/* 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
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
if ((cpu->regs->ss&0x3) != GUEST_PL) {
/* The Guest told us their kernel stack with the SET_STACK
* hypercall: both the virtual address and the segment */
- virtstack = lg->esp1;
- ss = lg->ss1;
+ virtstack = cpu->esp1;
+ ss = cpu->ss1;
- origstack = gstack = guest_pa(lg, virtstack);
+ origstack = gstack = guest_pa(cpu, virtstack);
/* We push the old stack segment and pointer onto the new
* 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;
ss = cpu->regs->ss;
- origstack = gstack = guest_pa(lg, virtstack);
+ origstack = gstack = guest_pa(cpu, virtstack);
}
/* Remember that we never let the Guest actually disable interrupts, so
* 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. */
/* 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
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;
-
bitmap_andnot(blk, cpu->irqs_pending, blk, LGUEST_IRQS);
/* Find the first interrupt. */
/* 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;
* 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);
}
/*:*/
clear_bit(syscall_vector, used_vectors);
}
-/*H:220 Now we've got the routines to deliver interrupts, delivering traps
- * like page fault is easy. The only trick is that Intel decided that some
- * traps should have error codes: */
+/*H:220 Now we've got the routines to deliver interrupts, delivering traps like
+ * page fault is easy. The only trick is that Intel decided that some traps
+ * should have error codes: */
static int has_err(unsigned int trap)
{
return (trap == 8 || (trap >= 10 && trap <= 14) || trap == 17);
* the Guest.
*
* Which is deeply unfair, because (literally!) it wasn't the Guests' fault. */
-void pin_stack_pages(struct lguest *lg)
+void pin_stack_pages(struct lg_cpu *cpu)
{
unsigned int i;
/* 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
* get to the rest of the stack pages. */
- pin_page(lg, lg->esp1 - 1 - i * PAGE_SIZE);
+ pin_page(cpu, cpu->esp1 - 1 - i * PAGE_SIZE);
}
/* Direct traps also mean that we need to know whenever the Guest wants to use
*
* In Linux each process has its own kernel stack, so this happens a lot: we
* change stacks on each context switch. */
-void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages)
+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(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(lg, "bad stack pages %u", pages);
+ kill_guest(cpu, "bad stack pages %u", pages);
/* Save where the stack is, and how many pages */
- lg->ss1 = seg;
- lg->esp1 = esp;
- lg->stack_pages = pages;
+ cpu->ss1 = seg;
+ cpu->esp1 = esp;
+ cpu->lg->stack_pages = pages;
/* Make sure the new stack pages are mapped */
- pin_stack_pages(lg);
+ pin_stack_pages(cpu);
}
/* All this reference to mapping stacks leads us neatly into the other complex
/*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);
/* 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
/* Mark the IDT as changed: next time the Guest runs we'll know we have
* to copy this again. */
- cpu->lg->changed |= CHANGED_IDT;
+ cpu->changed |= CHANGED_IDT;
/* 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