diff options
Diffstat (limited to 'arch/riscv/kvm/main.c')
| -rw-r--r-- | arch/riscv/kvm/main.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c new file mode 100644 index 000000000000..45536af521f0 --- /dev/null +++ b/arch/riscv/kvm/main.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Western Digital Corporation or its affiliates. + * + * Authors: + * Anup Patel <anup.patel@wdc.com> + */ + +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/kvm_host.h> +#include <asm/cpufeature.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_nacl.h> +#include <asm/sbi.h> + +DEFINE_STATIC_KEY_FALSE(kvm_riscv_vsstage_tlb_no_gpa); + +static void kvm_riscv_setup_vendor_features(void) +{ + /* Andes AX66: split two-stage TLBs */ + if (riscv_cached_mvendorid(0) == ANDES_VENDOR_ID && + (riscv_cached_marchid(0) & 0xFFFF) == 0x8A66) { + static_branch_enable(&kvm_riscv_vsstage_tlb_no_gpa); + kvm_info("VS-stage TLB does not cache guest physical address and VMID\n"); + } +} + +long kvm_arch_dev_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg) +{ + return -EINVAL; +} + +int kvm_arch_enable_virtualization_cpu(void) +{ + int rc; + + rc = kvm_riscv_nacl_enable(); + if (rc) + return rc; + + csr_write(CSR_HEDELEG, KVM_HEDELEG_DEFAULT); + csr_write(CSR_HIDELEG, KVM_HIDELEG_DEFAULT); + + /* VS should access only the time counter directly. Everything else should trap */ + csr_write(CSR_HCOUNTEREN, 0x02); + + csr_write(CSR_HVIP, 0); + + kvm_riscv_aia_enable(); + + return 0; +} + +void kvm_arch_disable_virtualization_cpu(void) +{ + kvm_riscv_aia_disable(); + + /* + * After clearing the hideleg CSR, the host kernel will receive + * spurious interrupts if hvip CSR has pending interrupts and the + * corresponding enable bits in vsie CSR are asserted. To avoid it, + * hvip CSR and vsie CSR must be cleared before clearing hideleg CSR. + */ + csr_write(CSR_VSIE, 0); + csr_write(CSR_HVIP, 0); + csr_write(CSR_HEDELEG, 0); + csr_write(CSR_HIDELEG, 0); + + kvm_riscv_nacl_disable(); +} + +static void kvm_riscv_teardown(void) +{ + kvm_riscv_aia_exit(); + kvm_riscv_nacl_exit(); + kvm_unregister_perf_callbacks(); +} + +static int __init riscv_kvm_init(void) +{ + int rc; + char slist[64]; + const char *str; + + if (!riscv_isa_extension_available(NULL, h)) { + kvm_info("hypervisor extension not available\n"); + return -ENODEV; + } + + if (sbi_spec_is_0_1()) { + kvm_info("require SBI v0.2 or higher\n"); + return -ENODEV; + } + + if (!sbi_probe_extension(SBI_EXT_RFENCE)) { + kvm_info("require SBI RFENCE extension\n"); + return -ENODEV; + } + + rc = kvm_riscv_nacl_init(); + if (rc && rc != -ENODEV) + return rc; + + kvm_riscv_gstage_mode_detect(); + switch (kvm_riscv_gstage_mode) { + case HGATP_MODE_SV32X4: + str = "Sv32x4"; + break; + case HGATP_MODE_SV39X4: + str = "Sv39x4"; + break; + case HGATP_MODE_SV48X4: + str = "Sv48x4"; + break; + case HGATP_MODE_SV57X4: + str = "Sv57x4"; + break; + default: + kvm_riscv_nacl_exit(); + return -ENODEV; + } + + kvm_riscv_gstage_vmid_detect(); + + rc = kvm_riscv_aia_init(); + if (rc && rc != -ENODEV) { + kvm_riscv_nacl_exit(); + return rc; + } + + kvm_info("hypervisor extension available\n"); + + if (kvm_riscv_nacl_available()) { + rc = 0; + slist[0] = '\0'; + if (kvm_riscv_nacl_sync_csr_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "sync_csr"); + rc++; + } + if (kvm_riscv_nacl_sync_hfence_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "sync_hfence"); + rc++; + } + if (kvm_riscv_nacl_sync_sret_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "sync_sret"); + rc++; + } + if (kvm_riscv_nacl_autoswap_csr_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "autoswap_csr"); + rc++; + } + kvm_info("using SBI nested acceleration with %s\n", + (rc) ? slist : "no features"); + } + + kvm_info("using %s G-stage page table format\n", str); + + kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits()); + + if (kvm_riscv_aia_available()) + kvm_info("AIA available with %d guest external interrupts\n", + kvm_riscv_aia_nr_hgei); + + kvm_riscv_setup_vendor_features(); + + kvm_register_perf_callbacks(NULL); + + rc = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE); + if (rc) { + kvm_riscv_teardown(); + return rc; + } + + return 0; +} +module_init(riscv_kvm_init); + +static void __exit riscv_kvm_exit(void) +{ + kvm_exit(); + + kvm_riscv_teardown(); +} +module_exit(riscv_kvm_exit); |