RISC-V: KVM: lock the correct mp_state during reset

[PATCH] RISC-V: KVM: lock the correct mp_state during reset

Posted by Radim Krčmář 7 months ago

We're writing to *tmp, but locking *vcpu.

Fixes: 2121cadec45a ("RISCV: KVM: Introduce mp_state_lock to avoid lock inversion")
Signed-off-by: Radim Krčmář <rkrcmar@ventanamicro.com>
---
 arch/riscv/kvm/vcpu_sbi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 31fd3cc98d66..6e09b518a5d1 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -143,9 +143,9 @@ void kvm_riscv_vcpu_sbi_system_reset(struct kvm_vcpu *vcpu,
 	struct kvm_vcpu *tmp;
 
 	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
-		spin_lock(&vcpu->arch.mp_state_lock);
+		spin_lock(&tmp->arch.mp_state_lock);
 		WRITE_ONCE(tmp->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
-		spin_unlock(&vcpu->arch.mp_state_lock);
+		spin_unlock(&tmp->arch.mp_state_lock);
 	}
 	kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
 
-- 
2.49.0

Re: [PATCH] RISC-V: KVM: lock the correct mp_state during reset

Posted by Anup Patel 6 months, 4 weeks ago

On Fri, May 23, 2025 at 4:22 PM Radim Krčmář <rkrcmar@ventanamicro.com> wrote:
>
> We're writing to *tmp, but locking *vcpu.
>
> Fixes: 2121cadec45a ("RISCV: KVM: Introduce mp_state_lock to avoid lock inversion")
> Signed-off-by: Radim Krčmář <rkrcmar@ventanamicro.com>

LGTM.

Reviewed-by: Anup Patel <anup@brainfault.org>

Improved commit description at the time of queuing.

Queued this patch for Linux-6.16

Thanks,
Anup

> ---
>  arch/riscv/kvm/vcpu_sbi.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
> index 31fd3cc98d66..6e09b518a5d1 100644
> --- a/arch/riscv/kvm/vcpu_sbi.c
> +++ b/arch/riscv/kvm/vcpu_sbi.c
> @@ -143,9 +143,9 @@ void kvm_riscv_vcpu_sbi_system_reset(struct kvm_vcpu *vcpu,
>         struct kvm_vcpu *tmp;
>
>         kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
> -               spin_lock(&vcpu->arch.mp_state_lock);
> +               spin_lock(&tmp->arch.mp_state_lock);
>                 WRITE_ONCE(tmp->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
> -               spin_unlock(&vcpu->arch.mp_state_lock);
> +               spin_unlock(&tmp->arch.mp_state_lock);
>         }
>         kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
>
> --
> 2.49.0
>