Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-14 Thread Stefano Stabellini
On Mon, 14 Dec 2015, Jan Beulich wrote: > >>> On 11.12.15 at 17:56, wrote: > > For the original issue here, could the flag be exposed as a > > XEN_SYSCTL_PHYSCAP_ > > Yes, I think it could, albeit calling this a "capability" or "feature" > seems odd (since really the original behavior was bog

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-14 Thread Jan Beulich
>>> On 11.12.15 at 17:56, wrote: > For the original issue here, could the flag be exposed as a > XEN_SYSCTL_PHYSCAP_ Yes, I think it could, albeit calling this a "capability" or "feature" seems odd (since really the original behavior was bogus/buggy). But - with sysctl not being a stable inte

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-14 Thread Ian Campbell
On Mon, 2015-12-14 at 11:19 +, Stefano Stabellini wrote: > On Fri, 11 Dec 2015, Ian Campbell wrote: > > On Fri, 2015-12-11 at 16:44 +, Stefano Stabellini wrote: > > >   > > > It is not possible to do this at runtime. I think we should do this > > > at > > > compile time because in any case

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-14 Thread Stefano Stabellini
On Mon, 14 Dec 2015, Jan Beulich wrote: > >>> On 11.12.15 at 17:56, wrote: > > On Fri, 2015-12-11 at 16:44 +, Stefano Stabellini wrote: > >> > >> It is not possible to do this at runtime. I think we should do this at > >> compile time because in any case it is not supported to run a QEMU bui

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-14 Thread Stefano Stabellini
On Fri, 11 Dec 2015, Ian Campbell wrote: > On Fri, 2015-12-11 at 16:44 +, Stefano Stabellini wrote: > >   > > It is not possible to do this at runtime. I think we should do this at > > compile time because in any case it is not supported to run a QEMU built > > for a given Xen version on a diff

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-14 Thread Jan Beulich
>>> On 11.12.15 at 17:56, wrote: > On Fri, 2015-12-11 at 16:44 +, Stefano Stabellini wrote: >> >> It is not possible to do this at runtime. I think we should do this at >> compile time because in any case it is not supported to run a QEMU built >> for a given Xen version on a different Xen v

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-11 Thread Ian Campbell
On Fri, 2015-12-11 at 16:44 +, Stefano Stabellini wrote: >   > It is not possible to do this at runtime. I think we should do this at > compile time because in any case it is not supported to run a QEMU built > for a given Xen version on a different Xen version. I am currently working pretty h

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-11 Thread Stefano Stabellini
On Fri, 11 Dec 2015, Jan Beulich wrote: > >>> On 11.12.15 at 15:33, wrote: > > On Mon, 7 Dec 2015, Jan Beulich wrote: > >> >>> On 07.12.15 at 15:56, wrote: > >> > On Mon, 7 Dec 2015, Jan Beulich wrote: > >> >> >>> On 07.12.15 at 13:45, wrote: > >> >> > On Tue, 24 Nov 2015, Jan Beulich wrote: > >

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-11 Thread Jan Beulich
>>> On 11.12.15 at 15:33, wrote: > On Mon, 7 Dec 2015, Jan Beulich wrote: >> >>> On 07.12.15 at 15:56, wrote: >> > On Mon, 7 Dec 2015, Jan Beulich wrote: >> >> >>> On 07.12.15 at 13:45, wrote: >> >> > On Tue, 24 Nov 2015, Jan Beulich wrote: >> >> >> TBD: We probably need to deal with running on

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-11 Thread Stefano Stabellini
On Mon, 7 Dec 2015, Jan Beulich wrote: > >>> On 07.12.15 at 15:56, wrote: > > On Mon, 7 Dec 2015, Jan Beulich wrote: > >> >>> On 07.12.15 at 13:45, wrote: > >> > On Tue, 24 Nov 2015, Jan Beulich wrote: > >> >> Now that the hypervisor intercepts all config space writes and monitors > >> >> changes

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-07 Thread Jan Beulich
>>> On 07.12.15 at 15:56, wrote: > On Mon, 7 Dec 2015, Jan Beulich wrote: >> >>> On 07.12.15 at 13:45, wrote: >> > On Tue, 24 Nov 2015, Jan Beulich wrote: >> >> Now that the hypervisor intercepts all config space writes and monitors >> >> changes to the masking flags, this undoes the main effect

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-07 Thread Stefano Stabellini
On Mon, 7 Dec 2015, Jan Beulich wrote: > >>> On 07.12.15 at 13:45, wrote: > > On Tue, 24 Nov 2015, Jan Beulich wrote: > >> Now that the hypervisor intercepts all config space writes and monitors > >> changes to the masking flags, this undoes the main effect of the > >> XSA-129 fix, exposing the ma

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-07 Thread Jan Beulich
>>> On 07.12.15 at 13:45, wrote: > On Tue, 24 Nov 2015, Jan Beulich wrote: >> Now that the hypervisor intercepts all config space writes and monitors >> changes to the masking flags, this undoes the main effect of the >> XSA-129 fix, exposing the masking capability again to guests. >> >> Signed-o

Re: [Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-12-07 Thread Stefano Stabellini
On Tue, 24 Nov 2015, Jan Beulich wrote: > Now that the hypervisor intercepts all config space writes and monitors > changes to the masking flags, this undoes the main effect of the > XSA-129 fix, exposing the masking capability again to guests. > > Signed-off-by: Jan Beulich > --- > TBD: We proba

[Xen-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

2015-11-24 Thread Jan Beulich
Now that the hypervisor intercepts all config space writes and monitors changes to the masking flags, this undoes the main effect of the XSA-129 fix, exposing the masking capability again to guests. Signed-off-by: Jan Beulich --- TBD: We probably need to deal with running on an older hypervisor.