[Backport] KVM support THP and huge pages spliting for dirty logging

[yechao-w]

支持THP以及巨页虚机dirty logging

• 1. Gstage支持大页映射，提升虚拟机内存访问性能；
  https://lore.kernel.org/r/20251127165137780QbUOVPKPAfWSGAFl5qtRy@zte.com.cn

编号	Commit	信息
1	ed7ae7a	RISC-V: KVM: Transparent huge page support

• 2. Gstage巨页拆分，支持巨页场景（HugeTlb，THP）虚拟机迁移；
  https://lore.kernel.org/r/202603301612587174XZ6QMCrymBqv30S6BN50@zte.com.cn

编号	Commit	信息
1	b342166	RISC-V: KVM: Skip THP support check during dirty logging
2	a216e24	RISC-V: KVM: Fix lost write protection on huge pages during dirty logging
3	6ad36f3	RISC-V: KVM: Split huge pages during fault handling for dirty logging

前置依赖：

• riscv: Support huge pfnmaps
  https://lore.kernel.org/r/20250108135700.2614848-1-abrestic@rivosinc.com

编号	Commit	信息
1	03dc00a	riscv: Support huge pfnmaps

• MMU related improvements for KVM RISC-V
  https://lore.kernel.org/all/20250618113532.471448-1-apatel@ventanamicro.com/

编号	Commit	信息
1/12	4a50578	RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value
2/12	7c67de2	RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init()
3/12	b79bf20	RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize()
4/12	7584eb6	RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH
5/12	eaa98ba	RISC-V: KVM: Don't flush TLB when PTE is unchanged
6/12	ca539ba	RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range()
7/12	77ba646	RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect()
8/12	4ecbd3e	RISC-V: KVM: Factor-out MMU related declarations into separate headers
9/12	f035b44	RISC-V: KVM: Introduce struct kvm_gstage_mapping
10/12	4c933f3	RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence
11/12	dd82e35	RISC-V: KVM: Factor-out g-stage page table management
12/12	1f6d0ee	RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs
fix	dec9ed9	RISC-V: KVM: Fix use-after-free in kvm_riscv_gstage_get_leaf()