Re: [PART1 RFC v2 05/10] KVM: x86: Detect and Initialize AVIC support

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

 



Hi,

On 03/16/2016 02:20 PM, Paolo Bonzini wrote:

On 16/03/2016 07:22, Suravee Suthikulpanit wrote:
>This is mainly causing a large number of VMEXIT due to NPF.
Got it, it's here in the manual: "System software is responsible for
setting up a translation in the nested page table granting guest read
and write permissions for accesses to the vAPIC Backing Page in SPA
space. AVIC hardware walks the nested page table to check permissions,
but does not use the SPA address specified in the leaf page table entry.
Instead, AVIC hardware finds this address in the AVIC_BACKING_PAGE
pointer field of the VMCB".

Strictly speaking the address of the 0xFEE00000 translation is
unnecessary and it could be all zeroes, but I suggest that you set up an
APIC access page like Intel does (4k only), using the special memslot.
The AVIC backing page can then point to lapic->regs.

Thanks for the explanation!

Paolo


Ahh... you are right, this works also. Thanks for the pointer. I'm fixing this, doing some more testing, and cleaning up the code. This has simplify the init logic quite a bit.

Thanks for suggestion,
Suravee
--
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