From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:45654 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726440AbgI1IWt (ORCPT ); Mon, 28 Sep 2020 04:22:49 -0400 Subject: Re: [PATCH v1 2/4] s390x: pv: implement routine to share/unshare memory References: <1601049764-11784-1-git-send-email-pmorel@linux.ibm.com> <1601049764-11784-3-git-send-email-pmorel@linux.ibm.com> From: Janosch Frank Message-ID: <6c87a0ef-63ef-a0b8-58ff-d60e58bdb223@linux.ibm.com> Date: Mon, 28 Sep 2020 10:22:40 +0200 MIME-Version: 1.0 In-Reply-To: <1601049764-11784-3-git-send-email-pmorel@linux.ibm.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="wlCwQ6Ss9n5G0nlWIqOLmcEv41lkqv5Og" List-ID: To: Pierre Morel , kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, david@redhat.com, thuth@redhat.com, cohuck@redhat.com, imbrenda@linux.ibm.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --wlCwQ6Ss9n5G0nlWIqOLmcEv41lkqv5Og Content-Type: multipart/mixed; boundary="Rzxd9G4bNo0gXEvb26jVDBGQpEComrMrA" --Rzxd9G4bNo0gXEvb26jVDBGQpEComrMrA Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 9/25/20 6:02 PM, Pierre Morel wrote: > When communicating with the host we need to share part of > the memory. >=20 > Let's implement the ultravisor calls for this. >=20 > Signed-off-by: Pierre Morel > Suggested-by: Janosch Frank > --- > lib/s390x/asm/uv.h | 33 +++++++++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) >=20 > diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h > index 4c2fc48..19019e4 100644 > --- a/lib/s390x/asm/uv.h > +++ b/lib/s390x/asm/uv.h > @@ -71,4 +71,37 @@ static inline int uv_call(unsigned long r1, unsigned= long r2) > return cc; > } > =20 > +static inline int share(unsigned long addr, u16 cmd) > +{ > + struct uv_cb_share uvcb =3D { > + .header.cmd =3D cmd, > + .header.len =3D sizeof(uvcb), > + .paddr =3D addr > + }; > + > + uv_call(0, (u64)&uvcb); > + return uvcb.header.rc; That's not a great idea, rc is > 1 for error codes... In the kernel we check for the cc instead since uv_call() has only 0/1 as possible cc return values. > +} > + > +/* > + * Guest 2 request to the Ultravisor to make a page shared with the > + * hypervisor for IO. > + * > + * @addr: Real or absolute address of the page to be shared > + */ > +static inline int uv_set_shared(unsigned long addr) > +{ > + return share(addr, UVC_CMD_SET_SHARED_ACCESS); > +} > + > +/* > + * Guest 2 request to the Ultravisor to make a page unshared. > + * > + * @addr: Real or absolute address of the page to be unshared > + */ > +static inline int uv_remove_shared(unsigned long addr) > +{ > + return share(addr, UVC_CMD_REMOVE_SHARED_ACCESS); > +} > + > #endif >=20 --Rzxd9G4bNo0gXEvb26jVDBGQpEComrMrA-- --wlCwQ6Ss9n5G0nlWIqOLmcEv41lkqv5Og Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEwGNS88vfc9+v45Yq41TmuOI4ufgFAl9xnVEACgkQ41TmuOI4 ufgrNg//SZGk2WtnjZ6BsyX9qY3dtFy4pt6J3yxgwnNMOAUPUbQ17nyRdXoTI20G 1XW9IyXC/R5cijZ43ih6jcd4oz+l4HfbMIRIPZdEX32GMTjDGxbbmEqxfL9uHz1h 1NXwJ5M8hE5GasyyZG50jlrp+awGgZ45K1/jDfuef2Okfa3+EjJWjgQ3mUrjxblC EctRzteBXQPGxy2nUP45CvESt0Q/bTOQsQZkCqWQpRcM6IvKDlNMAwdEZ2i00qb0 wmIix5bEFfVPspd6vCJ/t1EQK1+FOef2BPafaL0ldadgQdS38KHYjtEgaPSkDlEE jlifaQJNvS1m2xN4oSRzXZEUJxmogAjyHy8Dv943YZJiOnPrBhavaEnas5jauojf dGVGOzYNUy7Tz2YYyLPIWaYKcY0pJJ+/DsH0jSoHQKY2Tiz8MIV2L0rugDQQzlVN QcHl2+FOvJ+crCKHUAhgTRvXJmjn5s2qqdnv2Fz6VJxEy4W6JM4Ey+E8ejimo2qt OGgPrgcMGmhTNDcm5hHvSJX1T10U1A+temW4jT9OsYKvLR1aPKOrDeM+3JOz8Zx6 Sc56Kf1cTfvZs0VBj9FipsKn68KDlEGU9JafE/1iUcdJWsSbSOcIARdA82mVT+Br E6g5qEOKWhn0zUcp3aV8SMHJT1IvyqEH/QcvUF4F9bkFY6Fuwds= =Offx -----END PGP SIGNATURE----- --wlCwQ6Ss9n5G0nlWIqOLmcEv41lkqv5Og--