On Wed, Apr 17, 2024 at 1:15 PM Yong-Xuan Wang <yongxuan.wang@xxxxxxxxxx> wrote:
>
> Originally, the use of kvm->lock in SBI_EXT_HSM_HART_START also avoids
> the simultaneous updates to the reset context of target VCPU. Since this
> lock has been replace with vcpu->mp_state_lock, and this new lock also
> protects the vcpu->mp_state. We have to add a separate lock for
> vcpu->reset_cntx.
>
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@xxxxxxxxxx>
LGTM.
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Regards,
Anup
> ---
> arch/riscv/include/asm/kvm_host.h | 1 +
> arch/riscv/kvm/vcpu.c | 6 ++++++
> arch/riscv/kvm/vcpu_sbi_hsm.c | 3 +++
> 3 files changed, 10 insertions(+)
>
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 64d35a8c908c..664d1bb00368 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -211,6 +211,7 @@ struct kvm_vcpu_arch {
>
> /* CPU context upon Guest VCPU reset */
> struct kvm_cpu_context guest_reset_context;
> + spinlock_t reset_cntx_lock;
>
> /* CPU CSR context upon Guest VCPU reset */
> struct kvm_vcpu_csr guest_reset_csr;
> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> index 70937f71c3c4..1a2236e4c7f3 100644
> --- a/arch/riscv/kvm/vcpu.c
> +++ b/arch/riscv/kvm/vcpu.c
> @@ -64,7 +64,9 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
>
> memcpy(csr, reset_csr, sizeof(*csr));
>
> + spin_lock(&vcpu->arch.reset_cntx_lock);
> memcpy(cntx, reset_cntx, sizeof(*cntx));
> + spin_unlock(&vcpu->arch.reset_cntx_lock);
>
> kvm_riscv_vcpu_fp_reset(vcpu);
>
> @@ -121,12 +123,16 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
> spin_lock_init(&vcpu->arch.hfence_lock);
>
> /* Setup reset state of shadow SSTATUS and HSTATUS CSRs */
> + spin_lock_init(&vcpu->arch.reset_cntx_lock);
> +
> + spin_lock(&vcpu->arch.reset_cntx_lock);
> cntx = &vcpu->arch.guest_reset_context;
> cntx->sstatus = SR_SPP | SR_SPIE;
> cntx->hstatus = 0;
> cntx->hstatus |= HSTATUS_VTW;
> cntx->hstatus |= HSTATUS_SPVP;
> cntx->hstatus |= HSTATUS_SPV;
> + spin_unlock(&vcpu->arch.reset_cntx_lock);
>
> if (kvm_riscv_vcpu_alloc_vector_context(vcpu, cntx))
> return -ENOMEM;
> diff --git a/arch/riscv/kvm/vcpu_sbi_hsm.c b/arch/riscv/kvm/vcpu_sbi_hsm.c
> index 115a6c6525fd..cc5038b90e02 100644
> --- a/arch/riscv/kvm/vcpu_sbi_hsm.c
> +++ b/arch/riscv/kvm/vcpu_sbi_hsm.c
> @@ -31,6 +31,7 @@ static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu)
> goto out;
> }
>
> + spin_lock(&target_vcpu->arch.reset_cntx_lock);
> reset_cntx = &target_vcpu->arch.guest_reset_context;
> /* start address */
> reset_cntx->sepc = cp->a1;
> @@ -38,6 +39,8 @@ static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu)
> reset_cntx->a0 = target_vcpuid;
> /* private data passed from kernel */
> reset_cntx->a1 = cp->a2;
> + spin_unlock(&target_vcpu->arch.reset_cntx_lock);
> +
> kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu);
>
> __kvm_riscv_vcpu_power_on(target_vcpu);
> --
> 2.17.1
>
