On Thu, 27 Apr 2017 17:28:39 +1000 David Gibson <da...@gibson.dropbear.id.au> wrote:
> This is a rebased and revised version of my patches revising CPU > compatiblity mode handling on ppc, last posted in November. Since > then, many of the patches have already been merged (some for 2.9, some > since). This is what's left. > > * There was conceptual confusion about what a compatibility mode > means, and how it interacts with the machine type. This cleans > that up, clarifying that a compatibility mode (as an externally set > option) only makes sense on machine types that don't permit the > guest hypervisor privilege (i.e. 'pseries') > > * It was previously the user's (or management layer's) responsibility > to determine compatibility of CPUs on either end for migration. > This uses the compatibility modes to check that properly during an > incoming migration. > > This hasn't been extensively tested yet. There are quite a few > migration cases to consider, for example: > Hi David, I'll rerun the tests shortly. Cheers, -- Greg > Basic: > > 1) Boot guest with -cpu host > Should go into POWER8 compat mode after CAS > Previously would have been raw mode > > 2) Boot guest with -machine pseries,max-cpu-compat=power7 -cpu host > Should go into POWER7 compat mode > > 3) Boot guest with -cpu host,compat=power7 > Should act as (2), but print a warning > > 4) Boot guest via libvirt with power7 compat mode specified in XML > Should act as (3), (2) once we fix libvirt > > 5) Hack guest to only advertise power7 compatibility, boot with -cpu host > Should go into POWER7 compat mode after CAS > > 6) Hack guest to only advertise real PVRs > Should remain in POWER8 raw mode after CAS > > 7) Hack guest to only advertise real PVRs > Boot with -machine pseries,max-cpu-compat=power8 > Should fail at CAS time > > 8) Hack guest to only advertise power7 compatibility, boot with -cpu host > Reboot to normal guest > Should go to power7 compat mode after CAS of boot 1 > Should revert to raw mode on reboot > SHould go to power8 compat mode after CAS of boot 2 > > Migration: > > 9) Boot guest with qemu-2.6 -machine pseries-2.6 -cpu host > Migrate to qemu-2.8 -machine pseries-2.6 -cpu host > Should work, end up running in power8 raw mode > > 10) Boot guest with qemu-2.7 -machine pseries-2.7 -cpu host > Migrate to qemu-2.8 -machine pseries-2.7 -cpu host > Should work, end up running in power8 raw mode > > 11) Boot guest with qemu-2.7 -machine pseries-2.7 -cpu host,compat=power7 > Migrate to qemu-2.8 -machine pseries-2.7 -cpu host,compat=power7 > Should work, be running in POWER7 compat after, but give warning like > (3) > > 12) Boot guest with qemu-2.7 -machine pseries-2.7 -cpu host,compat=power7 > Migrate to qemu-2.8 -machine pseries-2.7,max-cpu-compat=power7 -cpu host > Should work, be running in POWER7 compat after, no warning > > 13) Boot to SLOF with qemu-2.6 -machine pseries-2.6 -cpu host > Migrate to qemu-2.8 -machine pseries-2.6 -cpu host > > ? > > 14) Boot to SLOF with qemu-2.7 -machine pseries-2.7 -cpu host > Migrate to qemu-2.8 -machine pseries-2.7 -cpu host > ? > > 15) Boot to SLOF with qemu-2.7 -machine pseries-2.7 -cpu host,compat=power7 > Migrate to qemu-2.8 -machine pseries-2.7 -cpu host,compat=power7 > ? > > 16) Boot to SLOF with qemu-2.7 -machine pseries-2.7 -cpu host,compat=power7 > Migrate to qemu-2.8 -machine pseries-2.7,max-cpu-compat=power7 -cpu host > ? > > 17) Boot guest with qemu-2.6 -machine pseries-2.6 -cpu host > Migrate to qemu-2.7.z -machine pseries-2.6 -cpu host > Should work > > 18) Hack guest to only advertise power7 compatibility, boot with -cpu host > Boot with qemu-2.8, migrate to qemu-2.8 > Should be in power7 compat mode after CAS on source, and still > in power7 compat mode on destination > > > Changes since RFCv2: > * Many patches dropped, since they're already merged > * Rebased, fixed conflicts > * Restored support for backwards migration (wasn't as complicated as > I thought) > * Updated final patch's description to more accurately reflect the > logic > > Changes since RFCv1: > * Change CAS logic to prefer compatibility modes over raw mode > * Simplified by giving up on half-hearted attempts to maintain > backwards migration > * Folded migration stream changes into a single patch > * Removed some preliminary patches which are already merged > > > > David Gibson (3): > pseries: Move CPU compatibility property to machine > pseries: Reset CPU compatibility mode > ppc: Rework CPU compatibility testing across migration > > Greg Kurz (1): > qapi: add explicit null to string input and output visitors > > hw/ppc/spapr.c | 8 ++++- > hw/ppc/spapr_cpu_core.c | 47 +++++++++++++++++++------ > hw/ppc/spapr_hcall.c | 2 +- > include/hw/ppc/spapr.h | 12 ++++--- > qapi/string-input-visitor.c | 11 ++++++ > qapi/string-output-visitor.c | 14 ++++++++ > target/ppc/compat.c | 65 ++++++++++++++++++++++++++++++++++ > target/ppc/cpu.h | 6 ++-- > target/ppc/machine.c | 71 +++++++++++++++++++++++++++++++++++-- > target/ppc/translate_init.c | 84 > ++++++++++++-------------------------------- > 10 files changed, 238 insertions(+), 82 deletions(-) >
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