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@xxxxxxxxxxx>
> ---
> 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?
> +
> +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;
> +}
