lguest: make registers per-vcpu
This is the most obvious per-vcpu field: registers. So this patch moves it from struct lguest to struct vcpu, and patch the places in which they are used, accordingly Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Родитель
a3863f68b0
Коммит
a53a35a8b4
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@ -70,7 +70,7 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
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/* There are two cases for interrupts: one where the Guest is already
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* in the kernel, and a more complex one where the Guest is in
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* userspace. We check the privilege level to find out. */
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if ((lg->regs->ss&0x3) != GUEST_PL) {
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if ((cpu->regs->ss&0x3) != GUEST_PL) {
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/* The Guest told us their kernel stack with the SET_STACK
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* hypercall: both the virtual address and the segment */
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virtstack = lg->esp1;
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@ -81,12 +81,12 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
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* stack: when the Guest does an "iret" back from the interrupt
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* handler the CPU will notice they're dropping privilege
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* levels and expect these here. */
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push_guest_stack(lg, &gstack, lg->regs->ss);
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push_guest_stack(lg, &gstack, lg->regs->esp);
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push_guest_stack(lg, &gstack, cpu->regs->ss);
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push_guest_stack(lg, &gstack, cpu->regs->esp);
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} else {
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/* We're staying on the same Guest (kernel) stack. */
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virtstack = lg->regs->esp;
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ss = lg->regs->ss;
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virtstack = cpu->regs->esp;
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ss = cpu->regs->ss;
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origstack = gstack = guest_pa(lg, virtstack);
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}
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@ -95,7 +95,7 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
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* the "Interrupt Flag" bit is always set. We copy that bit from the
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* Guest's "irq_enabled" field into the eflags word: we saw the Guest
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* copy it back in "lguest_iret". */
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eflags = lg->regs->eflags;
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eflags = cpu->regs->eflags;
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if (get_user(irq_enable, &lg->lguest_data->irq_enabled) == 0
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&& !(irq_enable & X86_EFLAGS_IF))
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eflags &= ~X86_EFLAGS_IF;
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@ -104,19 +104,19 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
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* "eflags" word, the old code segment, and the old instruction
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* pointer. */
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push_guest_stack(lg, &gstack, eflags);
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push_guest_stack(lg, &gstack, lg->regs->cs);
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push_guest_stack(lg, &gstack, lg->regs->eip);
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push_guest_stack(lg, &gstack, cpu->regs->cs);
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push_guest_stack(lg, &gstack, cpu->regs->eip);
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/* For the six traps which supply an error code, we push that, too. */
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if (has_err)
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push_guest_stack(lg, &gstack, lg->regs->errcode);
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push_guest_stack(lg, &gstack, cpu->regs->errcode);
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/* Now we've pushed all the old state, we change the stack, the code
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* segment and the address to execute. */
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lg->regs->ss = ss;
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lg->regs->esp = virtstack + (gstack - origstack);
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lg->regs->cs = (__KERNEL_CS|GUEST_PL);
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lg->regs->eip = idt_address(lo, hi);
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cpu->regs->ss = ss;
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cpu->regs->esp = virtstack + (gstack - origstack);
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cpu->regs->cs = (__KERNEL_CS|GUEST_PL);
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cpu->regs->eip = idt_address(lo, hi);
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/* There are two kinds of interrupt handlers: 0xE is an "interrupt
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* gate" which expects interrupts to be disabled on entry. */
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@ -157,7 +157,7 @@ void maybe_do_interrupt(struct lg_cpu *cpu)
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/* They may be in the middle of an iret, where they asked us never to
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* deliver interrupts. */
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if (lg->regs->eip >= lg->noirq_start && lg->regs->eip < lg->noirq_end)
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if (cpu->regs->eip >= lg->noirq_start && cpu->regs->eip < lg->noirq_end)
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return;
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/* If they're halted, interrupts restart them. */
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@ -44,6 +44,10 @@ struct lg_cpu {
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unsigned int id;
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struct lguest *lg;
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/* At end of a page shared mapped over lguest_pages in guest. */
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unsigned long regs_page;
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struct lguest_regs *regs;
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/* If a hypercall was asked for, this points to the arguments. */
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struct hcall_args *hcall;
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u32 next_hcall;
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@ -58,9 +62,6 @@ struct lg_cpu {
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/* The private info the thread maintains about the guest. */
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struct lguest
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{
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/* At end of a page shared mapped over lguest_pages in guest. */
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unsigned long regs_page;
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struct lguest_regs *regs;
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struct lguest_data __user *lguest_data;
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struct task_struct *tsk;
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struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
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@ -181,7 +182,7 @@ void lguest_arch_run_guest(struct lg_cpu *cpu);
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void lguest_arch_handle_trap(struct lg_cpu *cpu);
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int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
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int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
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void lguest_arch_setup_regs(struct lguest *lg, unsigned long start);
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void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
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/* <arch>/switcher.S: */
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extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
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@ -106,6 +106,19 @@ static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip)
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cpu->lg->nr_cpus++;
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init_clockdev(cpu);
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/* We need a complete page for the Guest registers: they are accessible
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* to the Guest and we can only grant it access to whole pages. */
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cpu->regs_page = get_zeroed_page(GFP_KERNEL);
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if (!cpu->regs_page)
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return -ENOMEM;
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/* We actually put the registers at the bottom of the page. */
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cpu->regs = (void *)cpu->regs_page + PAGE_SIZE - sizeof(*cpu->regs);
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/* Now we initialize the Guest's registers, handing it the start
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* address. */
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lguest_arch_setup_regs(cpu, start_ip);
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return 0;
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}
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@ -160,16 +173,6 @@ static int initialize(struct file *file, const unsigned long __user *input)
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if (err)
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goto release_guest;
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/* We need a complete page for the Guest registers: they are accessible
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* to the Guest and we can only grant it access to whole pages. */
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lg->regs_page = get_zeroed_page(GFP_KERNEL);
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if (!lg->regs_page) {
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err = -ENOMEM;
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goto release_guest;
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}
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/* We actually put the registers at the bottom of the page. */
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lg->regs = (void *)lg->regs_page + PAGE_SIZE - sizeof(*lg->regs);
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/* Initialize the Guest's shadow page tables, using the toplevel
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* address the Launcher gave us. This allocates memory, so can
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* fail. */
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@ -177,10 +180,6 @@ static int initialize(struct file *file, const unsigned long __user *input)
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if (err)
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goto free_regs;
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/* Now we initialize the Guest's registers, handing it the start
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* address. */
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lguest_arch_setup_regs(lg, args[3]);
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/* We keep a pointer to the Launcher task (ie. current task) for when
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* other Guests want to wake this one (inter-Guest I/O). */
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lg->tsk = current;
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@ -205,7 +204,8 @@ static int initialize(struct file *file, const unsigned long __user *input)
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return sizeof(args);
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free_regs:
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free_page(lg->regs_page);
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/* FIXME: This should be in free_vcpu */
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free_page(lg->cpus[0].regs_page);
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release_guest:
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kfree(lg);
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unlock:
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@ -280,9 +280,12 @@ static int close(struct inode *inode, struct file *file)
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/* We need the big lock, to protect from inter-guest I/O and other
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* Launchers initializing guests. */
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mutex_lock(&lguest_lock);
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for (i = 0; i < lg->nr_cpus; i++)
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for (i = 0; i < lg->nr_cpus; i++) {
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/* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
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hrtimer_cancel(&lg->cpus[i].hrt);
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/* We can free up the register page we allocated. */
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free_page(lg->cpus[i].regs_page);
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}
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/* Free up the shadow page tables for the Guest. */
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free_guest_pagetable(lg);
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/* Now all the memory cleanups are done, it's safe to release the
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@ -292,8 +295,6 @@ static int close(struct inode *inode, struct file *file)
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* kmalloc()ed string, either of which is ok to hand to kfree(). */
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if (!IS_ERR(lg->dead))
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kfree(lg->dead);
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/* We can free up the register page we allocated. */
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free_page(lg->regs_page);
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/* We clear the entire structure, which also marks it as free for the
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* next user. */
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memset(lg, 0, sizeof(*lg));
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@ -640,6 +640,7 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
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pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
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pgd_t switcher_pgd;
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pte_t regs_pte;
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unsigned long pfn;
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/* Make the last PGD entry for this Guest point to the Switcher's PTE
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* page for this CPU (with appropriate flags). */
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@ -654,7 +655,8 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
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* CPU's "struct lguest_pages": if we make sure the Guest's register
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* page is already mapped there, we don't have to copy them out
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* again. */
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regs_pte = pfn_pte (__pa(lg->regs_page) >> PAGE_SHIFT, __pgprot(_PAGE_KERNEL));
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pfn = __pa(cpu->regs_page) >> PAGE_SHIFT;
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regs_pte = pfn_pte(pfn, __pgprot(_PAGE_KERNEL));
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switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTRS_PER_PTE] = regs_pte;
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}
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/*:*/
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@ -127,7 +127,7 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
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/* Set the trap number to 256 (impossible value). If we fault while
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* switching to the Guest (bad segment registers or bug), this will
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* cause us to abort the Guest. */
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lg->regs->trapnum = 256;
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cpu->regs->trapnum = 256;
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/* Now: we push the "eflags" register on the stack, then do an "lcall".
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* This is how we change from using the kernel code segment to using
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@ -195,11 +195,11 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
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* bad virtual address. We have to grab this now, because once we
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* re-enable interrupts an interrupt could fault and thus overwrite
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* cr2, or we could even move off to a different CPU. */
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if (lg->regs->trapnum == 14)
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if (cpu->regs->trapnum == 14)
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lg->arch.last_pagefault = read_cr2();
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/* Similarly, if we took a trap because the Guest used the FPU,
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* we have to restore the FPU it expects to see. */
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else if (lg->regs->trapnum == 7)
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else if (cpu->regs->trapnum == 7)
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math_state_restore();
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/* Restore SYSENTER if it's supposed to be on. */
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@ -225,12 +225,12 @@ static int emulate_insn(struct lg_cpu *cpu)
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unsigned int insnlen = 0, in = 0, shift = 0;
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/* The eip contains the *virtual* address of the Guest's instruction:
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* guest_pa just subtracts the Guest's page_offset. */
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unsigned long physaddr = guest_pa(lg, lg->regs->eip);
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unsigned long physaddr = guest_pa(lg, cpu->regs->eip);
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/* This must be the Guest kernel trying to do something, not userspace!
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* The bottom two bits of the CS segment register are the privilege
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* level. */
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if ((lg->regs->cs & 3) != GUEST_PL)
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if ((cpu->regs->cs & 3) != GUEST_PL)
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return 0;
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/* Decoding x86 instructions is icky. */
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@ -273,12 +273,12 @@ static int emulate_insn(struct lg_cpu *cpu)
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if (in) {
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/* Lower bit tells is whether it's a 16 or 32 bit access */
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if (insn & 0x1)
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lg->regs->eax = 0xFFFFFFFF;
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cpu->regs->eax = 0xFFFFFFFF;
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else
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lg->regs->eax |= (0xFFFF << shift);
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cpu->regs->eax |= (0xFFFF << shift);
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}
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/* Finally, we've "done" the instruction, so move past it. */
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lg->regs->eip += insnlen;
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cpu->regs->eip += insnlen;
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/* Success! */
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return 1;
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}
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@ -287,12 +287,12 @@ static int emulate_insn(struct lg_cpu *cpu)
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void lguest_arch_handle_trap(struct lg_cpu *cpu)
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{
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struct lguest *lg = cpu->lg;
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switch (lg->regs->trapnum) {
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switch (cpu->regs->trapnum) {
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case 13: /* We've intercepted a General Protection Fault. */
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/* Check if this was one of those annoying IN or OUT
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* instructions which we need to emulate. If so, we just go
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* back into the Guest after we've done it. */
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if (lg->regs->errcode == 0) {
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if (cpu->regs->errcode == 0) {
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if (emulate_insn(cpu))
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return;
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}
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@ -307,7 +307,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
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*
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* The errcode tells whether this was a read or a write, and
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* whether kernel or userspace code. */
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if (demand_page(lg, lg->arch.last_pagefault, lg->regs->errcode))
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if (demand_page(lg, lg->arch.last_pagefault, cpu->regs->errcode))
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return;
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/* OK, it's really not there (or not OK): the Guest needs to
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@ -338,19 +338,19 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
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case LGUEST_TRAP_ENTRY:
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/* Our 'struct hcall_args' maps directly over our regs: we set
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* up the pointer now to indicate a hypercall is pending. */
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cpu->hcall = (struct hcall_args *)lg->regs;
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cpu->hcall = (struct hcall_args *)cpu->regs;
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return;
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}
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/* We didn't handle the trap, so it needs to go to the Guest. */
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if (!deliver_trap(cpu, lg->regs->trapnum))
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if (!deliver_trap(cpu, cpu->regs->trapnum))
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/* If the Guest doesn't have a handler (either it hasn't
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* registered any yet, or it's one of the faults we don't let
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* it handle), it dies with a cryptic error message. */
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kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
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lg->regs->trapnum, lg->regs->eip,
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lg->regs->trapnum == 14 ? lg->arch.last_pagefault
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: lg->regs->errcode);
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cpu->regs->trapnum, cpu->regs->eip,
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cpu->regs->trapnum == 14 ? lg->arch.last_pagefault
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: cpu->regs->errcode);
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}
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/* Now we can look at each of the routines this calls, in increasing order of
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@ -557,9 +557,9 @@ int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
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*
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* Most of the Guest's registers are left alone: we used get_zeroed_page() to
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* allocate the structure, so they will be 0. */
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void lguest_arch_setup_regs(struct lguest *lg, unsigned long start)
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void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start)
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{
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struct lguest_regs *regs = lg->regs;
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struct lguest_regs *regs = cpu->regs;
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/* There are four "segment" registers which the Guest needs to boot:
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* The "code segment" register (cs) refers to the kernel code segment
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@ -586,5 +586,5 @@ void lguest_arch_setup_regs(struct lguest *lg, unsigned long start)
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/* There are a couple of GDT entries the Guest expects when first
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* booting. */
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setup_guest_gdt(lg);
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setup_guest_gdt(cpu->lg);
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}
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