This is the guest code which replaces the parts of paravirt_ops with
hypercalls. It's fairly trivial. This patch also includes trivial
bus driver for lguest devices.
Signed-off-by: Rusty Russell <[email protected]>
===================================================================
--- /dev/null
+++ b/arch/i386/lguest/lguest.c
@@ -0,0 +1,595 @@
+/*
+ * Lguest specific paravirt-ops implementation
+ *
+ * Copyright (C) 2006, Rusty Russell <[email protected]> IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/kernel.h>
+#include <linux/start_kernel.h>
+#include <linux/string.h>
+#include <linux/console.h>
+#include <linux/screen_info.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/clocksource.h>
+#include <asm/paravirt.h>
+#include <asm/lguest.h>
+#include <asm/lguest_user.h>
+#include <asm/param.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/desc.h>
+#include <asm/setup.h>
+#include <asm/e820.h>
+#include <asm/pda.h>
+#include <asm/asm-offsets.h>
+
+extern int mce_disabled;
+
+struct lguest_data lguest_data;
+struct lguest_device_desc *lguest_devices;
+static __initdata const struct lguest_boot_info *boot = __va(0);
+
+void async_hcall(unsigned long call,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+ /* Note: This code assumes we're uniprocessor. */
+ static unsigned int next_call;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (lguest_data.hcall_status[next_call] != 0xFF) {
+ /* 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;
+ wmb();
+ lguest_data.hcall_status[next_call] = 0;
+ if (++next_call == LHCALL_RING_SIZE)
+ next_call = 0;
+ }
+ local_irq_restore(flags);
+}
+
+#ifdef PARAVIRT_LAZY_NONE /* Not in 2.6.20. */
+static int lazy_mode;
+static void fastcall lguest_lazy_mode(int mode)
+{
+ lazy_mode = mode;
+ if (mode == PARAVIRT_LAZY_NONE)
+ hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0);
+}
+
+static void lazy_hcall(unsigned long call,
+ unsigned long arg1,
+ unsigned long arg2,
+ unsigned long arg3)
+{
+ if (lazy_mode == PARAVIRT_LAZY_NONE)
+ hcall(call, arg1, arg2, arg3);
+ else
+ async_hcall(call, arg1, arg2, arg3);
+}
+#else
+#define lazy_hcall hcall
+#endif
+
+static unsigned long fastcall save_fl(void)
+{
+ return lguest_data.irq_enabled;
+}
+
+static void fastcall restore_fl(unsigned long flags)
+{
+ /* FIXME: Check if interrupt pending... */
+ lguest_data.irq_enabled = flags;
+}
+
+static void fastcall irq_disable(void)
+{
+ lguest_data.irq_enabled = 0;
+}
+
+static void fastcall irq_enable(void)
+{
+ /* Linux i386 code expects bit 9 set. */
+ /* FIXME: Check if interrupt pending... */
+ lguest_data.irq_enabled = 512;
+}
+
+static void fastcall lguest_load_gdt(const struct Xgt_desc_struct *desc)
+{
+ BUG_ON((desc->size+1)/8 != GDT_ENTRIES);
+ hcall(LHCALL_LOAD_GDT, __pa(desc->address), GDT_ENTRIES, 0);
+}
+
+static void fastcall lguest_load_idt(const struct Xgt_desc_struct *desc)
+{
+ unsigned int i;
+ struct desc_struct *idt = (void *)desc->address;
+
+ for (i = 0; i < (desc->size+1)/8; i++)
+ hcall(LHCALL_LOAD_IDT_ENTRY, i, idt[i].a, idt[i].b);
+}
+
+static int lguest_panic(struct notifier_block *nb, unsigned long l, void *p)
+{
+ hcall(LHCALL_CRASH, __pa(p), 0, 0);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block paniced = {
+ .notifier_call = lguest_panic
+};
+
+static cycle_t lguest_clock_read(void)
+{
+ /* FIXME: This is just the native one. Account stolen time! */
+ return paravirt_ops.read_tsc();
+}
+
+/* FIXME: Update iff tsc rate changes. */
+static struct clocksource lguest_clock = {
+ .name = "lguest",
+ .rating = 400,
+ .read = lguest_clock_read,
+ .mask = CLOCKSOURCE_MASK(64),
+ .mult = 0, /* to be set */
+ .shift = 22,
+ .is_continuous = 1,
+};
+
+static char *lguest_memory_setup(void)
+{
+ /* We do these here because lockcheck barfs if before start_kernel */
+ atomic_notifier_chain_register(&panic_notifier_list, &paniced);
+ lguest_clock.mult = lguest_data.clock_mult;
+ clocksource_register(&lguest_clock);
+
+ e820.nr_map = 0;
+ add_memory_region(0, PFN_PHYS(boot->max_pfn), E820_RAM);
+ return "LGUEST";
+}
+
+static fastcall void lguest_cpuid(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ int is_feature = (*eax == 1);
+
+ asm volatile ("cpuid"
+ : "=a" (*eax),
+ "=b" (*ebx),
+ "=c" (*ecx),
+ "=d" (*edx)
+ : "0" (*eax), "2" (*ecx));
+
+ if (is_feature) {
+ unsigned long *excap = (unsigned long *)ecx,
+ *features = (unsigned long *)edx;
+ /* Hypervisor needs to know when we flush kernel pages. */
+ set_bit(X86_FEATURE_PGE, features);
+ /* We don't have any features! */
+ clear_bit(X86_FEATURE_VME, features);
+ clear_bit(X86_FEATURE_DE, features);
+ clear_bit(X86_FEATURE_PSE, features);
+ clear_bit(X86_FEATURE_PAE, features);
+ clear_bit(X86_FEATURE_SEP, features);
+ clear_bit(X86_FEATURE_APIC, features);
+ clear_bit(X86_FEATURE_MTRR, features);
+ /* No MWAIT, either */
+ clear_bit(3, excap);
+ }
+}
+
+static unsigned long current_cr3;
+static void fastcall lguest_write_cr3(unsigned long cr3)
+{
+ hcall(LHCALL_NEW_PGTABLE, cr3, 0, 0);
+ current_cr3 = cr3;
+}
+
+static void fastcall lguest_flush_tlb(void)
+{
+ lazy_hcall(LHCALL_FLUSH_TLB, 0, 0, 0);
+}
+
+static void fastcall lguest_flush_tlb_kernel(void)
+{
+ lazy_hcall(LHCALL_FLUSH_TLB, 1, 0, 0);
+}
+
+static void fastcall lguest_flush_tlb_single(u32 addr)
+{
+ /* Simply set it to zero, and it will fault back in. */
+ lazy_hcall(LHCALL_SET_PTE, current_cr3, addr, 0);
+}
+
+/* FIXME: Eliminate all callers of this. */
+static fastcall void lguest_set_pte(pte_t *ptep, pte_t pteval)
+{
+ *ptep = pteval;
+ /* Don't bother with hypercall before initial setup. */
+ if (current_cr3)
+ hcall(LHCALL_SET_UNKNOWN_PTE, 0, 0, 0);
+}
+
+static fastcall void lguest_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
+{
+ *ptep = pteval;
+ lazy_hcall(LHCALL_SET_PTE, __pa(mm->pgd), addr, pteval.pte_low);
+}
+
+/* We only support two-level pagetables at the moment. */
+static fastcall void lguest_set_pud(pmd_t *pmdp, pmd_t pmdval)
+{
+ *pmdp = pmdval;
+ lazy_hcall(LHCALL_SET_PUD, __pa(pmdp)&PAGE_MASK,
+ (__pa(pmdp)&(PAGE_SIZE-1))/4, 0);
+}
+
+#ifdef CONFIG_X86_LOCAL_APIC
+static fastcall void lguest_apic_write(unsigned long reg, unsigned long v)
+{
+}
+
+static fastcall void lguest_apic_write_atomic(unsigned long reg, unsigned long v)
+{
+}
+
+static fastcall unsigned long lguest_apic_read(unsigned long reg)
+{
+ return 0;
+}
+#endif
+
+/* We move eflags word to lguest_data.irq_enabled to restore interrupt
+ state. For page faults, gpfs and virtual interrupts, the
+ hypervisor has saved eflags manually, otherwise it was delivered
+ directly and so eflags reflects the real machine IF state,
+ ie. interrupts on. Since the kernel always dies if it takes such a
+ trap with interrupts disabled anyway, turning interrupts back on
+ unconditionally here is OK. */
+asm("lguest_iret:"
+ " pushl %eax;"
+ " movl 12(%esp), %eax;"
+ "lguest_noirq_start:;"
+ " movl %eax,%ss:lguest_data+"__stringify(LGUEST_DATA_irq_enabled)";"
+ " popl %eax;"
+ " iret;"
+ "lguest_noirq_end:");
+extern void fastcall lguest_iret(void);
+extern char lguest_noirq_start[], lguest_noirq_end[];
+
+static void fastcall lguest_load_esp0(struct tss_struct *tss,
+ struct thread_struct *thread)
+{
+ lazy_hcall(LHCALL_SET_STACK, __KERNEL_DS|0x1, thread->esp0,
+ THREAD_SIZE/PAGE_SIZE);
+}
+
+static fastcall void lguest_load_tr_desc(void)
+{
+}
+
+static fastcall void lguest_set_ldt(const void *addr, unsigned entries)
+{
+ /* FIXME: Implement. */
+ BUG_ON(entries);
+}
+
+static fastcall void lguest_load_tls(struct thread_struct *t, unsigned int cpu)
+{
+ lazy_hcall(LHCALL_LOAD_TLS, __pa(&t->tls_array), cpu, 0);
+}
+
+static fastcall void lguest_set_debugreg(int regno, unsigned long value)
+{
+ /* FIXME: Implement */
+}
+
+static unsigned int lguest_cr0;
+static fastcall void lguest_clts(void)
+{
+ lazy_hcall(LHCALL_TS, 0, 0, 0);
+ lguest_cr0 &= ~8U;
+}
+
+static fastcall unsigned long lguest_read_cr0(void)
+{
+ return lguest_cr0;
+}
+
+static fastcall void lguest_write_cr0(unsigned long val)
+{
+ hcall(LHCALL_TS, val & 8, 0, 0);
+ lguest_cr0 = val;
+}
+
+static fastcall unsigned long lguest_read_cr2(void)
+{
+ return lguest_data.cr2;
+}
+
+static fastcall unsigned long lguest_read_cr3(void)
+{
+ return current_cr3;
+}
+
+/* Used to enable/disable PGE, but we don't care. */
+static fastcall unsigned long lguest_read_cr4(void)
+{
+ return 0;
+}
+
+static fastcall void lguest_write_cr4(unsigned long val)
+{
+}
+
+/* FIXME: These should be in a header somewhere */
+extern unsigned long init_pg_tables_end;
+
+static void fastcall lguest_time_irq(unsigned int irq, struct irq_desc *desc)
+{
+ do_timer(hcall(LHCALL_TIMER_READ, 0, 0, 0));
+ update_process_times(user_mode_vm(get_irq_regs()));
+}
+
+static void disable_lguest_irq(unsigned int irq)
+{
+ set_bit(irq, lguest_data.interrupts);
+}
+
+static void enable_lguest_irq(unsigned int irq)
+{
+ clear_bit(irq, lguest_data.interrupts);
+ /* FIXME: If it's pending? */
+}
+
+static struct irq_chip lguest_irq_controller = {
+ .name = "lguest",
+ .mask = disable_lguest_irq,
+ .mask_ack = disable_lguest_irq,
+ .unmask = enable_lguest_irq,
+};
+
+static void lguest_time_init(void)
+{
+ set_irq_handler(0, lguest_time_irq);
+ hcall(LHCALL_TIMER_START,HZ,0,0);
+}
+
+static void __init lguest_init_IRQ(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < LGUEST_IRQS; i++) {
+ int vector = FIRST_EXTERNAL_VECTOR + i;
+ if (i >= NR_IRQS)
+ break;
+ if (vector != SYSCALL_VECTOR) {
+ set_intr_gate(vector, interrupt[i]);
+ set_irq_chip_and_handler(i, &lguest_irq_controller,
+ handle_level_irq);
+ }
+ }
+ irq_ctx_init(smp_processor_id());
+}
+
+static inline void native_write_dt_entry(void *dt, int entry, u32 entry_low, u32 entry_high)
+{
+ u32 *lp = (u32 *)((char *)dt + entry*8);
+ lp[0] = entry_low;
+ lp[1] = entry_high;
+}
+
+static fastcall void lguest_write_ldt_entry(void *dt, int entrynum, u32 low, u32 high)
+{
+ /* FIXME: Allow this. */
+ BUG();
+}
+
+static fastcall void lguest_write_gdt_entry(void *dt, int entrynum,
+ u32 low, u32 high)
+{
+ native_write_dt_entry(dt, entrynum, low, high);
+ hcall(LHCALL_LOAD_GDT, __pa(dt), GDT_ENTRIES, 0);
+}
+
+static fastcall void lguest_write_idt_entry(void *dt, int entrynum,
+ u32 low, u32 high)
+{
+ native_write_dt_entry(dt, entrynum, low, high);
+ hcall(LHCALL_LOAD_IDT_ENTRY, entrynum, low, high);
+}
+
+#define LGUEST_IRQ "lguest_data+"__stringify(LGUEST_DATA_irq_enabled)
+#define DEF_LGUEST(name, code) \
+ extern const char start_##name[], end_##name[]; \
+ asm("start_" #name ": " code "; end_" #name ":")
+DEF_LGUEST(cli, "movl $0," LGUEST_IRQ);
+DEF_LGUEST(sti, "movl $512," LGUEST_IRQ);
+DEF_LGUEST(popf, "movl %eax," LGUEST_IRQ);
+DEF_LGUEST(pushf, "movl " LGUEST_IRQ ",%eax");
+DEF_LGUEST(pushf_cli, "movl " LGUEST_IRQ ",%eax; movl $0," LGUEST_IRQ);
+DEF_LGUEST(iret, ".byte 0xE9,0,0,0,0"); /* jmp ... */
+
+static const struct lguest_insns
+{
+ const char *start, *end;
+} lguest_insns[] = {
+ [PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli },
+ [PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti },
+ [PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf },
+ [PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf },
+ [PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli },
+ [PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret },
+};
+static unsigned lguest_patch(u8 type, u16 clobber, void *insns, unsigned len)
+{
+ unsigned int insn_len;
+
+ /* Don't touch it if we don't have a replacement */
+ if (type >= ARRAY_SIZE(lguest_insns) || !lguest_insns[type].start)
+ return len;
+
+ insn_len = lguest_insns[type].end - lguest_insns[type].start;
+
+ /* Similarly if we can't fit replacement. */
+ if (len < insn_len)
+ return len;
+
+ memcpy(insns, lguest_insns[type].start, insn_len);
+ if (type == PARAVIRT_INTERRUPT_RETURN) {
+ /* Jumps are relative. */
+ u32 off = (u32)lguest_iret - ((u32)insns + insn_len);
+ memcpy(insns+1, &off, sizeof(off));
+ }
+ return insn_len;
+}
+
+static void fastcall lguest_safe_halt(void)
+{
+ hcall(LHCALL_HALT, 0, 0, 0);
+}
+
+static unsigned long lguest_get_wallclock(void)
+{
+ return hcall(LHCALL_GET_WALLCLOCK, 0, 0, 0);
+}
+
+static void lguest_power_off(void)
+{
+ hcall(LHCALL_CRASH, __pa("Power down"), 0, 0);
+}
+
+static __attribute_used__ __init void lguest_init(void)
+{
+ extern struct Xgt_desc_struct cpu_gdt_descr;
+ extern struct i386_pda boot_pda;
+
+ paravirt_ops.name = "lguest";
+ paravirt_ops.paravirt_enabled = 1;
+ paravirt_ops.kernel_rpl = 1;
+
+ paravirt_ops.save_fl = save_fl;
+ paravirt_ops.restore_fl = restore_fl;
+ paravirt_ops.irq_disable = irq_disable;
+ paravirt_ops.irq_enable = irq_enable;
+ paravirt_ops.load_gdt = lguest_load_gdt;
+ paravirt_ops.memory_setup = lguest_memory_setup;
+ paravirt_ops.cpuid = lguest_cpuid;
+ paravirt_ops.write_cr3 = lguest_write_cr3;
+ paravirt_ops.flush_tlb_user = lguest_flush_tlb;
+ paravirt_ops.flush_tlb_single = lguest_flush_tlb_single;
+ paravirt_ops.flush_tlb_kernel = lguest_flush_tlb_kernel;
+ paravirt_ops.set_pte = lguest_set_pte;
+ paravirt_ops.set_pte_at = lguest_set_pte_at;
+ paravirt_ops.set_pmd = lguest_set_pud;
+#ifdef CONFIG_X86_LOCAL_APIC
+ paravirt_ops.apic_write = lguest_apic_write;
+ paravirt_ops.apic_write_atomic = lguest_apic_write_atomic;
+ paravirt_ops.apic_read = lguest_apic_read;
+#endif
+ paravirt_ops.load_idt = lguest_load_idt;
+ paravirt_ops.iret = lguest_iret;
+ paravirt_ops.load_esp0 = lguest_load_esp0;
+ paravirt_ops.load_tr_desc = lguest_load_tr_desc;
+ paravirt_ops.set_ldt = lguest_set_ldt;
+ paravirt_ops.load_tls = lguest_load_tls;
+ paravirt_ops.set_debugreg = lguest_set_debugreg;
+ paravirt_ops.clts = lguest_clts;
+ paravirt_ops.read_cr0 = lguest_read_cr0;
+ paravirt_ops.write_cr0 = lguest_write_cr0;
+ paravirt_ops.init_IRQ = lguest_init_IRQ;
+ paravirt_ops.read_cr2 = lguest_read_cr2;
+ paravirt_ops.read_cr3 = lguest_read_cr3;
+ paravirt_ops.read_cr4 = lguest_read_cr4;
+ paravirt_ops.write_cr4 = lguest_write_cr4;
+ paravirt_ops.write_ldt_entry = lguest_write_ldt_entry;
+ paravirt_ops.write_gdt_entry = lguest_write_gdt_entry;
+ paravirt_ops.write_idt_entry = lguest_write_idt_entry;
+ paravirt_ops.patch = lguest_patch;
+ paravirt_ops.safe_halt = lguest_safe_halt;
+ paravirt_ops.get_wallclock = lguest_get_wallclock;
+ paravirt_ops.time_init = lguest_time_init;
+#ifdef PARAVIRT_LAZY_NONE
+ paravirt_ops.set_lazy_mode = lguest_lazy_mode;
+#endif
+
+ memset(lguest_data.hcall_status,0xFF,sizeof(lguest_data.hcall_status));
+ lguest_data.noirq_start = (u32)lguest_noirq_start;
+ lguest_data.noirq_end = (u32)lguest_noirq_end;
+ hcall(LHCALL_LGUEST_INIT, __pa(&lguest_data), 0, 0);
+ strncpy(saved_command_line, boot->cmdline, COMMAND_LINE_SIZE);
+
+ /* We use top of mem for initial pagetables. */
+ init_pg_tables_end = __pa(pg0);
+
+ /* set up PDA descriptor */
+ pack_descriptor((u32 *)&cpu_gdt_table[GDT_ENTRY_PDA].a,
+ (u32 *)&cpu_gdt_table[GDT_ENTRY_PDA].b,
+ (unsigned)&boot_pda, sizeof(boot_pda)-1,
+ 0x80 | DESCTYPE_S | 0x02, 0);
+ load_gdt(&cpu_gdt_descr);
+ asm volatile ("mov %0, %%gs" : : "r" (__KERNEL_PDA) : "memory");
+
+ reserve_top_address(lguest_data.reserve_mem);
+
+ cpu_detect(&new_cpu_data);
+ /* Need this before paging_init. */
+ set_bit(X86_FEATURE_PGE, new_cpu_data.x86_capability);
+ /* Math is always hard! */
+ new_cpu_data.hard_math = 1;
+
+ /* FIXME: Better way? */
+ /* Suppress vgacon startup code */
+ SCREEN_INFO.orig_video_isVGA = VIDEO_TYPE_VLFB;
+
+ add_preferred_console("hvc", 0, NULL);
+
+#ifdef CONFIG_X86_MCE
+ mce_disabled = 1;
+#endif
+
+#ifdef CONFIG_ACPI
+ acpi_disabled = 1;
+ acpi_ht = 0;
+#endif
+ if (boot->initrd_size) {
+ /* We stash this at top of memory. */
+ INITRD_START = boot->max_pfn*PAGE_SIZE - boot->initrd_size;
+ INITRD_SIZE = boot->initrd_size;
+ LOADER_TYPE = 0xFF;
+ }
+
+ pm_power_off = lguest_power_off;
+ start_kernel();
+}
+
+asm("lguest_maybe_init:\n"
+ " cmpl $"__stringify(LGUEST_MAGIC_EBP)", %ebp\n"
+ " jne 1f\n"
+ " cmpl $"__stringify(LGUEST_MAGIC_EDI)", %edi\n"
+ " jne 1f\n"
+ " cmpl $"__stringify(LGUEST_MAGIC_ESI)", %esi\n"
+ " je lguest_init\n"
+ "1: ret");
+extern void asmlinkage lguest_maybe_init(void);
+paravirt_probe(lguest_maybe_init);
===================================================================
--- /dev/null
+++ b/arch/i386/lguest/lguest_bus.c
@@ -0,0 +1,180 @@
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <asm/lguest_device.h>
+#include <asm/lguest.h>
+#include <asm/io.h>
+
+static ssize_t type_show(struct device *_dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ return sprintf(buf, "%hu", lguest_devices[dev->index].type);
+}
+static ssize_t features_show(struct device *_dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ return sprintf(buf, "%hx", lguest_devices[dev->index].features);
+}
+static ssize_t pfn_show(struct device *_dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ return sprintf(buf, "%u", lguest_devices[dev->index].pfn);
+}
+static ssize_t status_show(struct device *_dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ return sprintf(buf, "%hx", lguest_devices[dev->index].status);
+}
+static ssize_t status_store(struct device *_dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ if (sscanf(buf, "%hi", &lguest_devices[dev->index].status) != 1)
+ return -EINVAL;
+ return count;
+}
+static struct device_attribute lguest_dev_attrs[] = {
+ __ATTR_RO(type),
+ __ATTR_RO(features),
+ __ATTR_RO(pfn),
+ __ATTR(status, 0644, status_show, status_store),
+ __ATTR_NULL
+};
+
+static int lguest_dev_match(struct device *_dev, struct device_driver *_drv)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ struct lguest_driver *drv = container_of(_drv,struct lguest_driver,drv);
+
+ return (drv->device_type == lguest_devices[dev->index].type);
+}
+
+struct lguest_bus {
+ struct bus_type bus;
+ struct device dev;
+};
+
+static struct lguest_bus lguest_bus = {
+ .bus = {
+ .name = "lguest",
+ .match = lguest_dev_match,
+ .dev_attrs = lguest_dev_attrs,
+ },
+ .dev = {
+ .parent = NULL,
+ .bus_id = "lguest",
+ }
+};
+
+static int lguest_dev_probe(struct device *_dev)
+{
+ int ret;
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ struct lguest_driver *drv = container_of(dev->dev.driver,
+ struct lguest_driver, drv);
+
+ lguest_devices[dev->index].status |= LGUEST_DEVICE_S_DRIVER;
+ ret = drv->probe(dev);
+ if (ret == 0)
+ lguest_devices[dev->index].status |= LGUEST_DEVICE_S_DRIVER_OK;
+ return ret;
+}
+
+static int lguest_dev_remove(struct device *_dev)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+ struct lguest_driver *drv = container_of(dev->dev.driver,
+ struct lguest_driver, drv);
+
+ if (dev->dev.driver && drv->remove)
+ drv->remove(dev);
+ put_device(&dev->dev);
+ return 0;
+}
+
+int register_lguest_driver(struct lguest_driver *drv)
+{
+ if (!lguest_devices)
+ return 0;
+
+ drv->drv.bus = &lguest_bus.bus;
+ drv->drv.name = drv->name;
+ drv->drv.owner = drv->owner;
+ drv->drv.probe = lguest_dev_probe;
+ drv->drv.remove = lguest_dev_remove;
+
+ return driver_register(&drv->drv);
+}
+EXPORT_SYMBOL_GPL(register_lguest_driver);
+
+void unregister_lguest_driver(struct lguest_driver *drv)
+{
+ if (!lguest_devices)
+ return;
+
+ driver_unregister(&drv->drv);
+}
+EXPORT_SYMBOL_GPL(unregister_lguest_driver);
+
+static void release_lguest_device(struct device *_dev)
+{
+ struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
+
+ lguest_devices[dev->index].status |= LGUEST_DEVICE_S_REMOVED_ACK;
+ kfree(dev);
+}
+
+static void add_lguest_device(unsigned int index)
+{
+ struct lguest_device *new;
+
+ lguest_devices[index].status |= LGUEST_DEVICE_S_ACKNOWLEDGE;
+ new = kmalloc(sizeof(struct lguest_device), GFP_KERNEL);
+ if (!new) {
+ printk(KERN_EMERG "Cannot allocate lguest device %u\n", index);
+ lguest_devices[index].status |= LGUEST_DEVICE_S_FAILED;
+ return;
+ }
+
+ new->index = index;
+ new->private = NULL;
+ memset(&new->dev, 0, sizeof(new->dev));
+ new->dev.parent = &lguest_bus.dev;
+ new->dev.bus = &lguest_bus.bus;
+ new->dev.release = release_lguest_device;
+ sprintf(new->dev.bus_id, "%u", index);
+ if (device_register(&new->dev) != 0) {
+ printk(KERN_EMERG "Cannot register lguest device %u\n", index);
+ lguest_devices[index].status |= LGUEST_DEVICE_S_FAILED;
+ kfree(new);
+ }
+}
+
+static void scan_devices(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < LGUEST_MAX_DEVICES; i++)
+ if (lguest_devices[i].type)
+ add_lguest_device(i);
+}
+
+static int __init lguest_bus_init(void)
+{
+ if (strcmp(paravirt_ops.name, "lguest") != 0)
+ return 0;
+
+ /* Devices are in page above top of "normal" mem. */
+ lguest_devices = ioremap(max_pfn << PAGE_SHIFT, PAGE_SIZE);
+
+ if (bus_register(&lguest_bus.bus) != 0
+ || device_register(&lguest_bus.dev) != 0)
+ panic("lguest bus registration failed");
+
+ scan_devices();
+ return 0;
+}
+postcore_initcall(lguest_bus_init);
-
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