From 07ad157f6e5d228be78acd5cea0291e5d0360398 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 19 Jul 2007 01:49:22 -0700 Subject: lguest: the guest code lguest is a simple hypervisor for Linux on Linux. Unlike kvm it doesn't need VT/SVM hardware. Unlike Xen it's simply "modprobe and go". Unlike both, it's 5000 lines and self-contained. Performance is ok, but not great (-30% on kernel compile). But given its hackability, I expect this to improve, along with the paravirt_ops code which it supplies a complete example for. There's also a 64-bit version being worked on and other craziness. But most of all, lguest is awesome fun! Too much of the kernel is a big ball of hair. lguest is simple enough to dive into and hack, plus has some warts which scream "fork me!". This patch: This is the code and headers required to make an i386 kernel an lguest guest. Signed-off-by: Rusty Russell Cc: Andi Kleen Cc: Jeremy Fitzhardinge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/lguest.h | 85 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/lguest_bus.h | 48 ++++++++++++++++++++++++++ 2 files changed, 133 insertions(+) create mode 100644 include/linux/lguest.h create mode 100644 include/linux/lguest_bus.h (limited to 'include') diff --git a/include/linux/lguest.h b/include/linux/lguest.h new file mode 100644 index 000000000000..f30c04fc22b7 --- /dev/null +++ b/include/linux/lguest.h @@ -0,0 +1,85 @@ +/* Things the lguest guest needs to know. Note: like all lguest interfaces, + * this is subject to wild and random change between versions. */ +#ifndef _ASM_LGUEST_H +#define _ASM_LGUEST_H + +/* These are randomly chosen numbers which indicate we're an lguest at boot */ +#define LGUEST_MAGIC_EBP 0x4C687970 +#define LGUEST_MAGIC_EDI 0x652D4D65 +#define LGUEST_MAGIC_ESI 0xFFFFFFFF + +#ifndef __ASSEMBLY__ +#include + +#define LHCALL_FLUSH_ASYNC 0 +#define LHCALL_LGUEST_INIT 1 +#define LHCALL_CRASH 2 +#define LHCALL_LOAD_GDT 3 +#define LHCALL_NEW_PGTABLE 4 +#define LHCALL_FLUSH_TLB 5 +#define LHCALL_LOAD_IDT_ENTRY 6 +#define LHCALL_SET_STACK 7 +#define LHCALL_TS 8 +#define LHCALL_TIMER_READ 9 +#define LHCALL_HALT 10 +#define LHCALL_GET_WALLCLOCK 11 +#define LHCALL_BIND_DMA 12 +#define LHCALL_SEND_DMA 13 +#define LHCALL_SET_PTE 14 +#define LHCALL_SET_PMD 15 +#define LHCALL_LOAD_TLS 16 + +#define LGUEST_TRAP_ENTRY 0x1F + +static inline unsigned long +hcall(unsigned long call, + unsigned long arg1, unsigned long arg2, unsigned long arg3) +{ + asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY) + : "=a"(call) + : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3) + : "memory"); + return call; +} + +void async_hcall(unsigned long call, + unsigned long arg1, unsigned long arg2, unsigned long arg3); + +/* Can't use our min() macro here: needs to be a constant */ +#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32) + +#define LHCALL_RING_SIZE 64 +struct hcall_ring +{ + u32 eax, edx, ebx, ecx; +}; + +/* All the good stuff happens here: guest registers it with LGUEST_INIT */ +struct lguest_data +{ +/* Fields which change during running: */ + /* 512 == enabled (same as eflags) */ + unsigned int irq_enabled; + /* Interrupts blocked by guest. */ + DECLARE_BITMAP(blocked_interrupts, LGUEST_IRQS); + + /* Virtual address of page fault. */ + unsigned long cr2; + + /* Async hypercall ring. 0xFF == done, 0 == pending. */ + u8 hcall_status[LHCALL_RING_SIZE]; + struct hcall_ring hcalls[LHCALL_RING_SIZE]; + +/* Fields initialized by the hypervisor at boot: */ + /* Memory not to try to access */ + unsigned long reserve_mem; + /* ID of this guest (used by network driver to set ethernet address) */ + u16 guestid; + +/* Fields initialized by the guest at boot: */ + /* Instruction range to suppress interrupts even if enabled */ + unsigned long noirq_start, noirq_end; +}; +extern struct lguest_data lguest_data; +#endif /* __ASSEMBLY__ */ +#endif /* _ASM_LGUEST_H */ diff --git a/include/linux/lguest_bus.h b/include/linux/lguest_bus.h new file mode 100644 index 000000000000..c9b4e05fee49 --- /dev/null +++ b/include/linux/lguest_bus.h @@ -0,0 +1,48 @@ +#ifndef _ASM_LGUEST_DEVICE_H +#define _ASM_LGUEST_DEVICE_H +/* Everything you need to know about lguest devices. */ +#include +#include +#include + +struct lguest_device { + /* Unique busid, and index into lguest_page->devices[] */ + unsigned int index; + + struct device dev; + + /* Driver can hang data off here. */ + void *private; +}; + +/* By convention, each device can use irq index+1 if it wants to. */ +static inline int lgdev_irq(const struct lguest_device *dev) +{ + return dev->index + 1; +} + +/* dma args must not be vmalloced! */ +void lguest_send_dma(unsigned long key, struct lguest_dma *dma); +int lguest_bind_dma(unsigned long key, struct lguest_dma *dmas, + unsigned int num, u8 irq); +void lguest_unbind_dma(unsigned long key, struct lguest_dma *dmas); + +/* Map the virtual device space */ +void *lguest_map(unsigned long phys_addr, unsigned long pages); +void lguest_unmap(void *); + +struct lguest_driver { + const char *name; + struct module *owner; + u16 device_type; + int (*probe)(struct lguest_device *dev); + void (*remove)(struct lguest_device *dev); + + struct device_driver drv; +}; + +extern int register_lguest_driver(struct lguest_driver *drv); +extern void unregister_lguest_driver(struct lguest_driver *drv); + +extern struct lguest_device_desc *lguest_devices; /* Just past max_pfn */ +#endif /* _ASM_LGUEST_DEVICE_H */ -- cgit v1.2.3