From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Date: Tue, 22 Jan 2019 05:14:30 +0000 Subject: Re: [PATCH 08/19] KVM: PPC: Book3S HV: add a VC_BASE control to the XIVE native device Message-Id: <20190122051430.GE15124@blackberry> List-Id: References: <20190107184331.8429-1-clg@kaod.org> <20190107184331.8429-9-clg@kaod.org> In-Reply-To: <20190107184331.8429-9-clg@kaod.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: =?iso-8859-1?Q?C=E9dric?= Le Goater Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, David Gibson On Mon, Jan 07, 2019 at 07:43:20PM +0100, C=E9dric Le Goater wrote: > The ESB MMIO region controls the interrupt sources of the guest. QEMU > will query an fd (GET_ESB_FD ioctl) and map this region at a specific > address for the guest to use. The guest will obtain this information > using the H_INT_GET_SOURCE_INFO hcall. To inform KVM of the address > setting used by QEMU, add a VC_BASE control to the KVM XIVE device This needs a little more explanation. I *think* the only way this gets used is that it gets returned to the guest by the new hypercalls. If that is indeed the case it would be useful to mention that in the patch description, because otherwise taking a value that userspace provides and which looks like it is an address, and not doing any validation on it, looks a bit scary. Paul.