RISC-V: KVM: Skip THP support check during dirty logging

When dirty logging is enabled, guest stage mappings are forced to
PAGE_SIZE granularity. Changing the mapping page size at this point
is incorrect.

Fixes: ed7ae7a ("RISC-V: KVM: Transparent huge page support")
Signed-off-by: Wang Yechao <wang.yechao255@zte.com.cn>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260226191231140_X1Juus7s2kgVlc0ZyW_K@zte.com.cn
Signed-off-by: Anup Patel <anup@brainfault.org>

Author: yechao-w

arch/riscv/kvm/mmu.c

@@ -539,7 +539,7 @@ int kvm_riscv_mmu_map(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
 		goto out_unlock;
 
 	/* Check if we are backed by a THP and thus use block mapping if possible */
-	if (vma_pagesize == PAGE_SIZE)
+	if (!logging && (vma_pagesize == PAGE_SIZE))
 		vma_pagesize = transparent_hugepage_adjust(kvm, memslot, hva, &hfn, &gpa);
 
 	if (writable) {