On Mon, 19 Jan 2026 18:27:29 +0100 Cornelia Huck <[email protected]> wrote:
Hi Cornelia, > Note: this is on top of <[email protected]> > ("[PATCH v3 0/2] arm: move DCZID_EL0 to idregs array") > > While trying to move to an autogenerated cpu-sysregs.h.inc (so that we > may keep a common view on registers), we should first address the ID > registers that are still kept outside of ARMISARegisters. Other than > DCZID_EL0 (addressed by the series this one goes on top of), that's > the CCSIDR_EL1 values kept in cpu->cssidr[] (indexed via CSSELR_EL1.) > > My idea was to provide {GET,SET}_IDREG_DEMUX helper that work similar > to {GET,SET}_IDREG and operate on a two-dimensional array. As a side > effect, this also allows to get the values KVM provides for CCSIDR_EL1 > (which are virtualized as well.) > > RFC because there are still some open questions: > - The demux array cannot easily be autogenerated. We can get rid of the > ccsidr[] array, but we now have an autogenerated entry in the non-demux > array that does nothing. Both are not that nice. > - I'm not sure if we need any compat handling for KVM (on TCG, everything > should stay the same.) In theory, the KVM interface allows setting > values from userspace (I didn't try.) > - There's a slight disagreement between the current code (providing 16 > entries for CCSIDR_EL1) and the KVM code (providing (7 cache levels) * > (data/unified, instruction) = 14 entries.) With FEAT_MTE2, we might be > needing 7 more entries. > > Feedback appreciated. > > Cornelia Huck (3): > arm: handle demuxed ID registers > arm: handle CCSIDR_EL1 as a demuxed register > arm/kvm: get demuxed ID registers from kvm > > hw/intc/armv7m_nvic.c | 2 +- > target/arm/cpu-sysregs.h | 6 ++++ > target/arm/cpu-sysregs.h.inc | 1 + > target/arm/cpu.h | 26 ++++++++++++---- > target/arm/cpu64.c | 12 ++++---- > target/arm/helper.c | 2 +- > target/arm/kvm.c | 33 ++++++++++++++++++++ > target/arm/tcg/cpu32.c | 32 +++++++++---------- > target/arm/tcg/cpu64.c | 60 ++++++++++++++++++------------------ > 9 files changed, 114 insertions(+), 60 deletions(-) > This impacts my set https://lore.kernel.org/all/[email protected]/ I tested it with mine of course it required a few changes, but looks like working on TCG, didn't try KVM. Tested-by: Alireza Sanaee <[email protected]>
