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2023-09-30KVM: arm64: Use vcpu_idx for invalidation trackingMarc Zyngier
While vcpu_id isn't necessarily a bad choice as an identifier for the currently running vcpu, it is provided by userspace, and there is close to no guarantee that it would be unique. Switch it to vcpu_idx instead, for which we have much stronger guarantees. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-7-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30KVM: arm64: vgic: Use vcpu_idx for the debug informationMarc Zyngier
When dumping the debug information, use vcpu_idx instead of vcpu_id, as this is independent of any userspace influence. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-6-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30KVM: arm64: vgic-v2: Use cpuid from userspace as vcpu_idMarc Zyngier
When parsing a GICv2 attribute that contains a cpuid, handle this as the vcpu_id, not a vcpu_idx, as userspace cannot really know the mapping between the two. For this, use kvm_get_vcpu_by_id() instead of kvm_get_vcpu(). Take this opportunity to get rid of the pointless check against online_vcpus, which doesn't make much sense either, and switch to FIELD_GET as a way to extract the vcpu_id. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-5-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30KVM: arm64: vgic-v3: Refactor GICv3 SGI generationMarc Zyngier
As we're about to change the way SGIs are sent, start by splitting out some of the basic functionnality: instead of intermingling the broadcast and non-broadcast cases with the actual SGI generation, perform the following cleanups: - move the SGI queuing into its own helper - split the broadcast code from the affinity-driven code - replace the mask/shift combinations with FIELD_GET() - fix the confusion between vcpu_id and vcpu when handling the broadcast case The result is much more readable, and paves the way for further optimisations. Tested-by: Joey Gouly <joey.gouly@arm.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-4-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30KVM: arm64: vgic-its: Treat the collection target address as a vcpu_idMarc Zyngier
Since our emulated ITS advertises GITS_TYPER.PTA=0, the target address associated to a collection is a PE number and not an address. So far, so good. However, the PE number is what userspace has provided given us (aka the vcpu_id), and not the internal vcpu index. Make sure we consistently retrieve the vcpu by ID rather than by index, adding a helper that deals with most of the cases. We also get rid of the pointless (and bogus) comparisons to online_vcpus, which don't really make sense. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointerMarc Zyngier
Passing a vcpu_id to kvm_vgic_inject_irq() is silly for two reasons: - we often confuse vcpu_id and vcpu_idx - we eventually have to convert it back to a vcpu - we can't count Instead, pass a vcpu pointer, which is unambiguous. A NULL vcpu is also allowed for interrupts that are not private to a vcpu (such as SPIs). Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30KVM: arm64: Do not transfer page refcount for THP adjustmentVincent Donnefort
GUP affects a refcount common to all pages forming the THP. There is therefore no need to move the refcount from a tail to the head page. Under the hood it decrements and increments the same counter. Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230928173205.2826598-2-vdonnefort@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Get rid of vCPU-scoped feature bitmapOliver Upton
The vCPU-scoped feature bitmap was left in place a couple of releases ago in case the change to VM-scoped vCPU features broke anyone. Nobody has complained and the interop between VM and vCPU bitmaps is pretty gross. Throw it out. Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Remove unused return value from kvm_reset_vcpu()Oliver Upton
Get rid of the return value for kvm_reset_vcpu() as there are no longer any cases where it returns a nonzero value. Link: https://lore.kernel.org/r/20230920195036.1169791-8-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Hoist NV+SVE check into KVM_ARM_VCPU_INIT ioctl handlerOliver Upton
Move the feature check out of kvm_reset_vcpu() so we can make the function succeed uncondtitionally. Link: https://lore.kernel.org/r/20230920195036.1169791-7-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Prevent NV feature flag on systems w/o nested virtOliver Upton
It would appear that userspace can select the NV feature flag regardless of whether the system actually supports the feature. Obviously a nested guest isn't getting far in this situation; let's reject the flag instead. Link: https://lore.kernel.org/r/20230920195036.1169791-6-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Hoist PAuth checks into KVM_ARM_VCPU_INIT ioctlOliver Upton
Test for feature support in the ioctl handler rather than kvm_reset_vcpu(). Continue to uphold our all-or-nothing policy with address and generic pointer authentication. Link: https://lore.kernel.org/r/20230920195036.1169791-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Hoist SVE check into KVM_ARM_VCPU_INIT ioctl handlerOliver Upton
Test that the system supports SVE before ever getting to kvm_reset_vcpu(). Link: https://lore.kernel.org/r/20230920195036.1169791-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Hoist PMUv3 check into KVM_ARM_VCPU_INIT ioctl handlerOliver Upton
Test that the system supports PMUv3 before ever getting to kvm_reset_vcpu(). Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Link: https://lore.kernel.org/r/20230920195036.1169791-3-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Add generic check for system-supported vCPU featuresOliver Upton
To date KVM has relied on kvm_reset_vcpu() failing when the vCPU feature flags are unsupported by the system. This is a bit messy since kvm_reset_vcpu() is called at runtime outside of the KVM_ARM_VCPU_INIT ioctl when it is expected to succeed. Further complicating the matter is that kvm_reset_vcpu() must tolerate be idemptotent to the config_lock, as it isn't consistently called with the lock held. Prepare to move feature compatibility checks out of kvm_reset_vcpu() with a 'generic' check that compares the user-provided flags with a computed maximum feature set for the system. Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Link: https://lore.kernel.org/r/20230920195036.1169791-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-18KVM: arm64: Don't use kerneldoc comment for arm64_check_features()Oliver Upton
A double-asterisk opening mark to the comment (i.e. '/**') indicates a comment block is in the kerneldoc format. There's automation in place to validate that kerneldoc blocks actually adhere to the formatting rules. The function comment for arm64_check_features() isn't kerneldoc; use a 'regular' comment to silence automation warnings. Link: https://lore.kernel.org/all/202309112251.e25LqfcK-lkp@intel.com/ Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20230913165645.2319017-1-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-12KVM: arm64: nvhe: Ignore SVE hint in SMCCC function IDJean-Philippe Brucker
When SVE is enabled, the host may set bit 16 in SMCCC function IDs, a hint that indicates an unused SVE state. At the moment NVHE doesn't account for this bit when inspecting the function ID, and rejects most calls. Clear the hint bit before comparing function IDs. About version compatibility: the host's PSCI driver initially probes the firmware for a SMCCC version number. If the firmware implements a protocol recent enough (1.3), subsequent SMCCC calls have the hint bit set. Since the hint bit was reserved in earlier versions of the protocol, clearing it is fine regardless of the version in use. When a new hint is added to the protocol in the future, it will be added to ARM_SMCCC_CALL_HINTS and NVHE will handle it straight away. This patch only clears known hints and leaves reserved bits as is, because future SMCCC versions could use reserved bits as modifiers for the function ID, rather than hints. Fixes: cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint") Reported-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230911145254.934414-4-jean-philippe@linaro.org
2023-09-12KVM: arm64: Properly return allocated EL2 VA from hyp_alloc_private_va_range()Marc Zyngier
Marek reports that his RPi4 spits out a warning at boot time, right at the point where the GICv2 virtual CPU interface gets mapped. Upon investigation, it seems that we never return the allocated VA and use whatever was on the stack at this point. Yes, this is good stuff, and Marek was pretty lucky that he ended-up with a VA that intersected with something that was already mapped. On my setup, this random value is plausible enough for the mapping to take place. Who knows what happens... Fixes: f156a7d13fc3 ("KVM: arm64: Remove size-order align in the nVHE hyp private VA range") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/79b0ad6e-0c2a-f777-d504-e40e8123d81d@samsung.com Link: https://lore.kernel.org/r/20230828153121.4179627-1-maz@kernel.org
2023-09-07Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Clean up vCPU targets, always returning generic v8 as the preferred target - Trap forwarding infrastructure for nested virtualization (used for traps that are taken from an L2 guest and are needed by the L1 hypervisor) - FEAT_TLBIRANGE support to only invalidate specific ranges of addresses when collapsing a table PTE to a block PTE. This avoids that the guest refills the TLBs again for addresses that aren't covered by the table PTE. - Fix vPMU issues related to handling of PMUver. - Don't unnecessary align non-stack allocations in the EL2 VA space - Drop HCR_VIRT_EXCP_MASK, which was never used... - Don't use smp_processor_id() in kvm_arch_vcpu_load(), but the cpu parameter instead - Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort() - Remove prototypes without implementations RISC-V: - Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for guest - Added ONE_REG interface for SATP mode - Added ONE_REG interface to enable/disable multiple ISA extensions - Improved error codes returned by ONE_REG interfaces - Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V - Added get-reg-list selftest for KVM RISC-V s390: - PV crypto passthrough enablement (Tony, Steffen, Viktor, Janosch) Allows a PV guest to use crypto cards. Card access is governed by the firmware and once a crypto queue is "bound" to a PV VM every other entity (PV or not) looses access until it is not bound anymore. Enablement is done via flags when creating the PV VM. - Guest debug fixes (Ilya) x86: - Clean up KVM's handling of Intel architectural events - Intel bugfixes - Add support for SEV-ES DebugSwap, allowing SEV-ES guests to use debug registers and generate/handle #DBs - Clean up LBR virtualization code - Fix a bug where KVM fails to set the target pCPU during an IRTE update - Fix fatal bugs in SEV-ES intrahost migration - Fix a bug where the recent (architecturally correct) change to reinject #BP and skip INT3 broke SEV guests (can't decode INT3 to skip it) - Retry APIC map recalculation if a vCPU is added/enabled - Overhaul emergency reboot code to bring SVM up to par with VMX, tie the "emergency disabling" behavior to KVM actually being loaded, and move all of the logic within KVM - Fix user triggerable WARNs in SVM where KVM incorrectly assumes the TSC ratio MSR cannot diverge from the default when TSC scaling is disabled up related code - Add a framework to allow "caching" feature flags so that KVM can check if the guest can use a feature without needing to search guest CPUID - Rip out the ancient MMU_DEBUG crud and replace the useful bits with CONFIG_KVM_PROVE_MMU - Fix KVM's handling of !visible guest roots to avoid premature triple fault injection - Overhaul KVM's page-track APIs, and KVMGT's usage, to reduce the API surface that is needed by external users (currently only KVMGT), and fix a variety of issues in the process Generic: - Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier events to pass action specific data without needing to constantly update the main handlers. - Drop unused function declarations Selftests: - Add testcases to x86's sync_regs_test for detecting KVM TOCTOU bugs - Add support for printf() in guest code and covert all guest asserts to use printf-based reporting - Clean up the PMU event filter test and add new testcases - Include x86 selftests in the KVM x86 MAINTAINERS entry" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (279 commits) KVM: x86/mmu: Include mmu.h in spte.h KVM: x86/mmu: Use dummy root, backed by zero page, for !visible guest roots KVM: x86/mmu: Disallow guest from using !visible slots for page tables KVM: x86/mmu: Harden TDP MMU iteration against root w/o shadow page KVM: x86/mmu: Harden new PGD against roots without shadow pages KVM: x86/mmu: Add helper to convert root hpa to shadow page drm/i915/gvt: Drop final dependencies on KVM internal details KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers KVM: x86/mmu: Drop @slot param from exported/external page-track APIs KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled KVM: x86/mmu: Assert that correct locks are held for page write-tracking KVM: x86/mmu: Rename page-track APIs to reflect the new reality KVM: x86/mmu: Drop infrastructure for multiple page-track modes KVM: x86/mmu: Use page-track notifiers iff there are external users KVM: x86/mmu: Move KVM-only page-track declarations to internal header KVM: x86: Remove the unused page-track hook track_flush_slot() drm/i915/gvt: switch from ->track_flush_slot() to ->track_remove_region() KVM: x86: Add a new page-track hook to handle memslot deletion drm/i915/gvt: Don't bother removing write-protection on to-be-deleted slot KVM: x86: Reject memslot MOVE operations if KVMGT is attached ...
2023-08-31Merge tag 'kvm-x86-generic-6.6' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
Common KVM changes for 6.6: - Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier events to pass action specific data without needing to constantly update the main handlers. - Drop unused function declarations
2023-08-31Merge tag 'kvmarm-6.6' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 6.6 - Add support for TLB range invalidation of Stage-2 page tables, avoiding unnecessary invalidations. Systems that do not implement range invalidation still rely on a full invalidation when dealing with large ranges. - Add infrastructure for forwarding traps taken from a L2 guest to the L1 guest, with L0 acting as the dispatcher, another baby step towards the full nested support. - Simplify the way we deal with the (long deprecated) 'CPU target', resulting in a much needed cleanup. - Fix another set of PMU bugs, both on the guest and host sides, as we seem to never have any shortage of those... - Relax the alignment requirements of EL2 VA allocations for non-stack allocations, as we were otherwise wasting a lot of that precious VA space. - The usual set of non-functional cleanups, although I note the lack of spelling fixes...
2023-08-28Merge tag 'hardening-v6.6-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: "As has become normal, changes are scattered around the tree (either explicitly maintainer Acked or for trivial stuff that went ignored): - Carve out the new CONFIG_LIST_HARDENED as a more focused subset of CONFIG_DEBUG_LIST (Marco Elver) - Fix kallsyms lookup failure under Clang LTO (Yonghong Song) - Clarify documentation for CONFIG_UBSAN_TRAP (Jann Horn) - Flexible array member conversion not carried in other tree (Gustavo A. R. Silva) - Various strlcpy() and strncpy() removals not carried in other trees (Azeem Shaikh, Justin Stitt) - Convert nsproxy.count to refcount_t (Elena Reshetova) - Add handful of __counted_by annotations not carried in other trees, as well as an LKDTM test - Fix build failure with gcc-plugins on GCC 14+ - Fix selftests to respect SKIP for signal-delivery tests - Fix CFI warning for paravirt callback prototype - Clarify documentation for seq_show_option_n() usage" * tag 'hardening-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits) LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by kallsyms: Change func signature for cleanup_symbol_name() kallsyms: Fix kallsyms_selftest failure nsproxy: Convert nsproxy.count to refcount_t integrity: Annotate struct ima_rule_opt_list with __counted_by lkdtm: Add FAM_BOUNDS test for __counted_by Compiler Attributes: counted_by: Adjust name and identifier expansion um: refactor deprecated strncpy to memcpy um: vector: refactor deprecated strncpy alpha: Replace one-element array with flexible-array member hardening: Move BUG_ON_DATA_CORRUPTION to hardening options list: Introduce CONFIG_LIST_HARDENED list_debug: Introduce inline wrappers for debug checks compiler_types: Introduce the Clang __preserve_most function attribute gcc-plugins: Rename last_stmt() for GCC 14+ selftests/harness: Actually report SKIP for signal tests x86/paravirt: Fix tlb_remove_table function callback prototype warning EISA: Replace all non-returning strlcpy with strscpy perf: Replace strlcpy with strscpy um: Remove strlcpy declaration ...
2023-08-28Merge branch kvm-arm64/6.6/misc into kvmarm-master/nextMarc Zyngier
* kvm-arm64/6.6/misc: : . : Misc KVM/arm64 updates for 6.6: : : - Don't unnecessary align non-stack allocations in the EL2 VA space : : - Drop HCR_VIRT_EXCP_MASK, which was never used... : : - Don't use smp_processor_id() in kvm_arch_vcpu_load(), : but the cpu parameter instead : : - Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort() : : - Remove prototypes without implementations : . KVM: arm64: Remove size-order align in the nVHE hyp private VA range KVM: arm64: Remove unused declarations KVM: arm64: Remove redundant kvm_set_pfn_accessed() from user_mem_abort() KVM: arm64: Drop HCR_VIRT_EXCP_MASK KVM: arm64: Use the known cpu id instead of smp_processor_id() Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-28Merge branch kvm-arm64/6.6/pmu-fixes into kvmarm-master/nextMarc Zyngier
* kvm-arm64/6.6/pmu-fixes: : . : Another set of PMU fixes, coutrtesy of Reiji Watanabe. : From the cover letter: : : "This series fixes a couple of PMUver related handling of : vPMU support. : : On systems where the PMUVer is not uniform across all PEs, : KVM currently does not advertise PMUv3 to the guest, : even if userspace successfully runs KVM_ARM_VCPU_INIT with : KVM_ARM_VCPU_PMU_V3." : : Additionally, a fix for an obscure counter oversubscription : issue happening when the hsot profines the guest's EL0. : . KVM: arm64: pmu: Guard PMU emulation definitions with CONFIG_KVM KVM: arm64: pmu: Resync EL0 state on counter rotation KVM: arm64: PMU: Don't advertise STALL_SLOT_{FRONTEND,BACKEND} KVM: arm64: PMU: Don't advertise the STALL_SLOT event KVM: arm64: PMU: Avoid inappropriate use of host's PMUVer KVM: arm64: PMU: Disallow vPMU on non-uniform PMUVer Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-28Merge branch kvm-arm64/tlbi-range into kvmarm-master/nextMarc Zyngier
* kvm-arm64/tlbi-range: : . : FEAT_TLBIRANGE support, courtesy of Raghavendra Rao Ananta. : From the cover letter: : : "In certain code paths, KVM/ARM currently invalidates the entire VM's : page-tables instead of just invalidating a necessary range. For example, : when collapsing a table PTE to a block PTE, instead of iterating over : each PTE and flushing them, KVM uses 'vmalls12e1is' TLBI operation to : flush all the entries. This is inefficient since the guest would have : to refill the TLBs again, even for the addresses that aren't covered : by the table entry. The performance impact would scale poorly if many : addresses in the VM is going through this remapping. : : For architectures that implement FEAT_TLBIRANGE, KVM can replace such : inefficient paths by performing the invalidations only on the range of : addresses that are in scope. This series tries to achieve the same in : the areas of stage-2 map, unmap and write-protecting the pages." : . KVM: arm64: Use TLBI range-based instructions for unmap KVM: arm64: Invalidate the table entries upon a range KVM: arm64: Flush only the memslot after write-protect KVM: arm64: Implement kvm_arch_flush_remote_tlbs_range() KVM: arm64: Define kvm_tlb_flush_vmid_range() KVM: arm64: Implement __kvm_tlb_flush_vmid_range() arm64: tlb: Implement __flush_s2_tlb_range_op() arm64: tlb: Refactor the core flush algorithm of __flush_tlb_range KVM: Move kvm_arch_flush_remote_tlbs_memslot() to common code KVM: Allow range-based TLB invalidation from common code KVM: Remove CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL KVM: arm64: Use kvm_arch_flush_remote_tlbs() KVM: Declare kvm_arch_flush_remote_tlbs() globally KVM: Rename kvm_arch_flush_remote_tlb() to kvm_arch_flush_remote_tlbs() Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-28Merge branch kvm-arm64/nv-trap-forwarding into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-trap-forwarding: (30 commits) : . : This implements the so called "trap forwarding" infrastructure, which : gets used when we take a trap from an L2 guest and that the L1 guest : wants to see the trap for itself. : . KVM: arm64: nv: Add trap description for SPSR_EL2 and ELR_EL2 KVM: arm64: nv: Select XARRAY_MULTI to fix build error KVM: arm64: nv: Add support for HCRX_EL2 KVM: arm64: Move HCRX_EL2 switch to load/put on VHE systems KVM: arm64: nv: Expose FGT to nested guests KVM: arm64: nv: Add switching support for HFGxTR/HDFGxTR KVM: arm64: nv: Expand ERET trap forwarding to handle FGT KVM: arm64: nv: Add SVC trap forwarding KVM: arm64: nv: Add trap forwarding for HDFGxTR_EL2 KVM: arm64: nv: Add trap forwarding for HFGITR_EL2 KVM: arm64: nv: Add trap forwarding for HFGxTR_EL2 KVM: arm64: nv: Add fine grained trap forwarding infrastructure KVM: arm64: nv: Add trap forwarding for CNTHCTL_EL2 KVM: arm64: nv: Add trap forwarding for MDCR_EL2 KVM: arm64: nv: Expose FEAT_EVT to nested guests KVM: arm64: nv: Add trap forwarding for HCR_EL2 KVM: arm64: nv: Add trap forwarding infrastructure KVM: arm64: Restructure FGT register switching KVM: arm64: nv: Add FGT registers KVM: arm64: Add missing HCR_EL2 trap bits ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-26KVM: arm64: Remove size-order align in the nVHE hyp private VA rangeVincent Donnefort
commit f922c13e778d ("KVM: arm64: Introduce pkvm_alloc_private_va_range()") and commit 92abe0f81e13 ("KVM: arm64: Introduce hyp_alloc_private_va_range()") added an alignment for the start address of any allocation into the nVHE hypervisor private VA range. This alignment (order of the size of the allocation) intends to enable efficient stack verification (if the PAGE_SHIFT bit is zero, the stack pointer is on the guard page and a stack overflow occurred). But this is only necessary for stack allocation and can waste a lot of VA space. So instead make stack-specific functions, handling the guard page requirements, while other users (e.g. fixmap) will only get page alignment. Reviewed-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230811112037.1147863-1-vdonnefort@google.com
2023-08-23KVM: arm64: nv: Add trap description for SPSR_EL2 and ELR_EL2Marc Zyngier
Having carved a hole for SP_EL1, we are now missing the entries for SPSR_EL2 and ELR_EL2. Add them back. Reported-by: Miguel Luis <miguel.luis@oracle.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-22KVM: arm64: pmu: Resync EL0 state on counter rotationMarc Zyngier
Huang Shijie reports that, when profiling a guest from the host with a number of events that exceeds the number of available counters, the reported counts are wildly inaccurate. Without the counter oversubscription, the reported counts are correct. Their investigation indicates that upon counter rotation (which takes place on the back of a timer interrupt), we fail to re-apply the guest EL0 enabling, leading to the counting of host events instead of guest events. In order to solve this, add yet another hook between the host PMU driver and KVM, re-applying the guest EL0 configuration if the right conditions apply (the host is VHE, we are in interrupt context, and we interrupted a running vcpu). This triggers a new vcpu request which will apply the correct configuration on guest reentry. With this, we have the correct counts, even when the counters are oversubscribed. Reported-by: Huang Shijie <shijie@os.amperecomputing.com> Suggested-by: Oliver Upton <oliver.upton@linux.dev> Tested_by: Huang Shijie <shijie@os.amperecomputing.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230809013953.7692-1-shijie@os.amperecomputing.com Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20230820090108.177817-1-maz@kernel.org
2023-08-20KVM: arm64: PMU: Don't advertise STALL_SLOT_{FRONTEND,BACKEND}Reiji Watanabe
Don't advertise STALL_SLOT_{FRONT,BACK}END events to the guest, similar to STALL_SLOT event, as when any of these three events are implemented, all three of them should be implemented, according to the Arm ARM. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230819043947.4100985-5-reijiw@google.com
2023-08-20KVM: arm64: PMU: Don't advertise the STALL_SLOT eventReiji Watanabe
Currently, KVM hides the STALL_SLOT event for guests if the host PMU version is PMUv3p4 or newer, as PMMIR_EL1 is handled as RAZ for the guests. But, this should be based on the guests' PMU version (instead of the host PMU version), as an older PMU that doesn't support PMMIR_EL1 could support the STALL_SLOT event, according to the Arm ARM. Exposing the STALL_SLOT event without PMMIR_EL1 won't be very useful anyway though. Stop advertising the STALL_SLOT event for guests unconditionally, rather than fixing or keeping the inaccurate checking to advertise the event for the case, where it is not very useful. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230819043947.4100985-4-reijiw@google.com
2023-08-20KVM: arm64: PMU: Avoid inappropriate use of host's PMUVerReiji Watanabe
Avoid using the PMUVer of the host's PMU hardware to determine the PMU event mask, except in one case, as the value of host's PMUVer may differ from the value of ID_AA64DFR0_EL1.PMUVer for the guest. The exception case is when using the PMUVer to determine the valid range of events for KVM_ARM_VCPU_PMU_V3_FILTER, as it has been allowing userspace to specify events that are valid for the PMU hardware, regardless of the value of the guest's ID_AA64DFR0_EL1.PMUVer. KVM will use a valid range of events based on the value of the guest's ID_AA64DFR0_EL1.PMUVer, in order to effectively filter events that the guest attempts to program though. Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230819043947.4100985-3-reijiw@google.com
2023-08-20KVM: arm64: PMU: Disallow vPMU on non-uniform PMUVerReiji Watanabe
Disallow userspace from configuring vPMU for guests on systems where the PMUVer is not uniform across all PEs. KVM has not been advertising PMUv3 to the guests with vPMU on such systems anyway, and such systems would be extremely uncommon and unlikely to even use KVM. Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230819043947.4100985-2-reijiw@google.com
2023-08-17KVM: Wrap kvm_{gfn,hva}_range.pte in a per-action unionSean Christopherson
Wrap kvm_{gfn,hva}_range.pte in a union so that future notifier events can pass event specific information up and down the stack without needing to constantly expand and churn the APIs. Lockless aging of SPTEs will pass around a bitmap, and support for memory attributes will pass around the new attributes for the range. Add a "KVM_NO_ARG" placeholder to simplify handling events without an argument (creating a dummy union variable is midly annoying). Opportunstically drop explicit zero-initialization of the "pte" field, as omitting the field (now a union) has the same effect. Cc: Yu Zhao <yuzhao@google.com> Link: https://lore.kernel.org/all/CAOUHufagkd2Jk3_HrVoFFptRXM=hX2CV8f+M-dka-hJU4bP8kw@mail.gmail.com Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Acked-by: Yu Zhao <yuzhao@google.com> Link: https://lore.kernel.org/r/20230729004144.1054885-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-08-17KVM: arm64: nv: Select XARRAY_MULTI to fix build errorRandy Dunlap
populate_nv_trap_config() uses xa_store_range(), which is only built when XARRAY_MULTI is set, so select that symbol to prevent the build error. aarch64-linux-ld: arch/arm64/kvm/emulate-nested.o: in function `populate_nv_trap_config': emulate-nested.c:(.init.text+0x17c): undefined reference to `xa_store_range' Fixes: e58ec47bf68d ("KVM: arm64: nv: Add trap forwarding infrastructure") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: kvmarm@lists.linux.dev Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230816210949.17117-1-rdunlap@infradead.org
2023-08-17KVM: arm64: nv: Add support for HCRX_EL2Marc Zyngier
HCRX_EL2 has an interesting effect on HFGITR_EL2, as it conditions the traps of TLBI*nXS. Expand the FGT support to add a new Fine Grained Filter that will get checked when the instruction gets trapped, allowing the shadow register to override the trap as needed. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-29-maz@kernel.org
2023-08-17KVM: arm64: Move HCRX_EL2 switch to load/put on VHE systemsMarc Zyngier
Although the nVHE behaviour requires HCRX_EL2 to be switched on each switch between host and guest, there is nothing in this register that would affect a VHE host. It is thus possible to save/restore this register on load/put on VHE systems, avoiding unnecessary sysreg access on the hot path. Additionally, it avoids unnecessary traps when running with NV. To achieve this, simply move the read/writes to the *_common() helpers, which are called on load/put on VHE, and more eagerly on nVHE. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-28-maz@kernel.org
2023-08-17KVM: arm64: nv: Expose FGT to nested guestsMarc Zyngier
Now that we have FGT support, expose the feature to NV guests. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-27-maz@kernel.org
2023-08-17KVM: arm64: nv: Add switching support for HFGxTR/HDFGxTRMarc Zyngier
Now that we can evaluate the FGT registers, allow them to be merged with the hypervisor's own configuration (in the case of HFG{RW}TR_EL2) or simply set for HFGITR_EL2, HDGFRTR_EL2 and HDFGWTR_EL2. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-26-maz@kernel.org
2023-08-17KVM: arm64: nv: Expand ERET trap forwarding to handle FGTMarc Zyngier
We already handle ERET being trapped from a L1 guest in hyp context. However, with FGT, we can also have ERET being trapped from L2, and this needs to be reinjected into L1. Add the required exception routing. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-25-maz@kernel.org
2023-08-17KVM: arm64: nv: Add SVC trap forwardingMarc Zyngier
HFGITR_EL2 allows the trap of SVC instructions to EL2. Allow these traps to be forwarded. Take this opportunity to deny any 32bit activity when NV is enabled. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-24-maz@kernel.org
2023-08-17KVM: arm64: nv: Add trap forwarding for HDFGxTR_EL2Marc Zyngier
... and finally, the Debug version of FGT, with its *enormous* list of trapped registers. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-23-maz@kernel.org
2023-08-17KVM: arm64: nv: Add trap forwarding for HFGITR_EL2Marc Zyngier
Similarly, implement the trap forwarding for instructions affected by HFGITR_EL2. Note that the TLBI*nXS instructions should be affected by HCRX_EL2, which will be dealt with down the line. Also, ERET* and SVC traps are handled separately. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-22-maz@kernel.org
2023-08-17KVM: arm64: nv: Add trap forwarding for HFGxTR_EL2Marc Zyngier
Implement the trap forwarding for traps described by HFGxTR_EL2, reusing the Fine Grained Traps infrastructure previously implemented. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-21-maz@kernel.org
2023-08-17KVM: arm64: nv: Add fine grained trap forwarding infrastructureMarc Zyngier
Fine Grained Traps are fun. Not. Implement the fine grained trap forwarding, reusing the Coarse Grained Traps infrastructure previously implemented. Each sysreg/instruction inserted in the xarray gets a FGT group (vaguely equivalent to a register number), a bit number in that register, and a polarity. It is then pretty easy to check the FGT state at handling time, just like we do for the coarse version (it is just faster). Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-20-maz@kernel.org
2023-08-17KVM: arm64: nv: Add trap forwarding for CNTHCTL_EL2Marc Zyngier
Describe the CNTHCTL_EL2 register, and associate it with all the sysregs it allows to trap. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-19-maz@kernel.org
2023-08-17KVM: arm64: nv: Add trap forwarding for MDCR_EL2Marc Zyngier
Describe the MDCR_EL2 register, and associate it with all the sysregs it allows to trap. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-18-maz@kernel.org
2023-08-17KVM: arm64: nv: Expose FEAT_EVT to nested guestsMarc Zyngier
Now that we properly implement FEAT_EVT (as we correctly forward traps), expose it to guests. Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Jing Zhang <jingzhangos@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230815183903.2735724-17-maz@kernel.org
2023-08-17KVM: arm64: nv: Add trap forwarding for HCR_EL2Marc Zyngier
Describe the HCR_EL2 register, and associate it with all the sysregs it allows to trap. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-16-maz@kernel.org
2023-08-17KVM: arm64: nv: Add trap forwarding infrastructureMarc Zyngier
A significant part of what a NV hypervisor needs to do is to decide whether a trap from a L2+ guest has to be forwarded to a L1 guest or handled locally. This is done by checking for the trap bits that the guest hypervisor has set and acting accordingly, as described by the architecture. A previous approach was to sprinkle a bunch of checks in all the system register accessors, but this is pretty error prone and doesn't help getting an overview of what is happening. Instead, implement a set of global tables that describe a trap bit, combinations of trap bits, behaviours on trap, and what bits must be evaluated on a system register trap. Although this is painful to describe, this allows to specify each and every control bit in a static manner. To make it efficient, the table is inserted in an xarray that is global to the system, and checked each time we trap a system register while running a L2 guest. Add the basic infrastructure for now, while additional patches will implement configuration registers. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Link: https://lore.kernel.org/r/20230815183903.2735724-15-maz@kernel.org