RISC-V: KVM: Remove unnecessary HGATP csr_read

The HGATP has been set to zero in gstage_mode_detect(), so there
is no need to save the old context. Unify the code convention
with gstage_mode_detect().

Reviewed-by: Fangyu Yu <fangyu.yu@linux.alibaba.com>
Signed-off-by: Fangyu Yu <fangyu.yu@linux.alibaba.com>
Signed-off-by: Guo Ren (Alibaba DAMO Academy) <guoren@kernel.org>
Reviewed-by: Nutty Liu <nutty.liu@hotmail.com>
Link: https://lore.kernel.org/r/20250821142542.2472079-3-guoren@kernel.org
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c
index 5f33625f40706535f50fb3e814932845f937e748..abb1c2bf25423444e6e7d336141830773f2d4696 100644 (file)
--- a/arch/riscv/kvm/vmid.c
+++ b/arch/riscv/kvm/vmid.c
@@ -25,15 +25,12 @@ static DEFINE_SPINLOCK(vmid_lock);
 
 void __init kvm_riscv_gstage_vmid_detect(void)
 {
-       unsigned long old;
-
        /* Figure-out number of VMID bits in HW */
-       old = csr_read(CSR_HGATP);
        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);
-       csr_write(CSR_HGATP, old);
+       csr_write(CSR_HGATP, 0);
 
        /* We polluted local TLB so flush all guest TLB */
        kvm_riscv_local_hfence_gvma_all();