From b410e7b1499c49513cab18275db8a8ab549d9e09 Mon Sep 17 00:00:00 2001 From: Jes Sorensen Date: Mon, 22 Oct 2007 11:03:31 +1000 Subject: Make hypercalls arch-independent. Clean up the hypercall code to make the code in hypercalls.c architecture independent. First process the common hypercalls and then call lguest_arch_do_hcall() if the call hasn't been handled. Rename struct hcall_ring to hcall_args. This patch requires the previous patch which reorganize the layout of struct lguest_regs on i386 so they match the layout of struct hcall_args. Signed-off-by: Jes Sorensen Signed-off-by: Rusty Russell --- drivers/lguest/hypercalls.c | 104 +++++++++++++------------------------------- 1 file changed, 30 insertions(+), 74 deletions(-) (limited to 'drivers/lguest/hypercalls.c') diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index 0175a9f0334..2859a768728 100644 --- a/drivers/lguest/hypercalls.c +++ b/drivers/lguest/hypercalls.c @@ -25,17 +25,13 @@ #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. - * - * 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 -- cgit v1.2.3