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authorRusty Russell <rusty@rustcorp.com.au>2007-07-19 01:49:22 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-19 10:04:52 -0700
commit07ad157f6e5d228be78acd5cea0291e5d0360398 (patch)
tree87180c2d1aa53857f46d1dc293e08c0fbea0608a /include/linux
parent5992b6dac0d23a2b51a1ccbaf8f1a2e62097b12b (diff)
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 <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/lguest.h85
-rw-r--r--include/linux/lguest_bus.h48
2 files changed, 133 insertions, 0 deletions
diff --git a/include/linux/lguest.h b/include/linux/lguest.h
new file mode 100644
index 00000000000..f30c04fc22b
--- /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 <asm/irq.h>
+
+#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 00000000000..c9b4e05fee4
--- /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 <linux/device.h>
+#include <linux/lguest.h>
+#include <linux/lguest_launcher.h>
+
+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 */