From d547106ed940ac95669622d9a12b1de225a422d4 Mon Sep 17 00:00:00 2001 From: Fangyu Yu Date: Sat, 16 Aug 2025 15:32:34 +0800 Subject: [PATCH] RISC-V: KVM: Write hgatp register with valid mode bits According to the RISC-V Privileged Architecture Spec, when MODE=Bare is selected,software must write zero to the remaining fields of hgatp. We have detected the valid mode supported by the HW before, So using a valid mode to detect how many vmid bits are supported. Signed-off-by: Fangyu Yu Signed-off-by: Linux RISC-V bot --- arch/riscv/kvm/vmid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c index 3b426c800480c8..d176a5c2f9a419 100644 --- a/arch/riscv/kvm/vmid.c +++ b/arch/riscv/kvm/vmid.c @@ -28,7 +28,7 @@ void __init kvm_riscv_gstage_vmid_detect(void) /* Figure-out number of VMID bits in HW */ old = csr_read(CSR_HGATP); - csr_write(CSR_HGATP, old | HGATP_VMID); + csr_write(CSR_HGATP, (kvm_riscv_gstage_mode() << HGATP_MODE_SHIFT) | HGATP_VMID); vmid_bits = csr_read(CSR_HGATP); vmid_bits = (vmid_bits & HGATP_VMID) >> HGATP_VMID_SHIFT; vmid_bits = fls_long(vmid_bits);