Subject: Re: [PATCH v4 2/7] KVM: arm64: clean up redundant 'kvm_run' parameters

From: Vitaly Kuznetsov <[email-masked]>
Date: Wed, 29 Apr 2020 14:07:10 +0200

Tianjia Zhang <[email-masked]> writes:

> 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 <[email-masked]>
> ---
>  arch/arm64/include/asm/kvm_coproc.h | 12 +++++-----
>  arch/arm64/include/asm/kvm_host.h   | 11 ++++-----
>  arch/arm64/include/asm/kvm_mmu.h    |  2 +-
>  arch/arm64/kvm/handle_exit.c        | 36 ++++++++++++++---------------
>  arch/arm64/kvm/sys_regs.c           | 13 +++++------
>  virt/kvm/arm/arm.c                  |  6 ++---
>  virt/kvm/arm/mmio.c                 | 11 +++++----
>  virt/kvm/arm/mmu.c                  |  5 ++--
>  8 files changed, 46 insertions(+), 50 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_coproc.h b/arch/arm64/include/asm/kvm_coproc.h
> index 0185ee8b8b5e..454373704b8a 100644
> --- a/arch/arm64/include/asm/kvm_coproc.h
> +++ b/arch/arm64/include/asm/kvm_coproc.h
> @@ -27,12 +27,12 @@ struct kvm_sys_reg_target_table {
>  void kvm_register_target_sys_reg_table(unsigned int target,
>  				       struct kvm_sys_reg_target_table *table);
>  
> -int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run);
> -int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run);
> -int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run);
> -int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run);
> -int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run);
> -int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run);
> +int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu);
> +int kvm_handle_cp14_32(struct kvm_vcpu *vcpu);
> +int kvm_handle_cp14_64(struct kvm_vcpu *vcpu);
> +int kvm_handle_cp15_32(struct kvm_vcpu *vcpu);
> +int kvm_handle_cp15_64(struct kvm_vcpu *vcpu);
> +int kvm_handle_sys_reg(struct kvm_vcpu *vcpu);
>  
>  #define kvm_coproc_table_init kvm_sys_reg_table_init
>  void kvm_sys_reg_table_init(void);
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 32c8a675e5a4..3fab32e4948c 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -481,18 +481,15 @@ u64 __kvm_call_hyp(void *hypfn, ...);
>  void force_vm_exit(const cpumask_t *mask);
>  void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
>  
> -int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -		int exception_index);
> -void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -		       int exception_index);
> +int handle_exit(struct kvm_vcpu *vcpu, int exception_index);
> +void handle_exit_early(struct kvm_vcpu *vcpu, int exception_index);
>  
>  /* MMIO helpers */
>  void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
>  unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
>  
> -int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
> -int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -		 phys_addr_t fault_ipa);
> +int kvm_handle_mmio_return(struct kvm_vcpu *vcpu);
> +int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa);
>  
>  int kvm_perf_init(void);
>  int kvm_perf_teardown(void);
> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
> index 30b0e8d6b895..2ec7b9bb25d3 100644
> --- a/arch/arm64/include/asm/kvm_mmu.h
> +++ b/arch/arm64/include/asm/kvm_mmu.h
> @@ -159,7 +159,7 @@ void kvm_free_stage2_pgd(struct kvm *kvm);
>  int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
>  			  phys_addr_t pa, unsigned long size, bool writable);
>  
> -int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
> +int kvm_handle_guest_abort(struct kvm_vcpu *vcpu);
>  
>  void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
>  
> diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
> index aacfc55de44c..ec3a66642ea5 100644
> --- a/arch/arm64/kvm/handle_exit.c
> +++ b/arch/arm64/kvm/handle_exit.c
> @@ -25,7 +25,7 @@
>  #define CREATE_TRACE_POINTS
>  #include "trace.h"
>  
> -typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
> +typedef int (*exit_handle_fn)(struct kvm_vcpu *);
>  
>  static void kvm_handle_guest_serror(struct kvm_vcpu *vcpu, u32 esr)
>  {
> @@ -33,7 +33,7 @@ static void kvm_handle_guest_serror(struct kvm_vcpu *vcpu, u32 esr)
>  		kvm_inject_vabt(vcpu);
>  }
>  
> -static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int handle_hvc(struct kvm_vcpu *vcpu)
>  {
>  	int ret;
>  
> @@ -50,7 +50,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  	return ret;
>  }
>  
> -static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int handle_smc(struct kvm_vcpu *vcpu)
>  {
>  	/*
>  	 * "If an SMC instruction executed at Non-secure EL1 is
> @@ -69,7 +69,7 @@ static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
>   * Guest access to FP/ASIMD registers are routed to this handler only
>   * when the system doesn't support FP/ASIMD.
>   */
> -static int handle_no_fpsimd(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int handle_no_fpsimd(struct kvm_vcpu *vcpu)
>  {
>  	kvm_inject_undefined(vcpu);
>  	return 1;
> @@ -87,7 +87,7 @@ static int handle_no_fpsimd(struct kvm_vcpu *vcpu, struct kvm_run *run)
>   * world-switches and schedule other host processes until there is an
>   * incoming IRQ or FIQ to the VM.
>   */
> -static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int kvm_handle_wfx(struct kvm_vcpu *vcpu)
>  {
>  	if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) {
>  		trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true);
> @@ -109,16 +109,16 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
>   * kvm_handle_guest_debug - handle a debug exception instruction
>   *
>   * @vcpu:	the vcpu pointer
> - * @run:	access to the kvm_run structure for results
>   *
>   * We route all debug exceptions through the same handler. If both the
>   * guest and host are using the same debug facilities it will be up to
>   * userspace to re-inject the correct exception for guest delivery.
>   *
> - * @return: 0 (while setting run->exit_reason), -1 for error
> + * @return: 0 (while setting vcpu->run->exit_reason), -1 for error
>   */
> -static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu)
>  {
> +	struct kvm_run *run = vcpu->run;
>  	u32 hsr = kvm_vcpu_get_hsr(vcpu);
>  	int ret = 0;
>  
> @@ -144,7 +144,7 @@ static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  	return ret;
>  }
>  
> -static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu)
>  {
>  	u32 hsr = kvm_vcpu_get_hsr(vcpu);
>  
> @@ -155,7 +155,7 @@ static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  	return 1;
>  }
>  
> -static int handle_sve(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int handle_sve(struct kvm_vcpu *vcpu)
>  {
>  	/* Until SVE is supported for guests: */
>  	kvm_inject_undefined(vcpu);
> @@ -193,7 +193,7 @@ void kvm_arm_vcpu_ptrauth_trap(struct kvm_vcpu *vcpu)
>   * Guest usage of a ptrauth instruction (which the guest EL1 did not turn into
>   * a NOP).
>   */
> -static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu)
>  {
>  	kvm_arm_vcpu_ptrauth_trap(vcpu);
>  	return 1;
> @@ -238,7 +238,7 @@ static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
>   * KVM_EXIT_DEBUG, otherwise userspace needs to complete its
>   * emulation first.
>   */
> -static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +static int handle_trap_exceptions(struct kvm_vcpu *vcpu)
>  {
>  	int handled;
>  
> @@ -253,7 +253,7 @@ static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  		exit_handle_fn exit_handler;
>  
>  		exit_handler = kvm_get_exit_handler(vcpu);
> -		handled = exit_handler(vcpu, run);
> +		handled = exit_handler(vcpu);
>  	}
>  
>  	return handled;
> @@ -263,9 +263,10 @@ static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run)
>   * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
>   * proper exit to userspace.
>   */
> -int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -		       int exception_index)
> +int handle_exit(struct kvm_vcpu *vcpu, int exception_index)
>  {
> +	struct kvm_run *run = vcpu->run;
> +
>  	if (ARM_SERROR_PENDING(exception_index)) {
>  		u8 hsr_ec = ESR_ELx_EC(kvm_vcpu_get_hsr(vcpu));
>  
> @@ -291,7 +292,7 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
>  	case ARM_EXCEPTION_EL1_SERROR:
>  		return 1;
>  	case ARM_EXCEPTION_TRAP:
> -		return handle_trap_exceptions(vcpu, run);
> +		return handle_trap_exceptions(vcpu);
>  	case ARM_EXCEPTION_HYP_GONE:
>  		/*
>  		 * EL2 has been reset to the hyp-stub. This happens when a guest
> @@ -315,8 +316,7 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
>  }
>  
>  /* For exit types that need handling before we can be preempted */
> -void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -		       int exception_index)
> +void handle_exit_early(struct kvm_vcpu *vcpu, int exception_index)
>  {
>  	if (ARM_SERROR_PENDING(exception_index)) {
>  		if (this_cpu_has_cap(ARM64_HAS_RAS_EXTN)) {
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 51db934702b6..e5a0d0d676c8 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -2116,7 +2116,7 @@ static const struct sys_reg_desc *find_reg(const struct sys_reg_params *params,
>  	return bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
>  }
>  
> -int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu)
>  {
>  	kvm_inject_undefined(vcpu);
>  	return 1;
> @@ -2295,7 +2295,7 @@ static int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
>  	return 1;
>  }
>  
> -int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_cp15_64(struct kvm_vcpu *vcpu)
>  {
>  	const struct sys_reg_desc *target_specific;
>  	size_t num;
> @@ -2306,7 +2306,7 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  				target_specific, num);
>  }
>  
> -int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_cp15_32(struct kvm_vcpu *vcpu)
>  {
>  	const struct sys_reg_desc *target_specific;
>  	size_t num;
> @@ -2317,14 +2317,14 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  				target_specific, num);
>  }
>  
> -int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_cp14_64(struct kvm_vcpu *vcpu)
>  {
>  	return kvm_handle_cp_64(vcpu,
>  				cp14_64_regs, ARRAY_SIZE(cp14_64_regs),
>  				NULL, 0);
>  }
>  
> -int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_cp14_32(struct kvm_vcpu *vcpu)
>  {
>  	return kvm_handle_cp_32(vcpu,
>  				cp14_regs, ARRAY_SIZE(cp14_regs),
> @@ -2382,9 +2382,8 @@ static void reset_sys_reg_descs(struct kvm_vcpu *vcpu,
>  /**
>   * kvm_handle_sys_reg -- handles a mrs/msr trap on a guest sys_reg access
>   * @vcpu: The VCPU pointer
> - * @run:  The kvm_run struct
>   */
> -int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)
>  {
>  	struct sys_reg_params params;
>  	unsigned long esr = kvm_vcpu_get_hsr(vcpu);
> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> index f5390ac2165b..dbeb20804a75 100644
> --- a/virt/kvm/arm/arm.c
> +++ b/virt/kvm/arm/arm.c
> @@ -659,7 +659,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
>  		return ret;
>  
>  	if (run->exit_reason == KVM_EXIT_MMIO) {
> -		ret = kvm_handle_mmio_return(vcpu, run);
> +		ret = kvm_handle_mmio_return(vcpu);
>  		if (ret)
>  			return ret;
>  	}
> @@ -811,11 +811,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
>  		trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
>  
>  		/* Exit types that need handling before we can be preempted */
> -		handle_exit_early(vcpu, run, ret);
> +		handle_exit_early(vcpu, ret);
>  
>  		preempt_enable();
>  
> -		ret = handle_exit(vcpu, run, ret);
> +		ret = handle_exit(vcpu, ret);
>  	}
>  
>  	/* Tell userspace about in-kernel device output levels */
> diff --git a/virt/kvm/arm/mmio.c b/virt/kvm/arm/mmio.c
> index aedfcff99ac5..41ef5c5dbc62 100644
> --- a/virt/kvm/arm/mmio.c
> +++ b/virt/kvm/arm/mmio.c
> @@ -77,9 +77,8 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len)
>   *			     or in-kernel IO emulation
>   *
>   * @vcpu: The VCPU pointer
> - * @run:  The VCPU run struct containing the mmio data
>   */
> -int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_mmio_return(struct kvm_vcpu *vcpu)
>  {
>  	unsigned long data;
>  	unsigned int len;
> @@ -92,6 +91,8 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  	vcpu->mmio_needed = 0;
>  
>  	if (!kvm_vcpu_dabt_iswrite(vcpu)) {
> +		struct kvm_run *run = vcpu->run;
> +
>  		len = kvm_vcpu_dabt_get_as(vcpu);
>  		data = kvm_mmio_read_buf(run->mmio.data, len);
>  
> @@ -119,9 +120,9 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  	return 0;
>  }
>  
> -int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
> -		 phys_addr_t fault_ipa)
> +int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
>  {
> +	struct kvm_run *run = vcpu->run;
>  	unsigned long data;
>  	unsigned long rt;
>  	int ret;
> @@ -188,7 +189,7 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
>  		if (!is_write)
>  			memcpy(run->mmio.data, data_buf, len);
>  		vcpu->stat.mmio_exit_kernel++;
> -		kvm_handle_mmio_return(vcpu, run);
> +		kvm_handle_mmio_return(vcpu);
>  		return 1;
>  	}
>  
> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
> index e3b9ee268823..c5dc58226b5b 100644
> --- a/virt/kvm/arm/mmu.c
> +++ b/virt/kvm/arm/mmu.c
> @@ -1892,7 +1892,6 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
>  /**
>   * kvm_handle_guest_abort - handles all 2nd stage aborts
>   * @vcpu:	the VCPU pointer
> - * @run:	the kvm_run structure
>   *
>   * Any abort that gets to the host is almost guaranteed to be caused by a
>   * missing second stage translation table entry, which can mean that either the
> @@ -1901,7 +1900,7 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
>   * space. The distinction is based on the IPA causing the fault and whether this
>   * memory region has been registered as standard RAM by user space.
>   */
> -int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
>  {
>  	unsigned long fault_status;
>  	phys_addr_t fault_ipa;
> @@ -1980,7 +1979,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  		 * of the page size.
>  		 */
>  		fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
> -		ret = io_mem_abort(vcpu, run, fault_ipa);
> +		ret = io_mem_abort(vcpu, fault_ipa);
>  		goto out_unlock;
>  	}

Haven't tried to compile this but the change itself looks obviously
correct, so

Reviewed-by: Vitaly Kuznetsov <[email-masked]>

-- 
Vitaly