#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_CRASH, both. */
+ * Or gets killed. Or, in the case of LHCALL_SHUTDOWN, 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
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
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:
/* FLUSH_TLB comes in two flavors, depending on the
* argument: */
if (args->arg1)
- guest_pagetable_clear_all(lg);
+ guest_pagetable_clear_all(cpu);
else
- guest_pagetable_flush_user(lg);
+ 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(lg, args->arg1);
+ guest_new_pagetable(cpu, args->arg1);
break;
case LHCALL_SET_STACK:
- guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
+ 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);
break;
case LHCALL_TS:
/* This sets the TS flag, as we saw used in run_guest(). */
- lg->ts = args->arg1;
+ cpu->ts = args->arg1;
break;
case LHCALL_HALT:
/* Similarly, this sets the halted flag for run_guest(). */
- lg->halted = 1;
+ cpu->halted = 1;
break;
case LHCALL_NOTIFY:
- lg->pending_notify = args->arg1;
+ cpu->pending_notify = args->arg1;
break;
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);
}
}
/*:*/
{
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. */
/* 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;
}
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;
}
/* Stop doing hypercalls if they want to notify the Launcher:
* it needs to service this first. */
- if (lg->pending_notify)
+ if (cpu->pending_notify)
break;
}
}
* 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
* fault, but the old page might be (read-only) in the Guest
* pagetable. */
- guest_pagetable_clear_all(lg);
+ 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. :*/
/*H:100
* Hypercalls
/* 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->lg->pending_notify) {
+ if (!cpu->pending_notify) {
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
* 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. */
+ * 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 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");
}