X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Flguest%2Fhypercalls.c;h=54d66f05fefa0a82af7c96a78432cf2a763d6530;hb=8e6c81fe289e90b188203ec1db1dc2f3e992ebde;hp=b478affe8f91331733a288fa039fce50012e8409;hpb=37e58df30063e229ee5157f9d1c1fa1d749917c2;p=linux-2.6-omap-h63xx.git diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index b478affe8f9..54d66f05fef 100644 --- a/drivers/lguest/hypercalls.c +++ b/drivers/lguest/hypercalls.c @@ -23,13 +23,14 @@ #include #include #include +#include #include #include #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. */ -static void do_hcall(struct lguest *lg, struct hcall_args *args) + * Or gets killed. Or, in the case of LHCALL_SHUTDOWN, both. */ +static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args) { switch (args->arg0) { case LHCALL_FLUSH_ASYNC: @@ -39,60 +40,62 @@ static void do_hcall(struct lguest *lg, 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_CRASH: { - /* Crash is such a trivial hypercall that we do it in four + case LHCALL_SHUTDOWN: { + /* Shutdown is such a trivial hypercall that we do it in four * lines right here. */ 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) + 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(lg, args->arg1); + 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(lg, args)) - kill_guest(lg, "Bad hypercall %li\n", args->arg0); + if (lguest_arch_do_hcall(cpu, args)) + kill_guest(cpu, "Bad hypercall %li\n", args->arg0); } } /*:*/ @@ -104,13 +107,13 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args) * Guest put them in the ring, but we also promise the Guest that they will * happen before any normal hypercall (which is why we check this before * checking for a normal hcall). */ -static void do_async_hcalls(struct lguest *lg) +static void do_async_hcalls(struct lg_cpu *cpu) { unsigned int i; u8 st[LHCALL_RING_SIZE]; /* 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. */ @@ -119,7 +122,7 @@ static void do_async_hcalls(struct lguest *lg) /* 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. */ - unsigned int n = lg->next_hcall; + unsigned int n = cpu->next_hcall; /* 0xFF means there's no call here (yet). */ if (st[n] == 0xFF) @@ -127,66 +130,73 @@ static void do_async_hcalls(struct lguest *lg) /* OK, we have hypercall. Increment the "next_hcall" cursor, * and wrap back to 0 if we reach the end. */ - if (++lg->next_hcall == LHCALL_RING_SIZE) - lg->next_hcall = 0; + if (++cpu->next_hcall == LHCALL_RING_SIZE) + cpu->next_hcall = 0; /* 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 the hypercall, same as a normal one. */ - do_hcall(lg, &args); + 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; } } /* Last of all, we look at what happens first of all. The very first time the * Guest makes a hypercall, we end up here to set things up: */ -static void initialize(struct lguest *lg) +static void initialize(struct lg_cpu *cpu) { /* You can't do anything until you're initialized. The Guest knows the * rules, so we're unforgiving here. */ - if (lg->hcall->arg0 != LHCALL_LGUEST_INIT) { - kill_guest(lg, "hypercall %li before INIT", lg->hcall->arg0); + if (cpu->hcall->arg0 != LHCALL_LGUEST_INIT) { + kill_guest(cpu, "hypercall %li before INIT", cpu->hcall->arg0); return; } - if (lguest_arch_init_hypercalls(lg)) - kill_guest(lg, "bad guest page %p", lg->lguest_data); + if (lguest_arch_init_hypercalls(cpu)) + 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 @@ -194,27 +204,27 @@ static void initialize(struct lguest *lg) * Remember from the Guest, hypercalls come in two flavors: normal and * asynchronous. This file handles both of types. */ -void do_hypercalls(struct lguest *lg) +void do_hypercalls(struct lg_cpu *cpu) { /* Not initialized yet? This hypercall must do it. */ - if (unlikely(!lg->lguest_data)) { + if (unlikely(!cpu->lg->lguest_data)) { /* Set up the "struct lguest_data" */ - initialize(lg); + initialize(cpu); /* Hcall is done. */ - lg->hcall = NULL; + cpu->hcall = NULL; return; } /* The Guest has initialized. * * Look in the hypercall ring for the async hypercalls: */ - do_async_hcalls(lg); + do_async_hcalls(cpu); /* 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 (!lg->pending_notify) { - do_hcall(lg, lg->hcall); + 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 * the trap number to indicate a hypercall is pending. @@ -224,17 +234,18 @@ void do_hypercalls(struct lguest *lg) * 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. */ - lg->hcall = NULL; + * 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"); }