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2021-10-11KVM: arm64: Pass struct kvm to per-EC handlersFuad Tabba
We need struct kvm to check for protected VMs to be able to pick the right handlers for them in subsequent patches. Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211010145636.1950948-5-tabba@google.com
2021-10-11KVM: arm64: Move early handlers to per-EC handlersMarc Zyngier
Simplify the early exception handling by slicing the gigantic decoding tree into a more manageable set of functions, similar to what we have in handle_exit.c. This will also make the structure reusable for pKVM's own early exit handling. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20211010145636.1950948-4-tabba@google.com
2021-10-11KVM: arm64: Don't include switch.h into nvhe/kvm-main.cMarc Zyngier
hyp-main.c includes switch.h while it only requires adjust-pc.h. Fix it to remove an unnecessary dependency. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20211010145636.1950948-3-tabba@google.com
2021-10-11KVM: arm64: Move __get_fault_info() and co into their own include fileMarc Zyngier
In order to avoid including the whole of the switching helpers in unrelated files, move the __get_fault_info() and related helpers into their own include file. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20211010145636.1950948-2-tabba@google.com
2021-10-11Merge branch kvm-arm64/raz-sysregs into kvmarm-master/nextMarc Zyngier
* kvm-arm64/raz-sysregs: : . : Simplify the handling of RAZ register, removing pointless indirections. : . KVM: arm64: Replace get_raz_id_reg() with get_raz_reg() KVM: arm64: Use get_raz_reg() for userspace reads of PMSWINC_EL0 KVM: arm64: Return early from read_id_reg() if register is RAZ Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-11KVM: arm64: Replace get_raz_id_reg() with get_raz_reg()Alexandru Elisei
Reading a RAZ ID register isn't different from reading any other RAZ register, so get rid of get_raz_id_reg() and replace it with get_raz_reg(), which does the same thing, but does it without going through two layers of indirection. No functional change. Suggested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211011105840.155815-4-alexandru.elisei@arm.com
2021-10-11KVM: arm64: Use get_raz_reg() for userspace reads of PMSWINC_EL0Alexandru Elisei
PMSWINC_EL0 is a write-only register and was initially part of the VCPU register state, but was later removed in commit 7a3ba3095a32 ("KVM: arm64: Remove PMSWINC_EL0 shadow register"). To prevent regressions, the register was kept accessible from userspace as Read-As-Zero (RAZ). The read function that is used to handle userspace reads of this register is get_raz_id_reg(), which, while technically correct, as it returns 0, it is not semantically correct, as PMSWINC_EL0 is not an ID register as the function name suggests. Add a new function, get_raz_reg(), to use it as the accessor for PMSWINC_EL0, as to not conflate get_raz_id_reg() to handle other types of registers. No functional change intended. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211011105840.155815-3-alexandru.elisei@arm.com
2021-10-11KVM: arm64: Return early from read_id_reg() if register is RAZAlexandru Elisei
If read_id_reg() is called for an ID register which is Read-As-Zero (RAZ), it initializes the return value to zero, then goes through a list of registers which require special handling before returning the final value. By not returning as soon as it checks that the register should be RAZ, the function creates the opportunity for bugs, if, for example, a patch changes a register to RAZ (like has happened with PMSWINC_EL0 in commit 11663111cd49), but doesn't remove the special handling from read_id_reg(); or if a register is RAZ in certain situations, but readable in others. Return early to make it impossible for a RAZ register to be anything other than zero. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211011105840.155815-2-alexandru.elisei@arm.com
2021-10-11Merge branch kvm-arm64/misc-5.16 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/misc-5.16: : . : - Allow KVM to be disabled from the command-line : - Clean up CONFIG_KVM vs CONFIG_HAVE_KVM : . KVM: arm64: Depend on HAVE_KVM instead of OF KVM: arm64: Unconditionally include generic KVM's Kconfig KVM: arm64: Allow KVM to be disabled from the command line Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-11KVM: arm64: Depend on HAVE_KVM instead of OFSean Christopherson
Select HAVE_KVM at all times on arm64, as the OF requirement is always there (even in the case of an ACPI system, we still depend on some of the OF infrastructure), and won't fo away. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Will Deacon <will@kernel.org> [maz: Drop the "HAVE_KVM if OF" dependency, as OF is always there on arm64, new commit message] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210921222231.518092-3-seanjc@google.com
2021-10-11KVM: arm64: Unconditionally include generic KVM's KconfigSean Christopherson
Unconditionally "source" the generic KVM Kconfig instead of wrapping it with KVM=y. A future patch will select HAVE_KVM so that referencing HAVE_KVM in common kernel code doesn't break, and because KVM=y and HAVE_KVM=n is weird. Source the generic KVM Kconfig unconditionally so that HAVE_KVM and KVM don't end up with a circular dependency. Note, all but one of generic KVM's "configs" are of the HAVE_XYZ nature, and the one outlier correctly takes a dependency on CONFIG_KVM, i.e. the generic Kconfig is intended to be included unconditionally. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> [maz: made NVHE_EL2_DEBUG depend on KVM] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210921222231.518092-2-seanjc@google.com
2021-10-11KVM: arm64: Allow KVM to be disabled from the command lineMarc Zyngier
Although KVM can be compiled out of the kernel, it cannot be disabled at runtime. Allow this possibility by introducing a new mode that will prevent KVM from initialising. This is useful in the (limited) circumstances where you don't want KVM to be available (what is wrong with you?), or when you want to install another hypervisor instead (good luck with that). Reviewed-by: David Brazdil <dbrazdil@google.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Andrew Scull <ascull@google.com> Link: https://lore.kernel.org/r/20211001170553.3062988-1-maz@kernel.org
2021-10-11Merge branch kvm-arm64/vgic-ipa-checks into kvmarm-master/nextMarc Zyngier
* kvm-arm64/vgic-ipa-checks: : . : Add extra checks to prevent ther various GIC regions to land : outside of the IPA space (and tests to verify that it works). : . KVM: arm64: selftests: Add init ITS device test KVM: arm64: selftests: Add test for legacy GICv3 REDIST base partially above IPA range KVM: arm64: selftests: Add tests for GIC redist/cpuif partially above IPA range KVM: arm64: selftests: Add some tests for GICv2 in vgic_init KVM: arm64: selftests: Make vgic_init/vm_gic_create version agnostic KVM: arm64: selftests: Make vgic_init gic version agnostic KVM: arm64: vgic: Drop vgic_check_ioaddr() KVM: arm64: vgic-v3: Check ITS region is not above the VM IPA size KVM: arm64: vgic-v2: Check cpu interface region is not above the VM IPA size KVM: arm64: vgic-v3: Check redist region is not above the VM IPA size kvm: arm64: vgic: Introduce vgic_check_iorange Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-11KVM: arm64: selftests: Add init ITS device testRicardo Koller
Add some ITS device init tests: general KVM device tests (address not defined already, address aligned) and tests for the ITS region being within the addressable IPA range. Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-12-ricarkol@google.com
2021-10-11KVM: arm64: selftests: Add test for legacy GICv3 REDIST base partially above ↵Ricardo Koller
IPA range Add a new test into vgic_init which checks that the first vcpu fails to run if there is not sufficient REDIST space below the addressable IPA range. This only applies to the KVM_VGIC_V3_ADDR_TYPE_REDIST legacy API as the required REDIST space is not know when setting the DIST region. Note that using the REDIST_REGION API results in a different check at first vcpu run: that the number of redist regions is enough for all vcpus. And there is already a test for that case in, the first step of test_v3_new_redist_regions. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-11-ricarkol@google.com
2021-10-11KVM: arm64: selftests: Add tests for GIC redist/cpuif partially above IPA rangeRicardo Koller
Add tests for checking that KVM returns the right error when trying to set GICv2 CPU interfaces or GICv3 Redistributors partially above the addressable IPA range. Also tighten the IPA range by replacing KVM_CAP_ARM_VM_IPA_SIZE with the IPA range currently configured for the guest (i.e., the default). The check for the GICv3 redistributor created using the REDIST legacy API is not sufficient as this new test only checks the check done using vcpus already created when setting the base. The next commit will add the missing test which verifies that the KVM check is done at first vcpu run. Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-10-ricarkol@google.com
2021-10-11KVM: arm64: selftests: Add some tests for GICv2 in vgic_initRicardo Koller
Add some GICv2 tests: general KVM device tests and DIST/CPUIF overlap tests. Do this by making test_vcpus_then_vgic and test_vgic_then_vcpus in vgic_init GIC version agnostic. Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-9-ricarkol@google.com
2021-10-11KVM: arm64: selftests: Make vgic_init/vm_gic_create version agnosticRicardo Koller
Make vm_gic_create GIC version agnostic in the vgic_init test. Also add a nr_vcpus arg into it instead of defaulting to NR_VCPUS. No functional change. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-8-ricarkol@google.com
2021-10-11KVM: arm64: selftests: Make vgic_init gic version agnosticRicardo Koller
As a preparation for the next commits which will add some tests for GICv2, make aarch64/vgic_init GIC version agnostic. Add a new generic run_tests function(gic_dev_type) that starts all applicable tests using GICv3 or GICv2. GICv2 tests are attempted if GICv3 is not available in the system. There are currently no GICv2 tests, but the test passes now in GICv2 systems. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-7-ricarkol@google.com
2021-10-11KVM: arm64: vgic: Drop vgic_check_ioaddr()Ricardo Koller
There are no more users of vgic_check_ioaddr(). Move its checks to vgic_check_iorange() and then remove it. Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-6-ricarkol@google.com
2021-10-11KVM: arm64: vgic-v3: Check ITS region is not above the VM IPA sizeRicardo Koller
Verify that the ITS region does not extend beyond the VM-specified IPA range (phys_size). base + size > phys_size AND base < phys_size Add the missing check into vgic_its_set_attr() which is called when setting the region. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-5-ricarkol@google.com
2021-10-11KVM: arm64: vgic-v2: Check cpu interface region is not above the VM IPA sizeRicardo Koller
Verify that the GICv2 CPU interface does not extend beyond the VM-specified IPA range (phys_size). base + size > phys_size AND base < phys_size Add the missing check into kvm_vgic_addr() which is called when setting the region. This patch also enables some superfluous checks for the distributor (vgic_check_ioaddr was enough as alignment == size for the distributors). Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-4-ricarkol@google.com
2021-10-11KVM: arm64: vgic-v3: Check redist region is not above the VM IPA sizeRicardo Koller
Verify that the redistributor regions do not extend beyond the VM-specified IPA range (phys_size). This can happen when using KVM_VGIC_V3_ADDR_TYPE_REDIST or KVM_VGIC_V3_ADDR_TYPE_REDIST_REGIONS with: base + size > phys_size AND base < phys_size Add the missing check into vgic_v3_alloc_redist_region() which is called when setting the regions, and into vgic_v3_check_base() which is called when attempting the first vcpu-run. The vcpu-run check does not apply to KVM_VGIC_V3_ADDR_TYPE_REDIST_REGIONS because the regions size is known before the first vcpu-run. Note that using the REDIST_REGIONS API results in a different check, which already exists, at first vcpu run: that the number of redist regions is enough for all vcpus. Finally, this patch also enables some extra tests in vgic_v3_alloc_redist_region() by calculating "size" early for the legacy redist api: like checking that the REDIST region can fit all the already created vcpus. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-3-ricarkol@google.com
2021-10-11kvm: arm64: vgic: Introduce vgic_check_iorangeRicardo Koller
Add the new vgic_check_iorange helper that checks that an iorange is sane: the start address and size have valid alignments, the range is within the addressable PA range, start+size doesn't overflow, and the start wasn't already defined. No functional change. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-2-ricarkol@google.com
2021-10-11Merge branch kvm-arm64/pkvm/restrict-hypercalls into kvmarm-master/nextMarc Zyngier
* kvm-arm64/pkvm/restrict-hypercalls: : . : Restrict the use of some hypercalls as well as kexec once : the protected KVM mode has been initialised. : . KVM: arm64: Disable privileged hypercalls after pKVM finalisation KVM: arm64: Prevent re-finalisation of pKVM for a given CPU KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercall KVM: arm64: Reject stub hypercalls after pKVM has been initialised arm64: Prevent kexec and hibernation if is_protected_kvm_enabled() KVM: arm64: Turn __KVM_HOST_SMCCC_FUNC_* into an enum (mostly) Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-11KVM: arm64: Disable privileged hypercalls after pKVM finalisationWill Deacon
After pKVM has been 'finalised' using the __pkvm_prot_finalize hypercall, the calling CPU will have a Stage-2 translation enabled to prevent access to memory pages owned by EL2. Although this forms a significant part of the process to deprivilege the host kernel, we also need to ensure that the hypercall interface is reduced so that the EL2 code cannot, for example, be re-initialised using a new set of vectors. Re-order the hypercalls so that only a suffix remains available after finalisation of pKVM. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211008135839.1193-7-will@kernel.org
2021-10-11KVM: arm64: Prevent re-finalisation of pKVM for a given CPUWill Deacon
__pkvm_prot_finalize() completes the deprivilege of the host when pKVM is in use by installing a stage-2 translation table for the calling CPU. Issuing the hypercall multiple times for a given CPU makes little sense, but in such a case just return early with -EPERM rather than go through the whole page-table dance again. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211008135839.1193-6-will@kernel.org
2021-10-11KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercallWill Deacon
If the __pkvm_prot_finalize hypercall returns an error, we WARN but fail to propagate the failure code back to kvm_arch_init(). Pass a pointer to a zero-initialised return variable so that failure to finalise the pKVM protections on a host CPU can be reported back to KVM. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211008135839.1193-5-will@kernel.org
2021-10-11KVM: arm64: Reject stub hypercalls after pKVM has been initialisedWill Deacon
The stub hypercalls provide mechanisms to reset and replace the EL2 code, so uninstall them once pKVM has been initialised in order to ensure the integrity of the hypervisor code. To ensure pKVM initialisation remains functional, split cpu_hyp_reinit() into two helper functions to separate usage of the stub from usage of pkvm hypercalls either side of __pkvm_init on the boot CPU. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211008135839.1193-4-will@kernel.org
2021-10-11arm64: Prevent kexec and hibernation if is_protected_kvm_enabled()Will Deacon
When pKVM is enabled, the hypervisor code at EL2 and its data structures are inaccessible to the host kernel and cannot be torn down or replaced as this would defeat the integrity properies which pKVM aims to provide. Furthermore, the ABI between the host and EL2 is flexible and private to whatever the current implementation of KVM requires and so booting a new kernel with an old EL2 component is very likely to end in disaster. In preparation for uninstalling the hyp stub calls which are relied upon to reset EL2, disable kexec and hibernation in the host when protected KVM is enabled. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211008135839.1193-3-will@kernel.org
2021-10-11KVM: arm64: Turn __KVM_HOST_SMCCC_FUNC_* into an enum (mostly)Marc Zyngier
__KVM_HOST_SMCCC_FUNC_* is a royal pain, as there is a fair amount of churn around these #defines, and we avoid making it an enum only for the sake of the early init, low level code that requires __KVM_HOST_SMCCC_FUNC___kvm_hyp_init to be usable from assembly. Let's be brave and turn everything but this symbol into an enum, using a bit of arithmetic to avoid any overlap. Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/877depq9gw.wl-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20211008135839.1193-2-will@kernel.org
2021-10-05KVM: arm64: Release mmap_lock when using VM_SHARED with MTEQuentin Perret
VM_SHARED mappings are currently forbidden in a memslot with MTE to prevent two VMs racing to sanitise the same page. However, this check is performed while holding current->mm's mmap_lock, but fails to release it. Fix this by releasing the lock when needed. Fixes: ea7fc1bb1cd1 ("KVM: arm64: Introduce MTE VM feature") Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005122031.809857-1-qperret@google.com
2021-10-05KVM: arm64: Report corrupted refcount at EL2Quentin Perret
Some of the refcount manipulation helpers used at EL2 are instrumented to catch a corrupted state, but not all of them are treated equally. Let's make things more consistent by instrumenting hyp_page_ref_dec_and_test() as well. Acked-by: Will Deacon <will@kernel.org> Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005090155.734578-6-qperret@google.com
2021-10-05KVM: arm64: Fix host stage-2 PGD refcountQuentin Perret
The KVM page-table library refcounts the pages of concatenated stage-2 PGDs individually. However, when running KVM in protected mode, the host's stage-2 PGD is currently managed by EL2 as a single high-order compound page, which can cause the refcount of the tail pages to reach 0 when they shouldn't, hence corrupting the page-table. Fix this by introducing a new hyp_split_page() helper in the EL2 page allocator (matching the kernel's split_page() function), and make use of it from host_s2_zalloc_pages_exact(). Fixes: 1025c8c0c6ac ("KVM: arm64: Wrap the host with a stage 2") Acked-by: Will Deacon <will@kernel.org> Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005090155.734578-5-qperret@google.com
2021-10-05Merge tag 'kvm-riscv-5.16-1' of git://github.com/kvm-riscv/linux into HEADPaolo Bonzini
Initial KVM RISC-V support Following features are supported by the initial KVM RISC-V support: 1. No RISC-V specific KVM IOCTL 2. Loadable KVM RISC-V module 3. Minimal possible KVM world-switch which touches only GPRs and few CSRs 4. Works on both RV64 and RV32 host 5. Full Guest/VM switch via vcpu_get/vcpu_put infrastructure 6. KVM ONE_REG interface for VCPU register access from KVM user-space 7. Interrupt controller emulation in KVM user-space 8. Timer and IPI emuation in kernel 9. Both Sv39x4 and Sv48x4 supported for RV64 host 10. MMU notifiers supported 11. Generic dirty log supported 12. FP lazy save/restore supported 13. SBI v0.1 emulation for Guest/VM 14. Forward unhandled SBI calls to KVM user-space 15. Hugepage support for Guest/VM 16. IOEVENTFD support for Vhost
2021-10-04RISC-V: KVM: Add MAINTAINERS entryAnup Patel
Add myself as maintainer for KVM RISC-V and Atish as designated reviewer. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Document RISC-V specific parts of KVM APIAnup Patel
Document RISC-V specific parts of the KVM API, such as: - The interrupt numbers passed to the KVM_INTERRUPT ioctl. - The states supported by the KVM_{GET,SET}_MP_STATE ioctls. - The registers supported by the KVM_{GET,SET}_ONE_REG interface and the encoding of those register ids. - The exit reason KVM_EXIT_RISCV_SBI for SBI calls forwarded to userspace tool. CC: Jonathan Corbet <corbet@lwn.net> CC: linux-doc@vger.kernel.org Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Add SBI v0.1 supportAtish Patra
The KVM host kernel is running in HS-mode needs so we need to handle the SBI calls coming from guest kernel running in VS-mode. This patch adds SBI v0.1 support in KVM RISC-V. Almost all SBI v0.1 calls are implemented in KVM kernel module except GETCHAR and PUTCHART calls which are forwarded to user space because these calls cannot be implemented in kernel space. In future, when we implement SBI v0.2 for Guest, we will forward SBI v0.2 experimental and vendor extension calls to user space. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement ONE REG interface for FP registersAtish Patra
Add a KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctl interface for floating point registers such as F0-F31 and FCSR. This support is added for both 'F' and 'D' extensions. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: FP lazy save/restoreAtish Patra
This patch adds floating point (F and D extension) context save/restore for guest VCPUs. The FP context is saved and restored lazily only when kernel enter/exits the in-kernel run loop and not during the KVM world switch. This way FP save/restore has minimal impact on KVM performance. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Add timer functionalityAtish Patra
The RISC-V hypervisor specification doesn't have any virtual timer feature. Due to this, the guest VCPU timer will be programmed via SBI calls. The host will use a separate hrtimer event for each guest VCPU to provide timer functionality. We inject a virtual timer interrupt to the guest VCPU whenever the guest VCPU hrtimer event expires. This patch adds guest VCPU timer implementation along with ONE_REG interface to access VCPU timer state from user space. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement MMU notifiersAnup Patel
This patch implements MMU notifiers for KVM RISC-V so that Guest physical address space is in-sync with Host physical address space. This will allow swapping, page migration, etc to work transparently with KVM RISC-V. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement stage2 page table programmingAnup Patel
This patch implements all required functions for programming the stage2 page table for each Guest/VM. At high-level, the flow of stage2 related functions is similar from KVM ARM/ARM64 implementation but the stage2 page table format is quite different for KVM RISC-V. [jiangyifei: stage2 dirty log support] Signed-off-by: Yifei Jiang <jiangyifei@huawei.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement VMID allocatorAnup Patel
We implement a simple VMID allocator for Guests/VMs which: 1. Detects number of VMID bits at boot-time 2. Uses atomic number to track VMID version and increments VMID version whenever we run-out of VMIDs 3. Flushes Guest TLBs on all host CPUs whenever we run-out of VMIDs 4. Force updates HW Stage2 VMID for each Guest VCPU whenever VMID changes using VCPU request KVM_REQ_UPDATE_HGATP Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Handle WFI exits for VCPUAnup Patel
We get illegal instruction trap whenever Guest/VM executes WFI instruction. This patch handles WFI trap by blocking the trapped VCPU using kvm_vcpu_block() API. The blocked VCPU will be automatically resumed whenever a VCPU interrupt is injected from user-space or from in-kernel IRQCHIP emulation. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Handle MMIO exits for VCPUAnup Patel
We will get stage2 page faults whenever Guest/VM access SW emulated MMIO device or unmapped Guest RAM. This patch implements MMIO read/write emulation by extracting MMIO details from the trapped load/store instruction and forwarding the MMIO read/write to user-space. The actual MMIO emulation will happen in user-space and KVM kernel module will only take care of register updates before resuming the trapped VCPU. The handling for stage2 page faults for unmapped Guest RAM will be implemeted by a separate patch later. [jiangyifei: ioeventfd and in-kernel mmio device support] Signed-off-by: Yifei Jiang <jiangyifei@huawei.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement VCPU world-switchAnup Patel
This patch implements the VCPU world-switch for KVM RISC-V. The KVM RISC-V world-switch (i.e. __kvm_riscv_switch_to()) mostly switches general purpose registers, SSTATUS, STVEC, SSCRATCH and HSTATUS CSRs. Other CSRs are switched via vcpu_load() and vcpu_put() interface in kvm_arch_vcpu_load() and kvm_arch_vcpu_put() functions respectively. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctlsAnup Patel
For KVM RISC-V, we use KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls to access VCPU config and registers from user-space. We have three types of VCPU registers: 1. CONFIG - these are VCPU config and capabilities 2. CORE - these are VCPU general purpose registers 3. CSR - these are VCPU control and status registers The CONFIG register available to user-space is ISA. The ISA register is a read and write register where user-space can only write the desired VCPU ISA capabilities before running the VCPU. The CORE registers available to user-space are PC, RA, SP, GP, TP, A0-A7, T0-T6, S0-S11 and MODE. Most of these are RISC-V general registers except PC and MODE. The PC register represents program counter whereas the MODE register represent VCPU privilege mode (i.e. S/U-mode). The CSRs available to user-space are SSTATUS, SIE, STVEC, SSCRATCH, SEPC, SCAUSE, STVAL, SIP, and SATP. All of these are read/write registers. In future, more VCPU register types will be added (such as FP) for the KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement VCPU interrupts and requests handlingAnup Patel
This patch implements VCPU interrupts and requests which are both asynchronous events. The VCPU interrupts can be set/unset using KVM_INTERRUPT ioctl from user-space. In future, the in-kernel IRQCHIP emulation will use kvm_riscv_vcpu_set_interrupt() and kvm_riscv_vcpu_unset_interrupt() functions to set/unset VCPU interrupts. Important VCPU requests implemented by this patch are: KVM_REQ_SLEEP - set whenever VCPU itself goes to sleep state KVM_REQ_VCPU_RESET - set whenever VCPU reset is requested The WFI trap-n-emulate (added later) will use KVM_REQ_SLEEP request and kvm_riscv_vcpu_has_interrupt() function. The KVM_REQ_VCPU_RESET request will be used by SBI emulation (added later) to power-up a VCPU in power-off state. The user-space can use the GET_MPSTATE/SET_MPSTATE ioctls to get/set power state of a VCPU. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Implement VCPU create, init and destroy functionsAnup Patel
This patch implements VCPU create, init and destroy functions required by generic KVM module. We don't have much dynamic resources in struct kvm_vcpu_arch so these functions are quite simple for KVM RISC-V. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>