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-rw-r--r--arch/x86/include/asm/io_bitmap.h52
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