在 2023年06月06日 09:35, bibo, mao 写道:
>
> 在 2023/5/30 09:52, Tianrui Zhao 写道:
>> Implement kvm handle LoongArch vcpu exit caused by reading and
>> writing csr. Using csr structure to emulate the registers.
>>
>> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
>> ---
>> arch/loongarch/kvm/exit.c | 98 +++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 98 insertions(+)
>> create mode 100644 arch/loongarch/kvm/exit.c
>>
>> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
>> new file mode 100644
>> index 000000000000..508cbce31aa5
>> --- /dev/null
>> +++ b/arch/loongarch/kvm/exit.c
>> @@ -0,0 +1,98 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
>> + */
>> +
>> +#include <linux/errno.h>
>> +#include <linux/err.h>
>> +#include <linux/module.h>
>> +#include <linux/preempt.h>
>> +#include <linux/vmalloc.h>
>> +#include <asm/fpu.h>
>> +#include <asm/inst.h>
>> +#include <asm/time.h>
>> +#include <asm/tlb.h>
>> +#include <asm/loongarch.h>
>> +#include <asm/numa.h>
>> +#include <asm/kvm_vcpu.h>
>> +#include <asm/kvm_csr.h>
>> +#include <linux/kvm_host.h>
>> +#include <asm/mmzone.h>
>> +#include "trace.h"
>> +
>> +static unsigned long _kvm_emu_read_csr(struct kvm_vcpu *vcpu, int csrid)
>> +{
>> + struct loongarch_csrs *csr = vcpu->arch.csr;
>> + unsigned long val = 0;
>> +
>> + if (csrid < 4096 && (get_gcsr_flag(csrid) & SW_GCSR))
>> + val = kvm_read_sw_gcsr(csr, csrid);
>> + else
>> + pr_warn_once("Unsupport csrread 0x%x with pc %lx\n",
>> + csrid, vcpu->arch.pc);
>> + return val;
>> +}
> can 4096 be replace with macro, or be wrapped in function get_gcsr_flag and add GCSR_VALID flag?
Thanks, I will wrap the condition "csr < 4096" in the get_gcsr_flag
function.
Thanks
Tianrui Zhao
>> +
>> +static void _kvm_emu_write_csr(struct kvm_vcpu *vcpu, int csrid,
>> + unsigned long val)
>> +{
>> + struct loongarch_csrs *csr = vcpu->arch.csr;
>> +
>> + if (csrid < 4096 && (get_gcsr_flag(csrid) & SW_GCSR))
>> + kvm_write_sw_gcsr(csr, csrid, val);
>> + else
>> + pr_warn_once("Unsupport csrwrite 0x%x with pc %lx\n",
>> + csrid, vcpu->arch.pc);
>> +}
> ditto
>
>> +
>> +static void _kvm_emu_xchg_csr(struct kvm_vcpu *vcpu, int csrid,
>> + unsigned long csr_mask, unsigned long val)
>> +{
>> + struct loongarch_csrs *csr = vcpu->arch.csr;
>> +
>> + if (csrid < 4096 && (get_gcsr_flag(csrid) & SW_GCSR)) {
>> + unsigned long orig;
>> +
>> + orig = kvm_read_sw_gcsr(csr, csrid);
>> + orig &= ~csr_mask;
>> + orig |= val & csr_mask;
>> + kvm_write_sw_gcsr(csr, csrid, orig);
>> + } else
>> + pr_warn_once("Unsupport csrxchg 0x%x with pc %lx\n",
>> + csrid, vcpu->arch.pc);
>> +}
> ditto
>
> Regards
> Bibo, Mao
>> +
>> +static int _kvm_handle_csr(struct kvm_vcpu *vcpu, larch_inst inst)
>> +{
>> + unsigned int rd, rj, csrid;
>> + unsigned long csr_mask;
>> + unsigned long val = 0;
>> +
>> + /*
>> + * CSR value mask imm
>> + * rj = 0 means csrrd
>> + * rj = 1 means csrwr
>> + * rj != 0,1 means csrxchg
>> + */
>> + rd = inst.reg2csr_format.rd;
>> + rj = inst.reg2csr_format.rj;
>> + csrid = inst.reg2csr_format.csr;
>> +
>> + /* Process CSR ops */
>> + if (rj == 0) {
>> + /* process csrrd */
>> + val = _kvm_emu_read_csr(vcpu, csrid);
>> + vcpu->arch.gprs[rd] = val;
>> + } else if (rj == 1) {
>> + /* process csrwr */
>> + val = vcpu->arch.gprs[rd];
>> + _kvm_emu_write_csr(vcpu, csrid, val);
>> + } else {
>> + /* process csrxchg */
>> + val = vcpu->arch.gprs[rd];
>> + csr_mask = vcpu->arch.gprs[rj];
>> + _kvm_emu_xchg_csr(vcpu, csrid, csr_mask, val);
>> + }
>> +
>> + return EMULATE_DONE;
>> +}