diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-24 11:58:57 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-24 11:58:57 -0700 |
commit | 1ebdbeb03efe89f01f15df038a589077df3d21f5 (patch) | |
tree | 06b6b7bb565668d136c060c5104481e48cbf71e2 /arch/arm64 | |
parent | efee6c79298fd823c569d501d041de85caa102a6 (diff) | |
parent | c9b8fecddb5bb4b67e351bbaeaa648a6f7456912 (diff) | |
download | linux-1ebdbeb03efe89f01f15df038a589077df3d21f5.tar.bz2 |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"ARM:
- Proper emulation of the OSLock feature of the debug architecture
- Scalibility improvements for the MMU lock when dirty logging is on
- New VMID allocator, which will eventually help with SVA in VMs
- Better support for PMUs in heterogenous systems
- PSCI 1.1 support, enabling support for SYSTEM_RESET2
- Implement CONFIG_DEBUG_LIST at EL2
- Make CONFIG_ARM64_ERRATUM_2077057 default y
- Reduce the overhead of VM exit when no interrupt is pending
- Remove traces of 32bit ARM host support from the documentation
- Updated vgic selftests
- Various cleanups, doc updates and spelling fixes
RISC-V:
- Prevent KVM_COMPAT from being selected
- Optimize __kvm_riscv_switch_to() implementation
- RISC-V SBI v0.3 support
s390:
- memop selftest
- fix SCK locking
- adapter interruptions virtualization for secure guests
- add Claudio Imbrenda as maintainer
- first step to do proper storage key checking
x86:
- Continue switching kvm_x86_ops to static_call(); introduce
static_call_cond() and __static_call_ret0 when applicable.
- Cleanup unused arguments in several functions
- Synthesize AMD 0x80000021 leaf
- Fixes and optimization for Hyper-V sparse-bank hypercalls
- Implement Hyper-V's enlightened MSR bitmap for nested SVM
- Remove MMU auditing
- Eager splitting of page tables (new aka "TDP" MMU only) when dirty
page tracking is enabled
- Cleanup the implementation of the guest PGD cache
- Preparation for the implementation of Intel IPI virtualization
- Fix some segment descriptor checks in the emulator
- Allow AMD AVIC support on systems with physical APIC ID above 255
- Better API to disable virtualization quirks
- Fixes and optimizations for the zapping of page tables:
- Zap roots in two passes, avoiding RCU read-side critical
sections that last too long for very large guests backed by 4
KiB SPTEs.
- Zap invalid and defunct roots asynchronously via
concurrency-managed work queue.
- Allowing yielding when zapping TDP MMU roots in response to the
root's last reference being put.
- Batch more TLB flushes with an RCU trick. Whoever frees the
paging structure now holds RCU as a proxy for all vCPUs running
in the guest, i.e. to prolongs the grace period on their behalf.
It then kicks the the vCPUs out of guest mode before doing
rcu_read_unlock().
Generic:
- Introduce __vcalloc and use it for very large allocations that need
memcg accounting"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
KVM: use kvcalloc for array allocations
KVM: x86: Introduce KVM_CAP_DISABLE_QUIRKS2
kvm: x86: Require const tsc for RT
KVM: x86: synthesize CPUID leaf 0x80000021h if useful
KVM: x86: add support for CPUID leaf 0x80000021
KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_mask
Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
kvm: x86/mmu: Flush TLB before zap_gfn_range releases RCU
KVM: arm64: fix typos in comments
KVM: arm64: Generalise VM features into a set of flags
KVM: s390: selftests: Add error memop tests
KVM: s390: selftests: Add more copy memop tests
KVM: s390: selftests: Add named stages for memop test
KVM: s390: selftests: Add macro as abstraction for MEM_OP
KVM: s390: selftests: Split memop tests
KVM: s390x: fix SCK locking
RISC-V: KVM: Implement SBI HSM suspend call
RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
RISC-V: Add SBI HSM suspend related defines
RISC-V: KVM: Implement SBI v0.3 SRST extension
...
Diffstat (limited to 'arch/arm64')
26 files changed, 664 insertions, 228 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 13aa8d955c46..f8680892401b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -686,6 +686,7 @@ config ARM64_ERRATUM_2051678 config ARM64_ERRATUM_2077057 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" + default y help This option adds the workaround for ARM Cortex-A510 erratum 2077057. Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 031e3a2537fc..e3b25dc6c367 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -50,6 +50,8 @@ #define KVM_DIRTY_LOG_MANUAL_CAPS (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \ KVM_DIRTY_LOG_INITIALLY_SET) +#define KVM_HAVE_MMU_RWLOCK + /* * Mode of operation configurable with kvm-arm.mode early param. * See Documentation/admin-guide/kernel-parameters.txt for more information. @@ -71,9 +73,7 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu); void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu); struct kvm_vmid { - /* The VMID generation used for the virt. memory system */ - u64 vmid_gen; - u32 vmid; + atomic64_t id; }; struct kvm_s2_mmu { @@ -122,20 +122,24 @@ struct kvm_arch { * should) opt in to this feature if KVM_CAP_ARM_NISV_TO_USER is * supported. */ - bool return_nisv_io_abort_to_user; +#define KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER 0 + /* Memory Tagging Extension enabled for the guest */ +#define KVM_ARCH_FLAG_MTE_ENABLED 1 + /* At least one vCPU has ran in the VM */ +#define KVM_ARCH_FLAG_HAS_RAN_ONCE 2 + unsigned long flags; /* * VM-wide PMU filter, implemented as a bitmap and big enough for * up to 2^10 events (ARMv8.0) or 2^16 events (ARMv8.1+). */ unsigned long *pmu_filter; - unsigned int pmuver; + struct arm_pmu *arm_pmu; + + cpumask_var_t supported_cpus; u8 pfr0_csv2; u8 pfr0_csv3; - - /* Memory Tagging Extension enabled for the guest */ - bool mte_enabled; }; struct kvm_vcpu_fault_info { @@ -171,6 +175,7 @@ enum vcpu_sysreg { PAR_EL1, /* Physical Address Register */ MDSCR_EL1, /* Monitor Debug System Control Register */ MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */ + OSLSR_EL1, /* OS Lock Status Register */ DISR_EL1, /* Deferred Interrupt Status Register */ /* Performance Monitors Registers */ @@ -435,6 +440,7 @@ struct kvm_vcpu_arch { #define KVM_ARM64_DEBUG_STATE_SAVE_SPE (1 << 12) /* Save SPE context if active */ #define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context if active */ #define KVM_ARM64_FP_FOREIGN_FPSTATE (1 << 14) +#define KVM_ARM64_ON_UNSUPPORTED_CPU (1 << 15) /* Physical CPU not in supported_cpus */ #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \ KVM_GUESTDBG_USE_SW_BP | \ @@ -453,6 +459,15 @@ struct kvm_vcpu_arch { #define vcpu_has_ptrauth(vcpu) false #endif +#define vcpu_on_unsupported_cpu(vcpu) \ + ((vcpu)->arch.flags & KVM_ARM64_ON_UNSUPPORTED_CPU) + +#define vcpu_set_on_unsupported_cpu(vcpu) \ + ((vcpu)->arch.flags |= KVM_ARM64_ON_UNSUPPORTED_CPU) + +#define vcpu_clear_on_unsupported_cpu(vcpu) \ + ((vcpu)->arch.flags &= ~KVM_ARM64_ON_UNSUPPORTED_CPU) + #define vcpu_gp_regs(v) (&(v)->arch.ctxt.regs) /* @@ -692,6 +707,12 @@ int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); +extern unsigned int kvm_arm_vmid_bits; +int kvm_arm_vmid_alloc_init(void); +void kvm_arm_vmid_alloc_free(void); +void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid); +void kvm_arm_vmid_clear_active(void); + static inline void kvm_arm_pvtime_vcpu_init(struct kvm_vcpu_arch *vcpu_arch) { vcpu_arch->steal.base = GPA_INVALID; @@ -730,6 +751,10 @@ void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu); void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu); + +#define kvm_vcpu_os_lock_enabled(vcpu) \ + (!!(__vcpu_sys_reg(vcpu, OSLSR_EL1) & SYS_OSLSR_OSLK)) + int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, @@ -791,7 +816,9 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); #define kvm_arm_vcpu_sve_finalized(vcpu) \ ((vcpu)->arch.flags & KVM_ARM64_VCPU_SVE_FINALIZED) -#define kvm_has_mte(kvm) (system_supports_mte() && (kvm)->arch.mte_enabled) +#define kvm_has_mte(kvm) \ + (system_supports_mte() && \ + test_bit(KVM_ARCH_FLAG_MTE_ENABLED, &(kvm)->arch.flags)) #define kvm_vcpu_has_pmu(vcpu) \ (test_bit(KVM_ARM_VCPU_PMU_V3, (vcpu)->arch.features)) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 81839e9a8a24..74735a864eee 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -115,6 +115,7 @@ alternative_cb_end #include <asm/cache.h> #include <asm/cacheflush.h> #include <asm/mmu_context.h> +#include <asm/kvm_host.h> void kvm_update_va_mask(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst); @@ -266,7 +267,8 @@ static __always_inline u64 kvm_get_vttbr(struct kvm_s2_mmu *mmu) u64 cnp = system_supports_cnp() ? VTTBR_CNP_BIT : 0; baddr = mmu->pgd_phys; - vmid_field = (u64)READ_ONCE(vmid->vmid) << VTTBR_VMID_SHIFT; + vmid_field = atomic64_read(&vmid->id) << VTTBR_VMID_SHIFT; + vmid_field &= VTTBR_VMID_MASK(kvm_arm_vmid_bits); return kvm_phys_to_vttbr(baddr) | vmid_field | cnp; } diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index c7ca3a105528..fbf5f8bb9055 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -128,8 +128,16 @@ #define SYS_DBGWVRn_EL1(n) sys_reg(2, 0, 0, n, 6) #define SYS_DBGWCRn_EL1(n) sys_reg(2, 0, 0, n, 7) #define SYS_MDRAR_EL1 sys_reg(2, 0, 1, 0, 0) + #define SYS_OSLAR_EL1 sys_reg(2, 0, 1, 0, 4) +#define SYS_OSLAR_OSLK BIT(0) + #define SYS_OSLSR_EL1 sys_reg(2, 0, 1, 1, 4) +#define SYS_OSLSR_OSLM_MASK (BIT(3) | BIT(0)) +#define SYS_OSLSR_OSLM_NI 0 +#define SYS_OSLSR_OSLM_IMPLEMENTED BIT(3) +#define SYS_OSLSR_OSLK BIT(1) + #define SYS_OSDLR_EL1 sys_reg(2, 0, 1, 3, 4) #define SYS_DBGPRCR_EL1 sys_reg(2, 0, 1, 4, 4) #define SYS_DBGCLAIMSET_EL1 sys_reg(2, 0, 7, 8, 6) diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 323e251ed37b..c1b6ddc02d2f 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -367,6 +367,7 @@ struct kvm_arm_copy_mte_tags { #define KVM_ARM_VCPU_PMU_V3_IRQ 0 #define KVM_ARM_VCPU_PMU_V3_INIT 1 #define KVM_ARM_VCPU_PMU_V3_FILTER 2 +#define KVM_ARM_VCPU_PMU_V3_SET_PMU 3 #define KVM_ARM_VCPU_TIMER_CTRL 1 #define KVM_ARM_VCPU_TIMER_IRQ_VTIMER 0 #define KVM_ARM_VCPU_TIMER_IRQ_PTIMER 1 @@ -418,6 +419,16 @@ struct kvm_arm_copy_mte_tags { #define KVM_PSCI_RET_INVAL PSCI_RET_INVALID_PARAMS #define KVM_PSCI_RET_DENIED PSCI_RET_DENIED +/* arm64-specific kvm_run::system_event flags */ +/* + * Reset caused by a PSCI v1.1 SYSTEM_RESET2 call. + * Valid only when the system event has a type of KVM_SYSTEM_EVENT_RESET. + */ +#define KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2 (1ULL << 0) + +/* run->fail_entry.hardware_entry_failure_reason codes. */ +#define KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED (1ULL << 0) + #endif #endif /* __ARM_KVM_H__ */ diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 5280e098cfb5..47af76e53221 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -348,7 +348,13 @@ static void task_fpsimd_load(void) /* * Ensure FPSIMD/SVE storage in memory for the loaded context is up to - * date with respect to the CPU registers. + * date with respect to the CPU registers. Note carefully that the + * current context is the context last bound to the CPU stored in + * last, if KVM is involved this may be the guest VM context rather + * than the host thread for the VM pointed to by current. This means + * that we must always reference the state storage via last rather + * than via current, other than the TIF_ flags which KVM will + * carefully maintain for us. */ static void fpsimd_save(void) { diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index 55a1ced8eb77..241c86b67d01 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -83,6 +83,9 @@ KVM_NVHE_ALIAS(__hyp_stub_vectors); /* Kernel symbol used by icache_is_vpipt(). */ KVM_NVHE_ALIAS(__icache_flags); +/* VMID bits set by the KVM VMID allocator */ +KVM_NVHE_ALIAS(kvm_arm_vmid_bits); + /* Kernel symbols needed for cpus_have_final/const_caps checks. */ KVM_NVHE_ALIAS(arm64_const_caps_ready); KVM_NVHE_ALIAS(cpu_hwcap_keys); diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 91861fd8b897..261644b1a6bb 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -14,7 +14,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ inject_fault.o va_layout.o handle_exit.o \ guest.o debug.o reset.o sys_regs.o \ vgic-sys-reg-v3.o fpsimd.o pmu.o pkvm.o \ - arch_timer.o trng.o\ + arch_timer.o trng.o vmid.o \ vgic/vgic.o vgic/vgic-init.o \ vgic/vgic-irqfd.o vgic/vgic-v2.o \ vgic/vgic-v3.o vgic/vgic-v4.o \ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 946e401ef6b0..523bc934fe2f 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -53,11 +53,6 @@ static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); unsigned long kvm_arm_hyp_percpu_base[NR_CPUS]; DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); -/* The VMID used in the VTTBR */ -static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); -static u32 kvm_next_vmid; -static DEFINE_SPINLOCK(kvm_vmid_lock); - static bool vgic_present; static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled); @@ -89,7 +84,8 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, switch (cap->cap) { case KVM_CAP_ARM_NISV_TO_USER: r = 0; - kvm->arch.return_nisv_io_abort_to_user = true; + set_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER, + &kvm->arch.flags); break; case KVM_CAP_ARM_MTE: mutex_lock(&kvm->lock); @@ -97,7 +93,7 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r = -EINVAL; } else { r = 0; - kvm->arch.mte_enabled = true; + set_bit(KVM_ARCH_FLAG_MTE_ENABLED, &kvm->arch.flags); } mutex_unlock(&kvm->lock); break; @@ -150,6 +146,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) if (ret) goto out_free_stage2_pgd; + if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL)) + goto out_free_stage2_pgd; + cpumask_copy(kvm->arch.supported_cpus, cpu_possible_mask); + kvm_vgic_early_init(kvm); /* The maximum number of VCPUs is limited by the host's GIC model */ @@ -176,6 +176,7 @@ vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf) void kvm_arch_destroy_vm(struct kvm *kvm) { bitmap_free(kvm->arch.pmu_filter); + free_cpumask_var(kvm->arch.supported_cpus); kvm_vgic_destroy(kvm); @@ -411,6 +412,9 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) if (vcpu_has_ptrauth(vcpu)) vcpu_ptrauth_disable(vcpu); kvm_arch_vcpu_load_debug_state_flags(vcpu); + + if (!cpumask_test_cpu(smp_processor_id(), vcpu->kvm->arch.supported_cpus)) + vcpu_set_on_unsupported_cpu(vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) @@ -422,7 +426,9 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) kvm_timer_vcpu_put(vcpu); kvm_vgic_put(vcpu); kvm_vcpu_pmu_restore_host(vcpu); + kvm_arm_vmid_clear_active(); + vcpu_clear_on_unsupported_cpu(vcpu); vcpu->cpu = -1; } @@ -489,87 +495,6 @@ unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu) } #endif -/* Just ensure a guest exit from a particular CPU */ -static void exit_vm_noop(void *info) -{ -} - -void force_vm_exit(const cpumask_t *mask) -{ - preempt_disable(); - smp_call_function_many(mask, exit_vm_noop, NULL, true); - preempt_enable(); -} - -/** - * need_new_vmid_gen - check that the VMID is still valid - * @vmid: The VMID to check - * - * return true if there is a new generation of VMIDs being used - * - * The hardware supports a limited set of values with the value zero reserved - * for the host, so we check if an assigned value belongs to a previous - * generation, which requires us to assign a new value. If we're the first to - * use a VMID for the new generation, we must flush necessary caches and TLBs - * on all CPUs. - */ -static bool need_new_vmid_gen(struct kvm_vmid *vmid) -{ - u64 current_vmid_gen = atomic64_read(&kvm_vmid_gen); - smp_rmb(); /* Orders read of kvm_vmid_gen and kvm->arch.vmid */ - return unlikely(READ_ONCE(vmid->vmid_gen) != current_vmid_gen); -} - -/** - * update_vmid - Update the vmid with a valid VMID for the current generation - * @vmid: The stage-2 VMID information struct - */ -static void update_vmid(struct kvm_vmid *vmid) -{ - if (!need_new_vmid_gen(vmid)) - return; - - spin_lock(&kvm_vmid_lock); - - /* - * We need to re-check the vmid_gen here to ensure that if another vcpu - * already allocated a valid vmid for this vm, then this vcpu should - * use the same vmid. - */ - if (!need_new_vmid_gen(vmid)) { - spin_unlock(&kvm_vmid_lock); - return; - } - - /* First user of a new VMID generation? */ - if (unlikely(kvm_next_vmid == 0)) { - atomic64_inc(&kvm_vmid_gen); - kvm_next_vmid = 1; - - /* - * On SMP we know no other CPUs can use this CPU's or each - * other's VMID after force_vm_exit returns since the - * kvm_vmid_lock blocks them from reentry to the guest. - */ - force_vm_exit(cpu_all_mask); - /* - * Now broadcast TLB + ICACHE invalidation over the inner - * shareable domain to make sure all data structures are - * clean. - */ - kvm_call_hyp(__kvm_flush_vm_context); - } - - WRITE_ONCE(vmid->vmid, kvm_next_vmid); - kvm_next_vmid++; - kvm_next_vmid &= (1 << kvm_get_vmid_bits()) - 1; - - smp_wmb(); - WRITE_ONCE(vmid->vmid_gen, atomic64_read(&kvm_vmid_gen)); - - spin_unlock(&kvm_vmid_lock); -} - static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu) { return vcpu->arch.target >= 0; @@ -634,6 +559,10 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) if (kvm_vm_is_protected(kvm)) kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu); + mutex_lock(&kvm->lock); + set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags); + mutex_unlock(&kvm->lock); + return ret; } @@ -792,8 +721,15 @@ static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu, int *ret) } } + if (unlikely(vcpu_on_unsupported_cpu(vcpu))) { + run->exit_reason = KVM_EXIT_FAIL_ENTRY; + run->fail_entry.hardware_entry_failure_reason = KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED; + run->fail_entry.cpu = smp_processor_id(); + *ret = 0; + return true; + } + return kvm_request_pending(vcpu) || - need_new_vmid_gen(&vcpu->arch.hw_mmu->vmid) || xfer_to_guest_mode_work_pending(); } @@ -855,8 +791,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) if (!ret) ret = 1; - update_vmid(&vcpu->arch.hw_mmu->vmid); - check_vcpu_requests(vcpu); /* @@ -866,6 +800,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) */ preempt_disable(); + /* + * The VMID allocator only tracks active VMIDs per + * physical CPU, and therefore the VMID allocated may not be + * preserved on VMID roll-over if the task was preempted, + * making a thread's VMID inactive. So we need to call + * kvm_arm_vmid_update() in non-premptible context. + */ + kvm_arm_vmid_update(&vcpu->arch.hw_mmu->vmid); + kvm_pmu_flush_hwstate(vcpu); local_irq_disable(); @@ -945,9 +888,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) * context synchronization event) is necessary to ensure that * pending interrupts are taken. */ - local_irq_enable(); - isb(); - local_irq_disable(); + if (ARM_EXCEPTION_CODE(ret) == ARM_EXCEPTION_IRQ) { + local_irq_enable(); + isb(); + local_irq_disable(); + } guest_timing_exit_irqoff(); @@ -1742,7 +1687,7 @@ static void init_cpu_logical_map(void) /* * Copy the MPIDR <-> logical CPU ID mapping to hyp. - * Only copy the set of online CPUs whose features have been chacked + * Only copy the set of online CPUs whose features have been checked * against the finalized system capabilities. The hypervisor will not * allow any other CPUs from the `possible` set to boot. */ @@ -2159,6 +2104,12 @@ int kvm_arch_init(void *opaque) if (err) return err; + err = kvm_arm_vmid_alloc_init(); + if (err) { + kvm_err("Failed to initialize VMID allocator.\n"); + return err; + } + if (!in_hyp_mode) { err = init_hyp_mode(); if (err) @@ -2198,6 +2149,7 @@ out_hyp: if (!in_hyp_mode) teardown_hyp_mode(); out_err: + kvm_arm_vmid_alloc_free(); return err; } diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index db9361338b2a..4fd5c216c4bb 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -105,9 +105,11 @@ static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu) * - Userspace is using the hardware to debug the guest * (KVM_GUESTDBG_USE_HW is set). * - The guest is not using debug (KVM_ARM64_DEBUG_DIRTY is clear). + * - The guest has enabled the OS Lock (debug exceptions are blocked). */ if ((vcpu->guest_debug & KVM_GUESTDBG_USE_HW) || - !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)) + !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY) || + kvm_vcpu_os_lock_enabled(vcpu)) vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2); @@ -160,8 +162,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) kvm_arm_setup_mdcr_el2(vcpu); - /* Is Guest debugging in effect? */ - if (vcpu->guest_debug) { + /* Check if we need to use the debug registers. */ + if (vcpu->guest_debug || kvm_vcpu_os_lock_enabled(vcpu)) { /* Save guest debug state */ save_guest_debug_regs(vcpu); @@ -223,6 +225,19 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) trace_kvm_arm_set_regset("WAPTS", get_num_wrps(), &vcpu->arch.debug_ptr->dbg_wcr[0], &vcpu->arch.debug_ptr->dbg_wvr[0]); + + /* + * The OS Lock blocks debug exceptions in all ELs when it is + * enabled. If the guest has enabled the OS Lock, constrain its + * effects to the guest. Emulate the behavior by clearing + * MDSCR_EL1.MDE. In so doing, we ensure that host debug + * exceptions are unaffected by guest configuration of the OS + * Lock. + */ + } else if (kvm_vcpu_os_lock_enabled(vcpu)) { + mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1); + mdscr &= ~DBG_MDSCR_MDE; + vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1); } } @@ -244,7 +259,10 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) { trace_kvm_arm_clear_debug(vcpu->guest_debug); - if (vcpu->guest_debug) { + /* + * Restore the guest's debug registers if we were using them. + */ + if (vcpu->guest_debug || kvm_vcpu_os_lock_enabled(vcpu)) { restore_guest_debug_regs(vcpu); /* diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 2f48fd362a8c..397fdac75cb1 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -84,6 +84,11 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED; } +/* + * Called just before entering the guest once we are no longer + * preemptable. Syncs the host's TIF_FOREIGN_FPSTATE with the KVM + * mirror of the flag used by the hypervisor. + */ void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) { if (test_thread_flag(TIF_FOREIGN_FPSTATE)) @@ -93,10 +98,11 @@ void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) } /* - * If the guest FPSIMD state was loaded, update the host's context - * tracking data mark the CPU FPSIMD regs as dirty and belonging to vcpu - * so that they will be written back if the kernel clobbers them due to - * kernel-mode NEON before re-entry into the guest. + * Called just after exiting the guest. If the guest FPSIMD state + * was loaded, update the host's context tracking data mark the CPU + * FPSIMD regs as dirty and belonging to vcpu so that they will be + * written back if the kernel clobbers them due to kernel-mode NEON + * before re-entry into the guest. */ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) { diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index e116c7767730..7e15b03fbdf8 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -282,7 +282,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) break; /* - * Otherwide, this is a priviledged mode, and *all* the + * Otherwise, this is a privileged mode, and *all* the * registers must be narrowed to 32bit. */ default: diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index e3140abd2e2e..97fe14aab1a3 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -248,7 +248,7 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index) case ARM_EXCEPTION_HYP_GONE: /* * EL2 has been reset to the hyp-stub. This happens when a guest - * is pre-empted by kvm_reboot()'s shutdown call. + * is pre-emptied by kvm_reboot()'s shutdown call. */ run->exit_reason = KVM_EXIT_FAIL_ENTRY; return 0; diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 6379a1e3e6e5..5d31f6c64c8c 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -173,6 +173,8 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) return false; /* Valid trap. Switch the context: */ + + /* First disable enough traps to allow us to update the registers */ if (has_vhe()) { reg = CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN; if (sve_guest) @@ -188,11 +190,13 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) } isb(); + /* Write out the host state if it's in the registers */ if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { __fpsimd_save_state(vcpu->arch.host_fpsimd_state); vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; } + /* Restore the guest state */ if (sve_guest) __hyp_sve_restore_guest(vcpu); else diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index 24b2c2425b38..f9fe4dc21b1f 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -13,10 +13,11 @@ lib-objs := clear_page.o copy_page.o memcpy.o memset.o lib-objs := $(addprefix ../../../lib/, $(lib-objs)) obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \ - hyp-main.o hyp-smp.o psci-relay.o early_alloc.o stub.o page_alloc.o \ + hyp-main.o hyp-smp.o psci-relay.o early_alloc.o page_alloc.o \ cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o +obj-$(CONFIG_DEBUG_LIST) += list_debug.o obj-y += $(lib-objs) ## diff --git a/arch/arm64/kvm/hyp/nvhe/list_debug.c b/arch/arm64/kvm/hyp/nvhe/list_debug.c new file mode 100644 index 000000000000..d68abd7ea124 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/list_debug.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 - Google LLC + * Author: Keir Fraser <keirf@google.com> + */ + +#include <linux/list.h> +#include <linux/bug.h> + +static inline __must_check bool nvhe_check_data_corruption(bool v) +{ + return v; +} + +#define NVHE_CHECK_DATA_CORRUPTION(condition) \ + nvhe_check_data_corruption(({ \ + bool corruption = unlikely(condition); \ + if (corruption) { \ + if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \ + BUG_ON(1); \ + } else \ + WARN_ON(1); \ + } \ + corruption; \ + })) + +/* The predicates checked here are taken from lib/list_debug.c. */ + +bool __list_add_valid(struct list_head *new, struct list_head *prev, + struct list_head *next) +{ + if (NVHE_CHECK_DATA_CORRUPTION(next->prev != prev) || + NVHE_CHECK_DATA_CORRUPTION(prev->next != next) || + NVHE_CHECK_DATA_CORRUPTION(new == prev || new == next)) + return false; + + return true; +} + +bool __list_del_entry_valid(struct list_head *entry) +{ + struct list_head *prev, *next; + + prev = entry->prev; + next = entry->next; + + if (NVHE_CHECK_DATA_CORRUPTION(next == LIST_POISON1) || + NVHE_CHECK_DATA_CORRUPTION(prev == LIST_POISON2) || + NVHE_CHECK_DATA_CORRUPTION(prev->next != entry) || + NVHE_CHECK_DATA_CORRUPTION(next->prev != entry)) + return false; + + return true; +} diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 674f10564373..78edf077fa3b 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -138,8 +138,7 @@ int kvm_host_prepare_stage2(void *pgt_pool_base) mmu->pgd_phys = __hyp_pa(host_kvm.pgt.pgd); mmu->pgt = &host_kvm.pgt; - WRITE_ONCE(mmu->vmid.vmid_gen, 0); - WRITE_ONCE(mmu->vmid.vmid, 0); + atomic64_set(&mmu->vmid.id, 0); return 0; } diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c index 543cad6c376a..d40f0b30b534 100644 --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -102,7 +102,7 @@ static void __hyp_attach_page(struct hyp_pool *pool, * Only the first struct hyp_page of a high-order page (otherwise known * as the 'head') should have p->order set. The non-head pages should * have p->order = HYP_NO_ORDER. Here @p may no longer be the head - * after coallescing, so make sure to mark it HYP_NO_ORDER proactively. + * after coalescing, so make sure to mark it HYP_NO_ORDER proactively. */ p->order = HYP_NO_ORDER; for (; (order + 1) < pool->max_order; order++) { @@ -110,7 +110,7 @@ static void __hyp_attach_page(struct hyp_pool *pool, if (!buddy) break; - /* Take the buddy out of its list, and coallesce with @p */ + /* Take the buddy out of its list, and coalesce with @p */ page_remove_from_list(buddy); buddy->order = HYP_NO_ORDER; p = min(p, buddy); diff --git a/arch/arm64/kvm/hyp/nvhe/stub.c b/arch/arm64/kvm/hyp/nvhe/stub.c deleted file mode 100644 index c0aa6bbfd79d..000000000000 --- a/arch/arm64/kvm/hyp/nvhe/stub.c +++ /dev/null @@ -1,22 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Stubs for out-of-line function calls caused by re-using kernel - * infrastructure at EL2. - * - * Copyright (C) 2020 - Google LLC - */ - -#include <linux/list.h> - -#ifdef CONFIG_DEBUG_LIST -bool __list_add_valid(struct list_head *new, struct list_head *prev, - struct list_head *next) -{ - return true; -} - -bool __list_del_entry_valid(struct list_head *entry) -{ - return true; -} -#endif diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index 3e2d8ba11a02..3dd38a151d2a 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -135,7 +135,8 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) * volunteered to do so, and bail out otherwise. */ if (!kvm_vcpu_dabt_isvalid(vcpu)) { - if (vcpu->kvm->arch.return_nisv_io_abort_to_user) { + if (test_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER, + &vcpu->kvm->arch.flags)) { run->exit_reason = KVM_EXIT_ARM_NISV; run->arm_nisv.esr_iss = kvm_vcpu_dabt_iss_nisv_sanitized(vcpu); run->arm_nisv.fault_ipa = fault_ipa; diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index bc2aba953299..0d19259454d8 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -58,7 +58,7 @@ static int stage2_apply_range(struct kvm *kvm, phys_addr_t addr, break; if (resched && next != end) - cond_resched_lock(&kvm->mmu_lock); + cond_resched_rwlock_write(&kvm->mmu_lock); } while (addr = next, addr != end); return ret; @@ -179,7 +179,7 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); phys_addr_t end = start + size; - assert_spin_locked(&kvm->mmu_lock); + lockdep_assert_held_write(&kvm->mmu_lock); WARN_ON(size & ~PAGE_MASK); WARN_ON(stage2_apply_range(kvm, start, end, kvm_pgtable_stage2_unmap, may_block)); @@ -213,13 +213,13 @@ static void stage2_flush_vm(struct kvm *kvm) int idx, bkt; idx = srcu_read_lock(&kvm->srcu); - spin_lock(&kvm->mmu_lock); + write_lock(&kvm->mmu_lock); slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, bkt, slots) stage2_flush_memslot(kvm, memslot); - spin_unlock(&kvm->mmu_lock); + write_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); } @@ -615,7 +615,7 @@ static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = { }; /** - * kvm_init_stage2_mmu - Initialise a S2 MMU strucrure + * kvm_init_stage2_mmu - Initialise a S2 MMU structure * @kvm: The pointer to the KVM structure * @mmu: The pointer to the s2 MMU structure * @@ -653,7 +653,6 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu) mmu->pgt = pgt; mmu->pgd_phys = __pa(pgt->pgd); - WRITE_ONCE(mmu->vmid.vmid_gen, 0); return 0; out_destroy_pgtable: @@ -720,13 +719,13 @@ void stage2_unmap_vm(struct kvm *kvm) idx = srcu_read_lock(&kvm->srcu); mmap_read_lock(current->mm); - spin_lock(&kvm->mmu_lock); + write_lock(&kvm->mmu_lock); slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, bkt, slots) stage2_unmap_memslot(kvm, memslot); - spin_unlock(&kvm->mmu_lock); + write_unlock(&kvm->mmu_lock); mmap_read_unlock(current->mm); srcu_read_unlock(&kvm->srcu, idx); } @@ -736,14 +735,14 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu) struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); struct kvm_pgtable *pgt = NULL; - spin_lock(&kvm->mmu_lock); + write_lock(&kvm->mmu_lock); pgt = mmu->pgt; if (pgt) { mmu->pgd_phys = 0; mmu->pgt = NULL; free_percpu(mmu->last_vcpu_ran); } - spin_unlock(&kvm->mmu_lock); + write_unlock(&kvm->mmu_lock); if (pgt) { kvm_pgtable_stage2_destroy(pgt); @@ -783,10 +782,10 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, if (ret) break; - spin_lock(&kvm->mmu_lock); + write_lock(&kvm->mmu_lock); ret = kvm_pgtable_stage2_map(pgt, addr, PAGE_SIZE, pa, prot, &cache); - spin_unlock(&kvm->mmu_lock); + write_unlock(&kvm->mmu_lock); if (ret) break; @@ -834,9 +833,9 @@ static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot) start = memslot->base_gfn << PAGE_SHIFT; end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; - spin_lock(&kvm->mmu_lock); + write_lock(&kvm->mmu_lock); stage2_wp_range(&kvm->arch.mmu, start, end); - spin_unlock(&kvm->mmu_lock); + write_unlock(&kvm->mmu_lock); kvm_flush_remote_tlbs(kvm); } @@ -1080,6 +1079,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, gfn_t gfn; kvm_pfn_t pfn; bool logging_active = memslot_is_logging(memslot); + bool logging_perm_fault = false; unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu); unsigned long vma_pagesize, fault_granule; enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R; @@ -1114,6 +1114,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (logging_active) { force_pte = true; vma_shift = PAGE_SHIFT; + logging_perm_fault = (fault_status == FSC_PERM && write_fault); } else { vma_shift = get_vma_page_shift(vma, hva); } @@ -1212,7 +1213,15 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault && device) return -ENOEXEC; - spin_lock(&kvm->mmu_lock); + /* + * To reduce MMU contentions and enhance concurrency during dirty + * logging dirty logging, only acquire read lock for permission + * relaxation. + */ + if (logging_perm_fault) + read_lock(&kvm->mmu_lock); + else + write_lock(&kvm->mmu_lock); pgt = vcpu->arch.hw_mmu->pgt; if (mmu_notifier_retry(kvm, mmu_seq)) goto out_unlock; @@ -1271,7 +1280,10 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, } out_unlock: - spin_unlock(&kvm->mmu_lock); + if (logging_perm_fault) + read_unlock(&kvm->mmu_lock); + else + write_unlock(&kvm->mmu_lock); kvm_set_pfn_accessed(pfn); kvm_release_pfn_clean(pfn); return ret != -EAGAIN ? ret : 0; @@ -1286,10 +1298,10 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) trace_kvm_access_fault(fault_ipa); - spin_lock(&vcpu->kvm->mmu_lock); + write_lock(&vcpu->kvm->mmu_lock); mmu = vcpu->arch.hw_mmu; kpte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa); - spin_unlock(&vcpu->kvm->mmu_lock); + write_unlock(&vcpu->kvm->mmu_lock); pte = __pte(kpte); if (pte_valid(pte)) @@ -1692,9 +1704,9 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, gpa_t gpa = slot->base_gfn << PAGE_SHIFT; phys_addr_t size = slot->npages << PAGE_SHIFT; - spin_lock(&kvm->mmu_lock); + write_lock(&kvm->mmu_lock); unmap_stage2_range(&kvm->arch.mmu, gpa, size); - spin_unlock(&kvm->mmu_lock); + write_unlock(&kvm->mmu_lock); } /* diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index fbcfd4ec6f92..78fdc443adc7 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -7,6 +7,7 @@ #include <linux/cpu.h> #include <linux/kvm.h> #include <linux/kvm_host.h> +#include <linux/list.h> #include <linux/perf_event.h> #include <linux/perf/arm_pmu.h> #include <linux/uaccess.h> @@ -16,6 +17,9 @@ DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available); +static LIST_HEAD(arm_pmus); +static DEFINE_MUTEX(arm_pmus_lock); + static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx); static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx); static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc); @@ -24,7 +28,11 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc); static u32 kvm_pmu_event_mask(struct kvm *kvm) { - switch (kvm->arch.pmuver) { + unsigned int pmuver; + + pmuver = kvm->arch.arm_pmu->pmuver; + + switch (pmuver) { case ID_AA64DFR0_PMUVER_8_0: return GENMASK(9, 0); case ID_AA64DFR0_PMUVER_8_1: @@ -33,7 +41,7 @@ static u32 kvm_pmu_event_mask(struct kvm *kvm) case ID_AA64DFR0_PMUVER_8_7: return GENMASK(15, 0); default: /* Shouldn't be here, just for sanity */ - WARN_ONCE(1, "Unknown PMU version %d\n", kvm->arch.pmuver); + WARN_ONCE(1, "Unknown PMU version %d\n", pmuver); return 0; } } @@ -600,6 +608,7 @@ static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) */ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) { + struct arm_pmu *arm_pmu = vcpu->kvm->arch.arm_pmu; struct kvm_pmu *pmu = &vcpu->arch.pmu; struct kvm_pmc *pmc; struct perf_event *event; @@ -636,7 +645,7 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) return; memset(&attr, 0, sizeof(struct perf_event_attr)); - attr.type = PERF_TYPE_RAW; + attr.type = arm_pmu->pmu.type; attr.size = sizeof(attr); attr.pinned = 1; attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, pmc->idx); @@ -745,17 +754,33 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, void kvm_host_pmu_init(struct arm_pmu *pmu) { - if (pmu->pmuver != 0 && pmu->pmuver != ID_AA64DFR0_PMUVER_IMP_DEF && - !kvm_arm_support_pmu_v3() && !is_protected_kvm_enabled()) + struct arm_pmu_entry *entry; + + if (pmu->pmuver == 0 || pmu->pmuver == ID_AA64DFR0_PMUVER_IMP_DEF || + is_protected_kvm_enabled()) + return; + + mutex_lock(&arm_pmus_lock); + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + goto out_unlock; + + entry->arm_pmu = pmu; + list_add_tail(&entry->entry, &arm_pmus); + + if (list_is_singular(&arm_pmus)) static_branch_enable(&kvm_arm_pmu_available); + +out_unlock: + mutex_unlock(&arm_pmus_lock); } -static int kvm_pmu_probe_pmuver(void) +static struct arm_pmu *kvm_pmu_probe_armpmu(void) { struct perf_event_attr attr = { }; struct perf_event *event; - struct arm_pmu *pmu; - int pmuver = ID_AA64DFR0_PMUVER_IMP_DEF; + struct arm_pmu *pmu = NULL; /* * Create a dummy event that only counts user cycles. As we'll never @@ -780,19 +805,20 @@ static int kvm_pmu_probe_pmuver(void) if (IS_ERR(event)) { pr_err_once("kvm: pmu event creation failed %ld\n", PTR_ERR(event)); - return ID_AA64DFR0_PMUVER_IMP_DEF; + return NULL; } if (event->pmu) { pmu = to_arm_pmu(event->pmu); - if (pmu->pmuver) - pmuver = pmu->pmuver; + if (pmu->pmuver == 0 || + pmu->pmuver == ID_AA64DFR0_PMUVER_IMP_DEF) + pmu = NULL; } perf_event_disable(event); perf_event_release_kernel(event); - return pmuver; + return pmu; } u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) @@ -810,7 +836,7 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) * Don't advertise STALL_SLOT, as PMMIR_EL0 is handled * as RAZ */ - if (vcpu->kvm->arch.pmuver >= ID_AA64DFR0_PMUVER_8_4) + if (vcpu->kvm->arch.arm_pmu->pmuver >= ID_AA64DFR0_PMUVER_8_4) val &= ~BIT_ULL(ARMV8_PMUV3_PERFCTR_STALL_SLOT - 32); base = 32; } @@ -922,26 +948,64 @@ static bool pmu_irq_is_valid(struct kvm *kvm, int irq) return true; } +static int kvm_arm_pmu_v3_set_pmu(struct kvm_vcpu *vcpu, int pmu_id) +{ + struct kvm *kvm = vcpu->kvm; + struct arm_pmu_entry *entry; + struct arm_pmu *arm_pmu; + int ret = -ENXIO; + + mutex_lock(&kvm->lock); + mutex_lock(&arm_pmus_lock); + + list_for_each_entry(entry, &arm_pmus, entry) { + arm_pmu = entry->arm_pmu; + if (arm_pmu->pmu.type == pmu_id) { + if (test_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags) || + (kvm->arch.pmu_filter && kvm->arch.arm_pmu != arm_pmu)) { + ret = -EBUSY; + break; + } + + kvm->arch.arm_pmu = arm_pmu; + cpumask_copy(kvm->arch.supported_cpus, &arm_pmu->supported_cpus); + ret = 0; + break; + } + } + + mutex_unlock(&arm_pmus_lock); + mutex_unlock(&kvm->lock); + return ret; +} + int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { + struct kvm *kvm = vcpu->kvm; + if (!kvm_vcpu_has_pmu(vcpu)) return -ENODEV; if (vcpu->arch.pmu.created) return -EBUSY; - if (!vcpu->kvm->arch.pmuver) - vcpu->kvm->arch.pmuver = kvm_pmu_probe_pmuver(); - - if (vcpu->kvm->arch.pmuver == ID_AA64DFR0_PMUVER_IMP_DEF) - return -ENODEV; + mutex_lock(&kvm->lock); + if (!kvm->arch.arm_pmu) { + /* No PMU set, get the default one */ + kvm->arch.arm_pmu = kvm_pmu_probe_armpmu(); + if (!kvm->arch.arm_pmu) { + mutex_unlock(&kvm->lock); + return -ENODEV; + } + } + mutex_unlock(&kvm->lock); switch (attr->attr) { case KVM_ARM_VCPU_PMU_V3_IRQ: { int __user *uaddr = (int __user *)(long)attr->addr; int irq; - if (!irqchip_in_kernel(vcpu->kvm)) + if (!irqchip_in_kernel(kvm)) return -EINVAL; if (get_user(irq, uaddr)) @@ -951,7 +1015,7 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) if (!(irq_is_ppi(irq) || irq_is_spi(irq))) return -EINVAL; - if (!pmu_irq_is_valid(vcpu->kvm, irq)) + if (!pmu_irq_is_valid(kvm, irq)) return -EINVAL; if (kvm_arm_pmu_irq_initialized(vcpu)) @@ -966,7 +1030,7 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) struct kvm_pmu_event_filter filter; int nr_events; - nr_events = kvm_pmu_event_mask(vcpu->kvm) + 1; + nr_events = kvm_pmu_event_mask(kvm) + 1; uaddr = (struct kvm_pmu_event_filter __user *)(long)attr->addr; @@ -978,12 +1042,17 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) filter.action != KVM_PMU_EVENT_DENY)) return -EINVAL; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&kvm->lock); - if (!vcpu->kvm->arch.pmu_filter) { - vcpu->kvm->arch.pmu_filter = bitmap_alloc(nr_events, GFP_KERNEL_ACCOUNT); - if (!vcpu->kvm->arch.pmu_filter) { - mutex_unlock(&vcpu->kvm->lock); + if (test_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags)) { + mutex_unlock(&kvm->lock); + return -EBUSY; + } + + if (!kvm->arch.pmu_filter) { + kvm->arch.pmu_filter = bitmap_alloc(nr_events, GFP_KERNEL_ACCOUNT); + if (!kvm->arch.pmu_filter) { + mutex_unlock(&kvm->lock); return -ENOMEM; } @@ -994,20 +1063,29 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) * events, the default is to allow. */ if (filter.action == KVM_PMU_EVENT_ALLOW) - bitmap_zero(vcpu->kvm->arch.pmu_filter, nr_events); + bitmap_zero(kvm->arch.pmu_filter, nr_events); else - bitmap_fill(vcpu->kvm->arch.pmu_filter, nr_events); + bitmap_fill(kvm->arch.pmu_filter, nr_events); } if (filter.action == KVM_PMU_EVENT_ALLOW) - bitmap_set(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents); + bitmap_set(kvm->arch.pmu_filter, filter.base_event, filter.nevents); else - bitmap_clear(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents); + bitmap_clear(kvm->arch.pmu_filter, filter.base_event, filter.nevents); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&kvm->lock); return 0; } + case KVM_ARM_VCPU_PMU_V3_SET_PMU: { + int __user *uaddr = (int __user *)(long)attr->addr; + int pmu_id; + + if (get_user(pmu_id, uaddr)) + return -EFAULT; + + return kvm_arm_pmu_v3_set_pmu(vcpu, pmu_id); + } case KVM_ARM_VCPU_PMU_V3_INIT: return kvm_arm_pmu_v3_init(vcpu); } @@ -1045,6 +1123,7 @@ int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) case KVM_ARM_VCPU_PMU_V3_IRQ: case KVM_ARM_VCPU_PMU_V3_INIT: case KVM_ARM_VCPU_PMU_V3_FILTER: + case KVM_ARM_VCPU_PMU_V3_SET_PMU: if (kvm_vcpu_has_pmu(vcpu)) return 0; } diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 5918095c90a5..372da09a2fab 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -84,7 +84,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) if (!vcpu) return PSCI_RET_INVALID_PARAMS; if (!vcpu->arch.power_off) { - if (kvm_psci_version(source_vcpu, kvm) != KVM_ARM_PSCI_0_1) + if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) return PSCI_RET_ALREADY_ON; else return PSCI_RET_INVALID_PARAMS; @@ -161,7 +161,7 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) return PSCI_0_2_AFFINITY_LEVEL_OFF; } -static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) +static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type, u64 flags) { unsigned long i; struct kvm_vcpu *tmp; @@ -181,17 +181,24 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); vcpu->run->system_event.type = type; + vcpu->run->system_event.flags = flags; vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; } static void kvm_psci_system_off(struct kvm_vcpu *vcpu) { - kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN); + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN, 0); } static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) { - kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET); + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET, 0); +} + +static void kvm_psci_system_reset2(struct kvm_vcpu *vcpu) +{ + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET, + KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2); } static void kvm_psci_narrow_to_32bit(struct kvm_vcpu *vcpu) @@ -304,24 +311,27 @@ out: return ret; } -static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu) +static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) { u32 psci_fn = smccc_get_function(vcpu); - u32 feature; + u32 arg; unsigned long val; int ret = 1; + if (minor > 1) + return -EINVAL; + switch(psci_fn) { case PSCI_0_2_FN_PSCI_VERSION: - val = KVM_ARM_PSCI_1_0; + val = minor == 0 ? KVM_ARM_PSCI_1_0 : KVM_ARM_PSCI_1_1; break; case PSCI_1_0_FN_PSCI_FEATURES: - feature = smccc_get_arg1(vcpu); - val = kvm_psci_check_allowed_function(vcpu, feature); + arg = smccc_get_arg1(vcpu); + val = kvm_psci_check_allowed_function(vcpu, arg); if (val) break; - switch(feature) { + switch(arg) { case PSCI_0_2_FN_PSCI_VERSION: case PSCI_0_2_FN_CPU_SUSPEND: case PSCI_0_2_FN64_CPU_SUSPEND: @@ -337,11 +347,36 @@ static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu) case ARM_SMCCC_VERSION_FUNC_ID: val = 0; break; + case PSCI_1_1_FN_SYSTEM_RESET2: + case PSCI_1_1_FN64_SYSTEM_RESET2: + if (minor >= 1) { + val = 0; + break; + } + fallthrough; default: val = PSCI_RET_NOT_SUPPORTED; break; } break; + case PSCI_1_1_FN_SYSTEM_RESET2: + kvm_psci_narrow_to_32bit(vcpu); + fallthrough; + case PSCI_1_1_FN64_SYSTEM_RESET2: + if (minor >= 1) { + arg = smccc_get_arg1(vcpu); + + if (arg <= PSCI_1_1_RESET_TYPE_SYSTEM_WARM_RESET || + arg >= PSCI_1_1_RESET_TYPE_VENDOR_START) { + kvm_psci_system_reset2(vcpu); + vcpu_set_reg(vcpu, 0, PSCI_RET_INTERNAL_FAILURE); + return 0; + } + + val = PSCI_RET_INVALID_PARAMS; + break; + } + fallthrough; default: return kvm_psci_0_2_call(vcpu); } @@ -391,16 +426,18 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) */ int kvm_psci_call(struct kvm_vcpu *vcpu) { - switch (kvm_psci_version(vcpu, vcpu->kvm)) { + switch (kvm_psci_version(vcpu)) { + case KVM_ARM_PSCI_1_1: + return kvm_psci_1_x_call(vcpu, 1); case KVM_ARM_PSCI_1_0: - return kvm_psci_1_0_call(vcpu); + return kvm_psci_1_x_call(vcpu, 0); case KVM_ARM_PSCI_0_2: return kvm_psci_0_2_call(vcpu); case KVM_ARM_PSCI_0_1: return kvm_psci_0_1_call(vcpu); default: return -EINVAL; - }; + } } int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu) @@ -484,7 +521,7 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) switch (reg->id) { case KVM_REG_ARM_PSCI_VERSION: - val = kvm_psci_version(vcpu, vcpu->kvm); + val = kvm_psci_version(vcpu); break; case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2: @@ -525,6 +562,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) return 0; case KVM_ARM_PSCI_0_2: case KVM_ARM_PSCI_1_0: + case KVM_ARM_PSCI_1_1: if (!wants_02) return -EINVAL; vcpu->kvm->arch.psci_version = val; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index baa65292bbc2..7b45c040cc27 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -44,6 +44,10 @@ * 64bit interface. */ +static int reg_from_user(u64 *val, const void __user *uaddr, u64 id); +static int reg_to_user(void __user *uaddr, const u64 *val, u64 id); +static u64 sys_reg_to_index(const struct sys_reg_desc *reg); + static bool read_from_write_only(struct kvm_vcpu *vcpu, struct sys_reg_params *params, const struct sys_reg_desc *r) @@ -287,16 +291,55 @@ static bool trap_loregion(struct kvm_vcpu *vcpu, return trap_raz_wi(vcpu, p, r); } +static bool trap_oslar_el1(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 oslsr; + + if (!p->is_write) + return read_from_write_only(vcpu, p, r); + + /* Forward the OSLK bit to OSLSR */ + oslsr = __vcpu_sys_reg(vcpu, OSLSR_EL1) & ~SYS_OSLSR_OSLK; + if (p->regval & SYS_OSLAR_OSLK) + oslsr |= SYS_OSLSR_OSLK; + + __vcpu_sys_reg(vcpu, OSLSR_EL1) = oslsr; + return true; +} + static bool trap_oslsr_el1(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - if (p->is_write) { - return ignore_write(vcpu, p); - } else { - p->regval = (1 << 3); - return true; - } + if (p->is_write) + return write_to_read_only(vcpu, p, r); + + p->regval = __vcpu_sys_reg(vcpu, r->reg); + return true; +} + +static int set_oslsr_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, + const struct kvm_one_reg *reg, void __user *uaddr) +{ + u64 id = sys_reg_to_index(rd); + u64 val; + int err; + + err = reg_from_user(&val, uaddr, id); + if (err) + return err; + + /* + * The only modifiable bit is the OSLK bit. Refuse the write if + * userspace attempts to change any other bit in the register. + */ + if ((val ^ rd->val) & ~SYS_OSLSR_OSLK) + return -EINVAL; + + __vcpu_sys_reg(vcpu, rd->reg) = val; + return 0; } static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu, @@ -1169,10 +1212,6 @@ static bool access_raz_id_reg(struct kvm_vcpu *vcpu, return __access_id_reg(vcpu, p, r, true); } -static int reg_from_user(u64 *val, const void __user *uaddr, u64 id); -static int reg_to_user(void __user *uaddr, const u64 *val, u64 id); -static u64 sys_reg_to_index(const struct sys_reg_desc *reg); - /* Visibility overrides for SVE-specific control registers */ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) @@ -1423,9 +1462,9 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu, * Debug handling: We do trap most, if not all debug related system * registers. The implementation is good enough to ensure that a guest * can use these with minimal performance degradation. The drawback is - * that we don't implement any of the external debug, none of the - * OSlock protocol. This should be revisited if we ever encounter a - * more demanding guest... + * that we don't implement any of the external debug architecture. + * This should be revisited if we ever encounter a more demanding + * guest... */ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_DC_ISW), access_dcsw }, @@ -1452,8 +1491,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { DBG_BCR_BVR_WCR_WVR_EL1(15), { SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi }, - { SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi }, - { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1 }, + { SYS_DESC(SYS_OSLAR_EL1), trap_oslar_el1 }, + { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1, reset_val, OSLSR_EL1, + SYS_OSLSR_OSLM_IMPLEMENTED, .set_user = set_oslsr_el1, }, { SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi }, { SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi }, { SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi }, @@ -1925,10 +1965,10 @@ static const struct sys_reg_desc cp14_regs[] = { DBGBXVR(0), /* DBGOSLAR */ - { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi }, + { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_oslar_el1 }, DBGBXVR(1), /* DBGOSLSR */ - { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 }, + { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1, NULL, OSLSR_EL1 }, DBGBXVR(2), DBGBXVR(3), /* DBGOSDLR */ diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 9b98876a8a93..d97e6080b421 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -37,7 +37,7 @@ struct vgic_global kvm_vgic_global_state __ro_after_init = { * If you need to take multiple locks, always take the upper lock first, * then the lower ones, e.g. first take the its_lock, then the irq_lock. * If you are already holding a lock and need to take a higher one, you - * have to drop the lower ranking lock first and re-aquire it after having + * have to drop the lower ranking lock first and re-acquire it after having * taken the upper one. * * When taking more than one ap_list_lock at the same time, always take the diff --git a/arch/arm64/kvm/vmid.c b/arch/arm64/kvm/vmid.c new file mode 100644 index 000000000000..8d5f0506fd87 --- /dev/null +++ b/arch/arm64/kvm/vmid.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * VMID allocator. + * + * Based on Arm64 ASID allocator algorithm. + * Please refer arch/arm64/mm/context.c for detailed + * comments on algorithm. + * + * Copyright (C) 2002-2003 Deep Blue Solutions Ltd, all rights reserved. + * Copyright (C) 2012 ARM Ltd. + */ + +#include <linux/bitfield.h> +#include <linux/bitops.h> + +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> + +unsigned int kvm_arm_vmid_bits; +static DEFINE_RAW_SPINLOCK(cpu_vmid_lock); + +static atomic64_t vmid_generation; +static unsigned long *vmid_map; + +static DEFINE_PER_CPU(atomic64_t, active_vmids); +static DEFINE_PER_CPU(u64, reserved_vmids); + +#define VMID_MASK (~GENMASK(kvm_arm_vmid_bits - 1, 0)) +#define VMID_FIRST_VERSION (1UL << kvm_arm_vmid_bits) + +#define NUM_USER_VMIDS VMID_FIRST_VERSION +#define vmid2idx(vmid) ((vmid) & ~VMID_MASK) +#define idx2vmid(idx) vmid2idx(idx) + +/* + * As vmid #0 is always reserved, we will never allocate one + * as below and can be treated as invalid. This is used to + * set the active_vmids on vCPU schedule out. + */ +#define VMID_ACTIVE_INVALID VMID_FIRST_VERSION + +#define vmid_gen_match(vmid) \ + (!(((vmid) ^ atomic64_read(&vmid_generation)) >> kvm_arm_vmid_bits)) + +static void flush_context(void) +{ + int cpu; + u64 vmid; + + bitmap_clear(vmid_map, 0, NUM_USER_VMIDS); + + for_each_possible_cpu(cpu) { + vmid = atomic64_xchg_relaxed(&per_cpu(active_vmids, cpu), 0); + + /* Preserve reserved VMID */ + if (vmid == 0) + vmid = per_cpu(reserved_vmids, cpu); + __set_bit(vmid2idx(vmid), vmid_map); + per_cpu(reserved_vmids, cpu) = vmid; + } + + /* + * Unlike ASID allocator, we expect less frequent rollover in + * case of VMIDs. Hence, instead of marking the CPU as + * flush_pending and issuing a local context invalidation on + * the next context-switch, we broadcast TLB flush + I-cache + * invalidation over the inner shareable domain on rollover. + */ + kvm_call_hyp(__kvm_flush_vm_context); +} + +static bool check_update_reserved_vmid(u64 vmid, u64 newvmid) +{ + int cpu; + bool hit = false; + + /* + * Iterate over the set of reserved VMIDs looking for a match + * and update to use newvmid (i.e. the same VMID in the current + * generation). + */ + for_each_possible_cpu(cpu) { + if (per_cpu(reserved_vmids, cpu) == vmid) { + hit = true; + per_cpu(reserved_vmids, cpu) = newvmid; + } + } + + return hit; +} + +static u64 new_vmid(struct kvm_vmid *kvm_vmid) +{ + static u32 cur_idx = 1; + u64 vmid = atomic64_read(&kvm_vmid->id); + u64 generation = atomic64_read(&vmid_generation); + + if (vmid != 0) { + u64 newvmid = generation | (vmid & ~VMID_MASK); + + if (check_update_reserved_vmid(vmid, newvmid)) { + atomic64_set(&kvm_vmid->id, newvmid); + return newvmid; + } + + if (!__test_and_set_bit(vmid2idx(vmid), vmid_map)) { + atomic64_set(&kvm_vmid->id, newvmid); + return newvmid; + } + } + + vmid = find_next_zero_bit(vmid_map, NUM_USER_VMIDS, cur_idx); + if (vmid != NUM_USER_VMIDS) + goto set_vmid; + + /* We're out of VMIDs, so increment the global generation count */ + generation = atomic64_add_return_relaxed(VMID_FIRST_VERSION, + &vmid_generation); + flush_context(); + + /* We have more VMIDs than CPUs, so this will always succeed */ + vmid = find_next_zero_bit(vmid_map, NUM_USER_VMIDS, 1); + +set_vmid: + __set_bit(vmid, vmid_map); + cur_idx = vmid; + vmid = idx2vmid(vmid) | generation; + atomic64_set(&kvm_vmid->id, vmid); + return vmid; +} + +/* Called from vCPU sched out with preemption disabled */ +void kvm_arm_vmid_clear_active(void) +{ + atomic64_set(this_cpu_ptr(&active_vmids), VMID_ACTIVE_INVALID); +} + +void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid) +{ + unsigned long flags; + u64 vmid, old_active_vmid; + + vmid = atomic64_read(&kvm_vmid->id); + + /* + * Please refer comments in check_and_switch_context() in + * arch/arm64/mm/context.c. + * + * Unlike ASID allocator, we set the active_vmids to + * VMID_ACTIVE_INVALID on vCPU schedule out to avoid + * reserving the VMID space needlessly on rollover. + * Hence explicitly check here for a "!= 0" to + * handle the sync with a concurrent rollover. + */ + old_active_vmid = atomic64_read(this_cpu_ptr(&active_vmids)); + if (old_active_vmid != 0 && vmid_gen_match(vmid) && + 0 != atomic64_cmpxchg_relaxed(this_cpu_ptr(&active_vmids), + old_active_vmid, vmid)) + return; + + raw_spin_lock_irqsave(&cpu_vmid_lock, flags); + + /* Check that our VMID belongs to the current generation. */ + vmid = atomic64_read(&kvm_vmid->id); + if (!vmid_gen_match(vmid)) + vmid = new_vmid(kvm_vmid); + + atomic64_set(this_cpu_ptr(&active_vmids), vmid); + raw_spin_unlock_irqrestore(&cpu_vmid_lock, flags); +} + +/* + * Initialize the VMID allocator + */ +int kvm_arm_vmid_alloc_init(void) +{ + kvm_arm_vmid_bits = kvm_get_vmid_bits(); + + /* + * Expect allocation after rollover to fail if we don't have + * at least one more VMID than CPUs. VMID #0 is always reserved. + */ + WARN_ON(NUM_USER_VMIDS - 1 <= num_possible_cpus()); + atomic64_set(&vmid_generation, VMID_FIRST_VERSION); + vmid_map = kcalloc(BITS_TO_LONGS(NUM_USER_VMIDS), + sizeof(*vmid_map), GFP_KERNEL); + if (!vmid_map) + return -ENOMEM; + + return 0; +} + +void kvm_arm_vmid_alloc_free(void) +{ + kfree(vmid_map); +} |