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2024-06-19KVM: arm64: nv: Implement nested Stage-2 page table walk logicChristoffer Dall
Based on the pseudo-code in the ARM ARM, implement a stage 2 software page table walker. Co-developed-by: Jintack Lim <jintack.lim@linaro.org> Signed-off-by: Jintack Lim <jintack.lim@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240614144552.2773592-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-19KVM: arm64: nv: Support multiple nested Stage-2 mmu structuresMarc Zyngier
Add Stage-2 mmu data structures for virtual EL2 and for nested guests. We don't yet populate shadow Stage-2 page tables, but we now have a framework for getting to a shadow Stage-2 pgd. We allocate twice the number of vcpus as Stage-2 mmu structures because that's sufficient for each vcpu running two translation regimes without having to flush the Stage-2 page tables. Co-developed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240614144552.2773592-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-18KVM: Introduce vcpu->wants_to_runDavid Matlack
Introduce vcpu->wants_to_run to indicate when a vCPU is in its core run loop, i.e. when the vCPU is running the KVM_RUN ioctl and immediate_exit was not set. Replace all references to vcpu->run->immediate_exit with !vcpu->wants_to_run to avoid TOCTOU races with userspace. For example, a malicious userspace could invoked KVM_RUN with immediate_exit=true and then after KVM reads it to set wants_to_run=false, flip it to false. This would result in the vCPU running in KVM_RUN with wants_to_run=false. This wouldn't cause any real bugs today but is a dangerous landmine. Signed-off-by: David Matlack <dmatlack@google.com> Link: https://lore.kernel.org/r/20240503181734.1467938-2-dmatlack@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-14KVM: arm64: Use FF-A 1.1 with pKVMSebastian Ene
Now that the layout of the structures is compatible with 1.1 it is time to probe the 1.1 version of the FF-A protocol inside the hypervisor. If the TEE doesn't support it, it should return the minimum supported version. Signed-off-by: Sebastian Ene <sebastianene@google.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240613132035.1070360-5-sebastianene@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-14KVM: arm64: Update the identification range for the FF-A smcsSebastian Ene
The FF-A spec 1.2 reserves the following ranges for identifying FF-A calls: 0x84000060-0x840000FF: FF-A 32-bit calls 0xC4000060-0xC40000FF: FF-A 64-bit calls. Use the range identification according to the spec and allow calls that are currently out of the range(eg. FFA_MSG_SEND_DIRECT_REQ2) to be identified correctly. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Sebastian Ene <sebastianene@google.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240613132035.1070360-4-sebastianene@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-14KVM: arm64: Add support for FFA_PARTITION_INFO_GETSebastian Ene
Handle the FFA_PARTITION_INFO_GET host call inside the pKVM hypervisor and copy the response message back to the host buffers. Signed-off-by: Sebastian Ene <sebastianene@google.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240613132035.1070360-3-sebastianene@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-14KVM: arm64: Trap FFA_VERSION host call in pKVMSebastian Ene
The pKVM hypervisor initializes with FF-A version 1.0. The spec requires that no other FF-A calls to be issued before the version negotiation phase is complete. Split the hypervisor proxy initialization code in two parts so that we can move the later one after the host negotiates its version. Without trapping the call, the host drivers can negotiate a higher version number with TEE which can result in a different memory layout described during the memory sharing calls. Signed-off-by: Sebastian Ene <sebastianene@google.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240613132035.1070360-2-sebastianene@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-14KVM: arm64: nv: Fix RESx behaviour of disabled FGTs with negative polarityMarc Zyngier
The Fine Grained Trap extension is pretty messy as it doesn't consistently use the same polarity for all trap bits. A bunch of them, added later in the life of the architecture, have a *negative* priority. So if these bits are disabled, they must be RES1 and not RES0. But that's not what the code implements, making the traps for these negative trap bits being always on instead of disabled. Fix the relevant bits, and stick a brown paper bag on my head for the rest of the day... Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240614125858.78361-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-14KVM: arm64: Add early_param to control WFx trappingColton Lewis
Add an early_params to control WFI and WFE trapping. This is to control the degree guests can wait for interrupts on their own without being trapped by KVM. Options for each param are trap and notrap. trap enables the trap. notrap disables the trap. Note that when enabled, traps are allowed but not guaranteed by the CPU architecture. Absent an explicitly set policy, default to current behavior: disabling the trap if only a single task is running and enabling otherwise. Signed-off-by: Colton Lewis <coltonlewis@google.com> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20240523174056.1565133-1-coltonlewis@google.com [ oliver: rework kvm_vcpu_should_clear_tw*() for readability ] Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-11KVM: arm64: FFA: Release hyp rx bufferVincent Donnefort
According to the FF-A spec (Buffer states and ownership), after a producer has written into a buffer, it is "full" and now owned by the consumer. The producer won't be able to use that buffer, until the consumer hands it over with an invocation such as RX_RELEASE. It is clear in the following paragraph (Transfer of buffer ownership), that MEM_RETRIEVE_RESP is transferring the ownership from producer (in our case SPM) to consumer (hypervisor). RX_RELEASE is therefore mandatory here. It is less clear though what is happening with MEM_FRAG_TX. But this invocation, as a response to MEM_FRAG_RX writes into the same hypervisor RX buffer (see paragraph "Transmission of transaction descriptor in fragments"). Also this is matching the TF-A implementation where the RX buffer is marked "full" during a MEM_FRAG_RX. Release the RX hypervisor buffer in those two cases. This will unblock later invocations using this buffer which would otherwise fail. (RETRIEVE_REQ, MEM_FRAG_RX and PARTITION_INFO_GET). Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20240611175317.1220842-1-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-06KVM: arm64: Disassociate vcpus from redistributor region on teardownMarc Zyngier
When tearing down a redistributor region, make sure we don't have any dangling pointer to that region stored in a vcpu. Fixes: e5a35635464b ("kvm: arm64: vgic-v3: Introduce vgic_v3_free_redist_region()") Reported-by: Alexander Potapenko <glider@google.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240605175637.1635653-1-maz@kernel.org Cc: stable@vger.kernel.org
2024-06-04KVM: arm64: Ensure that SME controls are disabled in protected modeFuad Tabba
KVM (and pKVM) do not support SME guests. Therefore KVM ensures that the host's SME state is flushed and that SME controls for enabling access to ZA storage and for streaming are disabled. pKVM needs to protect against a buggy/malicious host. Ensure that it wouldn't run a guest when protected mode is enabled should any of the SME controls be enabled. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-10-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Refactor CPACR trap bit setting/clearing to use ELx formatFuad Tabba
When setting/clearing CPACR bits for EL0 and EL1, use the ELx format of the bits, which covers both. This makes the code clearer, and reduces the chances of accidentally missing a bit. No functional change intended. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-9-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Consolidate initializing the host data's fpsimd_state/sve in pKVMFuad Tabba
Now that we have introduced finalize_init_hyp_mode(), lets consolidate the initializing of the host_data fpsimd_state and sve state. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20240603122852.3923848-8-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Eagerly restore host fpsimd/sve state in pKVMFuad Tabba
When running in protected mode we don't want to leak protected guest state to the host, including whether a guest has used fpsimd/sve. Therefore, eagerly restore the host state on guest exit when running in protected mode, which happens only if the guest has used fpsimd/sve. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-7-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Allocate memory mapped at hyp for host sve state in pKVMFuad Tabba
Protected mode needs to maintain (save/restore) the host's sve state, rather than relying on the host kernel to do that. This is to avoid leaking information to the host about guests and the type of operations they are performing. As a first step towards that, allocate memory mapped at hyp, per cpu, for the host sve state. The following patch will use this memory to save/restore the host state. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-6-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Specialize handling of host fpsimd state on trapFuad Tabba
In subsequent patches, n/vhe will diverge on saving the host fpsimd/sve state when taking a guest fpsimd/sve trap. Add a specialized helper to handle it. No functional change intended. Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-5-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Abstract set/clear of CPTR_EL2 bits behind helperFuad Tabba
The same traps controlled by CPTR_EL2 or CPACR_EL1 need to be toggled in different parts of the code, but the exact bits and their polarity differ between these two formats and the mode (vhe/nvhe/hvhe). To reduce the amount of duplicated code and the chance of getting the wrong bit/polarity or missing a field, abstract the set/clear of CPTR_EL2 bits behind a helper. Since (h)VHE is the way of the future, use the CPACR_EL1 format, which is a subset of the VHE CPTR_EL2, as a reference. No functional change intended. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-4-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Fix prototype for __sve_save_state/__sve_restore_stateFuad Tabba
Since the prototypes for __sve_save_state/__sve_restore_state at hyp were added, the underlying macro has acquired a third parameter for saving/restoring ffr. Fix the prototypes to account for the third parameter, and restore the ffr for the guest since it is saved. Suggested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20240603122852.3923848-3-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Reintroduce __sve_save_stateFuad Tabba
Now that the hypervisor is handling the host sve state in protected mode, it needs to be able to save it. This reverts commit e66425fc9ba3 ("KVM: arm64: Remove unused __sve_save_state"). Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-2-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-30KVM: arm64: nv: Expose BTI and CSV_frac to a guest hypervisorMarc Zyngier
Now that we expose PAC to NV guests, we can also expose BTI (as the two as joined at the hip, due to some of the PAC instructions being landing pads). While we're at it, also propagate CSV_frac, which requires no particular emulation. Fixes: f4f6a95bac49 ("KVM: arm64: nv: Advertise support for PAuth") Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240528100632.1831995-3-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-30KVM: arm64: nv: Fix relative priorities of exceptions generated by ERETAxMarc Zyngier
ERETAx can fail in multiple ways: (1) ELR_EL2 points lalaland (2) we get a PAC failure (3) SPSR_EL2 has the wrong mode (1) is easy, as we just let the CPU do its thing and deliver an Instruction Abort. However, (2) and (3) are interesting, because the PAC failure priority is way below that of the Illegal Execution State exception. Which means that if we have detected a PAC failure (and that we have FPACCOMBINE), we must be careful to give priority to the Illegal Execution State exception, should one be pending. Solving this involves hoisting the SPSR calculation earlier and testing for the IL bit before injecting the FPAC exception. In the extreme case of a ERETAx returning to an invalid mode *and* failing its PAC check, we end up with an Instruction Abort (due to the new PC being mangled by the failed Auth) *and* PSTATE.IL being set. Which matches the requirements of the architecture. Whilst we're at it, remove a stale comment that states the obvious and only confuses the reader. Fixes: 213b3d1ea161 ("KVM: arm64: nv: Handle ERETA[AB] instructions") Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240528100632.1831995-2-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-27KVM: arm64: AArch32: Fix spurious trapping of conditional instructionsMarc Zyngier
We recently upgraded the view of ESR_EL2 to 64bit, in keeping with the requirements of the architecture. However, the AArch32 emulation code was left unaudited, and the (already dodgy) code that triages whether a trap is spurious or not (because the condition code failed) broke in a subtle way: If ESR_EL2.ISS2 is ever non-zero (unlikely, but hey, this is the ARM architecture we're talking about), the hack that tests the top bits of ESR_EL2.EC will break in an interesting way. Instead, use kvm_vcpu_trap_get_class() to obtain the EC, and list all the possible ECs that can fail a condition code check. While we're at it, add SMC32 to the list, as it is explicitly listed as being allowed to trap despite failing a condition code check (as described in the HCR_EL2.TSC documentation). Fixes: 0b12620fddb8 ("KVM: arm64: Treat ESR_EL2 as a 64-bit register") Cc: stable@vger.kernel.org Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240524141956.1450304-4-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-27KVM: arm64: Allow AArch32 PSTATE.M to be restored as System modeMarc Zyngier
It appears that we don't allow a vcpu to be restored in AArch32 System mode, as we *never* included it in the list of valid modes. Just add it to the list of allowed modes. Fixes: 0d854a60b1d7 ("arm64: KVM: enable initialization of a 32bit vcpu") Cc: stable@vger.kernel.org Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240524141956.1450304-3-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-27KVM: arm64: Fix AArch32 register narrowing on userspace writeMarc Zyngier
When userspace writes to one of the core registers, we make sure to narrow the corresponding GPRs if PSTATE indicates an AArch32 context. The code tries to check whether the context is EL0 or EL1 so that it narrows the correct registers. But it does so by checking the full PSTATE instead of PSTATE.M. As a consequence, and if we are restoring an AArch32 EL0 context in a 64bit guest, and that PSTATE has *any* bit set outside of PSTATE.M, we narrow *all* registers instead of only the first 15, destroying the 64bit state. Obviously, this is not something the guest is likely to enjoy. Correctly masking PSTATE to only evaluate PSTATE.M fixes it. Fixes: 90c1f934ed71 ("KVM: arm64: Get rid of the AArch32 register mapping code") Reported-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Cc: stable@vger.kernel.org Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240524141956.1450304-2-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-18Merge tag 'kbuild-v6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Avoid 'constexpr', which is a keyword in C23 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of 'dt_binding_check' - Fix weak references to avoid GOT entries in position-independent code generation - Convert the last use of 'optional' property in arch/sh/Kconfig - Remove support for the 'optional' property in Kconfig - Remove support for Clang's ThinLTO caching, which does not work with the .incbin directive - Change the semantics of $(src) so it always points to the source directory, which fixes Makefile inconsistencies between upstream and downstream - Fix 'make tar-pkg' for RISC-V to produce a consistent package - Provide reasonable default coverage for objtool, sanitizers, and profilers - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc. - Remove the last use of tristate choice in drivers/rapidio/Kconfig - Various cleanups and fixes in Kconfig * tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits) kconfig: use sym_get_choice_menu() in sym_check_prop() rapidio: remove choice for enumeration kconfig: lxdialog: remove initialization with A_NORMAL kconfig: m/nconf: merge two item_add_str() calls kconfig: m/nconf: remove dead code to display value of bool choice kconfig: m/nconf: remove dead code to display children of choice members kconfig: gconf: show checkbox for choice correctly kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal Makefile: remove redundant tool coverage variables kbuild: provide reasonable defaults for tool coverage modules: Drop the .export_symbol section from the final modules kconfig: use menu_list_for_each_sym() in sym_check_choice_deps() kconfig: use sym_get_choice_menu() in conf_write_defconfig() kconfig: add sym_get_choice_menu() helper kconfig: turn defaults and additional prompt for choice members into error kconfig: turn missing prompt for choice members into error kconfig: turn conf_choice() into void function kconfig: use linked list in sym_set_changed() kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED kconfig: gconf: remove debug code ...
2024-05-14Makefile: remove redundant tool coverage variablesMasahiro Yamada
Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
2024-05-12Merge tag 'kvmarm-6.10-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 6.10 - Move a lot of state that was previously stored on a per vcpu basis into a per-CPU area, because it is only pertinent to the host while the vcpu is loaded. This results in better state tracking, and a smaller vcpu structure. - Add full handling of the ERET/ERETAA/ERETAB instructions in nested virtualisation. The last two instructions also require emulating part of the pointer authentication extension. As a result, the trap handling of pointer authentication has been greattly simplified. - Turn the global (and not very scalable) LPI translation cache into a per-ITS, scalable cache, making non directly injected LPIs much cheaper to make visible to the vcpu. - A batch of pKVM patches, mostly fixes and cleanups, as the upstreaming process seems to be resuming. Fingers crossed! - Allocate PPIs and SGIs outside of the vcpu structure, allowing for smaller EL2 mapping and some flexibility in implementing more or less than 32 private IRQs. - Purge stale mpidr_data if a vcpu is created after the MPIDR map has been created. - Preserve vcpu-specific ID registers across a vcpu reset. - Various minor cleanups and improvements.
2024-05-10Merge tag 'loongarch-kvm-6.10' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.10 1. Add ParaVirt IPI support. 2. Add software breakpoint support. 3. Add mmio trace events support.
2024-05-10kbuild: use $(src) instead of $(srctree)/$(src) for source directoryMasahiro Yamada
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-09Merge branch kvm-arm64/mpidr-reset into kvmarm-master/nextMarc Zyngier
* kvm-arm64/mpidr-reset: : . : Fixes for CLIDR_EL1 and MPIDR_EL1 being accidentally mutable across : a vcpu reset, courtesy of Oliver. From the cover letter: : : "For VM-wide feature ID registers we ensure they get initialized once for : the lifetime of a VM. On the other hand, vCPU-local feature ID registers : get re-initialized on every vCPU reset, potentially clobbering the : values userspace set up. : : MPIDR_EL1 and CLIDR_EL1 are the only registers in this space that we : allow userspace to modify for now. Clobbering the value of MPIDR_EL1 has : some disastrous side effects as the compressed index used by the : MPIDR-to-vCPU lookup table assumes MPIDR_EL1 is immutable after KVM_RUN. : : Series + reproducer test case to address the problem of KVM wiping out : userspace changes to these registers. Note that there are still some : differences between VM and vCPU scoped feature ID registers from the : perspective of userspace. We do not allow the value of VM-scope : registers to change after KVM_RUN, but vCPU registers remain mutable." : . KVM: selftests: arm64: Test vCPU-scoped feature ID registers KVM: selftests: arm64: Test that feature ID regs survive a reset KVM: selftests: arm64: Store expected register value in set_id_regs KVM: selftests: arm64: Rename helper in set_id_regs to imply VM scope KVM: arm64: Only reset vCPU-scoped feature ID regs once KVM: arm64: Reset VM feature ID regs from kvm_reset_sys_regs() KVM: arm64: Rename is_id_reg() to imply VM scope Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-09KVM: arm64: Only reset vCPU-scoped feature ID regs onceOliver Upton
The general expecation with feature ID registers is that they're 'reset' exactly once by KVM for the lifetime of a vCPU/VM, such that any userspace changes to the CPU features / identity are honored after a vCPU gets reset (e.g. PSCI_ON). KVM handles what it calls VM-scoped feature ID registers correctly, but feature ID registers local to a vCPU (CLIDR_EL1, MPIDR_EL1) get wiped after every reset. What's especially concerning is that a potentially-changing MPIDR_EL1 breaks MPIDR compression for indexing mpidr_data, as the mask of useful bits to build the index could change. This is absolutely no good. Avoid resetting vCPU feature ID registers more than once. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240502233529.1958459-4-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-09KVM: arm64: Reset VM feature ID regs from kvm_reset_sys_regs()Oliver Upton
A subsequent change to KVM will expand the range of feature ID registers that get special treatment at reset. Fold the existing ones back in to kvm_reset_sys_regs() to avoid the need for an additional table walk. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240502233529.1958459-3-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-09KVM: arm64: Rename is_id_reg() to imply VM scopeOliver Upton
The naming of some of the feature ID checks is ambiguous. Rephrase the is_id_reg() helper to make its purpose slightly clearer. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240502233529.1958459-2-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-08Merge branch kvm-arm64/misc-6.10 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/misc-6.10: : . : Misc fixes and updates targeting 6.10 : : - Improve boot-time diagnostics when the sysreg tables : are not correctly sorted : : - Allow FFA_MSG_SEND_DIRECT_REQ in the FFA proxy : : - Fix duplicate XNX field in the ID_AA64MMFR1_EL1 : writeable mask : : - Allocate PPIs and SGIs outside of the vcpu structure, allowing : for smaller EL2 mapping and some flexibility in implementing : more or less than 32 private IRQs. : : - Use bitmap_gather() instead of its open-coded equivalent : : - Make protected mode use hVHE if available : : - Purge stale mpidr_data if a vcpu is created after the MPIDR : map has been created : . KVM: arm64: Destroy mpidr_data for 'late' vCPU creation KVM: arm64: Use hVHE in pKVM by default on CPUs with VHE support KVM: arm64: Fix hvhe/nvhe early alias parsing KVM: arm64: Convert kvm_mpidr_index() to bitmap_gather() KVM: arm64: vgic: Allocate private interrupts on demand KVM: arm64: Remove duplicated AA64MMFR1_EL1 XNX KVM: arm64: Remove FFA_MSG_SEND_DIRECT_REQ from the denylist KVM: arm64: Improve out-of-order sysreg table diagnostics Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-08KVM: arm64: Destroy mpidr_data for 'late' vCPU creationOliver Upton
A particularly annoying userspace could create a vCPU after KVM has computed mpidr_data for the VM, either by racing against VGIC initialization or having a userspace irqchip. In any case, this means mpidr_data no longer fully describes the VM, and attempts to find the new vCPU with kvm_mpidr_to_vcpu() will fail. The fix is to discard mpidr_data altogether, as it is only a performance optimization and not required for correctness. In all likelihood KVM will recompute the mappings when KVM_RUN is called on the new vCPU. Note that reads of mpidr_data are not guarded by a lock; promote to RCU to cope with the possibility of mpidr_data being invalidated at runtime. Fixes: 54a8006d0b49 ("KVM: arm64: Fast-track kvm_mpidr_to_vcpu() when mpidr_data is available") Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240508071952.2035422-1-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/pkvm-6.10 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/pkvm-6.10: (25 commits) : . : At last, a bunch of pKVM patches, courtesy of Fuad Tabba. : From the cover letter: : : "This series is a bit of a bombay-mix of patches we've been : carrying. There's no one overarching theme, but they do improve : the code by fixing existing bugs in pKVM, refactoring code to : make it more readable and easier to re-use for pKVM, or adding : functionality to the existing pKVM code upstream." : . KVM: arm64: Force injection of a data abort on NISV MMIO exit KVM: arm64: Restrict supported capabilities for protected VMs KVM: arm64: Refactor setting the return value in kvm_vm_ioctl_enable_cap() KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst KVM: arm64: Rename firmware pseudo-register documentation file KVM: arm64: Reformat/beautify PTP hypercall documentation KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exit KVM: arm64: Introduce and use predicates that check for protected VMs KVM: arm64: Add is_pkvm_initialized() helper KVM: arm64: Simplify vgic-v3 hypercalls KVM: arm64: Move setting the page as dirty out of the critical section KVM: arm64: Change kvm_handle_mmio_return() return polarity KVM: arm64: Fix comment for __pkvm_vcpu_init_traps() KVM: arm64: Prevent kmemleak from accessing .hyp.data KVM: arm64: Do not map the host fpsimd state to hyp in pKVM KVM: arm64: Rename __tlb_switch_to_{guest,host}() in VHE KVM: arm64: Support TLB invalidation in guest context KVM: arm64: Avoid BBM when changing only s/w bits in Stage-2 PTE KVM: arm64: Check for PTE validity when checking for executable/cacheable KVM: arm64: Avoid BUG-ing from the host abort path ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/lpi-xa-cache into kvmarm-master/nextMarc Zyngier
* kvm-arm64/lpi-xa-cache: : . : New and improved LPI translation cache from Oliver Upton. : : From the cover letter: : : "As discussed [*], here is the new take on the LPI translation cache, : migrating to an xarray indexed by (devid, eventid) per ITS. : : The end result is quite satisfying, as it becomes possible to rip out : other nasties such as the lpi_list_lock. To that end, patches 2-6 aren't : _directly_ related to the translation cache cleanup, but instead are : done to enable the cleanups at the end of the series. : : I changed out my test machine from the last time so the baseline has : moved a bit, but here are the results from the vgic_lpi_stress test: : : +----------------------------+------------+-------------------+ : | Configuration | v6.8-rc1 | v6.8-rc1 + series | : +----------------------------+------------+-------------------+ : | -v 1 -d 1 -e 1 -i 1000000 | 2063296.81 | 1362602.35 | : | -v 16 -d 16 -e 16 -i 10000 | 610678.33 | 5200910.01 | : | -v 16 -d 16 -e 17 -i 10000 | 678361.53 | 5890675.51 | : | -v 32 -d 32 -e 1 -i 100000 | 580918.96 | 8304552.67 | : | -v 1 -d 1 -e 17 -i 1000 | 1512443.94 | 1425953.8 | : +----------------------------+------------+-------------------+ : : Unlike last time, no dramatic regressions at any performance point. The : regression on a single interrupt stream is to be expected, as the : overheads of SRCU and two tree traversals (kvm_io_bus_get_dev(), : translation cache xarray) are likely greater than that of a linked-list : with a single node." : . KVM: selftests: Add stress test for LPI injection KVM: selftests: Use MPIDR_HWID_BITMASK from cputype.h KVM: selftests: Add helper for enabling LPIs on a redistributor KVM: selftests: Add a minimal library for interacting with an ITS KVM: selftests: Add quadword MMIO accessors KVM: selftests: Standardise layout of GIC frames KVM: selftests: Align with kernel's GIC definitions KVM: arm64: vgic-its: Get rid of the lpi_list_lock KVM: arm64: vgic-its: Rip out the global translation cache KVM: arm64: vgic-its: Use the per-ITS translation cache for injection KVM: arm64: vgic-its: Spin off helper for finding ITS by doorbell addr KVM: arm64: vgic-its: Maintain a translation cache per ITS KVM: arm64: vgic-its: Scope translation cache invalidations to an ITS KVM: arm64: vgic-its: Get rid of vgic_copy_lpi_list() KVM: arm64: vgic-debug: Use an xarray mark for debug iterator KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_cmd_handle_movall() KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_invall() KVM: arm64: vgic-its: Walk LPI xarray in its_sync_lpi_pending_table() KVM: Treat the device list as an rculist Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/nv-eret-pauth into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-eret-pauth: : . : Add NV support for the ERETAA/ERETAB instructions. From the cover letter: : : "Although the current upstream NV support has *some* support for : correctly emulating ERET, that support is only partial as it doesn't : support the ERETAA and ERETAB variants. : : Supporting these instructions was cast aside for a long time as it : involves implementing some form of PAuth emulation, something I wasn't : overly keen on. But I have reached a point where enough of the : infrastructure is there that it actually makes sense. So here it is!" : . KVM: arm64: nv: Work around lack of pauth support in old toolchains KVM: arm64: Drop trapping of PAuth instructions/keys KVM: arm64: nv: Advertise support for PAuth KVM: arm64: nv: Handle ERETA[AB] instructions KVM: arm64: nv: Add emulation for ERETAx instructions KVM: arm64: nv: Add kvm_has_pauth() helper KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently KVM: arm64: nv: Honor HFGITR_EL2.ERET being set KVM: arm64: nv: Fast-track 'InHost' exception returns KVM: arm64: nv: Add trap forwarding for ERET and SMC KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2 KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag KVM: arm64: Constraint PAuth support to consistent implementations KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET* KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/host_data into kvmarm-master/nextMarc Zyngier
* kvm-arm64/host_data: : . : Rationalise the host-specific data to live as part of the per-CPU state. : : From the cover letter: : : "It appears that over the years, we have accumulated a lot of cruft in : the kvm_vcpu_arch structure. Part of the gunk is data that is strictly : host CPU specific, and this result in two main problems: : : - the structure itself is stupidly large, over 8kB. With the : arch-agnostic kvm_vcpu, we're above 10kB, which is insane. This has : some ripple effects, as we need physically contiguous allocation to : be able to map it at EL2 for !VHE. There is more to it though, as : some data structures, although per-vcpu, could be allocated : separately. : : - We lose track of the life-cycle of this data, because we're : guaranteed that it will be around forever and we start relying on : wrong assumptions. This is becoming a maintenance burden. : : This series rectifies some of these things, starting with the two main : offenders: debug and FP, a lot of which gets pushed out to the per-CPU : host structure. Indeed, their lifetime really isn't that of the vcpu, : but tied to the physical CPU the vpcu runs on. : : This results in a small reduction of the vcpu size, but mainly a much : clearer understanding of the life-cycle of these structures." : . KVM: arm64: Move management of __hyp_running_vcpu to load/put on VHE KVM: arm64: Exclude FP ownership from kvm_vcpu_arch KVM: arm64: Exclude host_fpsimd_state pointer from kvm_vcpu_arch KVM: arm64: Exclude mdcr_el2_host from kvm_vcpu_arch KVM: arm64: Exclude host_debug_data from vcpu_arch KVM: arm64: Add accessor for per-CPU state Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03KVM: arm64: Move management of __hyp_running_vcpu to load/put on VHEMarc Zyngier
The per-CPU host context structure contains a __hyp_running_vcpu that serves as a replacement for kvm_get_current_vcpu() in contexts where we cannot make direct use of it (such as in the nVHE hypervisor). Since there is a lot of common code between nVHE and VHE, the latter also populates this field even if kvm_get_running_vcpu() always works. We currently pretty inconsistent when populating __hyp_running_vcpu to point to the currently running vcpu: - on {n,h}VHE, we set __hyp_running_vcpu on entry to __kvm_vcpu_run and clear it on exit. - on VHE, we set __hyp_running_vcpu on entry to __kvm_vcpu_run_vhe and never clear it, effectively leaving a dangling pointer... VHE is obviously the odd one here. Although we could make it behave just like nVHE, this wouldn't match the behaviour of KVM with VHE, where the load phase is where most of the context-switch gets done. So move all the __hyp_running_vcpu management to the VHE-specific load/put phases, giving us a bit more sanity and matching the behaviour of kvm_get_running_vcpu(). Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240502154030.3011995-1-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03KVM: arm64: vgic: Allocate private interrupts on demandMarc Zyngier
Private interrupts are currently part of the CPU interface structure that is part of each and every vcpu we create. Currently, we have 32 of them per vcpu, resulting in a per-vcpu array that is just shy of 4kB. On its own, that's no big deal, but it gets in the way of other things: - each vcpu gets mapped at EL2 on nVHE/hVHE configurations. This requires memory that is physically contiguous. However, the EL2 code has no purpose looking at the interrupt structures and could do without them being mapped. - supporting features such as EPPIs, which extend the number of private interrupts past the 32 limit would make the array even larger, even for VMs that do not use the EPPI feature. Address these issues by moving the private interrupt array outside of the vcpu, and replace it with a simple pointer. We take this opportunity to make it obvious what gets initialised when, as that path was remarkably opaque, and tighten the locking. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240502154545.3012089-1-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Force injection of a data abort on NISV MMIO exitMarc Zyngier
If a vcpu exits for a data abort with an invalid syndrome, the expectations are that userspace has a chance to save the day if it has requested to see such exits. However, this is completely futile in the case of a protected VM, as none of the state is available. In this particular case, inject a data abort directly into the vcpu, consistent with what userspace could do. This also helps with pKVM, which discards all syndrome information when forwarding data aborts that are not known to be MMIO. Finally, document this tweak to the API. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-31-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Restrict supported capabilities for protected VMsFuad Tabba
For practical reasons as well as security related ones, not all capabilities are supported for protected VMs in pKVM. Add a function that restricts the capabilities for protected VMs. This behaves as an allow-list to ensure that future capabilities are checked for compatibility and security before being allowed for protected VMs. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-30-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Refactor setting the return value in kvm_vm_ioctl_enable_cap()Fuad Tabba
Initialize r = -EINVAL to get rid of the error-path initializations in kvm_vm_ioctl_enable_cap(). No functional change intended. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-29-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exitFuad Tabba
Expand comment clarifying why the host value representing SVE vector length being restored for ZCR_EL1 on guest exit isn't the same as it was on guest entry. Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-21-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Introduce and use predicates that check for protected VMsFuad Tabba
In order to determine whether or not a VM or vcpu are protected, introduce helpers to query this state. While at it, use the vcpu helper to check vcpus protected state instead of the kvm one. Co-authored-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-19-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Simplify vgic-v3 hypercallsMarc Zyngier
Consolidate the GICv3 VMCR accessor hypercalls into the APR save/restore hypercalls so that all of the EL2 GICv3 state is covered by a single pair of hypercalls. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-17-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Move setting the page as dirty out of the critical sectionFuad Tabba
Move the unlock earlier in user_mem_abort() to shorten the critical section. This also helps for future refactoring and reuse of similar code. This moves out marking the page as dirty outside of the critical section. That code does not interact with the stage-2 page tables, which the read lock in the critical section protects. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-16-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Change kvm_handle_mmio_return() return polarityFuad Tabba
Most exit handlers return <= 0 to indicate that the host needs to handle the exit. Make kvm_handle_mmio_return() consistent with the exit handlers in handle_exit(). This makes the code easier to reason about, and makes it easier to add other handlers in future patches. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-15-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>