On Wed, Jan 23, 2019 at 05:56:26PM +0100, Cédric Le Goater wrote: > On 1/22/19 6:14 AM, Paul Mackerras wrote: > > On Mon, Jan 07, 2019 at 07:43:20PM +0100, Cédric 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. > > I think we have solved this problem in another email thread. > > The H_INT_GET_SOURCE_INFO hcall does not need to be implemented in KVM > as all the source information should already be available in QEMU. In > that case, there is no need to inform KVM of where the ESB pages are > mapped in the guest address space. So we don't need that extra control > on the KVM device. This is good news. Ah, good to hear. I thought this looked strange. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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