Re: [PATCH v12 06/31] LoongArch: KVM: Implement vcpu create and destroy interface

["bibo, mao" <maobibo@loongson.cn>]

Reviewed-by: Bibo, Mao <maobibo@loongson.cn>

在 2023/5/30 09:51, Tianrui Zhao 写道:
> Implement vcpu create and destroy interface, saving some info
> into vcpu arch structure such as vcpu exception entrance, vcpu
> enter guest pointer, etc. Init vcpu timer and set address
> translation mode when vcpu create.
> 
> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
> ---
>  arch/loongarch/kvm/vcpu.c | 88 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 88 insertions(+)
>  create mode 100644 arch/loongarch/kvm/vcpu.c
> 
> diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
> new file mode 100644
> index 000000000000..24b5b00266a1
> --- /dev/null
> +++ b/arch/loongarch/kvm/vcpu.c
> @@ -0,0 +1,88 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/kvm_host.h>
> +#include <asm/fpu.h>
> +#include <asm/loongarch.h>
> +#include <asm/setup.h>
> +#include <asm/time.h>
> +
> +#define CREATE_TRACE_POINTS
> +#include "trace.h"
> +
> +int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
> +{
> +	return 0;
> +}
> +
> +int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
> +{
> +	unsigned long timer_hz;
> +	struct loongarch_csrs *csr;
> +
> +	vcpu->arch.vpid = 0;
> +
> +	hrtimer_init(&vcpu->arch.swtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
> +	vcpu->arch.swtimer.function = kvm_swtimer_wakeup;
> +	vcpu->kvm->arch.online_vcpus = vcpu->vcpu_id + 1;
> +
> +	vcpu->arch.guest_eentry = (unsigned long)kvm_loongarch_ops->guest_eentry;
> +	vcpu->arch.handle_exit = _kvm_handle_exit;
> +	vcpu->arch.csr = kzalloc(sizeof(struct loongarch_csrs), GFP_KERNEL);
> +	if (!vcpu->arch.csr)
> +		return -ENOMEM;
> +
> +	/*
> +	 * kvm all exceptions share one exception entry, and host <-> guest switch
> +	 * also switch excfg.VS field, keep host excfg.VS info here
> +	 */
> +	vcpu->arch.host_ecfg = (read_csr_ecfg() & CSR_ECFG_VS);
> +
> +	/* Init */
> +	vcpu->arch.last_sched_cpu = -1;
> +	vcpu->arch.last_exec_cpu = -1;
> +
> +	/*
> +	 * Initialize guest register state to valid architectural reset state.
> +	 */
> +	timer_hz = calc_const_freq();
> +	kvm_init_timer(vcpu, timer_hz);
> +
> +	/* Set Initialize mode for GUEST */
> +	csr = vcpu->arch.csr;
> +	kvm_write_sw_gcsr(csr, LOONGARCH_CSR_CRMD, CSR_CRMD_DA);
> +
> +	/* Set cpuid */
> +	kvm_write_sw_gcsr(csr, LOONGARCH_CSR_TMID, vcpu->vcpu_id);
> +
> +	/* start with no pending virtual guest interrupts */
> +	csr->csrs[LOONGARCH_CSR_GINTC] = 0;
> +
> +	return 0;
> +}
> +
> +void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> +void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
> +{
> +	int cpu;
> +	struct kvm_context *context;
> +
> +	hrtimer_cancel(&vcpu->arch.swtimer);
> +	kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
> +	kfree(vcpu->arch.csr);
> +
> +	/*
> +	 * If the vCPU is freed and reused as another vCPU, we don't want the
> +	 * matching pointer wrongly hanging around in last_vcpu.
> +	 */
> +	for_each_possible_cpu(cpu) {
> +		context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
> +		if (context->last_vcpu == vcpu)
> +			context->last_vcpu = NULL;
> +	}
> +}