lguest: get rid of lg variable assignments

We can save some lines of code by getting rid of
*lg = cpu... lines of code spread everywhere by now.
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/lguest/core.c

@@ -151,23 +151,23 @@ int lguest_address_ok(const struct lguest *lg,
 /* This routine copies memory from the Guest.  Here we can see how useful the
  * kill_lguest() routine we met in the Launcher can be: we return a random
  * value (all zeroes) instead of needing to return an error. */
-void __lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes)
+void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
 {
-	if (!lguest_address_ok(lg, addr, bytes)
-	    || copy_from_user(b, lg->mem_base + addr, bytes) != 0) {
+	if (!lguest_address_ok(cpu->lg, addr, bytes)
+	    || copy_from_user(b, cpu->lg->mem_base + addr, bytes) != 0) {
 		/* copy_from_user should do this, but as we rely on it... */
 		memset(b, 0, bytes);
-		kill_guest(lg, "bad read address %#lx len %u", addr, bytes);
+		kill_guest(cpu, "bad read address %#lx len %u", addr, bytes);
 	}
 }
 
 /* This is the write (copy into guest) version. */
-void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
+void __lgwrite(struct lg_cpu *cpu, unsigned long addr, const void *b,
 	       unsigned bytes)
 {
-	if (!lguest_address_ok(lg, addr, bytes)
-	    || copy_to_user(lg->mem_base + addr, b, bytes) != 0)
-		kill_guest(lg, "bad write address %#lx len %u", addr, bytes);
+	if (!lguest_address_ok(cpu->lg, addr, bytes)
+	    || copy_to_user(cpu->lg->mem_base + addr, b, bytes) != 0)
+		kill_guest(cpu, "bad write address %#lx len %u", addr, bytes);
 }
 /*:*/
 
@@ -176,10 +176,8 @@ void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
  * going around and around until something interesting happens. */
 int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 {
-	struct lguest *lg = cpu->lg;
-
 	/* We stop running once the Guest is dead. */
-	while (!lg->dead) {
+	while (!cpu->lg->dead) {
 		/* First we run any hypercalls the Guest wants done. */
 		if (cpu->hcall)
 			do_hypercalls(cpu);
@@ -212,7 +210,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 
 		/* Just make absolutely sure the Guest is still alive.  One of
 		 * those hypercalls could have been fatal, for example. */
-		if (lg->dead)
+		if (cpu->lg->dead)
 			break;
 
 		/* If the Guest asked to be stopped, we sleep.  The Guest's
@@ -237,7 +235,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 		lguest_arch_handle_trap(cpu);
 	}
 
-	if (lg->dead == ERR_PTR(-ERESTART))
+	if (cpu->lg->dead == ERR_PTR(-ERESTART))
 		return -ERESTART;
 	/* The Guest is dead => "No such file or directory" */
 	return -ENOENT;

drivers/lguest/hypercalls.c

@@ -31,8 +31,6 @@
  * Or gets killed.  Or, in the case of LHCALL_CRASH, both. */
 static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
-	struct lguest *lg = cpu->lg;
-
 	switch (args->arg0) {
 	case LHCALL_FLUSH_ASYNC:
 		/* This call does nothing, except by breaking out of the Guest
@@ -41,7 +39,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 	case LHCALL_LGUEST_INIT:
 		/* You can't get here unless you're already initialized.  Don't
 		 * do that. */
-		kill_guest(lg, "already have lguest_data");
+		kill_guest(cpu, "already have lguest_data");
 		break;
 	case LHCALL_SHUTDOWN: {
 		/* Shutdown is such a trivial hypercall that we do it in four
@@ -49,11 +47,11 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 		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, args->arg1, sizeof(msg));
+		__lgread(cpu, msg, args->arg1, sizeof(msg));
 		msg[sizeof(msg)-1] = '\0';
-		kill_guest(lg, "CRASH: %s", msg);
+		kill_guest(cpu, "CRASH: %s", msg);
 		if (args->arg2 == LGUEST_SHUTDOWN_RESTART)
-			lg->dead = ERR_PTR(-ERESTART);
+			cpu->lg->dead = ERR_PTR(-ERESTART);
 		break;
 	}
 	case LHCALL_FLUSH_TLB:
@@ -74,10 +72,10 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 		guest_set_stack(cpu, args->arg1, args->arg2, args->arg3);
 		break;
 	case LHCALL_SET_PTE:
-		guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
+		guest_set_pte(cpu, args->arg1, args->arg2, __pte(args->arg3));
 		break;
 	case LHCALL_SET_PMD:
-		guest_set_pmd(lg, args->arg1, args->arg2);
+		guest_set_pmd(cpu->lg, args->arg1, args->arg2);
 		break;
 	case LHCALL_SET_CLOCKEVENT:
 		guest_set_clockevent(cpu, args->arg1);
@@ -96,7 +94,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 	default:
 		/* It should be an architecture-specific hypercall. */
 		if (lguest_arch_do_hcall(cpu, args))
-			kill_guest(lg, "Bad hypercall %li\n", args->arg0);
+			kill_guest(cpu, "Bad hypercall %li\n", args->arg0);
 	}
 }
 /*:*/
@@ -112,10 +110,9 @@ static void do_async_hcalls(struct lg_cpu *cpu)
 {
 	unsigned int i;
 	u8 st[LHCALL_RING_SIZE];
-	struct lguest *lg = cpu->lg;
 
 	/* For simplicity, we copy the entire call status array in at once. */
-	if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
+	if (copy_from_user(&st, &cpu->lg->lguest_data->hcall_status, sizeof(st)))
 		return;
 
 	/* We process "struct lguest_data"s hcalls[] ring once. */
@@ -137,9 +134,9 @@ static void do_async_hcalls(struct lg_cpu *cpu)
 
 		/* Copy the hypercall arguments into a local copy of
 		 * the hcall_args struct. */
-		if (copy_from_user(&args, &lg->lguest_data->hcalls[n],
+		if (copy_from_user(&args, &cpu->lg->lguest_data->hcalls[n],
 				   sizeof(struct hcall_args))) {
-			kill_guest(lg, "Fetching async hypercalls");
+			kill_guest(cpu, "Fetching async hypercalls");
 			break;
 		}
 
@@ -147,8 +144,8 @@ static void do_async_hcalls(struct lg_cpu *cpu)
 		do_hcall(cpu, &args);
 
 		/* Mark the hypercall done. */
-		if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
-			kill_guest(lg, "Writing result for async hypercall");
+		if (put_user(0xFF, &cpu->lg->lguest_data->hcall_status[n])) {
+			kill_guest(cpu, "Writing result for async hypercall");
 			break;
 		}
 
@@ -163,29 +160,28 @@ static void do_async_hcalls(struct lg_cpu *cpu)
  * Guest makes a hypercall, we end up here to set things up: */
 static void initialize(struct lg_cpu *cpu)
 {
-	struct lguest *lg = cpu->lg;
 	/* 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(lg, "hypercall %li before INIT", cpu->hcall->arg0);
+		kill_guest(cpu, "hypercall %li before INIT", cpu->hcall->arg0);
 		return;
 	}
 
 	if (lguest_arch_init_hypercalls(cpu))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+		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 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))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+	if (get_user(cpu->lg->noirq_start, &cpu->lg->lguest_data->noirq_start)
+	    || get_user(cpu->lg->noirq_end, &cpu->lg->lguest_data->noirq_end))
+		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(lg);
+	write_timestamp(cpu);
 
 	/* page_tables.c will also do some setup. */
-	page_table_guest_data_init(lg);
+	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
@@ -237,10 +233,11 @@ void do_hypercalls(struct lg_cpu *cpu)
 
 /* 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 lguest *lg)
+void write_timestamp(struct lg_cpu *cpu)
 {
 	struct timespec now;
 	ktime_get_real_ts(&now);
-	if (copy_to_user(&lg->lguest_data->time, &now, sizeof(struct timespec)))
-		kill_guest(lg, "Writing timestamp");
+	if (copy_to_user(&cpu->lg->lguest_data->time,
+			 &now, sizeof(struct timespec)))
+		kill_guest(cpu, "Writing timestamp");
 }

drivers/lguest/interrupts_and_traps.c

@@ -41,11 +41,11 @@ static int idt_present(u32 lo, u32 hi)
 
 /* We need a helper to "push" a value onto the Guest's stack, since that's a
  * big part of what delivering an interrupt does. */
-static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
+static void push_guest_stack(struct lg_cpu *cpu, unsigned long *gstack, u32 val)
 {
 	/* Stack grows upwards: move stack then write value. */
 	*gstack -= 4;
-	lgwrite(lg, *gstack, u32, val);
+	lgwrite(cpu, *gstack, u32, val);
 }
 
 /*H:210 The set_guest_interrupt() routine actually delivers the interrupt or
@@ -65,7 +65,6 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
 	unsigned long gstack, origstack;
 	u32 eflags, ss, irq_enable;
 	unsigned long virtstack;
-	struct lguest *lg = cpu->lg;
 
 	/* There are two cases for interrupts: one where the Guest is already
 	 * in the kernel, and a more complex one where the Guest is in
@@ -81,8 +80,8 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
 		 * stack: when the Guest does an "iret" back from the interrupt
 		 * handler the CPU will notice they're dropping privilege
 		 * levels and expect these here. */
-		push_guest_stack(lg, &gstack, cpu->regs->ss);
-		push_guest_stack(lg, &gstack, cpu->regs->esp);
+		push_guest_stack(cpu, &gstack, cpu->regs->ss);
+		push_guest_stack(cpu, &gstack, cpu->regs->esp);
 	} else {
 		/* We're staying on the same Guest (kernel) stack. */
 		virtstack = cpu->regs->esp;
@@ -96,20 +95,20 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
 	 * Guest's "irq_enabled" field into the eflags word: we saw the Guest
 	 * copy it back in "lguest_iret". */
 	eflags = cpu->regs->eflags;
-	if (get_user(irq_enable, &lg->lguest_data->irq_enabled) == 0
+	if (get_user(irq_enable, &cpu->lg->lguest_data->irq_enabled) == 0
 	    && !(irq_enable & X86_EFLAGS_IF))
 		eflags &= ~X86_EFLAGS_IF;
 
 	/* An interrupt is expected to push three things on the stack: the old
 	 * "eflags" word, the old code segment, and the old instruction
 	 * pointer. */
-	push_guest_stack(lg, &gstack, eflags);
-	push_guest_stack(lg, &gstack, cpu->regs->cs);
-	push_guest_stack(lg, &gstack, cpu->regs->eip);
+	push_guest_stack(cpu, &gstack, eflags);
+	push_guest_stack(cpu, &gstack, cpu->regs->cs);
+	push_guest_stack(cpu, &gstack, cpu->regs->eip);
 
 	/* For the six traps which supply an error code, we push that, too. */
 	if (has_err)
-		push_guest_stack(lg, &gstack, cpu->regs->errcode);
+		push_guest_stack(cpu, &gstack, cpu->regs->errcode);
 
 	/* Now we've pushed all the old state, we change the stack, the code
 	 * segment and the address to execute. */
@@ -121,8 +120,8 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
 	/* There are two kinds of interrupt handlers: 0xE is an "interrupt
 	 * gate" which expects interrupts to be disabled on entry. */
 	if (idt_type(lo, hi) == 0xE)
-		if (put_user(0, &lg->lguest_data->irq_enabled))
-			kill_guest(lg, "Disabling interrupts");
+		if (put_user(0, &cpu->lg->lguest_data->irq_enabled))
+			kill_guest(cpu, "Disabling interrupts");
 }
 
 /*H:205
@@ -133,17 +132,16 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
 void maybe_do_interrupt(struct lg_cpu *cpu)
 {
 	unsigned int irq;
-	struct lguest *lg = cpu->lg;
 	DECLARE_BITMAP(blk, LGUEST_IRQS);
 	struct desc_struct *idt;
 
 	/* If the Guest hasn't even initialized yet, we can do nothing. */
-	if (!lg->lguest_data)
+	if (!cpu->lg->lguest_data)
 		return;
 
 	/* Take our "irqs_pending" array and remove any interrupts the Guest
 	 * wants blocked: the result ends up in "blk". */
-	if (copy_from_user(&blk, lg->lguest_data->blocked_interrupts,
+	if (copy_from_user(&blk, cpu->lg->lguest_data->blocked_interrupts,
 			   sizeof(blk)))
 		return;
 
@@ -157,19 +155,20 @@ void maybe_do_interrupt(struct lg_cpu *cpu)
 
 	/* They may be in the middle of an iret, where they asked us never to
 	 * deliver interrupts. */
-	if (cpu->regs->eip >= lg->noirq_start && cpu->regs->eip < lg->noirq_end)
+	if (cpu->regs->eip >= cpu->lg->noirq_start &&
+	   (cpu->regs->eip < cpu->lg->noirq_end))
 		return;
 
 	/* If they're halted, interrupts restart them. */
 	if (cpu->halted) {
 		/* Re-enable interrupts. */
-		if (put_user(X86_EFLAGS_IF, &lg->lguest_data->irq_enabled))
-			kill_guest(lg, "Re-enabling interrupts");
+		if (put_user(X86_EFLAGS_IF, &cpu->lg->lguest_data->irq_enabled))
+			kill_guest(cpu, "Re-enabling interrupts");
 		cpu->halted = 0;
 	} else {
 		/* Otherwise we check if they have interrupts disabled. */
 		u32 irq_enabled;
-		if (get_user(irq_enabled, &lg->lguest_data->irq_enabled))
+		if (get_user(irq_enabled, &cpu->lg->lguest_data->irq_enabled))
 			irq_enabled = 0;
 		if (!irq_enabled)
 			return;
@@ -194,7 +193,7 @@ void maybe_do_interrupt(struct lg_cpu *cpu)
 	 * did this more often, but it can actually be quite slow: doing it
 	 * here is a compromise which means at least it gets updated every
 	 * timer interrupt. */
-	write_timestamp(lg);
+	write_timestamp(cpu);
 }
 /*:*/
 
@@ -315,10 +314,9 @@ void pin_stack_pages(struct lg_cpu *cpu)
 {
 	unsigned int i;
 
-	struct lguest *lg = cpu->lg;
 	/* Depending on the CONFIG_4KSTACKS option, the Guest can have one or
 	 * two pages of stack space. */
-	for (i = 0; i < lg->stack_pages; i++)
+	for (i = 0; i < cpu->lg->stack_pages; i++)
 		/* The stack grows *upwards*, so the address we're given is the
 		 * start of the page after the kernel stack.  Subtract one to
 		 * get back onto the first stack page, and keep subtracting to
@@ -339,10 +337,10 @@ void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages)
 	/* You are not allowed have a stack segment with privilege level 0: bad
 	 * Guest! */
 	if ((seg & 0x3) != GUEST_PL)
-		kill_guest(cpu->lg, "bad stack segment %i", seg);
+		kill_guest(cpu, "bad stack segment %i", seg);
 	/* We only expect one or two stack pages. */
 	if (pages > 2)
-		kill_guest(cpu->lg, "bad stack pages %u", pages);
+		kill_guest(cpu, "bad stack pages %u", pages);
 	/* Save where the stack is, and how many pages */
 	cpu->ss1 = seg;
 	cpu->esp1 = esp;
@@ -356,7 +354,7 @@ void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages)
 
 /*H:235 This is the routine which actually checks the Guest's IDT entry and
  * transfers it into the entry in "struct lguest": */
-static void set_trap(struct lguest *lg, struct desc_struct *trap,
+static void set_trap(struct lg_cpu *cpu, struct desc_struct *trap,
 		     unsigned int num, u32 lo, u32 hi)
 {
 	u8 type = idt_type(lo, hi);
@@ -369,7 +367,7 @@ static void set_trap(struct lguest *lg, struct desc_struct *trap,
 
 	/* We only support interrupt and trap gates. */
 	if (type != 0xE && type != 0xF)
-		kill_guest(lg, "bad IDT type %i", type);
+		kill_guest(cpu, "bad IDT type %i", type);
 
 	/* We only copy the handler address, present bit, privilege level and
 	 * type.  The privilege level controls where the trap can be triggered
@@ -399,9 +397,9 @@ void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int num, u32 lo, u32 hi)
 
 	/* Check that the Guest doesn't try to step outside the bounds. */
 	if (num >= ARRAY_SIZE(cpu->arch.idt))
-		kill_guest(cpu->lg, "Setting idt entry %u", num);
+		kill_guest(cpu, "Setting idt entry %u", num);
 	else
-		set_trap(cpu->lg, &cpu->arch.idt[num], num, lo, hi);
+		set_trap(cpu, &cpu->arch.idt[num], num, lo, hi);
 }
 
 /* The default entry for each interrupt points into the Switcher routines which

drivers/lguest/lg.h

@@ -111,22 +111,22 @@ extern struct mutex lguest_lock;
 /* core.c: */
 int lguest_address_ok(const struct lguest *lg,
 		      unsigned long addr, unsigned long len);
-void __lgread(struct lguest *, void *, unsigned long, unsigned);
-void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
+void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
+void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
 
 /*H:035 Using memory-copy operations like that is usually inconvient, so we
  * have the following helper macros which read and write a specific type (often
  * an unsigned long).
  *
  * This reads into a variable of the given type then returns that. */
-#define lgread(lg, addr, type)						\
-	({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; })
+#define lgread(cpu, addr, type)						\
+	({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
 
 /* This checks that the variable is of the given type, then writes it out. */
-#define lgwrite(lg, addr, type, val)				\
+#define lgwrite(cpu, addr, type, val)				\
 	do {							\
 		typecheck(type, val);				\
-		__lgwrite((lg), (addr), &(val), sizeof(val));	\
+		__lgwrite((cpu), (addr), &(val), sizeof(val));	\
 	} while(0)
 /* (end of memory access helper routines) :*/
 
@@ -171,13 +171,13 @@ void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
 void guest_pagetable_clear_all(struct lg_cpu *cpu);
 void guest_pagetable_flush_user(struct lg_cpu *cpu);
-void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
+void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
 		   unsigned long vaddr, pte_t val);
 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
 int demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
 void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
 unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
-void page_table_guest_data_init(struct lguest *lg);
+void page_table_guest_data_init(struct lg_cpu *cpu);
 
 /* <arch>/core.c: */
 void lguest_arch_host_init(void);
@@ -197,7 +197,7 @@ void lguest_device_remove(void);
 
 /* hypercalls.c: */
 void do_hypercalls(struct lg_cpu *cpu);
-void write_timestamp(struct lguest *lg);
+void write_timestamp(struct lg_cpu *cpu);
 
 /*L:035
  * Let's step aside for the moment, to study one important routine that's used
@@ -223,12 +223,12 @@ void write_timestamp(struct lguest *lg);
  * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
  * } while(0)".
  */
-#define kill_guest(lg, fmt...)					\
+#define kill_guest(cpu, fmt...)					\
 do {								\
-	if (!(lg)->dead) {					\
-		(lg)->dead = kasprintf(GFP_ATOMIC, fmt);	\
-		if (!(lg)->dead)				\
-			(lg)->dead = ERR_PTR(-ENOMEM);		\
+	if (!(cpu)->lg->dead) {					\
+		(cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt);	\
+		if (!(cpu)->lg->dead)				\
+			(cpu)->lg->dead = ERR_PTR(-ENOMEM);	\
 	}							\
 } while(0)
 /* (End of aside) :*/

drivers/lguest/segments.c

@@ -148,14 +148,13 @@ void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt)
  * We copy it from the Guest and tweak the entries. */
 void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
 {
-	struct lguest *lg = cpu->lg;
 	/* We assume the Guest has the same number of GDT entries as the
 	 * Host, otherwise we'd have to dynamically allocate the Guest GDT. */
 	if (num > ARRAY_SIZE(cpu->arch.gdt))
-		kill_guest(lg, "too many gdt entries %i", num);
+		kill_guest(cpu, "too many gdt entries %i", num);
 
 	/* We read the whole thing in, then fix it up. */
-	__lgread(lg, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
+	__lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
 	fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
 	/* Mark that the GDT changed so the core knows it has to copy it again,
 	 * even if the Guest is run on the same CPU. */
@@ -169,9 +168,8 @@ void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
 void guest_load_tls(struct lg_cpu *cpu, unsigned long gtls)
 {
 	struct desc_struct *tls = &cpu->arch.gdt[GDT_ENTRY_TLS_MIN];
-	struct lguest *lg = cpu->lg;
 
-	__lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
+	__lgread(cpu, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
 	fixup_gdt_table(cpu, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
 	/* Note that just the TLS entries have changed. */
 	cpu->changed |= CHANGED_GDT_TLS;

drivers/lguest/x86/core.c

@@ -117,7 +117,6 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
 {
 	/* This is a dummy value we need for GCC's sake. */
 	unsigned int clobber;
-	struct lguest *lg = cpu->lg;
 
 	/* Copy the guest-specific information into this CPU's "struct
 	 * lguest_pages". */
@@ -144,7 +143,7 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
 		      * 0-th argument above, ie "a").  %ebx contains the
 		      * physical address of the Guest's top-level page
 		      * directory. */
-		     : "0"(pages), "1"(__pa(lg->pgdirs[cpu->cpu_pgd].pgdir))
+		     : "0"(pages), "1"(__pa(cpu->lg->pgdirs[cpu->cpu_pgd].pgdir))
 		     /* We tell gcc that all these registers could change,
 		      * which means we don't have to save and restore them in
 		      * the Switcher. */
@@ -217,7 +216,6 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
  * instructions and skip over it.  We return true if we did. */
 static int emulate_insn(struct lg_cpu *cpu)
 {
-	struct lguest *lg = cpu->lg;
 	u8 insn;
 	unsigned int insnlen = 0, in = 0, shift = 0;
 	/* The eip contains the *virtual* address of the Guest's instruction:
@@ -231,7 +229,7 @@ static int emulate_insn(struct lg_cpu *cpu)
 		return 0;
 
 	/* Decoding x86 instructions is icky. */
-	insn = lgread(lg, physaddr, u8);
+	insn = lgread(cpu, physaddr, u8);
 
 	/* 0x66 is an "operand prefix".  It means it's using the upper 16 bits
 	   of the eax register. */
@@ -239,7 +237,7 @@ static int emulate_insn(struct lg_cpu *cpu)
 		shift = 16;
 		/* The instruction is 1 byte so far, read the next byte. */
 		insnlen = 1;
-		insn = lgread(lg, physaddr + insnlen, u8);
+		insn = lgread(cpu, physaddr + insnlen, u8);
 	}
 
 	/* We can ignore the lower bit for the moment and decode the 4 opcodes
@@ -283,7 +281,6 @@ static int emulate_insn(struct lg_cpu *cpu)
 /*H:050 Once we've re-enabled interrupts, we look at why the Guest exited. */
 void lguest_arch_handle_trap(struct lg_cpu *cpu)
 {
-	struct lguest *lg = cpu->lg;
 	switch (cpu->regs->trapnum) {
 	case 13: /* We've intercepted a General Protection Fault. */
 		/* Check if this was one of those annoying IN or OUT
@@ -315,9 +312,10 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
 		 * Note that if the Guest were really messed up, this could
 		 * happen before it's done the LHCALL_LGUEST_INIT hypercall, so
 		 * lg->lguest_data could be NULL */
-		if (lg->lguest_data &&
-		    put_user(cpu->arch.last_pagefault, &lg->lguest_data->cr2))
-			kill_guest(lg, "Writing cr2");
+		if (cpu->lg->lguest_data &&
+		    put_user(cpu->arch.last_pagefault,
+			     &cpu->lg->lguest_data->cr2))
+			kill_guest(cpu, "Writing cr2");
 		break;
 	case 7: /* We've intercepted a Device Not Available fault. */
 		/* If the Guest doesn't want to know, we already restored the
@@ -345,7 +343,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
 		/* If the Guest doesn't have a handler (either it hasn't
 		 * registered any yet, or it's one of the faults we don't let
 		 * it handle), it dies with a cryptic error message. */
-		kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
+		kill_guest(cpu, "unhandled trap %li at %#lx (%#lx)",
 			   cpu->regs->trapnum, cpu->regs->eip,
 			   cpu->regs->trapnum == 14 ? cpu->arch.last_pagefault
 			   : cpu->regs->errcode);
@@ -514,11 +512,11 @@ int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
 {
 	u32 tsc_speed;
-	struct lguest *lg = cpu->lg;
 
 	/* The pointer to the Guest's "struct lguest_data" is the only
 	 * argument.  We check that address now. */
-	if (!lguest_address_ok(lg, cpu->hcall->arg1, sizeof(*lg->lguest_data)))
+	if (!lguest_address_ok(cpu->lg, cpu->hcall->arg1,
+			       sizeof(*cpu->lg->lguest_data)))
 		return -EFAULT;
 
 	/* Having checked it, we simply set lg->lguest_data to point straight
@@ -526,7 +524,7 @@ int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
 	 * copy_to_user/from_user from now on, instead of lgread/write.  I put
 	 * this in to show that I'm not immune to writing stupid
 	 * optimizations. */
-	lg->lguest_data = lg->mem_base + cpu->hcall->arg1;
+	cpu->lg->lguest_data = cpu->lg->mem_base + cpu->hcall->arg1;
 
 	/* We insist that the Time Stamp Counter exist and doesn't change with
 	 * cpu frequency.  Some devious chip manufacturers decided that TSC
@@ -539,12 +537,12 @@ int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
 		tsc_speed = tsc_khz;
 	else
 		tsc_speed = 0;
-	if (put_user(tsc_speed, &lg->lguest_data->tsc_khz))
+	if (put_user(tsc_speed, &cpu->lg->lguest_data->tsc_khz))
 		return -EFAULT;
 
 	/* The interrupt code might not like the system call vector. */
-	if (!check_syscall_vector(lg))
-		kill_guest(lg, "bad syscall vector");
+	if (!check_syscall_vector(cpu->lg))
+		kill_guest(cpu, "bad syscall vector");
 
 	return 0;
 }