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    Subject[PATCH v4 7/7] KVM: MIPS: clean up redundant kvm_run parameters in assembly
    Date
    In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
    structure. For historical reasons, many kvm-related function parameters
    retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
    patch does a unified cleanup of these remaining redundant parameters.

    Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
    ---
    arch/mips/include/asm/kvm_host.h | 4 ++--
    arch/mips/kvm/entry.c | 21 ++++++++-------------
    arch/mips/kvm/mips.c | 3 ++-
    arch/mips/kvm/trap_emul.c | 2 +-
    arch/mips/kvm/vz.c | 2 +-
    5 files changed, 14 insertions(+), 18 deletions(-)

    diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
    index 971439297cea..db915c55166d 100644
    --- a/arch/mips/include/asm/kvm_host.h
    +++ b/arch/mips/include/asm/kvm_host.h
    @@ -310,7 +310,7 @@ struct kvm_mmu_memory_cache {
    #define KVM_MIPS_GUEST_TLB_SIZE 64
    struct kvm_vcpu_arch {
    void *guest_ebase;
    - int (*vcpu_run)(struct kvm_run *run, struct kvm_vcpu *vcpu);
    + int (*vcpu_run)(struct kvm_vcpu *vcpu);

    /* Host registers preserved across guest mode execution */
    unsigned long host_stack;
    @@ -821,7 +821,7 @@ int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);
    /* Debug: dump vcpu state */
    int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);

    -extern int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu);
    +extern int kvm_mips_handle_exit(struct kvm_vcpu *vcpu);

    /* Building of entry/exception code */
    int kvm_mips_entry_setup(void);
    diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
    index 16e1c93b484f..1083f35361ea 100644
    --- a/arch/mips/kvm/entry.c
    +++ b/arch/mips/kvm/entry.c
    @@ -204,7 +204,7 @@ static inline void build_set_exc_base(u32 **p, unsigned int reg)
    * Assemble the start of the vcpu_run function to run a guest VCPU. The function
    * conforms to the following prototype:
    *
    - * int vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
    + * int vcpu_run(struct kvm_vcpu *vcpu);
    *
    * The exit from the guest and return to the caller is handled by the code
    * generated by kvm_mips_build_ret_to_host().
    @@ -217,8 +217,7 @@ void *kvm_mips_build_vcpu_run(void *addr)
    unsigned int i;

    /*
    - * A0: run
    - * A1: vcpu
    + * A0: vcpu
    */

    /* k0/k1 not being used in host kernel context */
    @@ -237,10 +236,10 @@ void *kvm_mips_build_vcpu_run(void *addr)
    kvm_mips_build_save_scratch(&p, V1, K1);

    /* VCPU scratch register has pointer to vcpu */
    - UASM_i_MTC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]);
    + UASM_i_MTC0(&p, A0, scratch_vcpu[0], scratch_vcpu[1]);

    /* Offset into vcpu->arch */
    - UASM_i_ADDIU(&p, K1, A1, offsetof(struct kvm_vcpu, arch));
    + UASM_i_ADDIU(&p, K1, A0, offsetof(struct kvm_vcpu, arch));

    /*
    * Save the host stack to VCPU, used for exception processing
    @@ -628,10 +627,7 @@ void *kvm_mips_build_exit(void *addr)
    /* Now that context has been saved, we can use other registers */

    /* Restore vcpu */
    - UASM_i_MFC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);
    -
    - /* Restore run (vcpu->run) */
    - UASM_i_LW(&p, S0, offsetof(struct kvm_vcpu, run), S1);
    + UASM_i_MFC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);

    /*
    * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
    @@ -793,7 +789,6 @@ void *kvm_mips_build_exit(void *addr)
    * with this in the kernel
    */
    uasm_i_move(&p, A0, S0);
    - uasm_i_move(&p, A1, S1);
    UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
    uasm_i_jalr(&p, RA, T9);
    UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ);
    @@ -835,7 +830,7 @@ static void *kvm_mips_build_ret_from_exit(void *addr)
    * guest, reload k1
    */

    - uasm_i_move(&p, K1, S1);
    + uasm_i_move(&p, K1, S0);
    UASM_i_ADDIU(&p, K1, K1, offsetof(struct kvm_vcpu, arch));

    /*
    @@ -869,8 +864,8 @@ static void *kvm_mips_build_ret_to_guest(void *addr)
    {
    u32 *p = addr;

    - /* Put the saved pointer to vcpu (s1) back into the scratch register */
    - UASM_i_MTC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);
    + /* Put the saved pointer to vcpu (s0) back into the scratch register */
    + UASM_i_MTC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);

    /* Load up the Guest EBASE to minimize the window where BEV is set */
    UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, guest_ebase), K1);
    diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
    index 9710477a9827..32850470c037 100644
    --- a/arch/mips/kvm/mips.c
    +++ b/arch/mips/kvm/mips.c
    @@ -1186,8 +1186,9 @@ static void kvm_mips_set_c0_status(void)
    /*
    * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
    */
    -int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
    +int kvm_mips_handle_exit(struct kvm_vcpu *vcpu)
    {
    + struct kvm_run *run = vcpu->run;
    u32 cause = vcpu->arch.host_cp0_cause;
    u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
    u32 __user *opc = (u32 __user *) vcpu->arch.pc;
    diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
    index d822f3aee3dc..04c864cc356a 100644
    --- a/arch/mips/kvm/trap_emul.c
    +++ b/arch/mips/kvm/trap_emul.c
    @@ -1238,7 +1238,7 @@ static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
    */
    kvm_mips_suspend_mm(cpu);

    - r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
    + r = vcpu->arch.vcpu_run(vcpu);

    /* We may have migrated while handling guest exits */
    cpu = smp_processor_id();
    diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
    index 94f1d23828e3..c5878fa0636d 100644
    --- a/arch/mips/kvm/vz.c
    +++ b/arch/mips/kvm/vz.c
    @@ -3152,7 +3152,7 @@ static int kvm_vz_vcpu_run(struct kvm_vcpu *vcpu)
    kvm_vz_vcpu_load_tlb(vcpu, cpu);
    kvm_vz_vcpu_load_wired(vcpu);

    - r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
    + r = vcpu->arch.vcpu_run(vcpu);

    kvm_vz_vcpu_save_wired(vcpu);

    --
    2.17.1
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