lkml.org 
[lkml]   [2006]   [Oct]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/7] KVM: userspace interface
Sorry if I missed this, but can you provide a link to the QEMU changes?

It's hard to tell what's going on without seeing the userspace portions
of this.

My initial impression is that you've taken the Xen approach of trying to
use QEMU only for IO emulation. If this is the case, it won't work long
term. While you can use vm86 mode for 16 bit virtualization for most
cases, it cannot handle big real mode. You need the ability to transfer
down to QEMU and allow it to do emulation.

Ideally, instead of having as large of an x86 emulator in kernel space,
you would just drop down to QEMU to do emulation as needed (doing only a
single basic block and returning). This would let you have a much
reduced partial emulator in kernel space that only did the most common
(and performance critical) instructions.

Regards,

Anthony Liguori

Avi Kivity wrote:
> 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 +1,202 @@
> +#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>
> +
> +#ifndef __user
> +#define __user
> +#endif
> +
> +/* 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
>
>

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-10-19 20:49    [W:0.244 / U:9.440 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site