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    SubjectRe: [Qemu-devel] [RFC] Next gen kvm api
    On 02/03/2012 04:52 PM, Anthony Liguori wrote:
    > On 02/03/2012 12:07 PM, Eric Northup wrote:
    >> On Thu, Feb 2, 2012 at 8:09 AM, Avi Kivity<> wrote:
    >> [...]
    >>> Moving to syscalls avoids these problems, but introduces new ones:
    >>> - adding new syscalls is generally frowned upon, and kvm will need
    >>> several
    >>> - syscalls into modules are harder and rarer than into core kernel code
    >>> - will need to add a vcpu pointer to task_struct, and a kvm pointer to
    >>> mm_struct
    >> - Lost a good place to put access control (permissions on /dev/kvm)
    >> for which user-mode processes can use KVM.
    >> How would the ability to use sys_kvm_* be regulated?
    > Why should it be regulated?
    > It's not a finite or privileged resource.

    You're exposing a large, complex kernel subsystem that does very
    low-level things with the hardware. It's a potential source of exploits
    (from bugs in KVM or in hardware). I can see people wanting to be
    selective with access because of that.

    And sometimes it is a finite resource. I don't know how x86 does it,
    but on at least some powerpc hardware we have a finite, relatively small
    number of hardware partition IDs.


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      Last update: 2012-02-06 20:49    [W:0.023 / U:2.820 seconds]
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