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Subject: Re: [PATCH v15 02/30] LoongArch: KVM: Implement kvm module related
 interface
To:     Jinyang He <hejinyang@loongson.cn>, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        WANG Xuerui <kernel@xen0n.name>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        loongarch@lists.linux.dev, Jens Axboe <axboe@kernel.dk>,
        Mark Brown <broonie@kernel.org>,
        Alex Deucher <alexander.deucher@amd.com>,
        Oliver Upton <oliver.upton@linux.dev>, maobibo@loongson.cn,
        Xi Ruoyao <xry111@xry111.site>, tangyouling@loongson.cn
References: <20230626084752.1138621-1-zhaotianrui@loongson.cn>
 <20230626084752.1138621-3-zhaotianrui@loongson.cn>
 <8a8efbfd-1ddf-8e25-01c8-111c691ee1c7@loongson.cn>
From:   zhaotianrui <zhaotianrui@loongson.cn>
Message-ID: <1ca9c7bf-bb97-b064-c59e-692792887396@loongson.cn>
Date:   Tue, 27 Jun 2023 19:28:09 +0800
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在 2023/6/27 下午4:36, Jinyang He 写道:
> On 2023-06-26 16:47, Tianrui Zhao 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@loongson.cn>
>> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
>> ---
>>   arch/loongarch/kvm/main.c | 283 ++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 283 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 000000000000..f98c1619725f
>> --- /dev/null
>> +++ b/arch/loongarch/kvm/main.c
>> @@ -0,0 +1,283 @@
>> +// 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/kvm_csr.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);
>> +
>> +    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 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 vmcs ?
Thanks, I will add free vmcs here.
>> +        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);
> free kvm_loongarch_ops ?
Thanks, I will add free kvm_loongarch_ops here.
>> +        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)
>> +{
>> +    free_pages((unsigned long)kvm_loongarch_ops->guest_eentry, 
>> kvm_loongarch_ops->page_order);
> free kvm_loongarch_ops ?
Thanks, I will also add free kvm_loongarch_ops here.
>> +    free_percpu(vmcs);
>> +}
>> +
>> +static int kvm_loongarch_init(void)
>> +{
>> +    int r;
>> +
>> +    if (!cpu_has_lvz)
>> +        return 0;
>
> I think we should do some print and return with errno.
>
>
> Jinyang
Thanks, I will add some report like "hardware virtualization not 
available" and return -ENODEV here.

Thanks
Tianrui Zhao
>
>> +
>> +    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);