diff options
| -rw-r--r-- | arch/x86/lguest/boot.c | 8 | ||||
| -rw-r--r-- | drivers/lguest/hypercalls.c | 104 | ||||
| -rw-r--r-- | drivers/lguest/lg.h | 4 | ||||
| -rw-r--r-- | drivers/lguest/x86/core.c | 62 | ||||
| -rw-r--r-- | include/asm-x86/lguest_hcall.h | 8 | ||||
| -rw-r--r-- | include/linux/lguest.h | 2 |
6 files changed, 104 insertions, 84 deletions
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index c7ebc131fe2c..1040f9b2f997 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -146,10 +146,10 @@ void async_hcall(unsigned long call, /* Table full, so do normal hcall which will flush table. */ hcall(call, arg1, arg2, arg3); } else { - lguest_data.hcalls[next_call].eax = call; - lguest_data.hcalls[next_call].edx = arg1; - lguest_data.hcalls[next_call].ebx = arg2; - lguest_data.hcalls[next_call].ecx = arg3; + lguest_data.hcalls[next_call].arg0 = call; + lguest_data.hcalls[next_call].arg1 = arg1; + lguest_data.hcalls[next_call].arg2 = arg2; + lguest_data.hcalls[next_call].arg3 = arg3; /* Arguments must all be written before we mark it to go */ wmb(); lguest_data.hcall_status[next_call] = 0; diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index 0175a9f03347..2859a7687288 100644 --- a/drivers/lguest/hypercalls.c +++ b/drivers/lguest/hypercalls.c @@ -25,17 +25,13 @@ #include <linux/mm.h> #include <asm/page.h> #include <asm/pgtable.h> -#include <irq_vectors.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. - * - * Remember from the Guest: %eax == which call to make, and the arguments are - * packed into %edx, %ebx and %ecx if needed. */ -static void do_hcall(struct lguest *lg, struct lguest_regs *regs) +/*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) { - switch (regs->eax) { + switch (args->arg0) { case LHCALL_FLUSH_ASYNC: /* This call does nothing, except by breaking out of the Guest * it makes us process all the asynchronous hypercalls. */ @@ -51,7 +47,7 @@ static void do_hcall(struct lguest *lg, struct lguest_regs *regs) 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, regs->edx, sizeof(msg)); + lgread(lg, msg, args->arg1, sizeof(msg)); msg[sizeof(msg)-1] = '\0'; kill_guest(lg, "CRASH: %s", msg); break; @@ -59,7 +55,7 @@ static void do_hcall(struct lguest *lg, struct lguest_regs *regs) case LHCALL_FLUSH_TLB: /* FLUSH_TLB comes in two flavors, depending on the * argument: */ - if (regs->edx) + if (args->arg1) guest_pagetable_clear_all(lg); else guest_pagetable_flush_user(lg); @@ -71,55 +67,47 @@ static void do_hcall(struct lguest *lg, struct lguest_regs *regs) * it here. This can legitimately fail, since we currently * place a limit on the number of DMA pools a Guest can have. * So we return true or false from this call. */ - regs->eax = bind_dma(lg, regs->edx, regs->ebx, - regs->ecx >> 8, regs->ecx & 0xFF); + args->arg0 = bind_dma(lg, args->arg1, args->arg2, + args->arg3 >> 8, args->arg3 & 0xFF); break; /* All these calls simply pass the arguments through to the right * routines. */ case LHCALL_SEND_DMA: - send_dma(lg, regs->edx, regs->ebx); - break; - case LHCALL_LOAD_GDT: - load_guest_gdt(lg, regs->edx, regs->ebx); - break; - case LHCALL_LOAD_IDT_ENTRY: - load_guest_idt_entry(lg, regs->edx, regs->ebx, regs->ecx); + send_dma(lg, args->arg1, args->arg2); break; case LHCALL_NEW_PGTABLE: - guest_new_pagetable(lg, regs->edx); + guest_new_pagetable(lg, args->arg1); break; case LHCALL_SET_STACK: - guest_set_stack(lg, regs->edx, regs->ebx, regs->ecx); + guest_set_stack(lg, args->arg1, args->arg2, args->arg3); break; case LHCALL_SET_PTE: - guest_set_pte(lg, regs->edx, regs->ebx, mkgpte(regs->ecx)); + guest_set_pte(lg, args->arg1, args->arg2, mkgpte(args->arg3)); break; case LHCALL_SET_PMD: - guest_set_pmd(lg, regs->edx, regs->ebx); - break; - case LHCALL_LOAD_TLS: - guest_load_tls(lg, regs->edx); + guest_set_pmd(lg, args->arg1, args->arg2); break; case LHCALL_SET_CLOCKEVENT: - guest_set_clockevent(lg, regs->edx); + guest_set_clockevent(lg, args->arg1); break; - case LHCALL_TS: /* This sets the TS flag, as we saw used in run_guest(). */ - lg->ts = regs->edx; + lg->ts = args->arg1; break; case LHCALL_HALT: /* Similarly, this sets the halted flag for run_guest(). */ lg->halted = 1; break; default: - kill_guest(lg, "Bad hypercall %li\n", regs->eax); + if (lguest_arch_do_hcall(lg, args)) + kill_guest(lg, "Bad hypercall %li\n", args->arg0); } } +/*:*/ -/* Asynchronous hypercalls are easy: we just look in the array in the Guest's - * "struct lguest_data" and see if there are any new ones marked "ready". +/*H:124 Asynchronous hypercalls are easy: we just look in the array in the + * Guest's "struct lguest_data" to see if any new ones are marked "ready". * * We are careful to do these in order: obviously we respect the order the * Guest put them in the ring, but we also promise the Guest that they will @@ -134,10 +122,9 @@ static void do_async_hcalls(struct lguest *lg) if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st))) return; - /* We process "struct lguest_data"s hcalls[] ring once. */ for (i = 0; i < ARRAY_SIZE(st); i++) { - struct lguest_regs regs; + struct hcall_args args; /* 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. */ @@ -152,18 +139,16 @@ static void do_async_hcalls(struct lguest *lg) if (++lg->next_hcall == LHCALL_RING_SIZE) lg->next_hcall = 0; - /* We copy the hypercall arguments into a fake register - * structure. This makes life simple for do_hcall(). */ - if (get_user(regs.eax, &lg->lguest_data->hcalls[n].eax) - || get_user(regs.edx, &lg->lguest_data->hcalls[n].edx) - || get_user(regs.ecx, &lg->lguest_data->hcalls[n].ecx) - || get_user(regs.ebx, &lg->lguest_data->hcalls[n].ebx)) { + /* Copy the hypercall arguments into a local copy of + * the hcall_args struct. */ + if (copy_from_user(&args, &lg->lguest_data->hcalls[n], + sizeof(struct hcall_args))) { kill_guest(lg, "Fetching async hypercalls"); break; } /* Do the hypercall, same as a normal one. */ - do_hcall(lg, ®s); + do_hcall(lg, &args); /* Mark the hypercall done. */ if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) { @@ -182,41 +167,16 @@ static void do_async_hcalls(struct lguest *lg) * Guest makes a hypercall, we end up here to set things up: */ static void initialize(struct lguest *lg) { - u32 tsc_speed; /* You can't do anything until you're initialized. The Guest knows the * rules, so we're unforgiving here. */ - if (lg->regs->eax != LHCALL_LGUEST_INIT) { - kill_guest(lg, "hypercall %li before LGUEST_INIT", - lg->regs->eax); + if (lg->hcall->arg0 != LHCALL_LGUEST_INIT) { + kill_guest(lg, "hypercall %li before INIT", lg->hcall->arg0); return; } - /* We insist that the Time Stamp Counter exist and doesn't change with - * cpu frequency. Some devious chip manufacturers decided that TSC - * changes could be handled in software. I decided that time going - * backwards might be good for benchmarks, but it's bad for users. - * - * We also insist that the TSC be stable: the kernel detects unreliable - * TSCs for its own purposes, and we use that here. */ - if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable()) - tsc_speed = tsc_khz; - else - tsc_speed = 0; - - /* The pointer to the Guest's "struct lguest_data" is the only - * argument. We check that address now. */ - if (!lguest_address_ok(lg, lg->regs->edx, sizeof(*lg->lguest_data))) { + if (lguest_arch_init_hypercalls(lg)) kill_guest(lg, "bad guest page %p", lg->lguest_data); - return; - } - - /* Having checked it, we simply set lg->lguest_data to point straight - * into the Launcher's memory at the right place and then use - * 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 + lg->regs->edx; /* The Guest tells us where we're not to deliver interrupts by putting * the range of addresses into "struct lguest_data". */ @@ -224,8 +184,7 @@ static void initialize(struct lguest *lg) || get_user(lg->noirq_end, &lg->lguest_data->noirq_end) /* 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(tsc_speed, &lg->lguest_data->tsc_khz)) + || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)) kill_guest(lg, "bad guest page %p", lg->lguest_data); /* We write the current time into the Guest's data page once now. */ @@ -237,9 +196,6 @@ static void initialize(struct lguest *lg) * page. */ guest_pagetable_clear_all(lg); } -/* Now we've examined the hypercall code; our Guest can make requests. There - * is one other way we can do things for the Guest, as we see in - * emulate_insn(). */ /*H:100 * Hypercalls diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index 662994b776cc..00c869bd9f79 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -107,7 +107,7 @@ struct lguest u8 ss1; /* If a hypercall was asked for, this points to the arguments. */ - struct lguest_regs *hcall; + struct hcall_args *hcall; /* Do we need to stop what we're doing and return to userspace? */ int break_out; @@ -197,6 +197,8 @@ void lguest_arch_host_init(void); void lguest_arch_host_fini(void); void lguest_arch_run_guest(struct lguest *lg); void lguest_arch_handle_trap(struct lguest *lg); +int lguest_arch_init_hypercalls(struct lguest *lg); +int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args); /* <arch>/switcher.S: */ extern char start_switcher_text[], end_switcher_text[], switch_to_guest[]; diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 0cc251cbc72a..2ef64a2734d3 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -323,7 +323,9 @@ void lguest_arch_handle_trap(struct lguest *lg) cond_resched(); return; case LGUEST_TRAP_ENTRY: - lg->hcall = lg->regs; + /* Our 'struct hcall_args' maps directly over our regs: we set + * up the pointer now to indicate a hypercall is pending. */ + lg->hcall = (struct hcall_args *)lg->regs; return; } @@ -475,3 +477,61 @@ void __exit lguest_arch_host_fini(void) } unlock_cpu_hotplug(); } + + +/*H:122 The i386-specific hypercalls simply farm out to the right functions. */ +int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args) +{ + switch (args->arg0) { + case LHCALL_LOAD_GDT: + load_guest_gdt(lg, args->arg1, args->arg2); + break; + case LHCALL_LOAD_IDT_ENTRY: + load_guest_idt_entry(lg, args->arg1, args->arg2, args->arg3); + break; + case LHCALL_LOAD_TLS: + guest_load_tls(lg, args->arg1); + break; + default: + /* Bad Guest. Bad! */ + return -EIO; + } + return 0; +} + +/*H:126 i386-specific hypercall initialization: */ +int lguest_arch_init_hypercalls(struct lguest *lg) +{ + u32 tsc_speed; + + /* The pointer to the Guest's "struct lguest_data" is the only + * argument. We check that address now. */ + if (!lguest_address_ok(lg, lg->hcall->arg1, sizeof(*lg->lguest_data))) + return -EFAULT; + + /* Having checked it, we simply set lg->lguest_data to point straight + * into the Launcher's memory at the right place and then use + * 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 + lg->hcall->arg1; + + /* We insist that the Time Stamp Counter exist and doesn't change with + * cpu frequency. Some devious chip manufacturers decided that TSC + * changes could be handled in software. I decided that time going + * backwards might be good for benchmarks, but it's bad for users. + * + * We also insist that the TSC be stable: the kernel detects unreliable + * TSCs for its own purposes, and we use that here. */ + if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable()) + tsc_speed = tsc_khz; + else + tsc_speed = 0; + if (put_user(tsc_speed, &lg->lguest_data->tsc_khz)) + return -EFAULT; + + return 0; +} +/* Now we've examined the hypercall code; our Guest can make requests. There + * is one other way we can do things for the Guest, as we see in + * emulate_insn(). :*/ diff --git a/include/asm-x86/lguest_hcall.h b/include/asm-x86/lguest_hcall.h index 7859cfe0ebb2..8f2a1edc4fe2 100644 --- a/include/asm-x86/lguest_hcall.h +++ b/include/asm-x86/lguest_hcall.h @@ -2,6 +2,8 @@ #ifndef _X86_LGUEST_HCALL_H #define _X86_LGUEST_HCALL_H +#include <asm/hw_irq.h> + #define LHCALL_FLUSH_ASYNC 0 #define LHCALL_LGUEST_INIT 1 #define LHCALL_CRASH 2 @@ -59,9 +61,9 @@ void async_hcall(unsigned long call, #define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32) #define LHCALL_RING_SIZE 64 -struct hcall_ring +struct hcall_args { - u32 eax, edx, ebx, ecx; + /* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */ + unsigned long arg0, arg2, arg3, arg1; }; - #endif /* _I386_LGUEST_HCALL_H */ diff --git a/include/linux/lguest.h b/include/linux/lguest.h index 8e959deed412..ea335c8f86c3 100644 --- a/include/linux/lguest.h +++ b/include/linux/lguest.h @@ -36,7 +36,7 @@ struct lguest_data /* 0xFF == done (set by Host), 0 == pending (set by Guest). */ u8 hcall_status[LHCALL_RING_SIZE]; /* The actual registers for the hypercalls. */ - struct hcall_ring hcalls[LHCALL_RING_SIZE]; + struct hcall_args hcalls[LHCALL_RING_SIZE]; /* Fields initialized by the Host at boot: */ /* Memory not to try to access */ |