Re: [PATCH v2] RISC-V: KVM: Serialize and atomize the IMSIC's TOPEI read-and-clear operation

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] riscv: kvm: build error due to undeclared 'eflags'
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commit 216b97a6c827bbe2a6897aa0efd6984c531cf514
Author: BillXiang <xiangwencheng@lanxincomputing.com>

RISC-V: KVM: Serialize and atomize the IMSIC's TOPEI read-and-clear operation
    
This commit adds synchronization to the IMSIC TOPEI read-and-clear path to
ensure it remains atomic with respect to interrupt injections.

Link: https://lore.kernel.org/kvm-riscv/20260923070332.1376132-1-xiangwencheng@lanxincomputing.com/

> diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c
> index c1af23e79ae06..490c55419eb22 100644
> --- a/arch/riscv/kvm/aia_imsic.c
> +++ b/arch/riscv/kvm/aia_imsic.c

[ ... ]

> @@ -912,12 +911,15 @@ int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu, unsigned long isel,
>  	struct imsic_mrif_eix *eix;
>  	int r, rc = KVM_INSN_CONTINUE_NEXT_SEPC;
>  	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> +	unsigned long flags;
>  
>  	/* If IMSIC vCPU state not initialized then forward to user space */
>  	if (!imsic)
>  		return KVM_INSN_EXIT_TO_USER_SPACE;
>  
>  	if (isel == KVM_RISCV_AIA_IMSIC_TOPEI) {
> +		raw_spin_lock_irqsave(&imsic->swfile_extirq_lock, flags);
> +
>  		/* Read pending and enabled interrupt with highest priority */
>  		topei = imsic_mrif_topei(imsic->swfile, imsic->nr_eix,
>  					 imsic->nr_msis);

[ ... ]

> @@ -934,16 +936,20 @@ int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu, unsigned long isel,
>  					  eix->eip);
>  			}
>  		}
> +		if (wr_mask)
> +			__imsic_swfile_extirq_update(vcpu);
> +
> +		raw_spin_unlock_irqrestore(&imsic->swfile_extirq_lock, eflags);

[Severity: Low]
Does this cause a build failure? The local variable is declared as flags at
the top of kvm_riscv_vcpu_aia_imsic_rmw(), but this unlock path attempts to
use eflags instead, which appears to be undeclared.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260923085631.1384021-1-xiangwencheng@lanxincomputing.com?part=1