[RFC PATCH part-6 03/13] pkvm: x86: Initialize the shadow EPT pool

[Jason Chen CJ <jason.cj.chen@xxxxxxxxx>]

From: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>

Shadow EPT pool is the memory pool to allocate the memory for the shadow
EPT paging structure pages. When destroy a shadow EPT, these pages will
be put back to this pool again.

Signed-off-by: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>
---
 arch/x86/kvm/vmx/pkvm/hyp/ept.c           |  9 +++++++++
 arch/x86/kvm/vmx/pkvm/hyp/ept.h           |  1 +
 arch/x86/kvm/vmx/pkvm/hyp/init_finalise.c | 13 +++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/arch/x86/kvm/vmx/pkvm/hyp/ept.c b/arch/x86/kvm/vmx/pkvm/hyp/ept.c
index b0a542b47e83..14bc8f4429db 100644
--- a/arch/x86/kvm/vmx/pkvm/hyp/ept.c
+++ b/arch/x86/kvm/vmx/pkvm/hyp/ept.c
@@ -24,6 +24,8 @@ static struct hyp_pool host_ept_pool;
 static struct pkvm_pgtable host_ept;
 static pkvm_spinlock_t host_ept_lock = __PKVM_SPINLOCK_UNLOCKED;
 
+static struct hyp_pool shadow_ept_pool;
+
 static void flush_tlb_noop(void) { };
 static void *host_ept_zalloc_page(void)
 {
@@ -221,3 +223,10 @@ int handle_host_ept_violation(unsigned long gpa)
 	pkvm_spin_unlock(&host_ept_lock);
 	return ret;
 }
+
+int pkvm_shadow_ept_pool_init(void *ept_pool_base, unsigned long ept_pool_pages)
+{
+	unsigned long pfn = __pkvm_pa(ept_pool_base) >> PAGE_SHIFT;
+
+	return hyp_pool_init(&shadow_ept_pool, pfn, ept_pool_pages, 0);
+}
diff --git a/arch/x86/kvm/vmx/pkvm/hyp/ept.h b/arch/x86/kvm/vmx/pkvm/hyp/ept.h
index d517bf8ec169..c4ad5c269d5c 100644
--- a/arch/x86/kvm/vmx/pkvm/hyp/ept.h
+++ b/arch/x86/kvm/vmx/pkvm/hyp/ept.h
@@ -17,5 +17,6 @@ int pkvm_host_ept_unmap(unsigned long vaddr_start, unsigned long phys_start,
 int pkvm_host_ept_init(struct pkvm_pgtable_cap *cap, void *ept_pool_base,
 		unsigned long ept_pool_pages);
 int handle_host_ept_violation(unsigned long gpa);
+int pkvm_shadow_ept_pool_init(void *ept_pool_base, unsigned long ept_pool_pages);
 
 #endif
diff --git a/arch/x86/kvm/vmx/pkvm/hyp/init_finalise.c b/arch/x86/kvm/vmx/pkvm/hyp/init_finalise.c
index c16b53b7bcd0..8d52a20f6497 100644
--- a/arch/x86/kvm/vmx/pkvm/hyp/init_finalise.c
+++ b/arch/x86/kvm/vmx/pkvm/hyp/init_finalise.c
@@ -23,6 +23,7 @@
 void *pkvm_mmu_pgt_base;
 void *pkvm_vmemmap_base;
 void *host_ept_pgt_base;
+static void *shadow_ept_base;
 
 static int divide_memory_pool(phys_addr_t phys, unsigned long size)
 {
@@ -49,6 +50,12 @@ static int divide_memory_pool(phys_addr_t phys, unsigned long size)
 	if (!host_ept_pgt_base)
 		return -ENOMEM;
 
+	nr_pages = pkvm_shadow_ept_pgtable_pages(PKVM_MAX_NORMAL_VM_NUM +
+						 PKVM_MAX_PROTECTED_VM_NUM);
+	shadow_ept_base = pkvm_early_alloc_contig(nr_pages);
+	if (!shadow_ept_base)
+		return -ENOMEM;
+
 	return 0;
 }
 
@@ -291,6 +298,12 @@ int __pkvm_init_finalise(struct kvm_vcpu *vcpu, struct pkvm_section sections[],
 
 	pkvm_init_nest();
 
+	ret = pkvm_shadow_ept_pool_init(shadow_ept_base,
+					pkvm_shadow_ept_pgtable_pages(PKVM_MAX_NORMAL_VM_NUM +
+								      PKVM_MAX_PROTECTED_VM_NUM));
+	if (ret)
+		goto out;
+
 	pkvm_init = true;
 
 switch_pgt:
-- 
2.25.1