Re: KVM: x86: drop alignment checks from KVM_MSR_SYSTEM_TIME address

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sat, Mar 23, 2013 at 04:12:11PM +0200, Gleb Natapov wrote:
> On Fri, Mar 22, 2013 at 05:17:38PM -0700, Andrew Honig wrote:
> > kvm_write_guest would work, but it will hurt performance a bit because
> > it'll be doing the address translation each time the time is updated,
> > which happens on most guest enters.
> > 
> Time updates are rare, so this should no be an issue. Marcelo?

Yes, performance is not an issue at this level.

> > Another possibility would be to change kvm_gfn_to_hva_cache_init to
> > accept a size parameter.  If the requested range is all on one page
> > then it operates the same as it currently does.  If the address range
> > is on more than one page then it falls back to kvm_write_guest.  This
> > preserves the good performance for all cases that currently work,
> > while still supporting the unlikely case of page straddling requests.
> > It also makes it harder to write a security bugs for other callers of
> > kvm_gfn_to_hva_cache_init by explicitly requiring a size parameter.
> > 
> > I can write a patch if you like the idea.
> Nice idea. Send a patch please.
> 
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux