On Fri, 9 Feb 2024 at 16:00, Eric Auger <eric.au...@redhat.com> wrote: > > This series adds ARM Nested Virtualization support in KVM mode. > This is a respin of previous contributions from Miguel [1] and Haibo [2]. > > This was tested with Marc's v11 [3] on Ampere HW with fedora L1 guest and > L2 guests booted without EDK2. However it does not work yet with > EDK2 but it looks unrelated to this qemu integration (host hard lockups). > > The host needs to be booted with "kvm-arm.mode=nested" option and > qemu needs to be invoked with : > > -machine virt,virtualization=on > > There is a known issue with hosts supporting SVE. Kernel does not support both > SVE and NV2 and the current qemu integration has an issue with the > scratch_host_vcpu startup because both are enabled if exposed by the kernel. > This is independent on whether sve is disabled on the command line. > Unfortunately > I lost access to the HW that expose that issue so I couldn't fix it in this > version. > > This series can be found at: > https://github.com/eauger/qemu/tree/v8.2-nv-rfcv2 > > Previous version from Miguel: > [1] https://lore.kernel.org/all/20230227163718.62003-1-miguel.l...@oracle.com/ > Previous version from Haibo: > [2] > https://lore.kernel.org/qemu-devel/cover.1617281290.git.haibo...@linaro.org/ > [3] Marc's kernel v11 series: > [PATCH v11 00/43] KVM: arm64: Nested Virtualization support (FEAT_NV2 > only) > > https://lore.kernel.org/linux-arm-kernel/20231120131027.854038-1-...@kernel.org/T/ > available at: https://github.com/eauger/linux/tree/nv-6.8-nv2-v11 > > Haibo Xu (5): > [Placeholder] headers: Partial headers update for NV2 enablement > hw/arm: Allow setting KVM vGIC maintenance IRQ > target/arm/kvm: Add helper to detect EL2 when using KVM > target/arm: Enable feature ARM_FEATURE_EL2 if EL2 is supported > hw/arm/virt: Allow virt extensions with KVM > > hw/arm/virt.c | 6 +++++- > hw/intc/arm_gicv3_common.c | 1 + > hw/intc/arm_gicv3_kvm.c | 21 +++++++++++++++++++++ > include/hw/intc/arm_gicv3_common.h | 1 + > linux-headers/asm-arm64/kvm.h | 1 + > linux-headers/linux/kvm.h | 1 + > target/arm/kvm.c | 21 +++++++++++++++++++++ > target/arm/kvm_arm.h | 12 ++++++++++++ > 8 files changed, 63 insertions(+), 1 deletion(-)
All the patches in this series seem reasonable, but the series as a whole is so short I wonder if we're missing something :-) Does migration Just Work? (I guess as long as the kernel exposes all the EL2 sysregs via the ONE_REG ioctl interface it ought to...) Anyway, I don't think there's anything that stood out as needing major changes, so for now I guess we just wait for whenever the KVM side patches eventually land. thanks -- PMM
