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-rw-r--r--drivers/lguest/lguest_asm.S93
1 files changed, 0 insertions, 93 deletions
diff --git a/drivers/lguest/lguest_asm.S b/drivers/lguest/lguest_asm.S
deleted file mode 100644
index 1ddcd5cd20f..00000000000
--- a/drivers/lguest/lguest_asm.S
+++ /dev/null
@@ -1,93 +0,0 @@
-#include <linux/linkage.h>
-#include <linux/lguest.h>
-#include <asm/asm-offsets.h>
-#include <asm/thread_info.h>
-#include <asm/processor-flags.h>
-
-/*G:020 This is where we begin: we have a magic signature which the launcher
- * looks for. The plan is that the Linux boot protocol will be extended with a
- * "platform type" field which will guide us here from the normal entry point,
- * but for the moment this suffices. The normal boot code uses %esi for the
- * boot header, so we do too. We convert it to a virtual address by adding
- * PAGE_OFFSET, and hand it to lguest_init() as its argument (ie. %eax).
- *
- * The .section line puts this code in .init.text so it will be discarded after
- * boot. */
-.section .init.text, "ax", @progbits
-.ascii "GenuineLguest"
- /* Set up initial stack. */
- movl $(init_thread_union+THREAD_SIZE),%esp
- movl %esi, %eax
- addl $__PAGE_OFFSET, %eax
- jmp lguest_init
-
-/*G:055 We create a macro which puts the assembler code between lgstart_ and
- * lgend_ markers. These templates are put in the .text section: they can't be
- * discarded after boot as we may need to patch modules, too. */
-.text
-#define LGUEST_PATCH(name, insns...) \
- lgstart_##name: insns; lgend_##name:; \
- .globl lgstart_##name; .globl lgend_##name
-
-LGUEST_PATCH(cli, movl $0, lguest_data+LGUEST_DATA_irq_enabled)
-LGUEST_PATCH(sti, movl $X86_EFLAGS_IF, lguest_data+LGUEST_DATA_irq_enabled)
-LGUEST_PATCH(popf, movl %eax, lguest_data+LGUEST_DATA_irq_enabled)
-LGUEST_PATCH(pushf, movl lguest_data+LGUEST_DATA_irq_enabled, %eax)
-/*:*/
-
-/* These demark the EIP range where host should never deliver interrupts. */
-.global lguest_noirq_start
-.global lguest_noirq_end
-
-/*M:004 When the Host reflects a trap or injects an interrupt into the Guest,
- * it sets the eflags interrupt bit on the stack based on
- * lguest_data.irq_enabled, so the Guest iret logic does the right thing when
- * restoring it. However, when the Host sets the Guest up for direct traps,
- * such as system calls, the processor is the one to push eflags onto the
- * stack, and the interrupt bit will be 1 (in reality, interrupts are always
- * enabled in the Guest).
- *
- * This turns out to be harmless: the only trap which should happen under Linux
- * with interrupts disabled is Page Fault (due to our lazy mapping of vmalloc
- * regions), which has to be reflected through the Host anyway. If another
- * trap *does* go off when interrupts are disabled, the Guest will panic, and
- * we'll never get to this iret! :*/
-
-/*G:045 There is one final paravirt_op that the Guest implements, and glancing
- * at it you can see why I left it to last. It's *cool*! It's in *assembler*!
- *
- * The "iret" instruction is used to return from an interrupt or trap. The
- * stack looks like this:
- * old address
- * old code segment & privilege level
- * old processor flags ("eflags")
- *
- * The "iret" instruction pops those values off the stack and restores them all
- * at once. The only problem is that eflags includes the Interrupt Flag which
- * the Guest can't change: the CPU will simply ignore it when we do an "iret".
- * So we have to copy eflags from the stack to lguest_data.irq_enabled before
- * we do the "iret".
- *
- * There are two problems with this: firstly, we need to use a register to do
- * the copy and secondly, the whole thing needs to be atomic. The first
- * problem is easy to solve: push %eax on the stack so we can use it, and then
- * restore it at the end just before the real "iret".
- *
- * The second is harder: copying eflags to lguest_data.irq_enabled will turn
- * interrupts on before we're finished, so we could be interrupted before we
- * return to userspace or wherever. Our solution to this is to surround the
- * code with lguest_noirq_start: and lguest_noirq_end: labels. We tell the
- * Host that it is *never* to interrupt us there, even if interrupts seem to be
- * enabled. */
-ENTRY(lguest_iret)
- pushl %eax
- movl 12(%esp), %eax
-lguest_noirq_start:
- /* Note the %ss: segment prefix here. Normal data accesses use the
- * "ds" segment, but that will have already been restored for whatever
- * we're returning to (such as userspace): we can't trust it. The %ss:
- * prefix makes sure we use the stack segment, which is still valid. */
- movl %eax,%ss:lguest_data+LGUEST_DATA_irq_enabled
- popl %eax
- iret
-lguest_noirq_end: