From 90165d3da0760a0353518740ac307f0d81c4e400 Mon Sep 17 00:00:00 2001 From: Suraj Jitindar Singh Date: Fri, 21 Dec 2018 14:28:42 +1100 Subject: 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 Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv_nested.c | 51 +++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) (limited to 'arch/powerpc/kvm/book3s_hv_nested.c') 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) { -- cgit v1.2.3