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authorSuraj Jitindar Singh <sjitindarsingh@gmail.com>2018-12-21 06:28:42 +0300
committerPaul Mackerras <paulus@ozlabs.org>2018-12-21 06:39:35 +0300
commit90165d3da0760a0353518740ac307f0d81c4e400 (patch)
treeb7b8aa93809f91b4ff357f32705f3e18e0f22c18 /arch/powerpc/kvm/book3s_hv_nested.c
parent8b23eee4e55a32a2b51a180dfd27a8d214acc7a1 (diff)
downloadlinux-90165d3da0760a0353518740ac307f0d81c4e400.tar.xz
KVM: PPC: Book3S HV: Introduce kvmhv_update_nest_rmap_rc_list()
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@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_nested.c')
-rw-r--r--arch/powerpc/kvm/book3s_hv_nested.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 0bd676ac38fe..735e0ac6f5b2 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -788,6 +788,57 @@ 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)
{