[PATCH v3 RESEND 1/5] RISC-V: KVM: Add the split page cache for ioctl context

[wang.yechao255 at zte.com.cn]

From: Wang Yechao <wang.yechao255 at zte.com.cn>

Add the split page cache for dirty logging enablement and the
KVM_CLEAR_DIRTY_LOG ioctl.

Signed-off-by: Wang Yechao <wang.yechao255 at zte.com.cn>
---
 arch/riscv/include/asm/kvm_host.h | 1 +
 arch/riscv/kvm/mmu.c              | 1 +
 arch/riscv/kvm/vm.c               | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 60017ceec9d2a..69f73fd106a94 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -86,6 +86,7 @@ struct kvm_arch {
 	pgd_t *pgd;
 	phys_addr_t pgd_phys;
 	unsigned long pgd_levels;
+	struct kvm_mmu_memory_cache pgd_split_page_cache;

 	/* Guest Timer */
 	struct kvm_guest_timer timer;
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index 082f9b2617338..9cf69bc28b9c5 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -676,6 +676,7 @@ int kvm_riscv_mmu_alloc_pgd(struct kvm *kvm)
 	kvm->arch.pgd = page_to_virt(pgd_page);
 	kvm->arch.pgd_phys = page_to_phys(pgd_page);
 	kvm->arch.pgd_levels = kvm_riscv_gstage_max_pgd_levels;
+	kvm->arch.pgd_split_page_cache.gfp_zero = __GFP_ZERO;

 	return 0;
 }
diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c
index a9f083feeb767..be38f24a297d6 100644
--- a/arch/riscv/kvm/vm.c
+++ b/arch/riscv/kvm/vm.c
@@ -54,6 +54,12 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_destroy_vcpus(kvm);

 	kvm_riscv_aia_destroy_vm(kvm);
+
+	/*
+	 * Free the split page cache after all vCPUs and devices are destroyed.
+	 * At this point, there are no concurrent accesses to the cache.
+	 */
+	kvm_mmu_free_memory_cache(&kvm->arch.pgd_split_page_cache);
 }

 int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irql,
-- 
2.43.5