Refactor sevstep kernel patch into repository

1 files changed, 205 insertions, 0 deletions

diff --git a/sevstep/kvm.c b/sevstep/kvm.c
new file mode 100644
index 0000000..b6b0d49
--- /dev/null
+++ b/sevstep/kvm.c
@@ -0,0 +1,205 @@
+#include "kvm.h"
+
+#include <linux/types.h>
+
+bool
+__untrack_single_page(struct kvm_vcpu *vcpu, gfn_t gfn,
+	enum kvm_page_track_mode mode)
+{
+	int idx;
+	bool ret;
+	struct kvm_memory_slot *slot;
+
+	ret = false;
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
+	if (mode == KVM_PAGE_TRACK_ACCESS) {
+		//printk("Removing gfn: %016llx from acess page track pool\n", gfn);
+	}
+	if (mode == KVM_PAGE_TRACK_WRITE) {
+		//printk("Removing gfn: %016llx from write page track pool\n", gfn);
+	}
+	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+
+	if (slot != NULL && kvm_slot_page_track_is_active(vcpu->kvm, slot, gfn, mode)) {
+		write_lock(&vcpu->kvm->mmu_lock);
+		kvm_slot_page_track_remove_page(vcpu->kvm, slot, gfn, mode);
+		write_unlock(&vcpu->kvm->mmu_lock);
+		ret = true;
+	} else {
+		printk("Failed to untrack %016llx because ", gfn);
+		if (slot == NULL) {
+			printk(KERN_CONT "slot was	null");
+		} else if (!kvm_slot_page_track_is_active(vcpu->kvm, slot, gfn, mode)) {
+			printk(KERN_CONT "page track was not active");
+		}
+		printk(KERN_CONT "\n");
+	}
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
+	return ret;
+}
+EXPORT_SYMBOL(__untrack_single_page);
+
+bool
+__reset_accessed_on_page(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+	int idx;
+	bool ret;
+	struct kvm_memory_slot *slot;
+
+	ret = false;
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
+	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+	if( slot != NULL ) {
+		write_lock(&vcpu->kvm->mmu_lock);
+		//Vincent: The kvm mmu function now requires min_level
+		//We want all pages to protected so we do PG_LEVEL_4K
+		//https://patchwork.kernel.org/project/kvm/patch/20210416082511.2856-2-zhukeqian1@huawei.com/
+		sevstep_kvm_mmu_slot_gfn_protect(vcpu->kvm,slot,gfn,PG_LEVEL_4K,KVM_PAGE_TRACK_RESET_ACCESSED);
+		write_unlock(&vcpu->kvm->mmu_lock);
+		ret = true;
+	}
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
+	return ret;
+}
+EXPORT_SYMBOL(__reset_accessed_on_page);
+
+bool
+__clear_nx_on_page(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+	int idx;
+	bool ret;
+	struct kvm_memory_slot *slot;
+
+	ret = false;
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
+	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+	if( slot != NULL ) {
+		write_lock(&vcpu->kvm->mmu_lock);
+		//Vincent: The kvm mmu function now requires min_level
+		//We want all pages to protected so we do PG_LEVEL_4K
+		//https://patchwork.kernel.org/project/kvm/patch/20210416082511.2856-2-zhukeqian1@huawei.com/
+		sevstep_kvm_mmu_slot_gfn_protect(vcpu->kvm, slot, gfn,
+			PG_LEVEL_4K, KVM_PAGE_TRACK_RESET_EXEC);
+		write_unlock(&vcpu->kvm->mmu_lock);
+		ret = true;
+	}
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
+	return ret;
+}
+EXPORT_SYMBOL(__clear_nx_on_page);
+
+bool
+__track_single_page(struct kvm_vcpu *vcpu, gfn_t gfn,
+	enum kvm_page_track_mode mode)
+{
+	int idx;
+	bool ret;
+	struct kvm_memory_slot *slot;
+
+	ret = false;
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
+	if (mode == KVM_PAGE_TRACK_ACCESS) {
+		//printk_ratelimited("Adding gfn: %016llx to acess page track pool\n", gfn);
+		//printk("Adding gfn: %016llx to acess page track pool\n", gfn);
+	}
+	if (mode == KVM_PAGE_TRACK_WRITE) {
+		//printk_ratelimited("Adding gfn: %016llx to write page track pool\n", gfn);
+	}
+	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+	if (slot != NULL && !kvm_slot_page_track_is_active(vcpu->kvm,slot, gfn, mode)) {
+
+		write_lock(&vcpu->kvm->mmu_lock);
+		kvm_slot_page_track_add_page(vcpu->kvm, slot, gfn, mode);
+		write_unlock(&vcpu->kvm->mmu_lock);
+		ret = true;
+
+	} else {
+
+		printk("Failed to track %016llx because ", gfn);
+		if (slot == NULL) {
+			printk(KERN_CONT "slot was	null");
+		}
+		if (kvm_slot_page_track_is_active(vcpu->kvm, slot, gfn, mode)) {
+			printk(KERN_CONT "page is already tracked");
+		}
+		printk(KERN_CONT "\n");
+	}
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
+	return ret;
+}
+EXPORT_SYMBOL(__track_single_page);
+
+long
+kvm_start_tracking(struct kvm_vcpu *vcpu,enum kvm_page_track_mode mode )
+{
+	long count = 0;
+	u64 iterator, iterat_max;
+	struct kvm_memory_slot *slot;
+	int idx;
+
+	//Vincent: Memslots interface changed into a rb tree, see
+	//here: https://lwn.net/Articles/856392/
+	//and here: https://lore.kernel.org/all/cover.1632171478.git.maciej.szmigiero@oracle.com/T/#u
+	//Thus we use instead of
+	//iterat_max = vcpu->kvm->memslots[0]->memslots[0].base_gfn
+	//	     + vcpu->kvm->memslots[0]->memslots[0].npages;
+	struct rb_node *node;
+	struct kvm_memory_slot *first_memslot;
+	node = rb_last(&(vcpu->kvm->memslots[0]->gfn_tree));
+	first_memslot = container_of(node, struct kvm_memory_slot, gfn_node[0]);
+	iterat_max = first_memslot->base_gfn + first_memslot->npages;
+	for (iterator=0; iterator < iterat_max; iterator++)
+	{
+		idx = srcu_read_lock(&vcpu->kvm->srcu);
+		slot = kvm_vcpu_gfn_to_memslot(vcpu, iterator);
+		if ( slot != NULL  && !kvm_slot_page_track_is_active(vcpu->kvm, slot, iterator, mode)) {
+			write_lock(&vcpu->kvm->mmu_lock);
+			kvm_slot_page_track_add_page(vcpu->kvm, slot, iterator, mode);
+			write_unlock(&vcpu->kvm->mmu_lock);
+			count++;
+		}
+		srcu_read_unlock(&vcpu->kvm->srcu, idx);
+	}
+
+	return count;
+}
+EXPORT_SYMBOL(kvm_start_tracking);
+
+long
+kvm_stop_tracking(struct kvm_vcpu *vcpu,enum kvm_page_track_mode mode)
+{
+	long count = 0;
+	u64 iterator, iterat_max;
+	struct kvm_memory_slot *slot;
+	int idx;
+
+
+	//Vincent: Memslots interface changed into a rb tree, see
+	//here: https://lwn.net/Articles/856392/
+	//and here: https://lore.kernel.org/all/cover.1632171478.git.maciej.szmigiero@oracle.com/T/#u
+	//Thus we use instead of
+	//iterat_max = vcpu->kvm->memslots[0]->memslots[0].base_gfn
+	//	     + vcpu->kvm->memslots[0]->memslots[0].npages;
+	struct rb_node *node;
+	struct kvm_memory_slot *first_memslot;
+	node = rb_last(&(vcpu->kvm->memslots[0]->gfn_tree));
+	first_memslot = container_of(node, struct kvm_memory_slot, gfn_node[0]);
+	iterat_max = first_memslot->base_gfn + first_memslot->npages;
+	for (iterator=0; iterator < iterat_max; iterator++)
+	{
+		idx = srcu_read_lock(&vcpu->kvm->srcu);
+		slot = kvm_vcpu_gfn_to_memslot(vcpu, iterator);
+			//Vincent: I think see here https://patchwork.kernel.org/project/kvm/patch/20210924163152.289027-22-pbonzini@redhat.com/
+			if ( slot != NULL && kvm_slot_page_track_is_active(vcpu->kvm, slot, iterator, mode)) {
+				write_lock(&vcpu->kvm->mmu_lock);
+				kvm_slot_page_track_remove_page(vcpu->kvm, slot, iterator, mode);
+				write_unlock(&vcpu->kvm->mmu_lock);
+				count++;
+		}
+		srcu_read_unlock(&vcpu->kvm->srcu, idx);
+	}
+
+	return count;
+}
+EXPORT_SYMBOL(kvm_stop_tracking);
+