Hi Haibo,
On 2021-01-11 07:20, Haibo Xu wrote:
On Fri, 11 Dec 2020 at 00:00, Marc Zyngier <maz@xxxxxxxxxx> wrote:
This is a rework of the NV series that I posted 10 months ago[1], as a
lot of the KVM code has changed since, and the series apply anymore
(not that anybody really cares as the the HW is, as usual, made of
unobtainium...).
From the previous version:
- Integration with the new page-table code
- New exception injection code
- No more messing with the nVHE code
- No AArch32!!!!
- Rebased on v5.10-rc4 + kvmarm/next for 5.11
From a functionality perspective, you can expect a L2 guest to work,
but don't even think of L3, as we only partially emulate the
ARMv8.{3,4}-NV extensions themselves. Same thing for vgic, debug, PMU,
as well as anything that would require a Stage-1 PTW. What we want to
achieve is that with NV disabled, there is no performance overhead and
no regression.
The series is roughly divided in 5 parts: exception handling, memory
virtualization, interrupts and timers for ARMv8.3, followed by the
ARMv8.4 support. There are of course some dependencies, but you'll
hopefully get the gist of it.
For the most courageous of you, I've put out a branch[2]. Of course,
you'll need some userspace. Andre maintains a hacked version of
kvmtool[3] that takes a --nested option, allowing the guest to be
started at EL2. You can run the whole stack in the Foundation
model. Don't be in a hurry ;-).
Hi Marc,
I got a kernel BUG message when booting the L2 guest kernel with the
kvmtool on a FVP setup.
Could you help have a look about the BUG message as well as my
environment configuration?
I think It probably caused by some local configurations of the FVP
setup.
No, this is likely a bug in your L1 guest, which was fixed in -rc3:
2a5f1b67ec57 ("KVM: arm64: Don't access PMCR_EL0 when no PMU is
available")
and was found in the exact same circumstances. Alternatively, and if
you don't want to change your L1 guest, you can just pass the --pmu
option to kvmtool when starting the L1 guest.
Hope this helps,
M.
--
Jazz is not dead. It just smells funny...
