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/page_tables.c

@@ -68,17 +68,17 @@ static DEFINE_PER_CPU(pte_t *, switcher_pte_pages);
  * page directory entry (PGD) for that address.  Since we keep track of several
  * page tables, the "i" argument tells us which one we're interested in (it's
  * usually the current one). */
-static pgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
+static pgd_t *spgd_addr(struct lg_cpu *cpu, u32 i, unsigned long vaddr)
 {
 	unsigned int index = pgd_index(vaddr);
 
 	/* We kill any Guest trying to touch the Switcher addresses. */
 	if (index >= SWITCHER_PGD_INDEX) {
-		kill_guest(lg, "attempt to access switcher pages");
+		kill_guest(cpu, "attempt to access switcher pages");
 		index = 0;
 	}
 	/* Return a pointer index'th pgd entry for the i'th page table. */
-	return &lg->pgdirs[i].pgdir[index];
+	return &cpu->lg->pgdirs[i].pgdir[index];
 }
 
 /* This routine then takes the page directory entry returned above, which
@@ -137,7 +137,7 @@ static unsigned long get_pfn(unsigned long virtpfn, int write)
  * entry can be a little tricky.  The flags are (almost) the same, but the
  * Guest PTE contains a virtual page number: the CPU needs the real page
  * number. */
-static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
+static pte_t gpte_to_spte(struct lg_cpu *cpu, pte_t gpte, int write)
 {
 	unsigned long pfn, base, flags;
 
@@ -148,7 +148,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
 	flags = (pte_flags(gpte) & ~_PAGE_GLOBAL);
 
 	/* The Guest's pages are offset inside the Launcher. */
-	base = (unsigned long)lg->mem_base / PAGE_SIZE;
+	base = (unsigned long)cpu->lg->mem_base / PAGE_SIZE;
 
 	/* We need a temporary "unsigned long" variable to hold the answer from
 	 * get_pfn(), because it returns 0xFFFFFFFF on failure, which wouldn't
@@ -156,7 +156,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
 	 * page, given the virtual number. */
 	pfn = get_pfn(base + pte_pfn(gpte), write);
 	if (pfn == -1UL) {
-		kill_guest(lg, "failed to get page %lu", pte_pfn(gpte));
+		kill_guest(cpu, "failed to get page %lu", pte_pfn(gpte));
 		/* When we destroy the Guest, we'll go through the shadow page
 		 * tables and release_pte() them.  Make sure we don't think
 		 * this one is valid! */
@@ -176,17 +176,18 @@ static void release_pte(pte_t pte)
 }
 /*:*/
 
-static void check_gpte(struct lguest *lg, pte_t gpte)
+static void check_gpte(struct lg_cpu *cpu, pte_t gpte)
 {
 	if ((pte_flags(gpte) & (_PAGE_PWT|_PAGE_PSE))
-	    || pte_pfn(gpte) >= lg->pfn_limit)
-		kill_guest(lg, "bad page table entry");
+	    || pte_pfn(gpte) >= cpu->lg->pfn_limit)
+		kill_guest(cpu, "bad page table entry");
 }
 
-static void check_gpgd(struct lguest *lg, pgd_t gpgd)
+static void check_gpgd(struct lg_cpu *cpu, pgd_t gpgd)
 {
-	if ((pgd_flags(gpgd) & ~_PAGE_TABLE) || pgd_pfn(gpgd) >= lg->pfn_limit)
-		kill_guest(lg, "bad page directory entry");
+	if ((pgd_flags(gpgd) & ~_PAGE_TABLE) ||
+	   (pgd_pfn(gpgd) >= cpu->lg->pfn_limit))
+		kill_guest(cpu, "bad page directory entry");
 }
 
 /*H:330
@@ -206,27 +207,26 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 	unsigned long gpte_ptr;
 	pte_t gpte;
 	pte_t *spte;
-	struct lguest *lg = cpu->lg;
 
 	/* First step: get the top-level Guest page table entry. */
-	gpgd = lgread(lg, gpgd_addr(cpu, vaddr), pgd_t);
+	gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
 	/* Toplevel not present?  We can't map it in. */
 	if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
 		return 0;
 
 	/* Now look at the matching shadow entry. */
-	spgd = spgd_addr(lg, cpu->cpu_pgd, vaddr);
+	spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
 	if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) {
 		/* No shadow entry: allocate a new shadow PTE page. */
 		unsigned long ptepage = get_zeroed_page(GFP_KERNEL);
 		/* This is not really the Guest's fault, but killing it is
 		 * simple for this corner case. */
 		if (!ptepage) {
-			kill_guest(lg, "out of memory allocating pte page");
+			kill_guest(cpu, "out of memory allocating pte page");
 			return 0;
 		}
 		/* We check that the Guest pgd is OK. */
-		check_gpgd(lg, gpgd);
+		check_gpgd(cpu, gpgd);
 		/* And we copy the flags to the shadow PGD entry.  The page
 		 * number in the shadow PGD is the page we just allocated. */
 		*spgd = __pgd(__pa(ptepage) | pgd_flags(gpgd));
@@ -235,7 +235,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 	/* OK, now we look at the lower level in the Guest page table: keep its
 	 * address, because we might update it later. */
 	gpte_ptr = gpte_addr(gpgd, vaddr);
-	gpte = lgread(lg, gpte_ptr, pte_t);
+	gpte = lgread(cpu, gpte_ptr, pte_t);
 
 	/* If this page isn't in the Guest page tables, we can't page it in. */
 	if (!(pte_flags(gpte) & _PAGE_PRESENT))
@@ -252,7 +252,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 
 	/* Check that the Guest PTE flags are OK, and the page number is below
 	 * the pfn_limit (ie. not mapping the Launcher binary). */
-	check_gpte(lg, gpte);
+	check_gpte(cpu, gpte);
 
 	/* Add the _PAGE_ACCESSED and (for a write) _PAGE_DIRTY flag */
 	gpte = pte_mkyoung(gpte);
@@ -268,17 +268,17 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 	/* If this is a write, we insist that the Guest page is writable (the
 	 * final arg to gpte_to_spte()). */
 	if (pte_dirty(gpte))
-		*spte = gpte_to_spte(lg, gpte, 1);
+		*spte = gpte_to_spte(cpu, gpte, 1);
 	else
 		/* If this is a read, don't set the "writable" bit in the page
 		 * table entry, even if the Guest says it's writable.  That way
 		 * we will come back here when a write does actually occur, so
 		 * we can update the Guest's _PAGE_DIRTY flag. */
-		*spte = gpte_to_spte(lg, pte_wrprotect(gpte), 0);
+		*spte = gpte_to_spte(cpu, pte_wrprotect(gpte), 0);
 
 	/* Finally, we write the Guest PTE entry back: we've set the
 	 * _PAGE_ACCESSED and maybe the _PAGE_DIRTY flags. */
-	lgwrite(lg, gpte_ptr, pte_t, gpte);
+	lgwrite(cpu, gpte_ptr, pte_t, gpte);
 
 	/* The fault is fixed, the page table is populated, the mapping
 	 * manipulated, the result returned and the code complete.  A small
@@ -303,7 +303,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
 	unsigned long flags;
 
 	/* Look at the current top level entry: is it present? */
-	spgd = spgd_addr(cpu->lg, cpu->cpu_pgd, vaddr);
+	spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
 	if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
 		return 0;
 
@@ -320,7 +320,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
 void pin_page(struct lg_cpu *cpu, unsigned long vaddr)
 {
 	if (!page_writable(cpu, vaddr) && !demand_page(cpu, vaddr, 2))
-		kill_guest(cpu->lg, "bad stack page %#lx", vaddr);
+		kill_guest(cpu, "bad stack page %#lx", vaddr);
 }
 
 /*H:450 If we chase down the release_pgd() code, it looks like this: */
@@ -372,14 +372,14 @@ unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr)
 	pte_t gpte;
 
 	/* First step: get the top-level Guest page table entry. */
-	gpgd = lgread(cpu->lg, gpgd_addr(cpu, vaddr), pgd_t);
+	gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
 	/* Toplevel not present?  We can't map it in. */
 	if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
-		kill_guest(cpu->lg, "Bad address %#lx", vaddr);
+		kill_guest(cpu, "Bad address %#lx", vaddr);
 
-	gpte = lgread(cpu->lg, gpte_addr(gpgd, vaddr), pte_t);
+	gpte = lgread(cpu, gpte_addr(gpgd, vaddr), pte_t);
 	if (!(pte_flags(gpte) & _PAGE_PRESENT))
-		kill_guest(cpu->lg, "Bad address %#lx", vaddr);
+		kill_guest(cpu, "Bad address %#lx", vaddr);
 
 	return pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK);
 }
@@ -404,16 +404,16 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
 			      int *blank_pgdir)
 {
 	unsigned int next;
-	struct lguest *lg = cpu->lg;
 
 	/* We pick one entry at random to throw out.  Choosing the Least
 	 * Recently Used might be better, but this is easy. */
-	next = random32() % ARRAY_SIZE(lg->pgdirs);
+	next = random32() % ARRAY_SIZE(cpu->lg->pgdirs);
 	/* If it's never been allocated at all before, try now. */
-	if (!lg->pgdirs[next].pgdir) {
-		lg->pgdirs[next].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL);
+	if (!cpu->lg->pgdirs[next].pgdir) {
+		cpu->lg->pgdirs[next].pgdir =
+					(pgd_t *)get_zeroed_page(GFP_KERNEL);
 		/* If the allocation fails, just keep using the one we have */
-		if (!lg->pgdirs[next].pgdir)
+		if (!cpu->lg->pgdirs[next].pgdir)
 			next = cpu->cpu_pgd;
 		else
 			/* This is a blank page, so there are no kernel
@@ -421,9 +421,9 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
 			*blank_pgdir = 1;
 	}
 	/* Record which Guest toplevel this shadows. */
-	lg->pgdirs[next].gpgdir = gpgdir;
+	cpu->lg->pgdirs[next].gpgdir = gpgdir;
 	/* Release all the non-kernel mappings. */
-	flush_user_mappings(lg, next);
+	flush_user_mappings(cpu->lg, next);
 
 	return next;
 }
@@ -436,13 +436,12 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable)
 {
 	int newpgdir, repin = 0;
-	struct lguest *lg = cpu->lg;
 
 	/* Look to see if we have this one already. */
-	newpgdir = find_pgdir(lg, pgtable);
+	newpgdir = find_pgdir(cpu->lg, pgtable);
 	/* If not, we allocate or mug an existing one: if it's a fresh one,
 	 * repin gets set to 1. */
-	if (newpgdir == ARRAY_SIZE(lg->pgdirs))
+	if (newpgdir == ARRAY_SIZE(cpu->lg->pgdirs))
 		newpgdir = new_pgdir(cpu, pgtable, &repin);
 	/* Change the current pgd index to the new one. */
 	cpu->cpu_pgd = newpgdir;
@@ -499,11 +498,11 @@ void guest_pagetable_clear_all(struct lg_cpu *cpu)
  * _PAGE_ACCESSED then we can put a read-only PTE entry in immediately, and if
  * they set _PAGE_DIRTY then we can put a writable PTE entry in immediately.
  */
-static void do_set_pte(struct lguest *lg, int idx,
+static void do_set_pte(struct lg_cpu *cpu, int idx,
 		       unsigned long vaddr, pte_t gpte)
 {
 	/* Look up the matching shadow page directory entry. */
-	pgd_t *spgd = spgd_addr(lg, idx, vaddr);
+	pgd_t *spgd = spgd_addr(cpu, idx, vaddr);
 
 	/* If the top level isn't present, there's no entry to update. */
 	if (pgd_flags(*spgd) & _PAGE_PRESENT) {
@@ -515,8 +514,8 @@ static void do_set_pte(struct lguest *lg, int idx,
 		 * as well put that entry they've given us in now.  This shaves
 		 * 10% off a copy-on-write micro-benchmark. */
 		if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
-			check_gpte(lg, gpte);
-			*spte = gpte_to_spte(lg, gpte,
+			check_gpte(cpu, gpte);
+			*spte = gpte_to_spte(cpu, gpte,
 					     pte_flags(gpte) & _PAGE_DIRTY);
 		} else
 			/* Otherwise kill it and we can demand_page() it in
@@ -535,22 +534,22 @@ static void do_set_pte(struct lguest *lg, int idx,
  *
  * The benefit is that when we have to track a new page table, we can copy keep
  * all the kernel mappings.  This speeds up context switch immensely. */
-void guest_set_pte(struct lguest *lg,
+void guest_set_pte(struct lg_cpu *cpu,
 		   unsigned long gpgdir, unsigned long vaddr, pte_t gpte)
 {
 	/* Kernel mappings must be changed on all top levels.  Slow, but
 	 * doesn't happen often. */
-	if (vaddr >= lg->kernel_address) {
+	if (vaddr >= cpu->lg->kernel_address) {
 		unsigned int i;
-		for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
-			if (lg->pgdirs[i].pgdir)
-				do_set_pte(lg, i, vaddr, gpte);
+		for (i = 0; i < ARRAY_SIZE(cpu->lg->pgdirs); i++)
+			if (cpu->lg->pgdirs[i].pgdir)
+				do_set_pte(cpu, i, vaddr, gpte);
 	} else {
 		/* Is this page table one we have a shadow for? */
-		int pgdir = find_pgdir(lg, gpgdir);
-		if (pgdir != ARRAY_SIZE(lg->pgdirs))
+		int pgdir = find_pgdir(cpu->lg, gpgdir);
+		if (pgdir != ARRAY_SIZE(cpu->lg->pgdirs))
 			/* If so, do the update. */
-			do_set_pte(lg, pgdir, vaddr, gpte);
+			do_set_pte(cpu, pgdir, vaddr, gpte);
 	}
 }
 
@@ -601,21 +600,23 @@ int init_guest_pagetable(struct lguest *lg, unsigned long pgtable)
 }
 
 /* When the Guest calls LHCALL_LGUEST_INIT we do more setup. */
-void page_table_guest_data_init(struct lguest *lg)
+void page_table_guest_data_init(struct lg_cpu *cpu)
 {
 	/* We get the kernel address: above this is all kernel memory. */
-	if (get_user(lg->kernel_address, &lg->lguest_data->kernel_address)
+	if (get_user(cpu->lg->kernel_address,
+		     &cpu->lg->lguest_data->kernel_address)
 	    /* 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(lg->pgdirs[0].gpgdir, &lg->lguest_data->pgdir))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+	    || put_user(4U*1024*1024, &cpu->lg->lguest_data->reserve_mem)
+	    || put_user(cpu->lg->pgdirs[0].gpgdir, &cpu->lg->lguest_data->pgdir))
+		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
 
 	/* In flush_user_mappings() we loop from 0 to
 	 * "pgd_index(lg->kernel_address)".  This assumes it won't hit the
 	 * Switcher mappings, so check that now. */
-	if (pgd_index(lg->kernel_address) >= SWITCHER_PGD_INDEX)
-		kill_guest(lg, "bad kernel address %#lx", lg->kernel_address);
+	if (pgd_index(cpu->lg->kernel_address) >= SWITCHER_PGD_INDEX)
+		kill_guest(cpu, "bad kernel address %#lx",
+				 cpu->lg->kernel_address);
 }
 
 /* When a Guest dies, our cleanup is fairly simple. */

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;
 }