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    SubjectRe: [PATCH 2/5] KVM: SVM: Optimize nested svm msrpm merging
    On Fri, Feb 26, 2010 at 03:10:13PM +0200, Avi Kivity wrote:
    > On 02/26/2010 03:04 PM, Joerg Roedel wrote:
    > >
    > >>I'm still not convinced on this way of doing things. If it's static,
    > >>make it static. If it's dynamic, make it dynamic. Dynamically
    > >>generating a static list just sounds plain wrong to me.
    > >Stop. I had a static list in the first version of the patch. This list
    > >was fine except the fact that a developer needs to remember to update
    > >this list if the list of non-intercepted msrs is expanded. The whole
    > >reason for a dynamically built list is to take the task of maintaining
    > >the list away from the developer and remove a possible source of hard to
    > >find bugs. This is what the current approach does.
    > The problem was the two lists. If you had a
    > static struct svm_direct_access_msrs = {
    > u32 index;
    > bool longmode_only;
    > } direct_access_msrs = {
    > ...
    > };
    > You could generate
    > static unsigned *msrpm_offsets_longmode, *msrpm_offsets_legacy;
    > as well as the original bitmaps at module init, no?

    True for the msrs the guest always has access too. But for the lbr-msrs
    the intercept bits may change at runtime. So an addtional flag is
    required to indicate if the bits should be cleared initially.


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      Last update: 2010-02-26 14:25    [W:0.025 / U:14.228 seconds]
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