[PATCH 1/13] KVM: userspace interface

[Avi Kivity <avi@qumranet.com>]

Changes from v1:

- removed #define __user for userspace

Still TODO:

- inode per vcpu
- pseudo filesystem + syscalls?

--

This patch defines a bunch of ioctl()s on /dev/kvm.  The ioctl()s allow adding
memory to a virtual machine, adding a virtual cpu to a virtual machine (at
most one at this time), transferring control to the virtual cpu, and querying
about guest pages changed by the virtual machine.

Signed-off-by: Yaniv Kamay <yaniv@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

Index: linux-2.6/include/linux/kvm.h
===================================================================
--- /dev/null
+++ linux-2.6/include/linux/kvm.h
@@ -0,0 +1,198 @@
+#ifndef __LINUX_KVM_H
+#define __LINUX_KVM_H
+
+/*
+ * Userspace interface for /dev/kvm - kernel based virtual machine
+ *
+ * Note: this interface is considered experimental and may change without
+ *       notice.
+ */
+
+#include <asm/types.h>
+#include <linux/ioctl.h>
+
+/* for KVM_CREATE_MEMORY_REGION */
+struct kvm_memory_region {
+	__u32 slot;
+	__u32 flags;
+	__u64 guest_phys_addr;
+	__u64 memory_size; /* bytes */
+};
+
+/* for kvm_memory_region::flags */
+#define KVM_MEM_LOG_DIRTY_PAGES  1UL
+
+
+#define KVM_EXIT_TYPE_FAIL_ENTRY 1
+#define KVM_EXIT_TYPE_VM_EXIT    2
+
+enum kvm_exit_reason {
+	KVM_EXIT_UNKNOWN,
+	KVM_EXIT_EXCEPTION,
+	KVM_EXIT_IO,
+	KVM_EXIT_CPUID,
+	KVM_EXIT_DEBUG,
+	KVM_EXIT_HLT,
+	KVM_EXIT_MMIO,
+};
+
+/* for KVM_RUN */
+struct kvm_run {
+	/* in */
+	__u32 vcpu;
+	__u32 emulated;  /* skip current instruction */
+	__u32 mmio_completed; /* mmio request completed */
+
+	/* out */
+	__u32 exit_type;
+	__u32 exit_reason;
+	__u32 instruction_length;
+	union {
+		/* KVM_EXIT_UNKNOWN */
+		struct {
+			__u32 hardware_exit_reason;
+		} hw;
+		/* KVM_EXIT_EXCEPTION */
+		struct {
+			__u32 exception;
+			__u32 error_code;
+		} ex;
+		/* KVM_EXIT_IO */
+		struct {
+#define KVM_EXIT_IO_IN  0
+#define KVM_EXIT_IO_OUT 1
+			__u8 direction;
+			__u8 size; /* bytes */
+			__u8 string;
+			__u8 string_down;
+			__u8 rep;
+			__u8 pad;
+			__u16 port;
+			__u64 count;
+			union {
+				__u64 address;
+				__u32 value;
+			};
+		} io;
+		struct {
+		} debug;
+		/* KVM_EXIT_MMIO */
+		struct {
+			__u64 phys_addr;
+			__u8  data[8];
+			__u32 len;
+			__u8  is_write;
+		} mmio;
+	};
+};
+
+/* for KVM_GET_REGS and KVM_SET_REGS */
+struct kvm_regs {
+	/* in */
+	__u32 vcpu;
+	__u32 padding;
+
+	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
+	__u64 rax, rbx, rcx, rdx;
+	__u64 rsi, rdi, rsp, rbp;
+	__u64 r8,  r9,  r10, r11;
+	__u64 r12, r13, r14, r15;
+	__u64 rip, rflags;
+};
+
+struct kvm_segment {
+	__u64 base;
+	__u32 limit;
+	__u16 selector;
+	__u8  type;
+	__u8  present, dpl, db, s, l, g, avl;
+	__u8  unusable;
+	__u8  padding;
+};
+
+struct kvm_dtable {
+	__u64 base;
+	__u16 limit;
+	__u16 padding[3];
+};
+
+/* for KVM_GET_SREGS and KVM_SET_SREGS */
+struct kvm_sregs {
+	/* in */
+	__u32 vcpu;
+	__u32 padding;
+
+	/* out (KVM_GET_SREGS) / in (KVM_SET_SREGS) */
+	struct kvm_segment cs, ds, es, fs, gs, ss;
+	struct kvm_segment tr, ldt;
+	struct kvm_dtable gdt, idt;
+	__u64 cr0, cr2, cr3, cr4, cr8;
+	__u64 efer;
+	__u64 apic_base;
+
+	/* out (KVM_GET_SREGS) */
+	__u32 pending_int;
+	__u32 padding2;
+};
+
+/* for KVM_TRANSLATE */
+struct kvm_translation {
+	/* in */
+	__u64 linear_address;
+	__u32 vcpu;
+	__u32 padding;
+
+	/* out */
+	__u64 physical_address;
+	__u8  valid;
+	__u8  writeable;
+	__u8  usermode;
+};
+
+/* for KVM_INTERRUPT */
+struct kvm_interrupt {
+	/* in */
+	__u32 vcpu;
+	__u32 irq;
+};
+
+struct kvm_breakpoint {
+	__u32 enabled;
+	__u32 padding;
+	__u64 address;
+};
+
+/* for KVM_DEBUG_GUEST */
+struct kvm_debug_guest {
+	/* int */
+	__u32 vcpu;
+	__u32 enabled;
+	struct kvm_breakpoint breakpoints[4];
+	__u32 singlestep;
+};
+
+/* for KVM_GET_DIRTY_LOG */
+struct kvm_dirty_log {
+	__u32 slot;
+	__u32 padding;
+	union {
+		void __user *dirty_bitmap; /* one bit per page */
+		__u64 padding;
+	};
+};
+
+#define KVMIO 0xAE
+
+#define KVM_RUN                   _IOWR(KVMIO, 2, struct kvm_run)
+#define KVM_GET_REGS              _IOWR(KVMIO, 3, struct kvm_regs)
+#define KVM_SET_REGS              _IOW(KVMIO, 4, struct kvm_regs)
+#define KVM_GET_SREGS             _IOWR(KVMIO, 5, struct kvm_sregs)
+#define KVM_SET_SREGS             _IOW(KVMIO, 6, struct kvm_sregs)
+#define KVM_TRANSLATE             _IOWR(KVMIO, 7, struct kvm_translation)
+#define KVM_INTERRUPT             _IOW(KVMIO, 8, struct kvm_interrupt)
+#define KVM_DEBUG_GUEST           _IOW(KVMIO, 9, struct kvm_debug_guest)
+#define KVM_SET_MEMORY_REGION     _IOW(KVMIO, 10, struct kvm_memory_region)
+#define KVM_CREATE_VCPU           _IOW(KVMIO, 11, int /* vcpu_slot */)
+#define KVM_GET_DIRTY_LOG         _IOW(KVMIO, 12, struct kvm_dirty_log)
+
+#endif