diff options
| -rw-r--r-- | arch/riscv/include/asm/sbi.h | 1 | ||||
| -rw-r--r-- | arch/riscv/kvm/Makefile | 1 | ||||
| -rw-r--r-- | arch/riscv/kvm/vcpu.c | 23 | ||||
| -rw-r--r-- | arch/riscv/kvm/vcpu_sbi.c | 4 | ||||
| -rw-r--r-- | arch/riscv/kvm/vcpu_sbi_hsm.c | 105 |
5 files changed, 134 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 9e4c79fd49d7..9c46dd3ff4a2 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -90,6 +90,7 @@ enum sbi_hsm_hart_status { #define SBI_ERR_INVALID_PARAM -3 #define SBI_ERR_DENIED -4 #define SBI_ERR_INVALID_ADDRESS -5 +#define SBI_ERR_ALREADY_AVAILABLE -6 extern unsigned long sbi_spec_version; struct sbiret { diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index 7fd9fc184ae9..e5c56182f48f 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -22,4 +22,5 @@ kvm-y += vcpu_sbi.o kvm-$(CONFIG_RISCV_SBI_V01) += vcpu_sbi_v01.o kvm-y += vcpu_sbi_base.o kvm-y += vcpu_sbi_replace.o +kvm-y += vcpu_sbi_hsm.o kvm-y += vcpu_timer.o diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 2ae11b4e93d1..0c5239e05721 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -53,6 +53,17 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; struct kvm_cpu_context *reset_cntx = &vcpu->arch.guest_reset_context; + bool loaded; + + /** + * The preemption should be disabled here because it races with + * kvm_sched_out/kvm_sched_in(called from preempt notifiers) which + * also calls vcpu_load/put. + */ + get_cpu(); + loaded = (vcpu->cpu != -1); + if (loaded) + kvm_arch_vcpu_put(vcpu); memcpy(csr, reset_csr, sizeof(*csr)); @@ -64,6 +75,11 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) WRITE_ONCE(vcpu->arch.irqs_pending, 0); WRITE_ONCE(vcpu->arch.irqs_pending_mask, 0); + + /* Reset the guest CSRs for hotplug usecase */ + if (loaded) + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + put_cpu(); } int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) @@ -101,6 +117,13 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) { + /** + * vcpu with id 0 is the designated boot cpu. + * Keep all vcpus with non-zero id in power-off state so that + * they can be brought up using SBI HSM extension. + */ + if (vcpu->vcpu_idx != 0) + kvm_riscv_vcpu_power_off(vcpu); } void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index cf284e080f3e..f62d25bc9733 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -25,6 +25,8 @@ static int kvm_linux_err_map_sbi(int err) return SBI_ERR_INVALID_ADDRESS; case -EOPNOTSUPP: return SBI_ERR_NOT_SUPPORTED; + case -EALREADY: + return SBI_ERR_ALREADY_AVAILABLE; default: return SBI_ERR_FAILURE; }; @@ -43,6 +45,7 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_time; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_ipi; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence; +extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm; static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { &vcpu_sbi_ext_v01, @@ -50,6 +53,7 @@ static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { &vcpu_sbi_ext_time, &vcpu_sbi_ext_ipi, &vcpu_sbi_ext_rfence, + &vcpu_sbi_ext_hsm, }; void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run) diff --git a/arch/riscv/kvm/vcpu_sbi_hsm.c b/arch/riscv/kvm/vcpu_sbi_hsm.c new file mode 100644 index 000000000000..2e383687fa48 --- /dev/null +++ b/arch/riscv/kvm/vcpu_sbi_hsm.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * + * Authors: + * Atish Patra <atish.patra@wdc.com> + */ + +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/kvm_host.h> +#include <asm/csr.h> +#include <asm/sbi.h> +#include <asm/kvm_vcpu_sbi.h> + +static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *reset_cntx; + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + struct kvm_vcpu *target_vcpu; + unsigned long target_vcpuid = cp->a0; + + target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); + if (!target_vcpu) + return -EINVAL; + if (!target_vcpu->arch.power_off) + return -EALREADY; + + reset_cntx = &target_vcpu->arch.guest_reset_context; + /* start address */ + reset_cntx->sepc = cp->a1; + /* target vcpu id to start */ + reset_cntx->a0 = target_vcpuid; + /* private data passed from kernel */ + reset_cntx->a1 = cp->a2; + kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu); + + kvm_riscv_vcpu_power_on(target_vcpu); + + return 0; +} + +static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu) +{ + if (vcpu->arch.power_off) + return -EINVAL; + + kvm_riscv_vcpu_power_off(vcpu); + + return 0; +} + +static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + unsigned long target_vcpuid = cp->a0; + struct kvm_vcpu *target_vcpu; + + target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); + if (!target_vcpu) + return -EINVAL; + if (!target_vcpu->arch.power_off) + return SBI_HSM_HART_STATUS_STARTED; + else + return SBI_HSM_HART_STATUS_STOPPED; +} + +static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, + unsigned long *out_val, + struct kvm_cpu_trap *utrap, + bool *exit) +{ + int ret = 0; + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + struct kvm *kvm = vcpu->kvm; + unsigned long funcid = cp->a6; + + switch (funcid) { + case SBI_EXT_HSM_HART_START: + mutex_lock(&kvm->lock); + ret = kvm_sbi_hsm_vcpu_start(vcpu); + mutex_unlock(&kvm->lock); + break; + case SBI_EXT_HSM_HART_STOP: + ret = kvm_sbi_hsm_vcpu_stop(vcpu); + break; + case SBI_EXT_HSM_HART_STATUS: + ret = kvm_sbi_hsm_vcpu_get_status(vcpu); + if (ret >= 0) { + *out_val = ret; + ret = 0; + } + break; + default: + ret = -EOPNOTSUPP; + } + + return ret; +} + +const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = { + .extid_start = SBI_EXT_HSM, + .extid_end = SBI_EXT_HSM, + .handler = kvm_sbi_ext_hsm_handler, +}; |