* FRED stack frame information */ +struct fred_info { + unsigned long edata; /* Event data: CR2, DR6, ... */ + unsigned long resv; +}; + +/* Full format of the FRED stack frame */ +struct fred_frame { + struct pt_regs regs; + struct fred_info info; +}; + +/* Getting the FRED frame information from a pt_regs pointer */ +static __always_inline struct fred_info *fred_info(struct pt_regs *regs) +{ + return &container_of(regs, struct fred_frame, regs)->info; +} + +static __always_inline unsigned long fred_event_data(struct pt_regs *regs) +{ + return fred_info(regs)->edata; +} + +/* + * How FRED event handlers are called. + * + * FRED event delivery establishes the full supervisor context + * by pushing everything related to the event being delivered + * to the FRED stack frame, e.g., the faulting linear address + * of a #PF is pushed as event data of the FRED #PF stack frame. + * Thus a struct pt_regs has everything needed and it's the only + * input parameter required for a FRED event handler. + */ +#define DECLARE_FRED_HANDLER(f) void f (struct pt_regs *regs) +#define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f) +typedef DECLARE_FRED_HANDLER((*fred_handler)); + +#endif /* __ASSEMBLY__ */ + +#endif /* CONFIG_X86_FRED */ + +#endif /* ASM_X86_FRED_H */ -- 2.34.1