[RFC PATCH v4 00/26] KVM: arm64: Make CPU ID registers writable by userspace
Reiji Watanabe
reijiw at google.com
Mon Jan 24 22:31:03 PST 2022
Hi Fuad,
On Mon, Jan 24, 2022 at 8:19 AM Fuad Tabba <tabba at google.com> wrote:
>
> Hi Reiji,
>
> On Thu, Jan 6, 2022 at 4:27 AM Reiji Watanabe <reijiw at google.com> wrote:
>
> > The patch series is for both VHE and non-VHE, except for protected VMs,
> > which have a different way of configuring ID registers based on its
> > different requirements [1].
>
> I am reviewing this patch series and I really like your approach. I
> think that once it's through we might be able to generalize it for
> protected VMs as well (I did some of the work for the ID registers for
> those).
Thank you for the review and comments for the series.
I will be looking at your comments.
> > The series is based on v5.16-rc8 with the patch [3] applied.
>
> I tried to apply this series on v5.16-rc8 after applying
> 20220104194918.373612-2-rananta at google.com, and it didn't apply
> cleanly. If you could point me to a working branch that I could
> checkout I would like to test it and experiment with it a bit more.
I'm sorry for the inconvenience. I'm not sure why though...
I tried that again (applied the series on v5.16-rc8 after applying
20220104194918.373612-2-rananta at google.com), and it worked fine.
Anyway, you can find the branch at:
https://github.com/reijiw-kvm/kvmarm-idreg/tree/id-regs-v4-5.16-rc8
Thanks,
Reiji
>
>
>
>
> > v4:
> > - Make ID registers storage per VM instead of per vCPU. [Marc]
> > - Implement arm64_check_features() in arch/arm64/kernel/cpufeature.c
> > by using existing codes in the file. [Marc]
> > - Use a configuration function to enable traps for disabled
> > features. [Marc]
> > - Document ID registers become immutable after the first KVM_RUN [Eric]
> > - Update ID_AA64PFR0.GIC at the point where a GICv3 is created. [Marc]
> > - Get TGranX's bit position by substracting 12 from TGranX_2's bit
> > position. [Eric]
> > - Don't validate AArch32 ID registers when the system doesn't support
> > 32bit EL0. [Eric]
> > - Add/fixes comments for patches. [Eric]
> > - Made bug fixes/improvements of the selftest. [Eric]
> > - Added .kunitconfig for arm64 KUnit tests
> >
> > v3: https://lore.kernel.org/all/20211117064359.2362060-1-reijiw@google.com/
> > - Remove ID register consistency checking across vCPUs. [Oliver]
> > - Change KVM_CAP_ARM_ID_REG_WRITABLE to
> > KVM_CAP_ARM_ID_REG_CONFIGURABLE. [Oliver]
> > - Add KUnit testing for ID register validation and trap initialization.
> > - Change read_id_reg() to take care of ID_AA64PFR0_EL1.GIC.
> > - Add a helper of read_id_reg() (__read_id_reg()) and use the helper
> > instead of directly using __vcpu_sys_reg().
> > - Change not to run kvm_id_regs_consistency_check() and
> > kvm_vcpu_init_traps() for protected VMs.
> > - Update selftest to remove test cases for ID register consistency.
> > checking across vCPUs and to add test cases for ID_AA64PFR0_EL1.GIC.
> >
> > v2: https://lore.kernel.org/all/20211103062520.1445832-1-reijiw@google.com/
> > - Remove unnecessary line breaks. [Andrew]
> > - Use @params for comments. [Andrew]
> > - Move arm64_check_features to arch/arm64/kvm/sys_regs.c and
> > change that KVM specific feature check function. [Andrew]
> > - Remove unnecessary raz handling from __set_id_reg. [Andrew]
> > - Remove sys_val field from the initial id_reg_info and add it
> > in the later patch. [Andrew]
> > - Call id_reg->init() from id_reg_info_init(). [Andrew]
> > - Fix cpuid_feature_cap_perfmon_field() to convert 0xf to 0x0
> > (and use it in the following patches).
> > - Change kvm_vcpu_first_run_init to set has_run_once to false
> > when kvm_id_regs_consistency_check() fails.
> > - Add a patch to introduce id_reg_info for ID_AA64MMFR0_EL1,
> > which requires special validity checking for TGran*_2 fields.
> > - Add patches to introduce id_reg_info for ID_DFR1_EL1 and
> > ID_MMFR0_EL1, which are required due to arm64_check_features
> > implementation change.
> > - Add a new argument, which is a pointer to id_reg_info, for
> > id_reg_info's validate().
> >
> > v1: https://lore.kernel.org/all/20211012043535.500493-1-reijiw@google.com/
> >
> > [1] https://lore.kernel.org/kvmarm/20211010145636.1950948-1-tabba@google.com/
> > [2] https://lore.kernel.org/kvm/20201102033422.657391-1-liangpeng10@huawei.com/
> > [3] https://lore.kernel.org/all/20220104194918.373612-2-rananta@google.com/
> >
> > Reiji Watanabe (26):
> > KVM: arm64: Introduce a validation function for an ID register
> > KVM: arm64: Save ID registers' sanitized value per guest
> > KVM: arm64: Introduce struct id_reg_info
> > KVM: arm64: Make ID_AA64PFR0_EL1 writable
> > KVM: arm64: Make ID_AA64PFR1_EL1 writable
> > KVM: arm64: Make ID_AA64ISAR0_EL1 writable
> > KVM: arm64: Make ID_AA64ISAR1_EL1 writable
> > KVM: arm64: Make ID_AA64MMFR0_EL1 writable
> > KVM: arm64: Hide IMPLEMENTATION DEFINED PMU support for the guest
> > KVM: arm64: Make ID_AA64DFR0_EL1 writable
> > KVM: arm64: Make ID_DFR0_EL1 writable
> > KVM: arm64: Make MVFR1_EL1 writable
> > KVM: arm64: Make ID registers without id_reg_info writable
> > KVM: arm64: Add consistency checking for frac fields of ID registers
> > KVM: arm64: Introduce KVM_CAP_ARM_ID_REG_CONFIGURABLE capability
> > KVM: arm64: Add kunit test for ID register validation
> > KVM: arm64: Use vcpu->arch cptr_el2 to track value of cptr_el2 for VHE
> > KVM: arm64: Use vcpu->arch.mdcr_el2 to track value of mdcr_el2
> > KVM: arm64: Introduce framework to trap disabled features
> > KVM: arm64: Trap disabled features of ID_AA64PFR0_EL1
> > KVM: arm64: Trap disabled features of ID_AA64PFR1_EL1
> > KVM: arm64: Trap disabled features of ID_AA64DFR0_EL1
> > KVM: arm64: Trap disabled features of ID_AA64MMFR1_EL1
> > KVM: arm64: Trap disabled features of ID_AA64ISAR1_EL1
> > KVM: arm64: Add kunit test for trap initialization
> > KVM: arm64: selftests: Introduce id_reg_test
> >
> > Documentation/virt/kvm/api.rst | 12 +
> > arch/arm64/include/asm/cpufeature.h | 3 +-
> > arch/arm64/include/asm/kvm_arm.h | 32 +
> > arch/arm64/include/asm/kvm_host.h | 19 +
> > arch/arm64/include/asm/sysreg.h | 3 +
> > arch/arm64/kernel/cpufeature.c | 228 +++
> > arch/arm64/kvm/.kunitconfig | 4 +
> > arch/arm64/kvm/Kconfig | 11 +
> > arch/arm64/kvm/arm.c | 24 +-
> > arch/arm64/kvm/debug.c | 13 +-
> > arch/arm64/kvm/hyp/vhe/switch.c | 14 +-
> > arch/arm64/kvm/sys_regs.c | 1329 +++++++++++++++--
> > arch/arm64/kvm/sys_regs_test.c | 1247 ++++++++++++++++
> > arch/arm64/kvm/vgic/vgic-init.c | 5 +
> > include/uapi/linux/kvm.h | 1 +
> > tools/arch/arm64/include/asm/sysreg.h | 1 +
> > tools/testing/selftests/kvm/.gitignore | 1 +
> > tools/testing/selftests/kvm/Makefile | 1 +
> > .../selftests/kvm/aarch64/id_reg_test.c | 1239 +++++++++++++++
> > 19 files changed, 4041 insertions(+), 146 deletions(-)
> > create mode 100644 arch/arm64/kvm/.kunitconfig
> > create mode 100644 arch/arm64/kvm/sys_regs_test.c
> > create mode 100644 tools/testing/selftests/kvm/aarch64/id_reg_test.c
> >
> >
> > base-commit: d399b107ee49bf5ea0391bd7614d512809e927b0
> > --
> > 2.34.1.448.ga2b2bfdf31-goog
> >
> > _______________________________________________
> > kvmarm mailing list
> > kvmarm at lists.cs.columbia.edu
> > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
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