Re: [PATCH v21 02/29] LoongArch: KVM: Implement kvm module related interface

From: Huacai Chen
Date: Mon Sep 18 2023 - 22:14:31 EST

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On Mon, Sep 18, 2023 at 4:39 PM bibo mao <maobibo@xxxxxxxxxxx> wrote:
>
>
>
> 在 2023/9/18 14:25, zhaotianrui 写道:
> >
> > 在 2023/9/18 下午12:03, Huacai Chen 写道:
> >> On Mon, Sep 18, 2023 at 11:20 AM zhaotianrui <zhaotianrui@xxxxxxxxxxx> wrote:
> >>>
> >>> 在 2023/9/18 上午11:12, Huacai Chen 写道:
> >>>> On Mon, Sep 18, 2023 at 11:08 AM zhaotianrui <zhaotianrui@xxxxxxxxxxx> wrote:
> >>>>> 在 2023/9/18 上午9:45, Huacai Chen 写道:
> >>>>>> On Mon, Sep 18, 2023 at 9:21 AM zhaotianrui <zhaotianrui@xxxxxxxxxxx> wrote:
> >>>>>>> 在 2023/9/16 下午4:51, Huacai Chen 写道:
> >>>>>>>> Hi, Tianrui,
> >>>>>>>>
> >>>>>>>> On Fri, Sep 15, 2023 at 9:50 AM Tianrui Zhao <zhaotianrui@xxxxxxxxxxx> wrote:
> >>>>>>>>> Implement LoongArch kvm module init, module exit interface,
> >>>>>>>>> using kvm context to save the vpid info and vcpu world switch
> >>>>>>>>> interface pointer.
> >>>>>>>>>
> >>>>>>>>> Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
> >>>>>>>>> Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
> >>>>>>>>> ---
> >>>>>>>>> arch/loongarch/kvm/main.c | 367 ++++++++++++++++++++++++++++++++++++++
> >>>>>>>>> 1 file changed, 367 insertions(+)
> >>>>>>>>> create mode 100644 arch/loongarch/kvm/main.c
> >>>>>>>>>
> >>>>>>>>> diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
> >>>>>>>>> new file mode 100644
> >>>>>>>>> index 0000000000..0deb9273d8
> >>>>>>>>> --- /dev/null
> >>>>>>>>> +++ b/arch/loongarch/kvm/main.c
> >>>>>>>>> @@ -0,0 +1,367 @@
> >>>>>>>>> +// SPDX-License-Identifier: GPL-2.0
> >>>>>>>>> +/*
> >>>>>>>>> + * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
> >>>>>>>>> + */
> >>>>>>>>> +
> >>>>>>>>> +#include <linux/err.h>
> >>>>>>>>> +#include <linux/module.h>
> >>>>>>>>> +#include <linux/kvm_host.h>
> >>>>>>>>> +#include <asm/cacheflush.h>
> >>>>>>>>> +#include <asm/cpufeature.h>
> >>>>>>>>> +#include <asm/kvm_csr.h>
> >>>>>>>>> +#include "trace.h"
> >>>>>>>>> +
> >>>>>>>>> +static struct kvm_context __percpu *vmcs;
> >>>>>>>>> +struct kvm_world_switch *kvm_loongarch_ops;
> >>>>>>>>> +unsigned long vpid_mask;
> >>>>>>>>> +static int gcsr_flag[CSR_MAX_NUMS];
> >>>>>>>>> +
> >>>>>>>>> +int get_gcsr_flag(int csr)
> >>>>>>>>> +{
> >>>>>>>>> + if (csr < CSR_MAX_NUMS)
> >>>>>>>>> + return gcsr_flag[csr];
> >>>>>>>>> +
> >>>>>>>>> + return INVALID_GCSR;
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +static inline void set_gcsr_sw_flag(int csr)
> >>>>>>>>> +{
> >>>>>>>>> + if (csr < CSR_MAX_NUMS)
> >>>>>>>>> + gcsr_flag[csr] |= SW_GCSR;
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +static inline void set_gcsr_hw_flag(int csr)
> >>>>>>>>> +{
> >>>>>>>>> + if (csr < CSR_MAX_NUMS)
> >>>>>>>>> + gcsr_flag[csr] |= HW_GCSR;
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +/*
> >>>>>>>>> + * The default value of gcsr_flag[CSR] is 0, and we use this
> >>>>>>>>> + * function to set the flag to 1(SW_GCSR) or 2(HW_GCSR) if the
> >>>>>>>>> + * gcsr is software or hardware. It will be used by get/set_gcsr,
> >>>>>>>>> + * if gcsr_flag is HW we should use gcsrrd/gcsrwr to access it,
> >>>>>>>>> + * else use sw csr to emulate it.
> >>>>>>>>> + */
> >>>>>>>>> +static void kvm_init_gcsr_flag(void)
> >>>>>>>>> +{
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_CRMD);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PRMD);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_EUEN);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_MISC);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_ECFG);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_ESTAT);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_ERA);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_BADV);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_BADI);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_EENTRY);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBIDX);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBEHI);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO0);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO1);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_ASID);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PGDL);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PGDH);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL0);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL1);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_STLBPGSIZE);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_RVACFG);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_CPUID);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG1);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG2);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG3);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS0);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS1);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS2);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS3);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS4);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS5);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS6);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_KS7);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TMID);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TCFG);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TVAL);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_CNTC);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_LLBCTL);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBRENTRY);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBRBADV);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBRERA);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBRSAVE);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO0);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO1);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBREHI);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_TLBRPRMD);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN0);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN1);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN2);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN3);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_MWPS);
> >>>>>>>>> + set_gcsr_hw_flag(LOONGARCH_CSR_FWPS);
> >>>>>>>>> +
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL1);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL2);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MERRCTL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO1);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO2);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MERRENTRY);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MERRERA);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MERRSAVE);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_CTAG);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DEBUG);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DERA);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DESAVE);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PRCFG1);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PRCFG2);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PRCFG3);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PGD);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_TINTCLR);
> >>>>>>>>> +
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_FWPS);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_FWPC);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MWPS);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_MWPC);
> >>>>>>>> FWPS and MWPS are both HW CSR and SW CSR?
> >>>>>>>>
> >>>>>>>> Huacai
> >>>>>>> The FWPC and MWPC should be SW GCSR, FWPS and MWPS should be HW GCSR, it
> >>>>>>> is my mistake.
> >>>>>> But in user manual vol 3, section 1.5, FWPC/FWPS/MWPC/MWPS are all HW
> >>>>>> GCSR, while DBxxxx and IBxxxx are SW GCSR.
> >>>>> Ok, It is my misunderstanding, as the FWPC and MWPC can control guest
> >>>>> debug register numbers, but I know they are all HW GCSR when I look up
> >>>>> the manual again.
> >>>> So these lines can be removed?
> >>>>
> >>>> set_gcsr_sw_flag(LOONGARCH_CSR_FWPS);
> >>>> set_gcsr_sw_flag(LOONGARCH_CSR_FWPC);
> >>>> set_gcsr_sw_flag(LOONGARCH_CSR_MWPS);
> >>>> set_gcsr_sw_flag(LOONGARCH_CSR_MWPC);
> >>>>
> >>>> And add FWPC/MWPC to hw list?
> >> Can you discuss more with our hw engineers? I found in section 1.8:
> >> PGD, TINTCLR, PRCFG1~3 are all HW GCSR.
> > If guest can access hw CSR directly and do not cause a exception, it means hw GCSR. on the other hand, if cause a exception to return to KVM to emulate it by software, it means SW GCSR. And I re-check the PGD, TINTCLR, PRCFG1~3 CSR, they should be hw GCSR.
>
> CSR_PGD is logical read only register instead, its content is the same
> CSR_PGDL if highest bit of BADV is 0, else its content is the same with
> CSR_PGDH.
>
> TINTCLR is write only register, write 1 to clear timer interrupt and read
> value is 0.
>
> So CSR_PGD and TINTCLR need not save and restore during vcpu switching or
> vm migration, it is not necessary to set CSR_PGD/TINTCLR from qemu user space.
>
> PRCFG1~3 is read only registers, it is decided by hardware and can not be
> set by kvm, it is not necessary to save or retore. However there maybe brings
> problems for vm migration on diferent hardwares if PRCFG1~3 is different.
During my tests, reading FWPC/FWPS/MWPC/MWPS causes guest exit, but
user manual vol 3 says they are HW GCSR, who can tell me why?

Huacai

>
> Regards
> Bibo Mao
> >
> > Thanks
> > Tianrui Zhao
> >>
> >> Huacai
> >>
> >>>> Huacai
> >>> Yes, It is.
> >>>
> >>> Thanks
> >>> Tianrui Zhao
> >>>>> Thanks
> >>>>> Tianrui Zhao
> >>>>>> Huacai
> >>>>>>
> >>>>>>> Thanks
> >>>>>>> Tianrui Zhao
> >>>>>>>>> +
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB0ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB0MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB0CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB0ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB1ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB1MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB1CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB1ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB2ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB2MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB2CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB2ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB3ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB3MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB3CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB3ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB4ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB4MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB4CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB4ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB5ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB5MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB5CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB5ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB6ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB6MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB6CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB6ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB7ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB7MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB7CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_DB7ASID);
> >>>>>>>>> +
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB0ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB0MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB0CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB0ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB1ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB1MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB1CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB1ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB2ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB2MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB2CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB2ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB3ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB3MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB3CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB3ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB4ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB4MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB4CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB4ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB5ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB5MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB5CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB5ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB6ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB6MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB6CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB6ASID);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB7ADDR);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB7MASK);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB7CTRL);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_IB7ASID);
> >>>>>>>>> +
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL0);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR0);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL1);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR1);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL2);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR2);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL3);
> >>>>>>>>> + set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR3);
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +static void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
> >>>>>>>>> +{
> >>>>>>>>> + struct kvm_context *context;
> >>>>>>>>> + unsigned long vpid;
> >>>>>>>>> +
> >>>>>>>>> + context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
> >>>>>>>>> + vpid = context->vpid_cache + 1;
> >>>>>>>>> + if (!(vpid & vpid_mask)) {
> >>>>>>>>> + /* finish round of 64 bit loop */
> >>>>>>>>> + if (unlikely(!vpid))
> >>>>>>>>> + vpid = vpid_mask + 1;
> >>>>>>>>> +
> >>>>>>>>> + /* vpid 0 reserved for root */
> >>>>>>>>> + ++vpid;
> >>>>>>>>> +
> >>>>>>>>> + /* start new vpid cycle */
> >>>>>>>>> + kvm_flush_tlb_all();
> >>>>>>>>> + }
> >>>>>>>>> +
> >>>>>>>>> + context->vpid_cache = vpid;
> >>>>>>>>> + vcpu->arch.vpid = vpid;
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +void kvm_check_vpid(struct kvm_vcpu *vcpu)
> >>>>>>>>> +{
> >>>>>>>>> + struct kvm_context *context;
> >>>>>>>>> + bool migrated;
> >>>>>>>>> + unsigned long ver, old, vpid;
> >>>>>>>>> + int cpu;
> >>>>>>>>> +
> >>>>>>>>> + cpu = smp_processor_id();
> >>>>>>>>> + /*
> >>>>>>>>> + * Are we entering guest context on a different CPU to last time?
> >>>>>>>>> + * If so, the vCPU's guest TLB state on this CPU may be stale.
> >>>>>>>>> + */
> >>>>>>>>> + context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
> >>>>>>>>> + migrated = (vcpu->cpu != cpu);
> >>>>>>>>> +
> >>>>>>>>> + /*
> >>>>>>>>> + * Check if our vpid is of an older version
> >>>>>>>>> + *
> >>>>>>>>> + * We also discard the stored vpid if we've executed on
> >>>>>>>>> + * another CPU, as the guest mappings may have changed without
> >>>>>>>>> + * hypervisor knowledge.
> >>>>>>>>> + */
> >>>>>>>>> + ver = vcpu->arch.vpid & ~vpid_mask;
> >>>>>>>>> + old = context->vpid_cache & ~vpid_mask;
> >>>>>>>>> + if (migrated || (ver != old)) {
> >>>>>>>>> + kvm_update_vpid(vcpu, cpu);
> >>>>>>>>> + trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
> >>>>>>>>> + vcpu->cpu = cpu;
> >>>>>>>>> + }
> >>>>>>>>> +
> >>>>>>>>> + /* Restore GSTAT(0x50).vpid */
> >>>>>>>>> + vpid = (vcpu->arch.vpid & vpid_mask) << CSR_GSTAT_GID_SHIFT;
> >>>>>>>>> + change_csr_gstat(vpid_mask << CSR_GSTAT_GID_SHIFT, vpid);
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +static int kvm_loongarch_env_init(void)
> >>>>>>>>> +{
> >>>>>>>>> + struct kvm_context *context;
> >>>>>>>>> + int cpu, order;
> >>>>>>>>> + void *addr;
> >>>>>>>>> +
> >>>>>>>>> + vmcs = alloc_percpu(struct kvm_context);
> >>>>>>>>> + if (!vmcs) {
> >>>>>>>>> + pr_err("kvm: failed to allocate percpu kvm_context\n");
> >>>>>>>>> + return -ENOMEM;
> >>>>>>>>> + }
> >>>>>>>>> +
> >>>>>>>>> + kvm_loongarch_ops = kzalloc(sizeof(*kvm_loongarch_ops), GFP_KERNEL);
> >>>>>>>>> + if (!kvm_loongarch_ops) {
> >>>>>>>>> + free_percpu(vmcs);
> >>>>>>>>> + vmcs = NULL;
> >>>>>>>>> + return -ENOMEM;
> >>>>>>>>> + }
> >>>>>>>>> + /*
> >>>>>>>>> + * There will be problem in world switch code if there
> >>>>>>>>> + * is page fault reenter, since pgd register is shared
> >>>>>>>>> + * between root kernel and kvm hypervisor. World switch
> >>>>>>>>> + * entry need be unmapped area, cannot be tlb mapped area.
> >>>>>>>>> + * In future if hw pagetable walking is supported, or there
> >>>>>>>>> + * is separate pgd registers between root kernel and kvm
> >>>>>>>>> + * hypervisor, copying about world switch code will not be used.
> >>>>>>>>> + */
> >>>>>>>>> +
> >>>>>>>>> + order = get_order(kvm_vector_size + kvm_enter_guest_size);
> >>>>>>>>> + addr = (void *)__get_free_pages(GFP_KERNEL, order);
> >>>>>>>>> + if (!addr) {
> >>>>>>>>> + free_percpu(vmcs);
> >>>>>>>>> + vmcs = NULL;
> >>>>>>>>> + kfree(kvm_loongarch_ops);
> >>>>>>>>> + kvm_loongarch_ops = NULL;
> >>>>>>>>> + return -ENOMEM;
> >>>>>>>>> + }
> >>>>>>>>> +
> >>>>>>>>> + memcpy(addr, kvm_vector_entry, kvm_vector_size);
> >>>>>>>>> + memcpy(addr + kvm_vector_size, kvm_enter_guest, kvm_enter_guest_size);
> >>>>>>>>> + flush_icache_range((unsigned long)addr, (unsigned long)addr +
> >>>>>>>>> + kvm_vector_size + kvm_enter_guest_size);
> >>>>>>>>> + kvm_loongarch_ops->guest_eentry = addr;
> >>>>>>>>> + kvm_loongarch_ops->enter_guest = addr + kvm_vector_size;
> >>>>>>>>> + kvm_loongarch_ops->page_order = order;
> >>>>>>>>> +
> >>>>>>>>> + vpid_mask = read_csr_gstat();
> >>>>>>>>> + vpid_mask = (vpid_mask & CSR_GSTAT_GIDBIT) >> CSR_GSTAT_GIDBIT_SHIFT;
> >>>>>>>>> + if (vpid_mask)
> >>>>>>>>> + vpid_mask = GENMASK(vpid_mask - 1, 0);
> >>>>>>>>> +
> >>>>>>>>> + for_each_possible_cpu(cpu) {
> >>>>>>>>> + context = per_cpu_ptr(vmcs, cpu);
> >>>>>>>>> + context->vpid_cache = vpid_mask + 1;
> >>>>>>>>> + context->last_vcpu = NULL;
> >>>>>>>>> + }
> >>>>>>>>> +
> >>>>>>>>> + kvm_init_fault();
> >>>>>>>>> + kvm_init_gcsr_flag();
> >>>>>>>>> +
> >>>>>>>>> + return 0;
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +static void kvm_loongarch_env_exit(void)
> >>>>>>>>> +{
> >>>>>>>>> + unsigned long addr;
> >>>>>>>>> +
> >>>>>>>>> + if (vmcs)
> >>>>>>>>> + free_percpu(vmcs);
> >>>>>>>>> +
> >>>>>>>>> + if (kvm_loongarch_ops) {
> >>>>>>>>> + if (kvm_loongarch_ops->guest_eentry) {
> >>>>>>>>> + addr = (unsigned long)kvm_loongarch_ops->guest_eentry;
> >>>>>>>>> + free_pages(addr, kvm_loongarch_ops->page_order);
> >>>>>>>>> + }
> >>>>>>>>> + kfree(kvm_loongarch_ops);
> >>>>>>>>> + }
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +static int kvm_loongarch_init(void)
> >>>>>>>>> +{
> >>>>>>>>> + int r;
> >>>>>>>>> +
> >>>>>>>>> + if (!cpu_has_lvz) {
> >>>>>>>>> + kvm_info("hardware virtualization not available\n");
> >>>>>>>>> + return -ENODEV;
> >>>>>>>>> + }
> >>>>>>>>> + r = kvm_loongarch_env_init();
> >>>>>>>>> + if (r)
> >>>>>>>>> + return r;
> >>>>>>>>> +
> >>>>>>>>> + return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +static void kvm_loongarch_exit(void)
> >>>>>>>>> +{
> >>>>>>>>> + kvm_exit();
> >>>>>>>>> + kvm_loongarch_env_exit();
> >>>>>>>>> +}
> >>>>>>>>> +
> >>>>>>>>> +module_init(kvm_loongarch_init);
> >>>>>>>>> +module_exit(kvm_loongarch_exit);
> >>>>>>>>> +
> >>>>>>>>> +#ifdef MODULE
> >>>>>>>>> +static const struct cpu_feature loongarch_kvm_feature[] = {
> >>>>>>>>> + { .feature = cpu_feature(LOONGARCH_LVZ) },
> >>>>>>>>> + {},
> >>>>>>>>> +};
> >>>>>>>>> +MODULE_DEVICE_TABLE(cpu, loongarch_kvm_feature);
> >>>>>>>>> +#endif
> >>>>>>>>> --
> >>>>>>>>> 2.39.1
> >>>>>>>>>
> >>>
>
>

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