diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 1fea13a0857e5358d265b7e2c3b3368e658fb302..47aeed22e2adef5069860472ce6791c9c07333af 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -71,9 +71,7 @@ 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 { diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 81839e9a8a242be1b228c6f617c0d92bc8bb7ec1..74735a864eeeccbfb2ee46a3d450015a587131d8 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 #include #include +#include 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/kvm/Makefile b/arch/arm64/kvm/Makefile index 91861fd8b897cb7f48494c88a5c2327a573e3650..261644b1a6bb44f3e56a3e9a12843212160c3497 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 ecc5958e27fe2b3fc69b9b1121a626495cb13c46..be2fd84d526b233afa1bdacfb5b344ac6a8fdedc 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); @@ -489,87 +484,6 @@ 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; @@ -793,7 +707,6 @@ static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu, int *ret) } return kvm_request_pending(vcpu) || - need_new_vmid_gen(&vcpu->arch.hw_mmu->vmid) || xfer_to_guest_mode_work_pending(); } @@ -855,8 +768,6 @@ 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 +777,15 @@ 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(); @@ -2161,6 +2081,12 @@ 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) @@ -2200,6 +2126,7 @@ int kvm_arch_init(void *opaque) if (!in_hyp_mode) teardown_hyp_mode(); out_err: + kvm_arm_vmid_alloc_free(); return err; } diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 674f10564373e4a1230b0bfa0a7c04f7c6d1372c..78edf077fa3b61e9d99bcba88b8e370b8dd09bd3 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/mmu.c b/arch/arm64/kvm/mmu.c index bc2aba9532994379daf94451f23658d662269ab8..cde9166edbefb682a5e804ea47411a0b792bd4d3 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -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: