From: Bibo Mao Date: Thu, 24 Apr 2025 12:15:52 +0000 (+0800) Subject: LoongArch: KVM: Fully clear some CSRs when VM reboot X-Git-Tag: v6.15-rc4~7^2~1 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=9ea86232a5520d9d21832d06031ea80f055a6ff8;p=linux-2.6-block.git LoongArch: KVM: Fully clear some CSRs when VM reboot Some registers such as LOONGARCH_CSR_ESTAT and LOONGARCH_CSR_GINTC are partly cleared with function _kvm_setcsr(). This comes from the hardware specification, some bits are read only in VM mode, and however they can be written in host mode. So they are partly cleared in VM mode, and can be fully cleared in host mode. These read only bits show pending interrupt or exception status. When VM reset, the read-only bits should be cleared, otherwise vCPU will receive unknown interrupts in boot stage. Here registers LOONGARCH_CSR_ESTAT/LOONGARCH_CSR_GINTC are fully cleared in ioctl KVM_REG_LOONGARCH_VCPU_RESET vCPU reset path. Cc: stable@vger.kernel.org Signed-off-by: Bibo Mao Signed-off-by: Huacai Chen --- diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index 8e427b379661..2d3c2a2d1d1c 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -902,6 +902,13 @@ static int kvm_set_one_reg(struct kvm_vcpu *vcpu, vcpu->arch.st.guest_addr = 0; memset(&vcpu->arch.irq_pending, 0, sizeof(vcpu->arch.irq_pending)); memset(&vcpu->arch.irq_clear, 0, sizeof(vcpu->arch.irq_clear)); + + /* + * When vCPU reset, clear the ESTAT and GINTC registers + * Other CSR registers are cleared with function _kvm_setcsr(). + */ + kvm_write_sw_gcsr(vcpu->arch.csr, LOONGARCH_CSR_GINTC, 0); + kvm_write_sw_gcsr(vcpu->arch.csr, LOONGARCH_CSR_ESTAT, 0); break; default: ret = -EINVAL;