> -----Original Message----- > From: Xen-devel <xen-devel-bounces@lists.xenproject.org> On Behalf Of Andrew Cooper > Sent: 15 June 2020 15:15 > To: Xen-devel <xen-devel@lists.xenproject.org> > Cc: Wei Liu <wl@xen.org>; Paul Durrant <paul@xen.org>; Andrew Cooper <andrew.cooper3@citrix.com>; Jan > Beulich <JBeulich@suse.com>; Ian Jackson <Ian.Jackson@citrix.com>; Roger Pau Monné > <roger.pau@citrix.com> > Subject: [PATCH for-4.14 0/9] XSA-320 follow for IvyBridge > > This is some work in light of IvyBridge not gaining microcode to combat SRBDS > / XSA-320. It is a mix of some work I'd planned for 4.15, and some patches > posted already and delayed due to dependence's I'd discovered after-the-fact. > > This provides a more user-friendly way of making IvyBridge safe by default > without encountering migration incompatibilities. > > In terms of functionality, it finishes the "fresh boot" vs "migrate/restore > from pre-4.14" split in the libxc CPUID logic, and uses this to let us safely > hide features by default without breaking the "divine what a guest may have > seen previously" logic on migrate. > > On top of that, we hide RDRAND by default to mitigate XSA-320. > > Additionally, take the opportunity of finally getting this logic working to > hide MPX by default (as posted previously), due to upcoming Intel timelines. > > Request for 4.14. The IvyBridge angle only became apparent after the public > embargo on Tue 9th. Otherwise, I would have made a concerted effort to get > this logic sorted sooner and/or part of XSA-320 itself. > > Strictly speaking, patches 1-4 aren't necessary, but without them the logic is > very confusing to follow, particularly the reasoning about the safely of later > changes. As it is a simple set of transforms, we're better with them than > without. > > Also, the MPX patch isn't related to the RDRAND issue, but I was planning to > get it into 4.14 already, until realising that the migration path was broken. > Now that the path is fixed for the RDRAND issue, include the MPX patch as it > pertains to future hardware compatibility (and would be backported to 4.14.1 > if it misses 4.14.0). > Fair enough. Once the series has all the requisite maintainer acks then I'll release-ack it. Paul > Andrew Cooper (9): > tools/libx[cl]: Introduce struct xc_xend_cpuid for xc_cpuid_set() > tests/cpu-policy: Confirm that CPUID serialisation is sorted > tools/libx[cl]: Move processing loop down into xc_cpuid_set() > tools/libx[cl]: Merge xc_cpuid_set() into xc_cpuid_apply_policy() > tools/libx[cl]: Plumb bool restore down into xc_cpuid_apply_policy() > x86/gen-cpuid: Distinguish default vs max in feature annotations > x86/hvm: Disable MPX by default > x86/cpuid: Introduce missing feature adjustment in calculate_pv_def_policy() > x86/spec-ctrl: Hide RDRAND by default on IvyBridge > > docs/misc/xen-command-line.pandoc | 20 ++- > tools/libxc/include/xenctrl.h | 42 ++++- > tools/libxc/xc_cpuid_x86.c | 239 ++++++++++++++++------------ > tools/libxl/libxl.h | 8 +- > tools/libxl/libxl_cpuid.c | 17 +- > tools/libxl/libxl_create.c | 2 +- > tools/libxl/libxl_dom.c | 2 +- > tools/libxl/libxl_internal.h | 12 +- > tools/libxl/libxl_nocpuid.c | 2 +- > tools/tests/cpu-policy/test-cpu-policy.c | 49 +++++- > xen/arch/x86/cpuid.c | 23 +++ > xen/include/public/arch-x86/cpufeatureset.h | 4 +- > xen/tools/gen-cpuid.py | 18 +-- > 13 files changed, 278 insertions(+), 160 deletions(-) > > -- > 2.11.0 >
> -----Original Message----- > From: Paul Durrant <xadimgnik@gmail.com> > Sent: 15 June 2020 18:04 > To: 'Andrew Cooper' <andrew.cooper3@citrix.com>; 'Xen-devel' <xen-devel@lists.xenproject.org> > Cc: 'Wei Liu' <wl@xen.org>; 'Jan Beulich' <JBeulich@suse.com>; 'Ian Jackson' <Ian.Jackson@citrix.com>; > 'Roger Pau Monné' <roger.pau@citrix.com> > Subject: RE: [PATCH for-4.14 0/9] XSA-320 follow for IvyBridge > > > -----Original Message----- > > From: Xen-devel <xen-devel-bounces@lists.xenproject.org> On Behalf Of Andrew Cooper > > Sent: 15 June 2020 15:15 > > To: Xen-devel <xen-devel@lists.xenproject.org> > > Cc: Wei Liu <wl@xen.org>; Paul Durrant <paul@xen.org>; Andrew Cooper <andrew.cooper3@citrix.com>; > Jan > > Beulich <JBeulich@suse.com>; Ian Jackson <Ian.Jackson@citrix.com>; Roger Pau Monné > > <roger.pau@citrix.com> > > Subject: [PATCH for-4.14 0/9] XSA-320 follow for IvyBridge > > > > This is some work in light of IvyBridge not gaining microcode to combat SRBDS > > / XSA-320. It is a mix of some work I'd planned for 4.15, and some patches > > posted already and delayed due to dependence's I'd discovered after-the-fact. > > > > This provides a more user-friendly way of making IvyBridge safe by default > > without encountering migration incompatibilities. > > > > In terms of functionality, it finishes the "fresh boot" vs "migrate/restore > > from pre-4.14" split in the libxc CPUID logic, and uses this to let us safely > > hide features by default without breaking the "divine what a guest may have > > seen previously" logic on migrate. > > > > On top of that, we hide RDRAND by default to mitigate XSA-320. > > > > Additionally, take the opportunity of finally getting this logic working to > > hide MPX by default (as posted previously), due to upcoming Intel timelines. > > > > Request for 4.14. The IvyBridge angle only became apparent after the public > > embargo on Tue 9th. Otherwise, I would have made a concerted effort to get > > this logic sorted sooner and/or part of XSA-320 itself. > > > > Strictly speaking, patches 1-4 aren't necessary, but without them the logic is > > very confusing to follow, particularly the reasoning about the safely of later > > changes. As it is a simple set of transforms, we're better with them than > > without. > > > > Also, the MPX patch isn't related to the RDRAND issue, but I was planning to > > get it into 4.14 already, until realising that the migration path was broken. > > Now that the path is fixed for the RDRAND issue, include the MPX patch as it > > pertains to future hardware compatibility (and would be backported to 4.14.1 > > if it misses 4.14.0). > > > > Fair enough. Once the series has all the requisite maintainer acks then I'll release-ack it. > I believe all acks are now place so the series is... Release-acked-by: Paul Durrant <paul@xen.org>
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