1 files changed, 58 insertions, 119 deletions

diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index db6caac..9d5184c 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -25,17 +25,13 @@
 #include <linux/mm.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
-#include <irq_vectors.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_CRASH, both.
- *
- * Remember from the Guest: %eax == which call to make, and the arguments are
- * packed into %edx, %ebx and %ecx if needed. */
-static void do_hcall(struct lguest *lg, struct lguest_regs *regs)
+/*H:120 This is the core hypercall routine: where the Guest gets what it wants.
+ * Or gets killed.  Or, in the case of LHCALL_CRASH, both. */
+static void do_hcall(struct lguest *lg, struct hcall_args *args)
 {
-	switch (regs->eax) {
+	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. */
@@ -51,7 +47,7 @@ static void do_hcall(struct lguest *lg, struct lguest_regs *regs)
 		char msg[128];
 		/* If the lgread fails, it will call kill_guest() itself; the
 		 * kill_guest() with the message will be ignored. */
-		lgread(lg, msg, regs->edx, sizeof(msg));
+		__lgread(lg, msg, args->arg1, sizeof(msg));
 		msg[sizeof(msg)-1] = '\0';
 		kill_guest(lg, "CRASH: %s", msg);
 		break;
@@ -59,67 +55,49 @@ static void do_hcall(struct lguest *lg, struct lguest_regs *regs)
 	case LHCALL_FLUSH_TLB:
 		/* FLUSH_TLB comes in two flavors, depending on the
 		 * argument: */
-		if (regs->edx)
+		if (args->arg1)
 			guest_pagetable_clear_all(lg);
 		else
 			guest_pagetable_flush_user(lg);
 		break;
-	case LHCALL_BIND_DMA:
-		/* BIND_DMA really wants four arguments, but it's the only call
-		 * which does.  So the Guest packs the number of buffers and
-		 * the interrupt number into the final argument, and we decode
-		 * it here.  This can legitimately fail, since we currently
-		 * place a limit on the number of DMA pools a Guest can have.
-		 * So we return true or false from this call. */
-		regs->eax = bind_dma(lg, regs->edx, regs->ebx,
-				     regs->ecx >> 8, regs->ecx & 0xFF);
-		break;
 
 	/* All these calls simply pass the arguments through to the right
 	 * routines. */
-	case LHCALL_SEND_DMA:
-		send_dma(lg, regs->edx, regs->ebx);
-		break;
-	case LHCALL_LOAD_GDT:
-		load_guest_gdt(lg, regs->edx, regs->ebx);
-		break;
-	case LHCALL_LOAD_IDT_ENTRY:
-		load_guest_idt_entry(lg, regs->edx, regs->ebx, regs->ecx);
-		break;
 	case LHCALL_NEW_PGTABLE:
-		guest_new_pagetable(lg, regs->edx);
+		guest_new_pagetable(lg, args->arg1);
 		break;
 	case LHCALL_SET_STACK:
-		guest_set_stack(lg, regs->edx, regs->ebx, regs->ecx);
+		guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
 		break;
 	case LHCALL_SET_PTE:
-		guest_set_pte(lg, regs->edx, regs->ebx, mkgpte(regs->ecx));
+		guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
 		break;
 	case LHCALL_SET_PMD:
-		guest_set_pmd(lg, regs->edx, regs->ebx);
-		break;
-	case LHCALL_LOAD_TLS:
-		guest_load_tls(lg, regs->edx);
+		guest_set_pmd(lg, args->arg1, args->arg2);
 		break;
 	case LHCALL_SET_CLOCKEVENT:
-		guest_set_clockevent(lg, regs->edx);
+		guest_set_clockevent(lg, args->arg1);
 		break;
-
 	case LHCALL_TS:
 		/* This sets the TS flag, as we saw used in run_guest(). */
-		lg->ts = regs->edx;
+		lg->ts = args->arg1;
 		break;
 	case LHCALL_HALT:
 		/* Similarly, this sets the halted flag for run_guest(). */
 		lg->halted = 1;
 		break;
+	case LHCALL_NOTIFY:
+		lg->pending_notify = args->arg1;
+		break;
 	default:
-		kill_guest(lg, "Bad hypercall %li\n", regs->eax);
+		if (lguest_arch_do_hcall(lg, args))
+			kill_guest(lg, "Bad hypercall %li\n", args->arg0);
 	}
 }
+/*:*/
 
-/* Asynchronous hypercalls are easy: we just look in the array in the Guest's
- * "struct lguest_data" and see if there are any new ones marked "ready".
+/*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
@@ -134,10 +112,9 @@ static void do_async_hcalls(struct lguest *lg)
 	if (copy_from_user(&st, &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 lguest_regs regs;
+		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. */
@@ -152,18 +129,16 @@ static void do_async_hcalls(struct lguest *lg)
 		if (++lg->next_hcall == LHCALL_RING_SIZE)
 			lg->next_hcall = 0;
 
-		/* We copy the hypercall arguments into a fake register
-		 * structure.  This makes life simple for do_hcall(). */
-		if (get_user(regs.eax, &lg->lguest_data->hcalls[n].eax)
-		    || get_user(regs.edx, &lg->lguest_data->hcalls[n].edx)
-		    || get_user(regs.ecx, &lg->lguest_data->hcalls[n].ecx)
-		    || get_user(regs.ebx, &lg->lguest_data->hcalls[n].ebx)) {
+		/* Copy the hypercall arguments into a local copy of
+		 * the hcall_args struct. */
+		if (copy_from_user(&args, &lg->lguest_data->hcalls[n],
+				   sizeof(struct hcall_args))) {
 			kill_guest(lg, "Fetching async hypercalls");
 			break;
 		}
 
 		/* Do the hypercall, same as a normal one. */
-		do_hcall(lg, &regs);
+		do_hcall(lg, &args);
 
 		/* Mark the hypercall done. */
 		if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
@@ -171,9 +146,9 @@ static void do_async_hcalls(struct lguest *lg)
 			break;
 		}
 
- 		/* Stop doing hypercalls if we've just done a DMA to the
-		 * Launcher: it needs to service this first. */
-		if (lg->dma_is_pending)
+		/* Stop doing hypercalls if they want to notify the Launcher:
+		 * it needs to service this first. */
+		if (lg->pending_notify)
 			break;
 	}
 }
@@ -182,76 +157,35 @@ static void do_async_hcalls(struct lguest *lg)
  * Guest makes a hypercall, we end up here to set things up: */
 static void initialize(struct lguest *lg)
 {
-	u32 tsc_speed;
 
 	/* You can't do anything until you're initialized.  The Guest knows the
 	 * rules, so we're unforgiving here. */
-	if (lg->regs->eax != LHCALL_LGUEST_INIT) {
-		kill_guest(lg, "hypercall %li before LGUEST_INIT",
-			   lg->regs->eax);
+	if (lg->hcall->arg0 != LHCALL_LGUEST_INIT) {
+		kill_guest(lg, "hypercall %li before INIT", lg->hcall->arg0);
 		return;
 	}
 
-	/* We insist that the Time Stamp Counter exist and doesn't change with
-	 * cpu frequency.  Some devious chip manufacturers decided that TSC
-	 * changes could be handled in software.  I decided that time going
-	 * backwards might be good for benchmarks, but it's bad for users.
-	 *
-	 * We also insist that the TSC be stable: the kernel detects unreliable
-	 * TSCs for its own purposes, and we use that here. */
-	if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable())
-		tsc_speed = tsc_khz;
-	else
-		tsc_speed = 0;
-
-	/* The pointer to the Guest's "struct lguest_data" is the only
-	 * argument. */
-	lg->lguest_data = (struct lguest_data __user *)lg->regs->edx;
-	/* If we check the address they gave is OK now, we can simply
-	 * copy_to_user/from_user from now on rather than using lgread/lgwrite.
-	 * I put this in to show that I'm not immune to writing stupid
-	 * optimizations. */
-	if (!lguest_address_ok(lg, lg->regs->edx, sizeof(*lg->lguest_data))) {
+	if (lguest_arch_init_hypercalls(lg))
 		kill_guest(lg, "bad guest page %p", lg->lguest_data);
-		return;
-	}
+
 	/* The Guest tells us where we're not to deliver interrupts by putting
 	 * the range of addresses into "struct lguest_data". */
 	if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
-	    || get_user(lg->noirq_end, &lg->lguest_data->noirq_end)
-	    /* We tell the Guest that it can't use the top 4MB of virtual
-	     * addresses used by the Switcher. */
-	    || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
-	    || put_user(tsc_speed, &lg->lguest_data->tsc_khz)
-	    /* We also give the Guest a unique id, as used in lguest_net.c. */
-	    || put_user(lg->guestid, &lg->lguest_data->guestid))
+	    || get_user(lg->noirq_end, &lg->lguest_data->noirq_end))
 		kill_guest(lg, "bad guest page %p", lg->lguest_data);
 
 	/* We write the current time into the Guest's data page once now. */
 	write_timestamp(lg);
 
+	/* page_tables.c will also do some setup. */
+	page_table_guest_data_init(lg);
+
 	/* 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 Guest might be referring to the old (read-only)
 	 * page. */
 	guest_pagetable_clear_all(lg);
 }
-/* Now we've examined the hypercall code; our Guest can make requests.  There
- * is one other way we can do things for the Guest, as we see in
- * emulate_insn(). */
-
-/*H:110 Tricky point: we mark the hypercall as "done" once we've done it.
- * Normally we don't need to do this: the Guest will run again and update the
- * trap number before we come back around the run_guest() loop to
- * do_hypercalls().
- *
- * However, if we are signalled or the Guest sends DMA to the Launcher, that
- * loop will exit without running the Guest.  When it comes back it would try
- * to re-run the hypercall. */
-static void clear_hcall(struct lguest *lg)
-{
-	lg->regs->trapnum = 255;
-}
 
 /*H:100
  * Hypercalls
@@ -261,16 +195,12 @@ static void clear_hcall(struct lguest *lg)
  */
 void do_hypercalls(struct lguest *lg)
 {
-	/* Not initialized yet? */
+	/* Not initialized yet?  This hypercall must do it. */
 	if (unlikely(!lg->lguest_data)) {
-		/* Did the Guest make a hypercall?  We might have come back for
-		 * some other reason (an interrupt, a different trap). */
-		if (lg->regs->trapnum == LGUEST_TRAP_ENTRY) {
-			/* Set up the "struct lguest_data" */
-			initialize(lg);
-			/* The hypercall is done. */
-			clear_hcall(lg);
-		}
+		/* Set up the "struct lguest_data" */
+		initialize(lg);
+		/* Hcall is done. */
+		lg->hcall = NULL;
 		return;
 	}
 
@@ -280,12 +210,21 @@ void do_hypercalls(struct lguest *lg)
 	do_async_hcalls(lg);
 
 	/* If we stopped reading the hypercall ring because the Guest did a
-	 * SEND_DMA to the Launcher, we want to return now.  Otherwise if the
-	 * Guest asked us to do a hypercall, we do it. */
-	if (!lg->dma_is_pending && lg->regs->trapnum == LGUEST_TRAP_ENTRY) {
-		do_hcall(lg, lg->regs);
-		/* The hypercall is done. */
-		clear_hcall(lg);
+	 * NOTIFY to the Launcher, we want to return now.  Otherwise we do
+	 * the hypercall. */
+	if (!lg->pending_notify) {
+		do_hcall(lg, lg->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 DMA 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. */
+		lg->hcall = NULL;
 	}
 }
 
@@ -295,6 +234,6 @@ void write_timestamp(struct lguest *lg)
 {
 	struct timespec now;
 	ktime_get_real_ts(&now);
-	if (put_user(now, &lg->lguest_data->time))
+	if (copy_to_user(&lg->lguest_data->time, &now, sizeof(struct timespec)))
 		kill_guest(lg, "Writing timestamp");
 }