Introduce a function kvmhv_update_nest_rmap_rc_list() which for a given
nest_rmap list will traverse it, find the corresponding pte in the shadow
page tables, and if it still maps the same host page update the rc bits
accordingly.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx>
---
arch/powerpc/include/asm/kvm_book3s.h | 2 ++
arch/powerpc/include/asm/kvm_book3s_64.h | 3 ++
arch/powerpc/kvm/book3s_64_mmu_radix.c | 4 +--
arch/powerpc/kvm/book3s_hv_nested.c | 51 ++++++++++++++++++++++++++++++++
4 files changed, 58 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 09f8e9ba69bc..fa9240c8f318 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -196,6 +196,8 @@ extern int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
int table_index, u64 *pte_ret_p);
extern int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, bool data, bool iswrite);
+extern void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
+ unsigned int pshift, unsigned int lpid);
extern void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
unsigned int shift, struct kvm_memory_slot *memslot,
unsigned int lpid);
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 6d298145d564..2a57c99d576f 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -624,6 +624,9 @@ extern int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
unsigned long *rmapp, struct rmap_nested **n_rmap);
extern void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
struct rmap_nested **n_rmap);
+extern void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long clr, unsigned long set,
+ unsigned long hpa, unsigned long nbytes);
extern void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
struct kvm_memory_slot *memslot,
unsigned long gpa, unsigned long hpa,
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index d68162ee159b..f920664aaa11 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -197,8 +197,8 @@ int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
return 0;
}
-static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
- unsigned int pshift, unsigned int lpid)
+void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
+ unsigned int pshift, unsigned int lpid)
{
unsigned long psize = PAGE_SIZE;
int psi;
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 4a52f82649e5..e69003aaf61d 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -687,6 +687,57 @@ void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
*n_rmap = NULL;
}
+static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap,
+ unsigned long clr, unsigned long set,
+ unsigned long hpa, unsigned long mask)
+{
+ struct kvm_nested_guest *gp;
+ unsigned long gpa;
+ unsigned int shift, lpid;
+ pte_t *ptep;
+
+ gpa = n_rmap & RMAP_NESTED_GPA_MASK;
+ lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
+ gp = kvmhv_find_nested(kvm, lpid);
+ if (!gp)
+ return;
+
+ /* Find the pte */
+ ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift);
+ /*
+ * If the pte is present and the pfn is still the same, update the pte.
+ * If the pfn has changed then this is a stale rmap entry, the nested
+ * gpa actually points somewhere else now, and there is nothing to do.
+ * XXX A future optimisation would be to remove the rmap entry here.
+ */
+ if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) {
+ __radix_pte_update(ptep, clr, set);
+ kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
+ }
+}
+
+/*
+ * For a given list of rmap entries, update the rc bits in all ptes in shadow
+ * page tables for nested guests which are referenced by the rmap list.
+ */
+void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long clr, unsigned long set,
+ unsigned long hpa, unsigned long nbytes)
+{
+ struct llist_node *entry = ((struct llist_head *) rmapp)->first;
+ struct rmap_nested *cursor;
+ unsigned long rmap, mask;
+
+ if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED))
+ return;
+
+ mask = PTE_RPN_MASK & ~(nbytes - 1);
+ hpa &= mask;
+
+ for_each_nest_rmap_safe(cursor, entry, &rmap)
+ kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask);
+}
+
static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
unsigned long hpa, unsigned long mask)
{
--
2.13.6
