diff options
Diffstat (limited to 'drivers/lguest/lguest.c')
| -rw-r--r-- | drivers/lguest/lguest.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/drivers/lguest/lguest.c b/drivers/lguest/lguest.c new file mode 100644 index 000000000000..18dade06d4a9 --- /dev/null +++ b/drivers/lguest/lguest.c @@ -0,0 +1,630 @@ +/* + * Lguest specific paravirt-ops implementation + * + * Copyright (C) 2006, Rusty Russell <rusty@rustcorp.com.au> 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 <linux/clockchips.h> +#include <linux/lguest.h> +#include <linux/lguest_launcher.h> +#include <linux/lguest_bus.h> +#include <asm/paravirt.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/mce.h> +#include <asm/io.h> + +/* Declarations for definitions in lguest_guest.S */ +extern char lguest_noirq_start[], lguest_noirq_end[]; +extern const char lgstart_cli[], lgend_cli[]; +extern const char lgstart_sti[], lgend_sti[]; +extern const char lgstart_popf[], lgend_popf[]; +extern const char lgstart_pushf[], lgend_pushf[]; +extern const char lgstart_iret[], lgend_iret[]; +extern void lguest_iret(void); + +struct lguest_data lguest_data = { + .hcall_status = { [0 ... LHCALL_RING_SIZE-1] = 0xFF }, + .noirq_start = (u32)lguest_noirq_start, + .noirq_end = (u32)lguest_noirq_end, + .blocked_interrupts = { 1 }, /* Block timer interrupts */ +}; +struct lguest_device_desc *lguest_devices; +static cycle_t clock_base; + +static enum paravirt_lazy_mode lazy_mode; +static void lguest_lazy_mode(enum paravirt_lazy_mode mode) +{ + if (mode == PARAVIRT_LAZY_FLUSH) { + if (unlikely(lazy_mode != PARAVIRT_LAZY_NONE)) + hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0); + } else { + 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); +} + +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; + /* Make sure host sees arguments before "valid" flag. */ + wmb(); + lguest_data.hcall_status[next_call] = 0; + if (++next_call == LHCALL_RING_SIZE) + next_call = 0; + } + local_irq_restore(flags); +} + +void lguest_send_dma(unsigned long key, struct lguest_dma *dma) +{ + dma->used_len = 0; + hcall(LHCALL_SEND_DMA, key, __pa(dma), 0); +} + +int lguest_bind_dma(unsigned long key, struct lguest_dma *dmas, + unsigned int num, u8 irq) +{ + if (!hcall(LHCALL_BIND_DMA, key, __pa(dmas), (num << 8) | irq)) + return -ENOMEM; + return 0; +} + +void lguest_unbind_dma(unsigned long key, struct lguest_dma *dmas) +{ + hcall(LHCALL_BIND_DMA, key, __pa(dmas), 0); +} + +/* For guests, device memory can be used as normal memory, so we cast away the + * __iomem to quieten sparse. */ +void *lguest_map(unsigned long phys_addr, unsigned long pages) +{ + return (__force void *)ioremap(phys_addr, PAGE_SIZE*pages); +} + +void lguest_unmap(void *addr) +{ + iounmap((__force void __iomem *)addr); +} + +static unsigned long save_fl(void) +{ + return lguest_data.irq_enabled; +} + +static void restore_fl(unsigned long flags) +{ + /* FIXME: Check if interrupt pending... */ + lguest_data.irq_enabled = flags; +} + +static void irq_disable(void) +{ + lguest_data.irq_enabled = 0; +} + +static void irq_enable(void) +{ + /* FIXME: Check if interrupt pending... */ + lguest_data.irq_enabled = X86_EFLAGS_IF; +} + +static void lguest_write_idt_entry(struct desc_struct *dt, + int entrynum, u32 low, u32 high) +{ + write_dt_entry(dt, entrynum, low, high); + hcall(LHCALL_LOAD_IDT_ENTRY, entrynum, low, high); +} + +static void 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 void 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 lguest_write_gdt_entry(struct desc_struct *dt, + int entrynum, u32 low, u32 high) +{ + write_dt_entry(dt, entrynum, low, high); + hcall(LHCALL_LOAD_GDT, __pa(dt), GDT_ENTRIES, 0); +} + +static void lguest_load_tls(struct thread_struct *t, unsigned int cpu) +{ + lazy_hcall(LHCALL_LOAD_TLS, __pa(&t->tls_array), cpu, 0); +} + +static void lguest_set_ldt(const void *addr, unsigned entries) +{ +} + +static void lguest_load_tr_desc(void) +{ +} + +static void lguest_cpuid(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx) +{ + int function = *eax; + + native_cpuid(eax, ebx, ecx, edx); + switch (function) { + case 1: /* Basic feature request. */ + /* We only allow kernel to see SSE3, CMPXCHG16B and SSSE3 */ + *ecx &= 0x00002201; + /* SSE, SSE2, FXSR, MMX, CMOV, CMPXCHG8B, FPU. */ + *edx &= 0x07808101; + /* Host wants to know when we flush kernel pages: set PGE. */ + *edx |= 0x00002000; + break; + case 0x80000000: + /* Futureproof this a little: if they ask how much extended + * processor information, limit it to known fields. */ + if (*eax > 0x80000008) + *eax = 0x80000008; + break; + } +} + +static unsigned long current_cr0, current_cr3; +static void lguest_write_cr0(unsigned long val) +{ + lazy_hcall(LHCALL_TS, val & 8, 0, 0); + current_cr0 = val; +} + +static unsigned long lguest_read_cr0(void) +{ + return current_cr0; +} + +static void lguest_clts(void) +{ + lazy_hcall(LHCALL_TS, 0, 0, 0); + current_cr0 &= ~8U; +} + +static unsigned long lguest_read_cr2(void) +{ + return lguest_data.cr2; +} + +static void lguest_write_cr3(unsigned long cr3) +{ + lazy_hcall(LHCALL_NEW_PGTABLE, cr3, 0, 0); + current_cr3 = cr3; +} + +static unsigned long lguest_read_cr3(void) +{ + return current_cr3; +} + +/* Used to enable/disable PGE, but we don't care. */ +static unsigned long lguest_read_cr4(void) +{ + return 0; +} + +static void lguest_write_cr4(unsigned long val) +{ +} + +static void lguest_set_pte_at(struct mm_struct *mm, unsigned long 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 void lguest_set_pmd(pmd_t *pmdp, pmd_t pmdval) +{ + *pmdp = pmdval; + lazy_hcall(LHCALL_SET_PMD, __pa(pmdp)&PAGE_MASK, + (__pa(pmdp)&(PAGE_SIZE-1))/4, 0); +} + +/* FIXME: Eliminate all callers of this. */ +static void lguest_set_pte(pte_t *ptep, pte_t pteval) +{ + *ptep = pteval; + /* Don't bother with hypercall before initial setup. */ + if (current_cr3) + lazy_hcall(LHCALL_FLUSH_TLB, 1, 0, 0); +} + +static void lguest_flush_tlb_single(unsigned long addr) +{ + /* Simply set it to zero, and it will fault back in. */ + lazy_hcall(LHCALL_SET_PTE, current_cr3, addr, 0); +} + +static void lguest_flush_tlb_user(void) +{ + lazy_hcall(LHCALL_FLUSH_TLB, 0, 0, 0); +} + +static void lguest_flush_tlb_kernel(void) +{ + lazy_hcall(LHCALL_FLUSH_TLB, 1, 0, 0); +} + +static void disable_lguest_irq(unsigned int irq) +{ + set_bit(irq, lguest_data.blocked_interrupts); +} + +static void enable_lguest_irq(unsigned int irq) +{ + clear_bit(irq, lguest_data.blocked_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 __init lguest_init_IRQ(void) +{ + unsigned int i; + + for (i = 0; i < LGUEST_IRQS; i++) { + int vector = FIRST_EXTERNAL_VECTOR + i; + 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 unsigned long lguest_get_wallclock(void) +{ + return hcall(LHCALL_GET_WALLCLOCK, 0, 0, 0); +} + +static cycle_t lguest_clock_read(void) +{ + if (lguest_data.tsc_khz) + return native_read_tsc(); + else + return jiffies; +} + +/* This is what we tell the kernel is our clocksource. */ +static struct clocksource lguest_clock = { + .name = "lguest", + .rating = 400, + .read = lguest_clock_read, +}; + +static unsigned long long lguest_sched_clock(void) +{ + return cyc2ns(&lguest_clock, lguest_clock_read() - clock_base); +} + +/* We also need a "struct clock_event_device": Linux asks us to set it to go + * off some time in the future. Actually, James Morris figured all this out, I + * just applied the patch. */ +static int lguest_clockevent_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + if (delta < LG_CLOCK_MIN_DELTA) { + if (printk_ratelimit()) + printk(KERN_DEBUG "%s: small delta %lu ns\n", + __FUNCTION__, delta); + return -ETIME; + } + hcall(LHCALL_SET_CLOCKEVENT, delta, 0, 0); + return 0; +} + +static void lguest_clockevent_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + switch (mode) { + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + /* A 0 argument shuts the clock down. */ + hcall(LHCALL_SET_CLOCKEVENT, 0, 0, 0); + break; + case CLOCK_EVT_MODE_ONESHOT: + /* This is what we expect. */ + break; + case CLOCK_EVT_MODE_PERIODIC: + BUG(); + case CLOCK_EVT_MODE_RESUME: + break; + } +} + +/* This describes our primitive timer chip. */ +static struct clock_event_device lguest_clockevent = { + .name = "lguest", + .features = CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = lguest_clockevent_set_next_event, + .set_mode = lguest_clockevent_set_mode, + .rating = INT_MAX, + .mult = 1, + .shift = 0, + .min_delta_ns = LG_CLOCK_MIN_DELTA, + .max_delta_ns = LG_CLOCK_MAX_DELTA, +}; + +/* This is the Guest timer interrupt handler (hardware interrupt 0). We just + * call the clockevent infrastructure and it does whatever needs doing. */ +static void lguest_time_irq(unsigned int irq, struct irq_desc *desc) +{ + unsigned long flags; + + /* Don't interrupt us while this is running. */ + local_irq_save(flags); + lguest_clockevent.event_handler(&lguest_clockevent); + local_irq_restore(flags); +} + +static void lguest_time_init(void) +{ + set_irq_handler(0, lguest_time_irq); + + /* We use the TSC if the Host tells us we can, otherwise a dumb + * jiffies-based clock. */ + if (lguest_data.tsc_khz) { + lguest_clock.shift = 22; + lguest_clock.mult = clocksource_khz2mult(lguest_data.tsc_khz, + lguest_clock.shift); + lguest_clock.mask = CLOCKSOURCE_MASK(64); + lguest_clock.flags = CLOCK_SOURCE_IS_CONTINUOUS; + } else { + /* To understand this, start at kernel/time/jiffies.c... */ + lguest_clock.shift = 8; + lguest_clock.mult = (((u64)NSEC_PER_SEC<<8)/ACTHZ) << 8; + lguest_clock.mask = CLOCKSOURCE_MASK(32); + } + clock_base = lguest_clock_read(); + clocksource_register(&lguest_clock); + + /* We can't set cpumask in the initializer: damn C limitations! */ + lguest_clockevent.cpumask = cpumask_of_cpu(0); + clockevents_register_device(&lguest_clockevent); + + enable_lguest_irq(0); +} + +static void 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 void lguest_set_debugreg(int regno, unsigned long value) +{ + /* FIXME: Implement */ +} + +static void lguest_wbinvd(void) +{ +} + +#ifdef CONFIG_X86_LOCAL_APIC +static void lguest_apic_write(unsigned long reg, unsigned long v) +{ +} + +static unsigned long lguest_apic_read(unsigned long reg) +{ + return 0; +} +#endif + +static void lguest_safe_halt(void) +{ + hcall(LHCALL_HALT, 0, 0, 0); +} + +static void lguest_power_off(void) +{ + hcall(LHCALL_CRASH, __pa("Power down"), 0, 0); +} + +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 __init char *lguest_memory_setup(void) +{ + /* We do this here because lockcheck barfs if before start_kernel */ + atomic_notifier_chain_register(&panic_notifier_list, &paniced); + + add_memory_region(E820_MAP->addr, E820_MAP->size, E820_MAP->type); + return "LGUEST"; +} + +static const struct lguest_insns +{ + const char *start, *end; +} lguest_insns[] = { + [PARAVIRT_PATCH(irq_disable)] = { lgstart_cli, lgend_cli }, + [PARAVIRT_PATCH(irq_enable)] = { lgstart_sti, lgend_sti }, + [PARAVIRT_PATCH(restore_fl)] = { lgstart_popf, lgend_popf }, + [PARAVIRT_PATCH(save_fl)] = { lgstart_pushf, lgend_pushf }, +}; +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 paravirt_patch_default(type, clobber, insns, len); + + insn_len = lguest_insns[type].end - lguest_insns[type].start; + + /* Similarly if we can't fit replacement. */ + if (len < insn_len) + return paravirt_patch_default(type, clobber, insns, len); + + memcpy(insns, lguest_insns[type].start, insn_len); + return insn_len; +} + +__init void lguest_init(void *boot) +{ + /* Copy boot parameters first. */ + memcpy(&boot_params, boot, PARAM_SIZE); + memcpy(boot_command_line, __va(boot_params.hdr.cmd_line_ptr), + COMMAND_LINE_SIZE); + + 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_user; + 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_pmd; +#ifdef CONFIG_X86_LOCAL_APIC + paravirt_ops.apic_write = lguest_apic_write; + paravirt_ops.apic_write_atomic = lguest_apic_write; + 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_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; + paravirt_ops.set_lazy_mode = lguest_lazy_mode; + paravirt_ops.wbinvd = lguest_wbinvd; + paravirt_ops.sched_clock = lguest_sched_clock; + + hcall(LHCALL_LGUEST_INIT, __pa(&lguest_data), 0, 0); + + /* We use top of mem for initial pagetables. */ + init_pg_tables_end = __pa(pg0); + + asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_DS) : "memory"); + + reserve_top_address(lguest_data.reserve_mem); + + lockdep_init(); + + paravirt_disable_iospace(); + + cpu_detect(&new_cpu_data); + /* head.S usually sets up the first capability word, so do it here. */ + new_cpu_data.x86_capability[0] = cpuid_edx(1); + + /* Math is always hard! */ + new_cpu_data.hard_math = 1; + +#ifdef CONFIG_X86_MCE + mce_disabled = 1; +#endif + +#ifdef CONFIG_ACPI + acpi_disabled = 1; + acpi_ht = 0; +#endif + + add_preferred_console("hvc", 0, NULL); + + pm_power_off = lguest_power_off; + start_kernel(); +} |