diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c index 8f59232f458b..468faf8233d6 100644 --- a/drivers/lguest/interrupts_and_traps.c +++ b/drivers/lguest/interrupts_and_traps.c @@ -70,7 +70,7 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err) /* 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 * userspace. We check the privilege level to find out. */ - if ((lg->regs->ss&0x3) != GUEST_PL) { + 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; @@ -81,12 +81,12 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err) * 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, lg->regs->ss); - push_guest_stack(lg, &gstack, lg->regs->esp); + push_guest_stack(lg, &gstack, cpu->regs->ss); + push_guest_stack(lg, &gstack, cpu->regs->esp); } else { /* We're staying on the same Guest (kernel) stack. */ - virtstack = lg->regs->esp; - ss = lg->regs->ss; + virtstack = cpu->regs->esp; + ss = cpu->regs->ss; origstack = gstack = guest_pa(lg, virtstack); } @@ -95,7 +95,7 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err) * the "Interrupt Flag" bit is always set. We copy that bit from the * Guest's "irq_enabled" field into the eflags word: we saw the Guest * copy it back in "lguest_iret". */ - eflags = lg->regs->eflags; + eflags = cpu->regs->eflags; if (get_user(irq_enable, &lg->lguest_data->irq_enabled) == 0 && !(irq_enable & X86_EFLAGS_IF)) eflags &= ~X86_EFLAGS_IF; @@ -104,19 +104,19 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err) * "eflags" word, the old code segment, and the old instruction * pointer. */ push_guest_stack(lg, &gstack, eflags); - push_guest_stack(lg, &gstack, lg->regs->cs); - push_guest_stack(lg, &gstack, lg->regs->eip); + push_guest_stack(lg, &gstack, cpu->regs->cs); + push_guest_stack(lg, &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, lg->regs->errcode); + push_guest_stack(lg, &gstack, cpu->regs->errcode); /* Now we've pushed all the old state, we change the stack, the code * segment and the address to execute. */ - lg->regs->ss = ss; - lg->regs->esp = virtstack + (gstack - origstack); - lg->regs->cs = (__KERNEL_CS|GUEST_PL); - lg->regs->eip = idt_address(lo, hi); + cpu->regs->ss = ss; + cpu->regs->esp = virtstack + (gstack - origstack); + cpu->regs->cs = (__KERNEL_CS|GUEST_PL); + cpu->regs->eip = idt_address(lo, hi); /* There are two kinds of interrupt handlers: 0xE is an "interrupt * gate" which expects interrupts to be disabled on entry. */ @@ -157,7 +157,7 @@ void maybe_do_interrupt(struct lg_cpu *cpu) /* They may be in the middle of an iret, where they asked us never to * deliver interrupts. */ - if (lg->regs->eip >= lg->noirq_start && lg->regs->eip < lg->noirq_end) + if (cpu->regs->eip >= lg->noirq_start && cpu->regs->eip < lg->noirq_end) return; /* If they're halted, interrupts restart them. */ diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index 072d0d4fd0b9..35b331230c55 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -44,6 +44,10 @@ struct lg_cpu { unsigned int id; struct lguest *lg; + /* At end of a page shared mapped over lguest_pages in guest. */ + unsigned long regs_page; + struct lguest_regs *regs; + /* If a hypercall was asked for, this points to the arguments. */ struct hcall_args *hcall; u32 next_hcall; @@ -58,9 +62,6 @@ struct lg_cpu { /* The private info the thread maintains about the guest. */ struct lguest { - /* At end of a page shared mapped over lguest_pages in guest. */ - unsigned long regs_page; - struct lguest_regs *regs; struct lguest_data __user *lguest_data; struct task_struct *tsk; struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */ @@ -181,7 +182,7 @@ void lguest_arch_run_guest(struct lg_cpu *cpu); void lguest_arch_handle_trap(struct lg_cpu *cpu); int lguest_arch_init_hypercalls(struct lg_cpu *cpu); int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args); -void lguest_arch_setup_regs(struct lguest *lg, unsigned long start); +void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start); /* /switcher.S: */ extern char start_switcher_text[], end_switcher_text[], switch_to_guest[]; diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c index 605db5c49e7f..d21d95b2b1fc 100644 --- a/drivers/lguest/lguest_user.c +++ b/drivers/lguest/lguest_user.c @@ -106,6 +106,19 @@ static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip) cpu->lg->nr_cpus++; init_clockdev(cpu); + /* We need a complete page for the Guest registers: they are accessible + * to the Guest and we can only grant it access to whole pages. */ + cpu->regs_page = get_zeroed_page(GFP_KERNEL); + if (!cpu->regs_page) + return -ENOMEM; + + /* We actually put the registers at the bottom of the page. */ + cpu->regs = (void *)cpu->regs_page + PAGE_SIZE - sizeof(*cpu->regs); + + /* Now we initialize the Guest's registers, handing it the start + * address. */ + lguest_arch_setup_regs(cpu, start_ip); + return 0; } @@ -160,16 +173,6 @@ static int initialize(struct file *file, const unsigned long __user *input) if (err) goto release_guest; - /* We need a complete page for the Guest registers: they are accessible - * to the Guest and we can only grant it access to whole pages. */ - lg->regs_page = get_zeroed_page(GFP_KERNEL); - if (!lg->regs_page) { - err = -ENOMEM; - goto release_guest; - } - /* We actually put the registers at the bottom of the page. */ - lg->regs = (void *)lg->regs_page + PAGE_SIZE - sizeof(*lg->regs); - /* Initialize the Guest's shadow page tables, using the toplevel * address the Launcher gave us. This allocates memory, so can * fail. */ @@ -177,10 +180,6 @@ static int initialize(struct file *file, const unsigned long __user *input) if (err) goto free_regs; - /* Now we initialize the Guest's registers, handing it the start - * address. */ - lguest_arch_setup_regs(lg, args[3]); - /* We keep a pointer to the Launcher task (ie. current task) for when * other Guests want to wake this one (inter-Guest I/O). */ lg->tsk = current; @@ -205,7 +204,8 @@ static int initialize(struct file *file, const unsigned long __user *input) return sizeof(args); free_regs: - free_page(lg->regs_page); + /* FIXME: This should be in free_vcpu */ + free_page(lg->cpus[0].regs_page); release_guest: kfree(lg); unlock: @@ -280,9 +280,12 @@ static int close(struct inode *inode, struct file *file) /* We need the big lock, to protect from inter-guest I/O and other * Launchers initializing guests. */ mutex_lock(&lguest_lock); - for (i = 0; i < lg->nr_cpus; i++) + for (i = 0; i < lg->nr_cpus; i++) { /* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */ hrtimer_cancel(&lg->cpus[i].hrt); + /* We can free up the register page we allocated. */ + free_page(lg->cpus[i].regs_page); + } /* Free up the shadow page tables for the Guest. */ free_guest_pagetable(lg); /* Now all the memory cleanups are done, it's safe to release the @@ -292,8 +295,6 @@ static int close(struct inode *inode, struct file *file) * kmalloc()ed string, either of which is ok to hand to kfree(). */ if (!IS_ERR(lg->dead)) kfree(lg->dead); - /* We can free up the register page we allocated. */ - free_page(lg->regs_page); /* We clear the entire structure, which also marks it as free for the * next user. */ memset(lg, 0, sizeof(*lg)); diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index 17d3329e34c2..f19add469944 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -640,6 +640,7 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages) pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages); pgd_t switcher_pgd; pte_t regs_pte; + unsigned long pfn; /* Make the last PGD entry for this Guest point to the Switcher's PTE * page for this CPU (with appropriate flags). */ @@ -654,7 +655,8 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages) * CPU's "struct lguest_pages": if we make sure the Guest's register * page is already mapped there, we don't have to copy them out * again. */ - regs_pte = pfn_pte (__pa(lg->regs_page) >> PAGE_SHIFT, __pgprot(_PAGE_KERNEL)); + pfn = __pa(cpu->regs_page) >> PAGE_SHIFT; + regs_pte = pfn_pte(pfn, __pgprot(_PAGE_KERNEL)); switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTRS_PER_PTE] = regs_pte; } /*:*/ diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index ae46c6b1f2f9..d96a93d95aea 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -127,7 +127,7 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages) /* Set the trap number to 256 (impossible value). If we fault while * switching to the Guest (bad segment registers or bug), this will * cause us to abort the Guest. */ - lg->regs->trapnum = 256; + cpu->regs->trapnum = 256; /* Now: we push the "eflags" register on the stack, then do an "lcall". * This is how we change from using the kernel code segment to using @@ -195,11 +195,11 @@ void lguest_arch_run_guest(struct lg_cpu *cpu) * bad virtual address. We have to grab this now, because once we * re-enable interrupts an interrupt could fault and thus overwrite * cr2, or we could even move off to a different CPU. */ - if (lg->regs->trapnum == 14) + if (cpu->regs->trapnum == 14) lg->arch.last_pagefault = read_cr2(); /* Similarly, if we took a trap because the Guest used the FPU, * we have to restore the FPU it expects to see. */ - else if (lg->regs->trapnum == 7) + else if (cpu->regs->trapnum == 7) math_state_restore(); /* Restore SYSENTER if it's supposed to be on. */ @@ -225,12 +225,12 @@ static int emulate_insn(struct lg_cpu *cpu) unsigned int insnlen = 0, in = 0, shift = 0; /* The eip contains the *virtual* address of the Guest's instruction: * guest_pa just subtracts the Guest's page_offset. */ - unsigned long physaddr = guest_pa(lg, lg->regs->eip); + unsigned long physaddr = guest_pa(lg, cpu->regs->eip); /* This must be the Guest kernel trying to do something, not userspace! * The bottom two bits of the CS segment register are the privilege * level. */ - if ((lg->regs->cs & 3) != GUEST_PL) + if ((cpu->regs->cs & 3) != GUEST_PL) return 0; /* Decoding x86 instructions is icky. */ @@ -273,12 +273,12 @@ static int emulate_insn(struct lg_cpu *cpu) if (in) { /* Lower bit tells is whether it's a 16 or 32 bit access */ if (insn & 0x1) - lg->regs->eax = 0xFFFFFFFF; + cpu->regs->eax = 0xFFFFFFFF; else - lg->regs->eax |= (0xFFFF << shift); + cpu->regs->eax |= (0xFFFF << shift); } /* Finally, we've "done" the instruction, so move past it. */ - lg->regs->eip += insnlen; + cpu->regs->eip += insnlen; /* Success! */ return 1; } @@ -287,12 +287,12 @@ static int emulate_insn(struct lg_cpu *cpu) void lguest_arch_handle_trap(struct lg_cpu *cpu) { struct lguest *lg = cpu->lg; - switch (lg->regs->trapnum) { + switch (cpu->regs->trapnum) { case 13: /* We've intercepted a General Protection Fault. */ /* Check if this was one of those annoying IN or OUT * instructions which we need to emulate. If so, we just go * back into the Guest after we've done it. */ - if (lg->regs->errcode == 0) { + if (cpu->regs->errcode == 0) { if (emulate_insn(cpu)) return; } @@ -307,7 +307,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu) * * The errcode tells whether this was a read or a write, and * whether kernel or userspace code. */ - if (demand_page(lg, lg->arch.last_pagefault, lg->regs->errcode)) + if (demand_page(lg, lg->arch.last_pagefault, cpu->regs->errcode)) return; /* OK, it's really not there (or not OK): the Guest needs to @@ -338,19 +338,19 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu) case LGUEST_TRAP_ENTRY: /* Our 'struct hcall_args' maps directly over our regs: we set * up the pointer now to indicate a hypercall is pending. */ - cpu->hcall = (struct hcall_args *)lg->regs; + cpu->hcall = (struct hcall_args *)cpu->regs; return; } /* We didn't handle the trap, so it needs to go to the Guest. */ - if (!deliver_trap(cpu, lg->regs->trapnum)) + if (!deliver_trap(cpu, cpu->regs->trapnum)) /* If the Guest doesn't have a handler (either it hasn't * registered any yet, or it's one of the faults we don't let * it handle), it dies with a cryptic error message. */ kill_guest(lg, "unhandled trap %li at %#lx (%#lx)", - lg->regs->trapnum, lg->regs->eip, - lg->regs->trapnum == 14 ? lg->arch.last_pagefault - : lg->regs->errcode); + cpu->regs->trapnum, cpu->regs->eip, + cpu->regs->trapnum == 14 ? lg->arch.last_pagefault + : cpu->regs->errcode); } /* Now we can look at each of the routines this calls, in increasing order of @@ -557,9 +557,9 @@ int lguest_arch_init_hypercalls(struct lg_cpu *cpu) * * Most of the Guest's registers are left alone: we used get_zeroed_page() to * allocate the structure, so they will be 0. */ -void lguest_arch_setup_regs(struct lguest *lg, unsigned long start) +void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start) { - struct lguest_regs *regs = lg->regs; + struct lguest_regs *regs = cpu->regs; /* There are four "segment" registers which the Guest needs to boot: * The "code segment" register (cs) refers to the kernel code segment @@ -586,5 +586,5 @@ void lguest_arch_setup_regs(struct lguest *lg, unsigned long start) /* There are a couple of GDT entries the Guest expects when first * booting. */ - setup_guest_gdt(lg); + setup_guest_gdt(cpu->lg); }