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>

1 files changed, 0 insertions, 304 deletions

diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
deleted file mode 100644
index 601f81c04873..000000000000
--- a/drivers/lguest/hypercalls.c
+++ /dev/null
@@ -1,304 +0,0 @@
-/*P:500
- * Just as userspace programs request kernel operations through a system
- * call, the Guest requests Host operations through a "hypercall".  You might
- * notice this nomenclature doesn't really follow any logic, but the name has
- * been around for long enough that we're stuck with it.  As you'd expect, this
- * code is basically a one big switch statement.
-:*/
-
-/*  Copyright (C) 2006 Rusty Russell IBM Corporation
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
-*/
-#include <linux/uaccess.h>
-#include <linux/syscalls.h>
-#include <linux/mm.h>
-#include <linux/ktime.h>
-#include <asm/page.h>
-#include <asm/pgtable.h>
-#include "lg.h"
-
-/*H:120
- * This is the core hypercall routine: where the Guest gets what it wants.
- * Or gets killed.  Or, in the case of LHCALL_SHUTDOWN, both.
- */
-static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
-{
-	switch (args->arg0) {
-	case LHCALL_FLUSH_ASYNC:
-		/*
-		 * This call does nothing, except by breaking out of the Guest
-		 * it makes us process all the asynchronous hypercalls.
-		 */
-		break;
-	case LHCALL_SEND_INTERRUPTS:
-		/*
-		 * This call does nothing too, but by breaking out of the Guest
-		 * it makes us process any pending interrupts.
-		 */
-		break;
-	case LHCALL_LGUEST_INIT:
-		/*
-		 * You can't get here unless you're already initialized.  Don't
-		 * do that.
-		 */
-		kill_guest(cpu, "already have lguest_data");
-		break;
-	case LHCALL_SHUTDOWN: {
-		char msg[128];
-		/*
-		 * Shutdown is such a trivial hypercall that we do it in five
-		 * lines right here.
-		 *
-		 * If the lgread fails, it will call kill_guest() itself; the
-		 * kill_guest() with the message will be ignored.
-		 */
-		__lgread(cpu, msg, args->arg1, sizeof(msg));
-		msg[sizeof(msg)-1] = '\0';
-		kill_guest(cpu, "CRASH: %s", msg);
-		if (args->arg2 == LGUEST_SHUTDOWN_RESTART)
-			cpu->lg->dead = ERR_PTR(-ERESTART);
-		break;
-	}
-	case LHCALL_FLUSH_TLB:
-		/* FLUSH_TLB comes in two flavors, depending on the argument: */
-		if (args->arg1)
-			guest_pagetable_clear_all(cpu);
-		else
-			guest_pagetable_flush_user(cpu);
-		break;
-
-	/*
-	 * All these calls simply pass the arguments through to the right
-	 * routines.
-	 */
-	case LHCALL_NEW_PGTABLE:
-		guest_new_pagetable(cpu, args->arg1);
-		break;
-	case LHCALL_SET_STACK:
-		guest_set_stack(cpu, args->arg1, args->arg2, args->arg3);
-		break;
-	case LHCALL_SET_PTE:
-#ifdef CONFIG_X86_PAE
-		guest_set_pte(cpu, args->arg1, args->arg2,
-				__pte(args->arg3 | (u64)args->arg4 << 32));
-#else
-		guest_set_pte(cpu, args->arg1, args->arg2, __pte(args->arg3));
-#endif
-		break;
-	case LHCALL_SET_PGD:
-		guest_set_pgd(cpu->lg, args->arg1, args->arg2);
-		break;
-#ifdef CONFIG_X86_PAE
-	case LHCALL_SET_PMD:
-		guest_set_pmd(cpu->lg, args->arg1, args->arg2);
-		break;
-#endif
-	case LHCALL_SET_CLOCKEVENT:
-		guest_set_clockevent(cpu, args->arg1);
-		break;
-	case LHCALL_HALT:
-		/* Similarly, this sets the halted flag for run_guest(). */
-		cpu->halted = 1;
-		break;
-	default:
-		/* It should be an architecture-specific hypercall. */
-		if (lguest_arch_do_hcall(cpu, args))
-			kill_guest(cpu, "Bad hypercall %li\n", args->arg0);
-	}
-}
-
-/*H:124
- * Asynchronous hypercalls are easy: we just look in the array in the
- * Guest's "struct lguest_data" to see if any new ones are marked "ready".
- *
- * We are careful to do these in order: obviously we respect the order the
- * Guest put them in the ring, but we also promise the Guest that they will
- * happen before any normal hypercall (which is why we check this before
- * checking for a normal hcall).
- */
-static void do_async_hcalls(struct lg_cpu *cpu)
-{
-	unsigned int i;
-	u8 st[LHCALL_RING_SIZE];
-
-	/* For simplicity, we copy the entire call status array in at once. */
-	if (copy_from_user(&st, &cpu->lg->lguest_data->hcall_status, sizeof(st)))
-		return;
-
-	/* We process "struct lguest_data"s hcalls[] ring once. */
-	for (i = 0; i < ARRAY_SIZE(st); i++) {
-		struct hcall_args args;
-		/*
-		 * We remember where we were up to from last time.  This makes
-		 * sure that the hypercalls are done in the order the Guest
-		 * places them in the ring.
-		 */
-		unsigned int n = cpu->next_hcall;
-
-		/* 0xFF means there's no call here (yet). */
-		if (st[n] == 0xFF)
-			break;
-
-		/*
-		 * OK, we have hypercall.  Increment the "next_hcall" cursor,
-		 * and wrap back to 0 if we reach the end.
-		 */
-		if (++cpu->next_hcall == LHCALL_RING_SIZE)
-			cpu->next_hcall = 0;
-
-		/*
-		 * Copy the hypercall arguments into a local copy of the
-		 * hcall_args struct.
-		 */
-		if (copy_from_user(&args, &cpu->lg->lguest_data->hcalls[n],
-				   sizeof(struct hcall_args))) {
-			kill_guest(cpu, "Fetching async hypercalls");
-			break;
-		}
-
-		/* Do the hypercall, same as a normal one. */
-		do_hcall(cpu, &args);
-
-		/* Mark the hypercall done. */
-		if (put_user(0xFF, &cpu->lg->lguest_data->hcall_status[n])) {
-			kill_guest(cpu, "Writing result for async hypercall");
-			break;
-		}
-
-		/*
-		 * Stop doing hypercalls if they want to notify the Launcher:
-		 * it needs to service this first.
-		 */
-		if (cpu->pending.trap)
-			break;
-	}
-}
-
-/*
- * Last of all, we look at what happens first of all.  The very first time the
- * Guest makes a hypercall, we end up here to set things up:
- */
-static void initialize(struct lg_cpu *cpu)
-{
-	/*
-	 * You can't do anything until you're initialized.  The Guest knows the
-	 * rules, so we're unforgiving here.
-	 */
-	if (cpu->hcall->arg0 != LHCALL_LGUEST_INIT) {
-		kill_guest(cpu, "hypercall %li before INIT", cpu->hcall->arg0);
-		return;
-	}
-
-	if (lguest_arch_init_hypercalls(cpu))
-		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
-
-	/*
-	 * The Guest tells us where we're not to deliver interrupts by putting
-	 * the instruction address into "struct lguest_data".
-	 */
-	if (get_user(cpu->lg->noirq_iret, &cpu->lg->lguest_data->noirq_iret))
-		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
-
-	/*
-	 * We write the current time into the Guest's data page once so it can
-	 * set its clock.
-	 */
-	write_timestamp(cpu);
-
-	/* page_tables.c will also do some setup. */
-	page_table_guest_data_init(cpu);
-
-	/*
-	 * This is the one case where the above accesses might have been the
-	 * first write to a Guest page.  This may have caused a copy-on-write
-	 * fault, but the old page might be (read-only) in the Guest
-	 * pagetable.
-	 */
-	guest_pagetable_clear_all(cpu);
-}
-/*:*/
-
-/*M:013
- * If a Guest reads from a page (so creates a mapping) that it has never
- * written to, and then the Launcher writes to it (ie. the output of a virtual
- * device), the Guest will still see the old page.  In practice, this never
- * happens: why would the Guest read a page which it has never written to?  But
- * a similar scenario might one day bite us, so it's worth mentioning.
- *
- * Note that if we used a shared anonymous mapping in the Launcher instead of
- * mapping /dev/zero private, we wouldn't worry about cop-on-write.  And we
- * need that to switch the Launcher to processes (away from threads) anyway.
-:*/
-
-/*H:100
- * Hypercalls
- *
- * Remember from the Guest, hypercalls come in two flavors: normal and
- * asynchronous.  This file handles both of types.
- */
-void do_hypercalls(struct lg_cpu *cpu)
-{
-	/* Not initialized yet?  This hypercall must do it. */
-	if (unlikely(!cpu->lg->lguest_data)) {
-		/* Set up the "struct lguest_data" */
-		initialize(cpu);
-		/* Hcall is done. */
-		cpu->hcall = NULL;
-		return;
-	}
-
-	/*
-	 * The Guest has initialized.
-	 *
-	 * Look in the hypercall ring for the async hypercalls:
-	 */
-	do_async_hcalls(cpu);
-
-	/*
-	 * If we stopped reading the hypercall ring because the Guest did a
-	 * NOTIFY to the Launcher, we want to return now.  Otherwise we do
-	 * the hypercall.
-	 */
-	if (!cpu->pending.trap) {
-		do_hcall(cpu, cpu->hcall);
-		/*
-		 * Tricky point: we reset the hcall pointer to mark the
-		 * hypercall as "done".  We use the hcall pointer rather than
-		 * the trap number to indicate a hypercall is pending.
-		 * Normally it doesn't matter: the Guest will run again and
-		 * update the trap number before we come back here.
-		 *
-		 * However, if we are signalled or the Guest sends I/O to the
-		 * Launcher, the run_guest() loop will exit without running the
-		 * Guest.  When it comes back it would try to re-run the
-		 * hypercall.  Finding that bug sucked.
-		 */
-		cpu->hcall = NULL;
-	}
-}
-
-/*
- * This routine supplies the Guest with time: it's used for wallclock time at
- * initial boot and as a rough time source if the TSC isn't available.
- */
-void write_timestamp(struct lg_cpu *cpu)
-{
-	struct timespec now;
-	ktime_get_real_ts(&now);
-	if (copy_to_user(&cpu->lg->lguest_data->time,
-			 &now, sizeof(struct timespec)))
-		kill_guest(cpu, "Writing timestamp");
-}