From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Date: Fri, 07 Jan 2011 15:38:35 +0000 Subject: Re: Guest reboot interface Message-Id: <4D27337B.8010001@web.de> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------enigF446274422FAD3FC581B8976" List-Id: References: In-Reply-To: To: kvm-ppc@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigF446274422FAD3FC581B8976 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Am 07.01.2011 13:40, Alexander Graf wrote: >=20 > On 07.01.2011, at 13:08, Liu Yu-B13201 wrote: >=20 >> >> Hi all, >> >> When guest reboot, it's better to reset status by qemu, and then sync = them back to kvm >> However as you know there's no BOOKE mmu emulation in qemu, >> So that qemu cannot directly reset BOOKE TLB. >> Moreover a lot SPR registers also cannot be reset by qemu. >> >> As a workaround, we need a interface that qemu can notify kvm to reset= the status. >> My question is, what should the interface be? >> Looks like there's no alike interface in other archs. >> Should we define a ioctl command number only used by BOOKE or powerpc?= >=20 > Wouldn't it make more sense to just fake-implement the registers (SPRs = and unused TLB) and sync that back on reset? You don't have to implement = the actual mmu logic, but that keeps things at the same place at least. >=20 This is how it's done on x86, and it's the preferred way. There will never be such things as KVM_IOCTL_RESET. BTW, isn't the TLB state relevant for vmsave/restore? Then it should be made accessible for user space anyway. Jan --------------enigF446274422FAD3FC581B8976 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAk0nM38ACgkQitSsb3rl5xRHFACeL80bJN/6rUpStMPipKLXByV8 uAsAoJ4pjZpmNU93kwHZp+/Qu13KtJRH =WY0y -----END PGP SIGNATURE----- --------------enigF446274422FAD3FC581B8976--