diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/i386/Makefile | 3 | ||||
| -rw-r--r-- | arch/i386/kernel/entry.S | 71 | ||||
| -rw-r--r-- | arch/i386/kernel/head.S | 5 | ||||
| -rw-r--r-- | arch/i386/kernel/vmlinux.lds.S | 1 | ||||
| -rw-r--r-- | arch/i386/xen/Makefile | 1 | ||||
| -rw-r--r-- | arch/i386/xen/enlighten.c | 745 | ||||
| -rw-r--r-- | arch/i386/xen/features.c | 29 | ||||
| -rw-r--r-- | arch/i386/xen/multicalls.c | 89 | ||||
| -rw-r--r-- | arch/i386/xen/multicalls.h | 45 | ||||
| -rw-r--r-- | arch/i386/xen/setup.c | 97 | ||||
| -rw-r--r-- | arch/i386/xen/xen-head.S | 36 | ||||
| -rw-r--r-- | arch/i386/xen/xen-ops.h | 31 |
12 files changed, 1152 insertions, 1 deletions
diff --git a/arch/i386/Makefile b/arch/i386/Makefile index 181cc29a7c4f..01f0ff0daaf4 100644 --- a/arch/i386/Makefile +++ b/arch/i386/Makefile @@ -93,6 +93,9 @@ mflags-$(CONFIG_X86_ES7000) := -Iinclude/asm-i386/mach-es7000 mcore-$(CONFIG_X86_ES7000) := mach-default core-$(CONFIG_X86_ES7000) := arch/i386/mach-es7000/ +# Xen paravirtualization support +core-$(CONFIG_XEN) += arch/i386/xen/ + # default subarch .h files mflags-y += -Iinclude/asm-i386/mach-default diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index 3c3c220488c9..ffb236544270 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -1023,6 +1023,77 @@ ENTRY(kernel_thread_helper) CFI_ENDPROC ENDPROC(kernel_thread_helper) +#ifdef CONFIG_XEN +ENTRY(xen_hypervisor_callback) + CFI_STARTPROC + pushl $0 + CFI_ADJUST_CFA_OFFSET 4 + SAVE_ALL + TRACE_IRQS_OFF + mov %esp, %eax + call xen_evtchn_do_upcall + jmp ret_from_intr + CFI_ENDPROC +ENDPROC(xen_hypervisor_callback) + +# Hypervisor uses this for application faults while it executes. +# We get here for two reasons: +# 1. Fault while reloading DS, ES, FS or GS +# 2. Fault while executing IRET +# Category 1 we fix up by reattempting the load, and zeroing the segment +# register if the load fails. +# Category 2 we fix up by jumping to do_iret_error. We cannot use the +# normal Linux return path in this case because if we use the IRET hypercall +# to pop the stack frame we end up in an infinite loop of failsafe callbacks. +# We distinguish between categories by maintaining a status value in EAX. +ENTRY(xen_failsafe_callback) + CFI_STARTPROC + pushl %eax + CFI_ADJUST_CFA_OFFSET 4 + movl $1,%eax +1: mov 4(%esp),%ds +2: mov 8(%esp),%es +3: mov 12(%esp),%fs +4: mov 16(%esp),%gs + testl %eax,%eax + popl %eax + CFI_ADJUST_CFA_OFFSET -4 + lea 16(%esp),%esp + CFI_ADJUST_CFA_OFFSET -16 + jz 5f + addl $16,%esp + jmp iret_exc # EAX != 0 => Category 2 (Bad IRET) +5: pushl $0 # EAX == 0 => Category 1 (Bad segment) + CFI_ADJUST_CFA_OFFSET 4 + SAVE_ALL + jmp ret_from_exception + CFI_ENDPROC + +.section .fixup,"ax" +6: xorl %eax,%eax + movl %eax,4(%esp) + jmp 1b +7: xorl %eax,%eax + movl %eax,8(%esp) + jmp 2b +8: xorl %eax,%eax + movl %eax,12(%esp) + jmp 3b +9: xorl %eax,%eax + movl %eax,16(%esp) + jmp 4b +.previous +.section __ex_table,"a" + .align 4 + .long 1b,6b + .long 2b,7b + .long 3b,8b + .long 4b,9b +.previous +ENDPROC(xen_failsafe_callback) + +#endif /* CONFIG_XEN */ + .section .rodata,"a" #include "syscall_table.S" diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S index 82714668d43b..7c52b222207e 100644 --- a/arch/i386/kernel/head.S +++ b/arch/i386/kernel/head.S @@ -510,7 +510,8 @@ ENTRY(_stext) /* * BSS section */ -.section ".bss.page_aligned","w" +.section ".bss.page_aligned","wa" + .align PAGE_SIZE_asm ENTRY(swapper_pg_dir) .fill 1024,4,0 ENTRY(swapper_pg_pmd) @@ -538,6 +539,8 @@ fault_msg: .ascii "Int %d: CR2 %p err %p EIP %p CS %p flags %p\n" .asciz "Stack: %p %p %p %p %p %p %p %p\n" +#include "../xen/xen-head.S" + /* * The IDT and GDT 'descriptors' are a strange 48-bit object * only used by the lidt and lgdt instructions. They are not diff --git a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S index aa87b06c7c82..00f1bc47d3a2 100644 --- a/arch/i386/kernel/vmlinux.lds.S +++ b/arch/i386/kernel/vmlinux.lds.S @@ -88,6 +88,7 @@ SECTIONS . = ALIGN(4096); .data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) { + *(.data.page_aligned) *(.data.idt) } diff --git a/arch/i386/xen/Makefile b/arch/i386/xen/Makefile new file mode 100644 index 000000000000..60bc1cfb101c --- /dev/null +++ b/arch/i386/xen/Makefile @@ -0,0 +1 @@ +obj-y := enlighten.o setup.o features.o multicalls.o diff --git a/arch/i386/xen/enlighten.c b/arch/i386/xen/enlighten.c new file mode 100644 index 000000000000..2d484f9320de --- /dev/null +++ b/arch/i386/xen/enlighten.c @@ -0,0 +1,745 @@ +/* + * Core of Xen paravirt_ops implementation. + * + * This file contains the xen_paravirt_ops structure itself, and the + * implementations for: + * - privileged instructions + * - interrupt flags + * - segment operations + * - booting and setup + * + * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/smp.h> +#include <linux/preempt.h> +#include <linux/percpu.h> +#include <linux/delay.h> +#include <linux/start_kernel.h> +#include <linux/sched.h> +#include <linux/bootmem.h> +#include <linux/module.h> + +#include <xen/interface/xen.h> +#include <xen/interface/physdev.h> +#include <xen/interface/vcpu.h> +#include <xen/features.h> +#include <xen/page.h> + +#include <asm/paravirt.h> +#include <asm/page.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/hypervisor.h> +#include <asm/fixmap.h> +#include <asm/processor.h> +#include <asm/setup.h> +#include <asm/desc.h> +#include <asm/pgtable.h> + +#include "xen-ops.h" +#include "multicalls.h" + +EXPORT_SYMBOL_GPL(hypercall_page); + +DEFINE_PER_CPU(enum paravirt_lazy_mode, xen_lazy_mode); + +DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); +DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); +DEFINE_PER_CPU(unsigned long, xen_cr3); + +struct start_info *xen_start_info; +EXPORT_SYMBOL_GPL(xen_start_info); + +static void xen_vcpu_setup(int cpu) +{ + per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; +} + +static void __init xen_banner(void) +{ + printk(KERN_INFO "Booting paravirtualized kernel on %s\n", + paravirt_ops.name); + printk(KERN_INFO "Hypervisor signature: %s\n", xen_start_info->magic); +} + +static void xen_cpuid(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx) +{ + unsigned maskedx = ~0; + + /* + * Mask out inconvenient features, to try and disable as many + * unsupported kernel subsystems as possible. + */ + if (*eax == 1) + maskedx = ~((1 << X86_FEATURE_APIC) | /* disable APIC */ + (1 << X86_FEATURE_ACPI) | /* disable ACPI */ + (1 << X86_FEATURE_ACC)); /* thermal monitoring */ + + asm(XEN_EMULATE_PREFIX "cpuid" + : "=a" (*eax), + "=b" (*ebx), + "=c" (*ecx), + "=d" (*edx) + : "0" (*eax), "2" (*ecx)); + *edx &= maskedx; +} + +static void xen_set_debugreg(int reg, unsigned long val) +{ + HYPERVISOR_set_debugreg(reg, val); +} + +static unsigned long xen_get_debugreg(int reg) +{ + return HYPERVISOR_get_debugreg(reg); +} + +static unsigned long xen_save_fl(void) +{ + struct vcpu_info *vcpu; + unsigned long flags; + + preempt_disable(); + vcpu = x86_read_percpu(xen_vcpu); + /* flag has opposite sense of mask */ + flags = !vcpu->evtchn_upcall_mask; + preempt_enable(); + + /* convert to IF type flag + -0 -> 0x00000000 + -1 -> 0xffffffff + */ + return (-flags) & X86_EFLAGS_IF; +} + +static void xen_restore_fl(unsigned long flags) +{ + struct vcpu_info *vcpu; + + preempt_disable(); + + /* convert from IF type flag */ + flags = !(flags & X86_EFLAGS_IF); + vcpu = x86_read_percpu(xen_vcpu); + vcpu->evtchn_upcall_mask = flags; + + if (flags == 0) { + /* Unmask then check (avoid races). We're only protecting + against updates by this CPU, so there's no need for + anything stronger. */ + barrier(); + + if (unlikely(vcpu->evtchn_upcall_pending)) + force_evtchn_callback(); + preempt_enable(); + } else + preempt_enable_no_resched(); +} + +static void xen_irq_disable(void) +{ + struct vcpu_info *vcpu; + preempt_disable(); + vcpu = x86_read_percpu(xen_vcpu); + vcpu->evtchn_upcall_mask = 1; + preempt_enable_no_resched(); +} + +static void xen_irq_enable(void) +{ + struct vcpu_info *vcpu; + + preempt_disable(); + vcpu = x86_read_percpu(xen_vcpu); + vcpu->evtchn_upcall_mask = 0; + + /* Unmask then check (avoid races). We're only protecting + against updates by this CPU, so there's no need for + anything stronger. */ + barrier(); + + if (unlikely(vcpu->evtchn_upcall_pending)) + force_evtchn_callback(); + preempt_enable(); +} + +static void xen_safe_halt(void) +{ + /* Blocking includes an implicit local_irq_enable(). */ + if (HYPERVISOR_sched_op(SCHEDOP_block, 0) != 0) + BUG(); +} + +static void xen_halt(void) +{ + if (irqs_disabled()) + HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL); + else + xen_safe_halt(); +} + +static void xen_set_lazy_mode(enum paravirt_lazy_mode mode) +{ + switch (mode) { + case PARAVIRT_LAZY_NONE: + BUG_ON(x86_read_percpu(xen_lazy_mode) == PARAVIRT_LAZY_NONE); + break; + + case PARAVIRT_LAZY_MMU: + case PARAVIRT_LAZY_CPU: + BUG_ON(x86_read_percpu(xen_lazy_mode) != PARAVIRT_LAZY_NONE); + break; + + case PARAVIRT_LAZY_FLUSH: + /* flush if necessary, but don't change state */ + if (x86_read_percpu(xen_lazy_mode) != PARAVIRT_LAZY_NONE) + xen_mc_flush(); + return; + } + + xen_mc_flush(); + x86_write_percpu(xen_lazy_mode, mode); +} + +static unsigned long xen_store_tr(void) +{ + return 0; +} + +static void xen_set_ldt(const void *addr, unsigned entries) +{ + unsigned long linear_addr = (unsigned long)addr; + struct mmuext_op *op; + struct multicall_space mcs = xen_mc_entry(sizeof(*op)); + + op = mcs.args; + op->cmd = MMUEXT_SET_LDT; + if (linear_addr) { + /* ldt my be vmalloced, use arbitrary_virt_to_machine */ + xmaddr_t maddr; + maddr = arbitrary_virt_to_machine((unsigned long)addr); + linear_addr = (unsigned long)maddr.maddr; + } + op->arg1.linear_addr = linear_addr; + op->arg2.nr_ents = entries; + + MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); + + xen_mc_issue(PARAVIRT_LAZY_CPU); +} + +static void xen_load_gdt(const struct Xgt_desc_struct *dtr) +{ + unsigned long *frames; + unsigned long va = dtr->address; + unsigned int size = dtr->size + 1; + unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; + int f; + struct multicall_space mcs; + + /* A GDT can be up to 64k in size, which corresponds to 8192 + 8-byte entries, or 16 4k pages.. */ + + BUG_ON(size > 65536); + BUG_ON(va & ~PAGE_MASK); + + mcs = xen_mc_entry(sizeof(*frames) * pages); + frames = mcs.args; + + for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { + frames[f] = virt_to_mfn(va); + make_lowmem_page_readonly((void *)va); + } + + MULTI_set_gdt(mcs.mc, frames, size / sizeof(struct desc_struct)); + + xen_mc_issue(PARAVIRT_LAZY_CPU); +} + +static void load_TLS_descriptor(struct thread_struct *t, + unsigned int cpu, unsigned int i) +{ + struct desc_struct *gdt = get_cpu_gdt_table(cpu); + xmaddr_t maddr = virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]); + struct multicall_space mc = __xen_mc_entry(0); + + MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]); +} + +static void xen_load_tls(struct thread_struct *t, unsigned int cpu) +{ + xen_mc_batch(); + + load_TLS_descriptor(t, cpu, 0); + load_TLS_descriptor(t, cpu, 1); + load_TLS_descriptor(t, cpu, 2); + + xen_mc_issue(PARAVIRT_LAZY_CPU); +} + +static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum, + u32 low, u32 high) +{ + unsigned long lp = (unsigned long)&dt[entrynum]; + xmaddr_t mach_lp = virt_to_machine(lp); + u64 entry = (u64)high << 32 | low; + + xen_mc_flush(); + if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry)) + BUG(); +} + +static int cvt_gate_to_trap(int vector, u32 low, u32 high, + struct trap_info *info) +{ + u8 type, dpl; + + type = (high >> 8) & 0x1f; + dpl = (high >> 13) & 3; + + if (type != 0xf && type != 0xe) + return 0; + + info->vector = vector; + info->address = (high & 0xffff0000) | (low & 0x0000ffff); + info->cs = low >> 16; + info->flags = dpl; + /* interrupt gates clear IF */ + if (type == 0xe) + info->flags |= 4; + + return 1; +} + +/* Locations of each CPU's IDT */ +static DEFINE_PER_CPU(struct Xgt_desc_struct, idt_desc); + +/* Set an IDT entry. If the entry is part of the current IDT, then + also update Xen. */ +static void xen_write_idt_entry(struct desc_struct *dt, int entrynum, + u32 low, u32 high) +{ + + int cpu = smp_processor_id(); + unsigned long p = (unsigned long)&dt[entrynum]; + unsigned long start = per_cpu(idt_desc, cpu).address; + unsigned long end = start + per_cpu(idt_desc, cpu).size + 1; + + xen_mc_flush(); + + write_dt_entry(dt, entrynum, low, high); + + if (p >= start && (p + 8) <= end) { + struct trap_info info[2]; + + info[1].address = 0; + + if (cvt_gate_to_trap(entrynum, low, high, &info[0])) + if (HYPERVISOR_set_trap_table(info)) + BUG(); + } +} + +/* Load a new IDT into Xen. In principle this can be per-CPU, so we + hold a spinlock to protect the static traps[] array (static because + it avoids allocation, and saves stack space). */ +static void xen_load_idt(const struct Xgt_desc_struct *desc) +{ + static DEFINE_SPINLOCK(lock); + static struct trap_info traps[257]; + + int cpu = smp_processor_id(); + unsigned in, out, count; + + per_cpu(idt_desc, cpu) = *desc; + + count = (desc->size+1) / 8; + BUG_ON(count > 256); + + spin_lock(&lock); + for (in = out = 0; in < count; in++) { + const u32 *entry = (u32 *)(desc->address + in * 8); + + if (cvt_gate_to_trap(in, entry[0], entry[1], &traps[out])) + out++; + } + traps[out].address = 0; + + xen_mc_flush(); + if (HYPERVISOR_set_trap_table(traps)) + BUG(); + + spin_unlock(&lock); +} + +/* Write a GDT descriptor entry. Ignore LDT descriptors, since + they're handled differently. */ +static void xen_write_gdt_entry(struct desc_struct *dt, int entry, + u32 low, u32 high) +{ + switch ((high >> 8) & 0xff) { + case DESCTYPE_LDT: + case DESCTYPE_TSS: + /* ignore */ + break; + + default: { + xmaddr_t maddr = virt_to_machine(&dt[entry]); + u64 desc = (u64)high << 32 | low; + + xen_mc_flush(); + if (HYPERVISOR_update_descriptor(maddr.maddr, desc)) + BUG(); + } + + } +} + +static void xen_load_esp0(struct tss_struct *tss, + struct thread_struct *thread) +{ + struct multicall_space mcs = xen_mc_entry(0); + MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->esp0); + xen_mc_issue(PARAVIRT_LAZY_CPU); +} + +static void xen_set_iopl_mask(unsigned mask) +{ + struct physdev_set_iopl set_iopl; + + /* Force the change at ring 0. */ + set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3; + HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); +} + +static void xen_io_delay(void) +{ +} + +#ifdef CONFIG_X86_LOCAL_APIC +static unsigned long xen_apic_read(unsigned long reg) +{ + return 0; +} +#endif + +static void xen_flush_tlb(void) +{ + struct mmuext_op op; + + op.cmd = MMUEXT_TLB_FLUSH_LOCAL; + if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF)) + BUG(); +} + +static void xen_flush_tlb_single(unsigned long addr) +{ + struct mmuext_op op; + + op.cmd = MMUEXT_INVLPG_LOCAL; + op.arg1.linear_addr = addr & PAGE_MASK; + if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF)) + BUG(); +} + +static unsigned long xen_read_cr2(void) +{ + return x86_read_percpu(xen_vcpu)->arch.cr2; +} + +static void xen_write_cr4(unsigned long cr4) +{ + /* never allow TSC to be disabled */ + native_write_cr4(cr4 & ~X86_CR4_TSD); +} + +/* + * Page-directory addresses above 4GB do not fit into architectural %cr3. + * When accessing %cr3, or equivalent field in vcpu_guest_context, guests + * must use the following accessor macros to pack/unpack valid MFNs. + * + * Note that Xen is using the fact that the pagetable base is always + * page-aligned, and putting the 12 MSB of the address into the 12 LSB + * of cr3. + */ +#define xen_pfn_to_cr3(pfn) (((unsigned)(pfn) << 12) | ((unsigned)(pfn) >> 20)) +#define xen_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20)) + +static unsigned long xen_read_cr3(void) +{ + return x86_read_percpu(xen_cr3); +} + +static void xen_write_cr3(unsigned long cr3) +{ + if (cr3 == x86_read_percpu(xen_cr3)) { + /* just a simple tlb flush */ + xen_flush_tlb(); + return; + } + + x86_write_percpu(xen_cr3, cr3); + + + { + struct mmuext_op *op; + struct multicall_space mcs = xen_mc_entry(sizeof(*op)); + unsigned long mfn = pfn_to_mfn(PFN_DOWN(cr3)); + + op = mcs.args; + op->cmd = MMUEXT_NEW_BASEPTR; + op->arg1.mfn = mfn; + + MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); + + xen_mc_issue(PARAVIRT_LAZY_CPU); + } +} + +static void xen_alloc_pt(struct mm_struct *mm, u32 pfn) +{ + /* XXX pfn isn't necessarily a lowmem page */ + make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); +} + +static void xen_alloc_pd(u32 pfn) +{ + make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); +} + +static void xen_release_pd(u32 pfn) +{ + make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); +} + +static void xen_release_pt(u32 pfn) +{ + make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); +} + +static void xen_alloc_pd_clone(u32 pfn, u32 clonepfn, + u32 start, u32 count) +{ + xen_alloc_pd(pfn); +} + +static __init void xen_pagetable_setup_start(pgd_t *base) +{ + pgd_t *xen_pgd = (pgd_t *)xen_start_info->pt_base; + + init_mm.pgd = base; + /* + * copy top-level of Xen-supplied pagetable into place. For + * !PAE we can use this as-is, but for PAE it is a stand-in + * while we copy the pmd pages. + */ + memcpy(base, xen_pgd, PTRS_PER_PGD * sizeof(pgd_t)); + + if (PTRS_PER_PMD > 1) { + int i; + /* + * For PAE, need to allocate new pmds, rather than + * share Xen's, since Xen doesn't like pmd's being + * shared between address spaces. + */ + for (i = 0; i < PTRS_PER_PGD; i++) { + if (pgd_val_ma(xen_pgd[i]) & _PAGE_PRESENT) { + pmd_t *pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); + + memcpy(pmd, (void *)pgd_page_vaddr(xen_pgd[i]), + PAGE_SIZE); + + xen_alloc_pd(PFN_DOWN(__pa(pmd))); + + set_pgd(&base[i], __pgd(1 + __pa(pmd))); + } else + pgd_clear(&base[i]); + } + } + + /* make sure zero_page is mapped RO so we can use it in pagetables */ + make_lowmem_page_readonly(empty_zero_page); + make_lowmem_page_readonly(base); + /* + * Switch to new pagetable. This is done before + * pagetable_init has done anything so that the new pages + * added to the table can be prepared properly for Xen. + */ + xen_write_cr3(__pa(base)); +} + +static __init void xen_pagetable_setup_done(pgd_t *base) +{ + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + /* + * Create a mapping for the shared info page. + * Should be set_fixmap(), but shared_info is a machine + * address with no corresponding pseudo-phys address. + */ +#if 0 + set_pte_mfn(fix_to_virt(FIX_PARAVIRT_BOOTMAP), + PFN_DOWN(xen_start_info->shared_info), + PAGE_KERNEL); +#endif + + HYPERVISOR_shared_info = + (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP); + + } else + HYPERVISOR_shared_info = + (struct shared_info *)__va(xen_start_info->shared_info); + +#if 0 + xen_pgd_pin(base); +#endif + + xen_vcpu_setup(smp_processor_id()); +} + +static const struct paravirt_ops xen_paravirt_ops __initdata = { + .paravirt_enabled = 1, + .shared_kernel_pmd = 0, + + .name = "Xen", + .banner = xen_banner, + + .patch = paravirt_patch_default, + + .memory_setup = xen_memory_setup, + .arch_setup = xen_arch_setup, + + .cpuid = xen_cpuid, + + .set_debugreg = xen_set_debugreg, + .get_debugreg = xen_get_debugreg, + + .clts = native_clts, + + .read_cr0 = native_read_cr0, + .write_cr0 = native_write_cr0, + + .read_cr2 = xen_read_cr2, + .write_cr2 = native_write_cr2, + + .read_cr3 = xen_read_cr3, + .write_cr3 = xen_write_cr3, + + .read_cr4 = native_read_cr4, + .read_cr4_safe = native_read_cr4_safe, + .write_cr4 = xen_write_cr4, + + .save_fl = xen_save_fl, + .restore_fl = xen_restore_fl, + .irq_disable = xen_irq_disable, + .irq_enable = xen_irq_enable, + .safe_halt = xen_safe_halt, + .halt = xen_halt, + .wbinvd = native_wbinvd, + + .read_msr = native_read_msr_safe, + .write_msr = native_write_msr_safe, + .read_tsc = native_read_tsc, + .read_pmc = native_read_pmc, + + .iret = (void *)&hypercall_page[__HYPERVISOR_iret], + .irq_enable_sysexit = NULL, /* never called */ + + .load_tr_desc = paravirt_nop, + .set_ldt = xen_set_ldt, + .load_gdt = xen_load_gdt, + .load_idt = xen_load_idt, + .load_tls = xen_load_tls, + + .store_gdt = native_store_gdt, + .store_idt = native_store_idt, + .store_tr = xen_store_tr, + + .write_ldt_entry = xen_write_ldt_entry, + .write_gdt_entry = xen_write_gdt_entry, + .write_idt_entry = xen_write_idt_entry, + .load_esp0 = xen_load_esp0, + + .set_iopl_mask = xen_set_iopl_mask, + .io_delay = xen_io_delay, + +#ifdef CONFIG_X86_LOCAL_APIC + .apic_write = paravirt_nop, + .apic_write_atomic = paravirt_nop, + .apic_read = xen_apic_read, + .setup_boot_clock = paravirt_nop, + .setup_secondary_clock = paravirt_nop, + .startup_ipi_hook = paravirt_nop, +#endif + + .flush_tlb_user = xen_flush_tlb, + .flush_tlb_kernel = xen_flush_tlb, + .flush_tlb_single = xen_flush_tlb_single, + + .pte_update = paravirt_nop, + .pte_update_defer = paravirt_nop, + + .pagetable_setup_start = xen_pagetable_setup_start, + .pagetable_setup_done = xen_pagetable_setup_done, + + .alloc_pt = xen_alloc_pt, + .alloc_pd = xen_alloc_pd, + .alloc_pd_clone = xen_alloc_pd_clone, + .release_pd = xen_release_pd, + .release_pt = xen_release_pt, + + .set_lazy_mode = xen_set_lazy_mode, +}; + +/* First C function to be called on Xen boot */ +asmlinkage void __init xen_start_kernel(void) +{ + pgd_t *pgd; + + if (!xen_start_info) + return; + + BUG_ON(memcmp(xen_start_info->magic, "xen-3.0", 7) != 0); + + /* Install Xen paravirt ops */ + paravirt_ops = xen_paravirt_ops; + + xen_setup_features(); + + /* Get mfn list */ + if (!xen_feature(XENFEAT_auto_translated_physmap)) + phys_to_machine_mapping = (unsigned long *)xen_start_info->mfn_list; + + pgd = (pgd_t *)xen_start_info->pt_base; + + init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE; + + init_mm.pgd = pgd; /* use the Xen pagetables to start */ + + /* keep using Xen gdt for now; no urgent need to change it */ + + x86_write_percpu(xen_cr3, __pa(pgd)); + xen_vcpu_setup(0); + + paravirt_ops.kernel_rpl = 1; + if (xen_feature(XENFEAT_supervisor_mode_kernel)) + paravirt_ops.kernel_rpl = 0; + + /* set the limit of our address space */ + reserve_top_address(-HYPERVISOR_VIRT_START + 2 * PAGE_SIZE); + + /* set up basic CPUID stuff */ + cpu_detect(&new_cpu_data); + new_cpu_data.hard_math = 1; + new_cpu_data.x86_capability[0] = cpuid_edx(1); + + /* Poke various useful things into boot_params */ + LOADER_TYPE = (9 << 4) | 0; + INITRD_START = xen_start_info->mod_start ? __pa(xen_start_info->mod_start) : 0; + INITRD_SIZE = xen_start_info->mod_len; + + /* Start the world */ + start_kernel(); +} diff --git a/arch/i386/xen/features.c b/arch/i386/xen/features.c new file mode 100644 index 000000000000..0707714e40d6 --- /dev/null +++ b/arch/i386/xen/features.c @@ -0,0 +1,29 @@ +/****************************************************************************** + * features.c + * + * Xen feature flags. + * + * Copyright (c) 2006, Ian Campbell, XenSource Inc. + */ +#include <linux/types.h> +#include <linux/cache.h> +#include <linux/module.h> +#include <asm/xen/hypervisor.h> +#include <xen/features.h> + +u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly; +EXPORT_SYMBOL_GPL(xen_features); + +void xen_setup_features(void) +{ + struct xen_feature_info fi; + int i, j; + + for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) { + fi.submap_idx = i; + if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0) + break; + for (j = 0; j < 32; j++) + xen_features[i * 32 + j] = !!(fi.submap & 1<<j); + } +} diff --git a/arch/i386/xen/multicalls.c b/arch/i386/xen/multicalls.c new file mode 100644 index 000000000000..869f9833f08f --- /dev/null +++ b/arch/i386/xen/multicalls.c @@ -0,0 +1,89 @@ +/* + * Xen hypercall batching. + * + * Xen allows multiple hypercalls to be issued at once, using the + * multicall interface. This allows the cost of trapping into the + * hypervisor to be amortized over several calls. + * + * This file implements a simple interface for multicalls. There's a + * per-cpu buffer of outstanding multicalls. When you want to queue a + * multicall for issuing, you can allocate a multicall slot for the + * call and its arguments, along with storage for space which is + * pointed to by the arguments (for passing pointers to structures, + * etc). When the multicall is actually issued, all the space for the + * commands and allocated memory is freed for reuse. + * + * Multicalls are flushed whenever any of the buffers get full, or + * when explicitly requested. There's no way to get per-multicall + * return results back. It will BUG if any of the multicalls fail. + * + * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 + */ +#include <linux/percpu.h> + +#include <asm/xen/hypercall.h> + +#include "multicalls.h" + +#define MC_BATCH 8 +#define MC_ARGS (MC_BATCH * 32 / sizeof(u64)) + +struct mc_buffer { + struct multicall_entry entries[MC_BATCH]; + u64 args[MC_ARGS]; + unsigned mcidx, argidx; +}; + +static DEFINE_PER_CPU(struct mc_buffer, mc_buffer); +DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags); + +void xen_mc_flush(void) +{ + struct mc_buffer *b = &get_cpu_var(mc_buffer); + int ret = 0; + unsigned long flags; + + /* Disable interrupts in case someone comes in and queues + something in the middle */ + local_irq_save(flags); + + if (b->mcidx) { + int i; + + if (HYPERVISOR_multicall(b->entries, b->mcidx) != 0) + BUG(); + for (i = 0; i < b->mcidx; i++) + if (b->entries[i].result < 0) + ret++; + b->mcidx = 0; + b->argidx = 0; + } else + BUG_ON(b->argidx != 0); + + put_cpu_var(mc_buffer); + local_irq_restore(flags); + + BUG_ON(ret); +} + +struct multicall_space __xen_mc_entry(size_t args) +{ + struct mc_buffer *b = &get_cpu_var(mc_buffer); + struct multicall_space ret; + unsigned argspace = (args + sizeof(u64) - 1) / sizeof(u64); + + BUG_ON(argspace > MC_ARGS); + + if (b->mcidx == MC_BATCH || + (b->argidx + argspace) > MC_ARGS) + xen_mc_flush(); + + ret.mc = &b->entries[b->mcidx]; + b->mcidx++; + ret.args = &b->args[b->argidx]; + b->argidx += argspace; + + put_cpu_var(mc_buffer); + + return ret; +} diff --git a/arch/i386/xen/multicalls.h b/arch/i386/xen/multicalls.h new file mode 100644 index 000000000000..e6f7530b156c --- /dev/null +++ b/arch/i386/xen/multicalls.h @@ -0,0 +1,45 @@ +#ifndef _XEN_MULTICALLS_H +#define _XEN_MULTICALLS_H + +#include "xen-ops.h" + +/* Multicalls */ +struct multicall_space +{ + struct multicall_entry *mc; + void *args; +}; + +/* Allocate room for a multicall and its args */ +struct multicall_space __xen_mc_entry(size_t args); + +DECLARE_PER_CPU(unsigned long, xen_mc_irq_flags); + +/* Call to start a batch of multiple __xen_mc_entry()s. Must be + paired with xen_mc_issue() */ +static inline void xen_mc_batch(void) +{ + /* need to disable interrupts until this entry is complete */ + local_irq_save(__get_cpu_var(xen_mc_irq_flags)); +} + +static inline struct multicall_space xen_mc_entry(size_t args) +{ + xen_mc_batch(); + return __xen_mc_entry(args); +} + +/* Flush all pending multicalls */ +void xen_mc_flush(void); + +/* Issue a multicall if we're not in a lazy mode */ +static inline void xen_mc_issue(unsigned mode) +{ + if ((xen_get_lazy_mode() & mode) == 0) + xen_mc_flush(); + + /* restore flags saved in xen_mc_batch */ + local_irq_restore(x86_read_percpu(xen_mc_irq_flags)); +} + +#endif /* _XEN_MULTICALLS_H */ diff --git a/arch/i386/xen/setup.c b/arch/i386/xen/setup.c new file mode 100644 index 000000000000..7da93ee612f6 --- /dev/null +++ b/arch/i386/xen/setup.c @@ -0,0 +1,97 @@ +/* + * Machine specific setup for xen + * + * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 + */ + +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/pm.h> + +#include <asm/elf.h> +#include <asm/e820.h> +#include <asm/setup.h> +#include <asm/xen/hypervisor.h> +#include <asm/xen/hypercall.h> + +#include <xen/interface/physdev.h> +#include <xen/features.h> + +#include "xen-ops.h" + +/* These are code, but not functions. Defined in entry.S */ +extern const char xen_hypervisor_callback[]; +extern const char xen_failsafe_callback[]; + +static __initdata struct shared_info init_shared; + +/* + * Point at some empty memory to start with. We map the real shared_info + * page as soon as fixmap is up and running. + */ +struct shared_info *HYPERVISOR_shared_info = &init_shared; + +unsigned long *phys_to_machine_mapping; +EXPORT_SYMBOL(phys_to_machine_mapping); + +/** + * machine_specific_memory_setup - Hook for machine specific memory setup. + **/ + +char * __init xen_memory_setup(void) +{ + unsigned long max_pfn = xen_start_info->nr_pages; + + e820.nr_map = 0; + add_memory_region(0, PFN_PHYS(max_pfn), E820_RAM); + + return "Xen"; +} + +static void xen_idle(void) +{ + local_irq_disable(); + + if (need_resched()) + local_irq_enable(); + else { + current_thread_info()->status &= ~TS_POLLING; + smp_mb__after_clear_bit(); + safe_halt(); + current_thread_info()->status |= TS_POLLING; + } +} + +void __init xen_arch_setup(void) +{ + struct physdev_set_iopl set_iopl; + int rc; + + HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); + HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); + + if (!xen_feature(XENFEAT_auto_translated_physmap)) + HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3); + + HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback, + __KERNEL_CS, (unsigned long)xen_failsafe_callback); + + set_iopl.iopl = 1; + rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); + if (rc != 0) + printk(KERN_INFO "physdev_op failed %d\n", rc); + +#ifdef CONFIG_ACPI + if (!(xen_start_info->flags & SIF_INITDOMAIN)) { + printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); + disable_acpi(); + } +#endif + + memcpy(boot_command_line, xen_start_info->cmd_line, + MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? + COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); + + pm_idle = xen_idle; +} diff --git a/arch/i386/xen/xen-head.S b/arch/i386/xen/xen-head.S new file mode 100644 index 000000000000..2998d55a0017 --- /dev/null +++ b/arch/i386/xen/xen-head.S @@ -0,0 +1,36 @@ +/* Xen-specific pieces of head.S, intended to be included in the right + place in head.S */ + +#ifdef CONFIG_XEN + +#include <linux/elfnote.h> +#include <asm/boot.h> +#include <xen/interface/elfnote.h> + +ENTRY(startup_xen) + movl %esi,xen_start_info + cld + movl $(init_thread_union+THREAD_SIZE),%esp + jmp xen_start_kernel + +.pushsection ".bss.page_aligned" + .align PAGE_SIZE_asm +ENTRY(hypercall_page) + .skip 0x1000 +.popsection + + ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS, .asciz "linux") + ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION, .asciz "2.6") + ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION, .asciz "xen-3.0") + ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE, .long __PAGE_OFFSET) + ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, .long startup_xen) + ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, .long hypercall_page) + ELFNOTE(Xen, XEN_ELFNOTE_FEATURES, .asciz "!writable_page_tables|pae_pgdir_above_4gb") +#ifdef CONFIG_X86_PAE + ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "yes") +#else + ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "no") +#endif + ELFNOTE(Xen, XEN_ELFNOTE_LOADER, .asciz "generic") + +#endif /*CONFIG_XEN */ diff --git a/arch/i386/xen/xen-ops.h b/arch/i386/xen/xen-ops.h new file mode 100644 index 000000000000..79648fe1ab77 --- /dev/null +++ b/arch/i386/xen/xen-ops.h @@ -0,0 +1,31 @@ +#ifndef XEN_OPS_H +#define XEN_OPS_H + +#include <linux/init.h> +#include <linux/clocksource.h> + +DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu); +DECLARE_PER_CPU(unsigned long, xen_cr3); + +extern struct start_info *xen_start_info; +extern struct shared_info *HYPERVISOR_shared_info; + +char * __init xen_memory_setup(void); +void __init xen_arch_setup(void); +void __init xen_init_IRQ(void); + +unsigned long xen_cpu_khz(void); +void __init xen_time_init(void); +unsigned long xen_get_wallclock(void); +int xen_set_wallclock(unsigned long time); +cycle_t xen_clocksource_read(void); + +DECLARE_PER_CPU(enum paravirt_lazy_mode, xen_lazy_mode); + +static inline unsigned xen_get_lazy_mode(void) +{ + return x86_read_percpu(xen_lazy_mode); +} + + +#endif /* XEN_OPS_H */ |