| Message ID | 20211105235852.3011900-6-atish.patra@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add SBI v0.2 support for KVM | expand |
On Sat, Nov 6, 2021 at 5:29 AM Atish Patra <atish.patra@wdc.com> wrote: > > SBI HSM extension allows OS to start/stop harts any time. It also allows > ordered booting of harts instead of random booting. > > Implement SBI HSM exntesion and designate the vcpu 0 as the boot vcpu id. > All other non-zero non-booting vcpus should be brought up by the OS > implementing HSM extension. If the guest OS doesn't implement HSM > extension, only single vcpu will be available to OS. > > Signed-off-by: Atish Patra <atish.patra@wdc.com> > --- > arch/riscv/include/asm/sbi.h | 1 + > arch/riscv/kvm/Makefile | 1 + > arch/riscv/kvm/vcpu.c | 23 ++++++++ > arch/riscv/kvm/vcpu_sbi.c | 4 ++ > arch/riscv/kvm/vcpu_sbi_hsm.c | 107 ++++++++++++++++++++++++++++++++++ > 5 files changed, 136 insertions(+) > create mode 100644 arch/riscv/kvm/vcpu_sbi_hsm.c > > diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h > index 4f9370b6032e..79af25c45c8d 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 4757ae158bf3..aaf181a3d74b 100644 > --- a/arch/riscv/kvm/Makefile > +++ b/arch/riscv/kvm/Makefile > @@ -26,4 +26,5 @@ 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 e3d3aed46184..50158867406d 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) > @@ -100,6 +116,13 @@ 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 cpu id in power-off state so that they > + * can brought to online 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 3502c6166eba..bff753b6e4b0 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..aefee16a1560 > --- /dev/null > +++ b/arch/riscv/kvm/vcpu_sbi_hsm.c > @@ -0,0 +1,107 @@ > +// 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; > + > + if (!cp) > + return -EINVAL; Same as other patches. Drop the check on "cp". > + 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, > +}; > -- > 2.31.1 > Otherwise it looks good to me. Reviewed-by: Anup Patel <anup.patel@wdc.com> Regards, Anup
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 4f9370b6032e..79af25c45c8d 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 4757ae158bf3..aaf181a3d74b 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -26,4 +26,5 @@ 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 e3d3aed46184..50158867406d 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) @@ -100,6 +116,13 @@ 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 cpu id in power-off state so that they + * can brought to online 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 3502c6166eba..bff753b6e4b0 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..aefee16a1560 --- /dev/null +++ b/arch/riscv/kvm/vcpu_sbi_hsm.c @@ -0,0 +1,107 @@ +// 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; + + if (!cp) + return -EINVAL; + 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, +};
SBI HSM extension allows OS to start/stop harts any time. It also allows ordered booting of harts instead of random booting. Implement SBI HSM exntesion and designate the vcpu 0 as the boot vcpu id. All other non-zero non-booting vcpus should be brought up by the OS implementing HSM extension. If the guest OS doesn't implement HSM extension, only single vcpu will be available to OS. Signed-off-by: Atish Patra <atish.patra@wdc.com> --- arch/riscv/include/asm/sbi.h | 1 + arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu.c | 23 ++++++++ arch/riscv/kvm/vcpu_sbi.c | 4 ++ arch/riscv/kvm/vcpu_sbi_hsm.c | 107 ++++++++++++++++++++++++++++++++++ 5 files changed, 136 insertions(+) create mode 100644 arch/riscv/kvm/vcpu_sbi_hsm.c