The locking rules for walking nested shadow linux page table is different from process
scoped table. Hence add a helper for nested page table walk and also
add check whether we are holding the right locks.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
arch/powerpc/kvm/book3s_hv_nested.c | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 7f1fc5db13ea..b2cc3eaec618 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -750,6 +750,24 @@ static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid)
return kvm->arch.nested_guests[lpid];
}
+static pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
+ unsigned long ea, unsigned *hshift)
+{
+ struct kvm_nested_guest *gp;
+ pte_t *pte;
+
+ gp = kvmhv_find_nested(kvm, lpid);
+ if (!gp)
+ return NULL;
+
+ VM_WARN(!spin_is_locked(&kvm->mmu_lock),
+ "%s called with kvm mmu_lock not held \n", __func__);
+ pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift);
+
+ return pte;
+}
+
+
static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2)
{
return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK |
@@ -792,19 +810,15 @@ 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);
+ ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &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
@@ -854,7 +868,7 @@ static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
return;
/* Find and invalidate the pte */
- ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift);
+ ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
/* Don't spuriously invalidate ptes if the pfn has changed */
if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa))
kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
@@ -921,7 +935,7 @@ static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
int shift;
spin_lock(&kvm->mmu_lock);
- ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift);
+ ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift);
if (!shift)
shift = PAGE_SHIFT;
if (ptep && pte_present(*ptep)) {
--
2.24.1
