diff options
Diffstat (limited to 'arch/x86/include/asm/io_bitmap.h')
| -rw-r--r-- | arch/x86/include/asm/io_bitmap.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/arch/x86/include/asm/io_bitmap.h b/arch/x86/include/asm/io_bitmap.h new file mode 100644 index 000000000..7f080f5c7 --- /dev/null +++ b/arch/x86/include/asm/io_bitmap.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_IOBITMAP_H +#define _ASM_X86_IOBITMAP_H + +#include <linux/refcount.h> +#include <asm/processor.h> + +struct io_bitmap { + u64 sequence; + refcount_t refcnt; + /* The maximum number of bytes to copy so all zero bits are covered */ + unsigned int max; + unsigned long bitmap[IO_BITMAP_LONGS]; +}; + +struct task_struct; + +#ifdef CONFIG_X86_IOPL_IOPERM +void io_bitmap_share(struct task_struct *tsk); +void io_bitmap_exit(struct task_struct *tsk); + +static inline void native_tss_invalidate_io_bitmap(void) +{ + /* + * Invalidate the I/O bitmap by moving io_bitmap_base outside the + * TSS limit so any subsequent I/O access from user space will + * trigger a #GP. + * + * This is correct even when VMEXIT rewrites the TSS limit + * to 0x67 as the only requirement is that the base points + * outside the limit. + */ + this_cpu_write(cpu_tss_rw.x86_tss.io_bitmap_base, + IO_BITMAP_OFFSET_INVALID); +} + +void native_tss_update_io_bitmap(void); + +#ifdef CONFIG_PARAVIRT_XXL +#include <asm/paravirt.h> +#else +#define tss_update_io_bitmap native_tss_update_io_bitmap +#define tss_invalidate_io_bitmap native_tss_invalidate_io_bitmap +#endif + +#else +static inline void io_bitmap_share(struct task_struct *tsk) { } +static inline void io_bitmap_exit(struct task_struct *tsk) { } +static inline void tss_update_io_bitmap(void) { } +#endif + +#endif |