diff options
Diffstat (limited to 'arch/riscv/kvm/tlb.c')
| -rw-r--r-- | arch/riscv/kvm/tlb.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/arch/riscv/kvm/tlb.c b/arch/riscv/kvm/tlb.c new file mode 100644 index 000000000000..1a76d0b1907d --- /dev/null +++ b/arch/riscv/kvm/tlb.c @@ -0,0 +1,461 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2022 Ventana Micro Systems Inc. + */ + +#include <linux/bitmap.h> +#include <linux/cpumask.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/smp.h> +#include <linux/kvm_host.h> +#include <asm/cacheflush.h> +#include <asm/csr.h> + +/* + * Instruction encoding of hfence.gvma is: + * HFENCE.GVMA rs1, rs2 + * HFENCE.GVMA zero, rs2 + * HFENCE.GVMA rs1 + * HFENCE.GVMA + * + * rs1!=zero and rs2!=zero ==> HFENCE.GVMA rs1, rs2 + * rs1==zero and rs2!=zero ==> HFENCE.GVMA zero, rs2 + * rs1!=zero and rs2==zero ==> HFENCE.GVMA rs1 + * rs1==zero and rs2==zero ==> HFENCE.GVMA + * + * Instruction encoding of HFENCE.GVMA is: + * 0110001 rs2(5) rs1(5) 000 00000 1110011 + */ + +void kvm_riscv_local_hfence_gvma_vmid_gpa(unsigned long vmid, + gpa_t gpa, gpa_t gpsz, + unsigned long order) +{ + gpa_t pos; + + if (PTRS_PER_PTE < (gpsz >> order)) { + kvm_riscv_local_hfence_gvma_vmid_all(vmid); + return; + } + + for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order)) { + /* + * rs1 = a0 (GPA >> 2) + * rs2 = a1 (VMID) + * HFENCE.GVMA a0, a1 + * 0110001 01011 01010 000 00000 1110011 + */ + asm volatile ("srli a0, %0, 2\n" + "add a1, %1, zero\n" + ".word 0x62b50073\n" + :: "r" (pos), "r" (vmid) + : "a0", "a1", "memory"); + } +} + +void kvm_riscv_local_hfence_gvma_vmid_all(unsigned long vmid) +{ + /* + * rs1 = zero + * rs2 = a0 (VMID) + * HFENCE.GVMA zero, a0 + * 0110001 01010 00000 000 00000 1110011 + */ + asm volatile ("add a0, %0, zero\n" + ".word 0x62a00073\n" + :: "r" (vmid) : "a0", "memory"); +} + +void kvm_riscv_local_hfence_gvma_gpa(gpa_t gpa, gpa_t gpsz, + unsigned long order) +{ + gpa_t pos; + + if (PTRS_PER_PTE < (gpsz >> order)) { + kvm_riscv_local_hfence_gvma_all(); + return; + } + + for (pos = gpa; pos < (gpa + gpsz); pos += BIT(order)) { + /* + * rs1 = a0 (GPA >> 2) + * rs2 = zero + * HFENCE.GVMA a0 + * 0110001 00000 01010 000 00000 1110011 + */ + asm volatile ("srli a0, %0, 2\n" + ".word 0x62050073\n" + :: "r" (pos) : "a0", "memory"); + } +} + +void kvm_riscv_local_hfence_gvma_all(void) +{ + /* + * rs1 = zero + * rs2 = zero + * HFENCE.GVMA + * 0110001 00000 00000 000 00000 1110011 + */ + asm volatile (".word 0x62000073" ::: "memory"); +} + +/* + * Instruction encoding of hfence.gvma is: + * HFENCE.VVMA rs1, rs2 + * HFENCE.VVMA zero, rs2 + * HFENCE.VVMA rs1 + * HFENCE.VVMA + * + * rs1!=zero and rs2!=zero ==> HFENCE.VVMA rs1, rs2 + * rs1==zero and rs2!=zero ==> HFENCE.VVMA zero, rs2 + * rs1!=zero and rs2==zero ==> HFENCE.VVMA rs1 + * rs1==zero and rs2==zero ==> HFENCE.VVMA + * + * Instruction encoding of HFENCE.VVMA is: + * 0010001 rs2(5) rs1(5) 000 00000 1110011 + */ + +void kvm_riscv_local_hfence_vvma_asid_gva(unsigned long vmid, + unsigned long asid, + unsigned long gva, + unsigned long gvsz, + unsigned long order) +{ + unsigned long pos, hgatp; + + if (PTRS_PER_PTE < (gvsz >> order)) { + kvm_riscv_local_hfence_vvma_asid_all(vmid, asid); + return; + } + + hgatp = csr_swap(CSR_HGATP, vmid << HGATP_VMID_SHIFT); + + for (pos = gva; pos < (gva + gvsz); pos += BIT(order)) { + /* + * rs1 = a0 (GVA) + * rs2 = a1 (ASID) + * HFENCE.VVMA a0, a1 + * 0010001 01011 01010 000 00000 1110011 + */ + asm volatile ("add a0, %0, zero\n" + "add a1, %1, zero\n" + ".word 0x22b50073\n" + :: "r" (pos), "r" (asid) + : "a0", "a1", "memory"); + } + + csr_write(CSR_HGATP, hgatp); +} + +void kvm_riscv_local_hfence_vvma_asid_all(unsigned long vmid, + unsigned long asid) +{ + unsigned long hgatp; + + hgatp = csr_swap(CSR_HGATP, vmid << HGATP_VMID_SHIFT); + + /* + * rs1 = zero + * rs2 = a0 (ASID) + * HFENCE.VVMA zero, a0 + * 0010001 01010 00000 000 00000 1110011 + */ + asm volatile ("add a0, %0, zero\n" + ".word 0x22a00073\n" + :: "r" (asid) : "a0", "memory"); + + csr_write(CSR_HGATP, hgatp); +} + +void kvm_riscv_local_hfence_vvma_gva(unsigned long vmid, + unsigned long gva, unsigned long gvsz, + unsigned long order) +{ + unsigned long pos, hgatp; + + if (PTRS_PER_PTE < (gvsz >> order)) { + kvm_riscv_local_hfence_vvma_all(vmid); + return; + } + + hgatp = csr_swap(CSR_HGATP, vmid << HGATP_VMID_SHIFT); + + for (pos = gva; pos < (gva + gvsz); pos += BIT(order)) { + /* + * rs1 = a0 (GVA) + * rs2 = zero + * HFENCE.VVMA a0 + * 0010001 00000 01010 000 00000 1110011 + */ + asm volatile ("add a0, %0, zero\n" + ".word 0x22050073\n" + :: "r" (pos) : "a0", "memory"); + } + + csr_write(CSR_HGATP, hgatp); +} + +void kvm_riscv_local_hfence_vvma_all(unsigned long vmid) +{ + unsigned long hgatp; + + hgatp = csr_swap(CSR_HGATP, vmid << HGATP_VMID_SHIFT); + + /* + * rs1 = zero + * rs2 = zero + * HFENCE.VVMA + * 0010001 00000 00000 000 00000 1110011 + */ + asm volatile (".word 0x22000073" ::: "memory"); + + csr_write(CSR_HGATP, hgatp); +} + +void kvm_riscv_local_tlb_sanitize(struct kvm_vcpu *vcpu) +{ + unsigned long vmid; + + if (!kvm_riscv_gstage_vmid_bits() || + vcpu->arch.last_exit_cpu == vcpu->cpu) + return; + + /* + * On RISC-V platforms with hardware VMID support, we share same + * VMID for all VCPUs of a particular Guest/VM. This means we might + * have stale G-stage TLB entries on the current Host CPU due to + * some other VCPU of the same Guest which ran previously on the + * current Host CPU. + * + * To cleanup stale TLB entries, we simply flush all G-stage TLB + * entries by VMID whenever underlying Host CPU changes for a VCPU. + */ + + vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid); + kvm_riscv_local_hfence_gvma_vmid_all(vmid); +} + +void kvm_riscv_fence_i_process(struct kvm_vcpu *vcpu) +{ + local_flush_icache_all(); +} + +void kvm_riscv_hfence_gvma_vmid_all_process(struct kvm_vcpu *vcpu) +{ + struct kvm_vmid *vmid; + + vmid = &vcpu->kvm->arch.vmid; + kvm_riscv_local_hfence_gvma_vmid_all(READ_ONCE(vmid->vmid)); +} + +void kvm_riscv_hfence_vvma_all_process(struct kvm_vcpu *vcpu) +{ + struct kvm_vmid *vmid; + + vmid = &vcpu->kvm->arch.vmid; + kvm_riscv_local_hfence_vvma_all(READ_ONCE(vmid->vmid)); +} + +static bool vcpu_hfence_dequeue(struct kvm_vcpu *vcpu, + struct kvm_riscv_hfence *out_data) +{ + bool ret = false; + struct kvm_vcpu_arch *varch = &vcpu->arch; + + spin_lock(&varch->hfence_lock); + + if (varch->hfence_queue[varch->hfence_head].type) { + memcpy(out_data, &varch->hfence_queue[varch->hfence_head], + sizeof(*out_data)); + varch->hfence_queue[varch->hfence_head].type = 0; + + varch->hfence_head++; + if (varch->hfence_head == KVM_RISCV_VCPU_MAX_HFENCE) + varch->hfence_head = 0; + + ret = true; + } + + spin_unlock(&varch->hfence_lock); + + return ret; +} + +static bool vcpu_hfence_enqueue(struct kvm_vcpu *vcpu, + const struct kvm_riscv_hfence *data) +{ + bool ret = false; + struct kvm_vcpu_arch *varch = &vcpu->arch; + + spin_lock(&varch->hfence_lock); + + if (!varch->hfence_queue[varch->hfence_tail].type) { + memcpy(&varch->hfence_queue[varch->hfence_tail], + data, sizeof(*data)); + + varch->hfence_tail++; + if (varch->hfence_tail == KVM_RISCV_VCPU_MAX_HFENCE) + varch->hfence_tail = 0; + + ret = true; + } + + spin_unlock(&varch->hfence_lock); + + return ret; +} + +void kvm_riscv_hfence_process(struct kvm_vcpu *vcpu) +{ + struct kvm_riscv_hfence d = { 0 }; + struct kvm_vmid *v = &vcpu->kvm->arch.vmid; + + while (vcpu_hfence_dequeue(vcpu, &d)) { + switch (d.type) { + case KVM_RISCV_HFENCE_UNKNOWN: + break; + case KVM_RISCV_HFENCE_GVMA_VMID_GPA: + kvm_riscv_local_hfence_gvma_vmid_gpa( + READ_ONCE(v->vmid), + d.addr, d.size, d.order); + break; + case KVM_RISCV_HFENCE_VVMA_ASID_GVA: + kvm_riscv_local_hfence_vvma_asid_gva( + READ_ONCE(v->vmid), d.asid, + d.addr, d.size, d.order); + break; + case KVM_RISCV_HFENCE_VVMA_ASID_ALL: + kvm_riscv_local_hfence_vvma_asid_all( + READ_ONCE(v->vmid), d.asid); + break; + case KVM_RISCV_HFENCE_VVMA_GVA: + kvm_riscv_local_hfence_vvma_gva( + READ_ONCE(v->vmid), + d.addr, d.size, d.order); + break; + default: + break; + } + } +} + +static void make_xfence_request(struct kvm *kvm, + unsigned long hbase, unsigned long hmask, + unsigned int req, unsigned int fallback_req, + const struct kvm_riscv_hfence *data) +{ + unsigned long i; + struct kvm_vcpu *vcpu; + unsigned int actual_req = req; + DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS); + + bitmap_clear(vcpu_mask, 0, KVM_MAX_VCPUS); + kvm_for_each_vcpu(i, vcpu, kvm) { + if (hbase != -1UL) { + if (vcpu->vcpu_id < hbase) + continue; + if (!(hmask & (1UL << (vcpu->vcpu_id - hbase)))) + continue; + } + + bitmap_set(vcpu_mask, i, 1); + + if (!data || !data->type) + continue; + + /* + * Enqueue hfence data to VCPU hfence queue. If we don't + * have space in the VCPU hfence queue then fallback to + * a more conservative hfence request. + */ + if (!vcpu_hfence_enqueue(vcpu, data)) + actual_req = fallback_req; + } + + kvm_make_vcpus_request_mask(kvm, actual_req, vcpu_mask); +} + +void kvm_riscv_fence_i(struct kvm *kvm, + unsigned long hbase, unsigned long hmask) +{ + make_xfence_request(kvm, hbase, hmask, KVM_REQ_FENCE_I, + KVM_REQ_FENCE_I, NULL); +} + +void kvm_riscv_hfence_gvma_vmid_gpa(struct kvm *kvm, + unsigned long hbase, unsigned long hmask, + gpa_t gpa, gpa_t gpsz, + unsigned long order) +{ + struct kvm_riscv_hfence data; + + data.type = KVM_RISCV_HFENCE_GVMA_VMID_GPA; + data.asid = 0; + data.addr = gpa; + data.size = gpsz; + data.order = order; + make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE, + KVM_REQ_HFENCE_GVMA_VMID_ALL, &data); +} + +void kvm_riscv_hfence_gvma_vmid_all(struct kvm *kvm, + unsigned long hbase, unsigned long hmask) +{ + make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE_GVMA_VMID_ALL, + KVM_REQ_HFENCE_GVMA_VMID_ALL, NULL); +} + +void kvm_riscv_hfence_vvma_asid_gva(struct kvm *kvm, + unsigned long hbase, unsigned long hmask, + unsigned long gva, unsigned long gvsz, + unsigned long order, unsigned long asid) +{ + struct kvm_riscv_hfence data; + + data.type = KVM_RISCV_HFENCE_VVMA_ASID_GVA; + data.asid = asid; + data.addr = gva; + data.size = gvsz; + data.order = order; + make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE, + KVM_REQ_HFENCE_VVMA_ALL, &data); +} + +void kvm_riscv_hfence_vvma_asid_all(struct kvm *kvm, + unsigned long hbase, unsigned long hmask, + unsigned long asid) +{ + struct kvm_riscv_hfence data; + + data.type = KVM_RISCV_HFENCE_VVMA_ASID_ALL; + data.asid = asid; + data.addr = data.size = data.order = 0; + make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE, + KVM_REQ_HFENCE_VVMA_ALL, &data); +} + +void kvm_riscv_hfence_vvma_gva(struct kvm *kvm, + unsigned long hbase, unsigned long hmask, + unsigned long gva, unsigned long gvsz, + unsigned long order) +{ + struct kvm_riscv_hfence data; + + data.type = KVM_RISCV_HFENCE_VVMA_GVA; + data.asid = 0; + data.addr = gva; + data.size = gvsz; + data.order = order; + make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE, + KVM_REQ_HFENCE_VVMA_ALL, &data); +} + +void kvm_riscv_hfence_vvma_all(struct kvm *kvm, + unsigned long hbase, unsigned long hmask) +{ + make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE_VVMA_ALL, + KVM_REQ_HFENCE_VVMA_ALL, NULL); +} |