On Tue, Sep 23, 2025 at 12:41:36PM +0200, Paolo Bonzini wrote: > Date: Tue, 23 Sep 2025 12:41:36 +0200 > From: Paolo Bonzini <pbonz...@redhat.com> > Subject: [RFT PATCH v2 2/2] target/i386: add compatibility property for > pdcm feature > X-Mailer: git-send-email 2.51.0 > > From: Hector Cao <hector....@canonical.com> > > The pdcm feature is supposed to be disabled when PMU is not > available. Up until v10.1, pdcm feature is enabled even when PMU > is off. This behavior has been fixed but this change breaks the > migration of VMs that are run with QEMU < 10.0 and expect the pdcm > feature to be enabled on the destination host. > > This commit restores the legacy behavior for machines with version > prior to 10.1 to allow the migration from older QEMU to QEMU 10.1. > > Signed-off-by: Hector Cao <hector....@canonical.com> > Link: > https://lore.kernel.org/r/20250910115733.21149-3-hector....@canonical.com > Fixes: e68ec298090 ("i386/cpu: Move adjustment of CPUID_EXT_PDCM before > feature_dependencies[] check", 2025-06-20) > [Move property from migration object to CPU. - Paolo] > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > --- > target/i386/cpu.h | 6 ++++++ > hw/i386/pc.c | 1 + > target/i386/cpu.c | 15 ++++++++++++--- > 3 files changed, 19 insertions(+), 3 deletions(-)
Reviewed-by: Zhao Liu <zhao1....@intel.com>
