x86/lguest: Remove lguest support

Lguest seems to be rather unused these days. It has seen only patches
ensuring it still builds the last two years and its official state is
"Odd Fixes".

Remove it in order to be able to clean up the paravirt code.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: boris.ostrovsky@oracle.com
Cc: lguest@lists.ozlabs.org
Cc: rusty@rustcorp.com.au
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170816173157.8633-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 1 insertions, 166 deletions

diff --git a/arch/x86/include/asm/lguest.h b/arch/x86/include/asm/lguest.h
deleted file mode 100644
index 73d0c9b92087..000000000000
--- a/arch/x86/include/asm/lguest.h
+++ /dev/null
@@ -1,91 +0,0 @@
-#ifndef _ASM_X86_LGUEST_H
-#define _ASM_X86_LGUEST_H
-
-#define GDT_ENTRY_LGUEST_CS	10
-#define GDT_ENTRY_LGUEST_DS	11
-#define LGUEST_CS		(GDT_ENTRY_LGUEST_CS * 8)
-#define LGUEST_DS		(GDT_ENTRY_LGUEST_DS * 8)
-
-#ifndef __ASSEMBLY__
-#include <asm/desc.h>
-
-#define GUEST_PL 1
-
-/* Page for Switcher text itself, then two pages per cpu */
-#define SWITCHER_TEXT_PAGES (1)
-#define SWITCHER_STACK_PAGES (2 * nr_cpu_ids)
-#define TOTAL_SWITCHER_PAGES (SWITCHER_TEXT_PAGES + SWITCHER_STACK_PAGES)
-
-/* Where we map the Switcher, in both Host and Guest. */
-extern unsigned long switcher_addr;
-
-/* Found in switcher.S */
-extern unsigned long default_idt_entries[];
-
-/* Declarations for definitions in arch/x86/lguest/head_32.S */
-extern char lguest_noirq_iret[];
-extern const char lgstart_cli[], lgend_cli[];
-extern const char lgstart_pushf[], lgend_pushf[];
-
-extern void lguest_iret(void);
-extern void lguest_init(void);
-
-struct lguest_regs {
-	/* Manually saved part. */
-	unsigned long eax, ebx, ecx, edx;
-	unsigned long esi, edi, ebp;
-	unsigned long gs;
-	unsigned long fs, ds, es;
-	unsigned long trapnum, errcode;
-	/* Trap pushed part */
-	unsigned long eip;
-	unsigned long cs;
-	unsigned long eflags;
-	unsigned long esp;
-	unsigned long ss;
-};
-
-/* This is a guest-specific page (mapped ro) into the guest. */
-struct lguest_ro_state {
-	/* Host information we need to restore when we switch back. */
-	u32 host_cr3;
-	struct desc_ptr host_idt_desc;
-	struct desc_ptr host_gdt_desc;
-	u32 host_sp;
-
-	/* Fields which are used when guest is running. */
-	struct desc_ptr guest_idt_desc;
-	struct desc_ptr guest_gdt_desc;
-	struct x86_hw_tss guest_tss;
-	struct desc_struct guest_idt[IDT_ENTRIES];
-	struct desc_struct guest_gdt[GDT_ENTRIES];
-};
-
-struct lg_cpu_arch {
-	/* The GDT entries copied into lguest_ro_state when running. */
-	struct desc_struct gdt[GDT_ENTRIES];
-
-	/* The IDT entries: some copied into lguest_ro_state when running. */
-	struct desc_struct idt[IDT_ENTRIES];
-
-	/* The address of the last guest-visible pagefault (ie. cr2). */
-	unsigned long last_pagefault;
-};
-
-static inline void lguest_set_ts(void)
-{
-	u32 cr0;
-
-	cr0 = read_cr0();
-	if (!(cr0 & 8))
-		write_cr0(cr0 | 8);
-}
-
-/* Full 4G segment descriptors, suitable for CS and DS. */
-#define FULL_EXEC_SEGMENT \
-	((struct desc_struct)GDT_ENTRY_INIT(0xc09b, 0, 0xfffff))
-#define FULL_SEGMENT ((struct desc_struct)GDT_ENTRY_INIT(0xc093, 0, 0xfffff))
-
-#endif /* __ASSEMBLY__ */
-
-#endif /* _ASM_X86_LGUEST_H */
diff --git a/arch/x86/include/asm/lguest_hcall.h b/arch/x86/include/asm/lguest_hcall.h
deleted file mode 100644
index 6c119cfae218..000000000000
--- a/arch/x86/include/asm/lguest_hcall.h
+++ /dev/null
@@ -1,74 +0,0 @@
-/* Architecture specific portion of the lguest hypercalls */
-#ifndef _ASM_X86_LGUEST_HCALL_H
-#define _ASM_X86_LGUEST_HCALL_H
-
-#define LHCALL_FLUSH_ASYNC	0
-#define LHCALL_LGUEST_INIT	1
-#define LHCALL_SHUTDOWN		2
-#define LHCALL_NEW_PGTABLE	4
-#define LHCALL_FLUSH_TLB	5
-#define LHCALL_LOAD_IDT_ENTRY	6
-#define LHCALL_SET_STACK	7
-#define LHCALL_SET_CLOCKEVENT	9
-#define LHCALL_HALT		10
-#define LHCALL_SET_PMD		13
-#define LHCALL_SET_PTE		14
-#define LHCALL_SET_PGD		15
-#define LHCALL_LOAD_TLS		16
-#define LHCALL_LOAD_GDT_ENTRY	18
-#define LHCALL_SEND_INTERRUPTS	19
-
-#define LGUEST_TRAP_ENTRY 0x1F
-
-/* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */
-#define LGUEST_SHUTDOWN_POWEROFF	1
-#define LGUEST_SHUTDOWN_RESTART		2
-
-#ifndef __ASSEMBLY__
-#include <asm/hw_irq.h>
-
-/*G:030
- * But first, how does our Guest contact the Host to ask for privileged
- * operations?  There are two ways: the direct way is to make a "hypercall",
- * to make requests of the Host Itself.
- *
- * Our hypercall mechanism uses the highest unused trap code (traps 32 and
- * above are used by real hardware interrupts).  Seventeen hypercalls are
- * available: the hypercall number is put in the %eax register, and the
- * arguments (when required) are placed in %ebx, %ecx, %edx and %esi.
- * If a return value makes sense, it's returned in %eax.
- *
- * Grossly invalid calls result in Sudden Death at the hands of the vengeful
- * Host, rather than returning failure.  This reflects Winston Churchill's
- * definition of a gentleman: "someone who is only rude intentionally".
- */
-static inline unsigned long
-hcall(unsigned long call,
-      unsigned long arg1, unsigned long arg2, unsigned long arg3,
-      unsigned long arg4)
-{
-	/* "int" is the Intel instruction to trigger a trap. */
-	asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
-		     /* The call in %eax (aka "a") might be overwritten */
-		     : "=a"(call)
-		       /* The arguments are in %eax, %ebx, %ecx, %edx & %esi */
-		     : "a"(call), "b"(arg1), "c"(arg2), "d"(arg3), "S"(arg4)
-		       /* "memory" means this might write somewhere in memory.
-			* This isn't true for all calls, but it's safe to tell
-			* gcc that it might happen so it doesn't get clever. */
-		     : "memory");
-	return call;
-}
-/*:*/
-
-/* Can't use our min() macro here: needs to be a constant */
-#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
-
-#define LHCALL_RING_SIZE 64
-struct hcall_args {
-	/* These map directly onto eax/ebx/ecx/edx/esi in struct lguest_regs */
-	unsigned long arg0, arg1, arg2, arg3, arg4;
-};
-
-#endif /* !__ASSEMBLY__ */
-#endif /* _ASM_X86_LGUEST_HCALL_H */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 0b03d655db7c..abc99b9c7ffd 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -662,7 +662,7 @@ static inline void sync_core(void)
 	 * In case NMI unmasking or performance ever becomes a problem,
 	 * the next best option appears to be MOV-to-CR2 and an
 	 * unconditional jump.  That sequence also works on all CPUs,
-	 * but it will fault at CPL3 (i.e. Xen PV and lguest).
+	 * but it will fault at CPL3 (i.e. Xen PV).
 	 *
 	 * CPUID is the conventional way, but it's nasty: it doesn't
 	 * exist on some 486-like CPUs, and it usually exits to a