arch/x86/include/asm/io_bitmap.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_IOBITMAP_H
   3 #define _ASM_X86_IOBITMAP_H
   4
   5 #include <linux/refcount.h>
   6 #include <asm/processor.h>
   7
   8 struct io_bitmap {
   9         u64             sequence;
  10         refcount_t      refcnt;
  11         /* The maximum number of bytes to copy so all zero bits are covered */
  12         unsigned int    max;
  13         unsigned long   bitmap[IO_BITMAP_LONGS];
  14 };
  15
  16 struct task_struct;
  17
  18 #ifdef CONFIG_X86_IOPL_IOPERM
  19 void io_bitmap_share(struct task_struct *tsk);
  20 void io_bitmap_exit(struct task_struct *tsk);
  21
  22 static inline void native_tss_invalidate_io_bitmap(void)
  23 {
  24         /*
  25          * Invalidate the I/O bitmap by moving io_bitmap_base outside the
  26          * TSS limit so any subsequent I/O access from user space will
  27          * trigger a #GP.
  28          *
  29          * This is correct even when VMEXIT rewrites the TSS limit
  30          * to 0x67 as the only requirement is that the base points
  31          * outside the limit.
  32          */
  33         this_cpu_write(cpu_tss_rw.x86_tss.io_bitmap_base,
  34                        IO_BITMAP_OFFSET_INVALID);
  35 }
  36
  37 void native_tss_update_io_bitmap(void);
  38
  39 #ifdef CONFIG_PARAVIRT_XXL
  40 #include <asm/paravirt.h>
  41 #else
  42 #define tss_update_io_bitmap native_tss_update_io_bitmap
  43 #define tss_invalidate_io_bitmap native_tss_invalidate_io_bitmap
  44 #endif
  45
  46 #else
  47 static inline void io_bitmap_share(struct task_struct *tsk) { }
  48 static inline void io_bitmap_exit(struct task_struct *tsk) { }
  49 static inline void tss_update_io_bitmap(void) { }
  50 #endif
  51
  52 #endif