[PATCH 5.7 022/112] powerpc/kvm/book3s: Add helper to walk partition scoped linux page table.

Greg Kroah-Hartman
2020-07-07T15:23:19Z

From: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

[ Upstream commit 4b99412ed6972cc77c1f16009e1d00323fcef9ab ]

The locking rules for walking partition scoped table is different from process
scoped table. Hence add a helper for secondary linux page table walk and also
add check whether we are holding the right locks.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200505071729.54912-10-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/include/asm/kvm_book3s_64.h | 13 +++++++++++++
arch/powerpc/kvm/book3s_64_mmu_radix.c | 12 ++++++------
arch/powerpc/kvm/book3s_hv_nested.c | 2 +-
3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 04b2b927bb5ae..2c2635967d6e0 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -14,6 +14,7 @@
#include <asm/book3s/64/mmu-hash.h>
#include <asm/cpu_has_feature.h>
#include <asm/ppc-opcode.h>
+#include <asm/pte-walk.h>

#ifdef CONFIG_PPC_PSERIES
static inline bool kvmhv_on_pseries(void)
@@ -634,6 +635,18 @@ extern void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
unsigned long gpa, unsigned long hpa,
unsigned long nbytes);

+static inline pte_t *find_kvm_secondary_pte(struct kvm *kvm, unsigned long ea,
+ unsigned *hshift)
+{
+ pte_t *pte;
+
+ VM_WARN(!spin_is_locked(&kvm->mmu_lock),
+ "%s called with kvm mmu_lock not held \n", __func__);
+ pte = __find_linux_pte(kvm->arch.pgtable, ea, NULL, hshift);
+
+ return pte;
+}
+
#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */

#endif /* __ASM_KVM_BOOK3S_64_H__ */
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index bc6c1aa3d0e92..e9b3622405b1d 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -993,11 +993,11 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
return 0;
}

- ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+ ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep))
kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
kvm->arch.lpid);
- return 0;
+ return 0;
}

/* Called with kvm->mmu_lock held */
@@ -1013,7 +1013,7 @@ int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return ref;

- ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+ ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
gpa, shift);
@@ -1040,7 +1040,7 @@ int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return ref;

- ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+ ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep) && pte_young(*ptep))
ref = 1;
return ref;
@@ -1060,7 +1060,7 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm,
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return ret;

- ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+ ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
ret = 1;
if (shift)
@@ -1121,7 +1121,7 @@ void kvmppc_radix_flush_memslot(struct kvm *kvm,
gpa = memslot->base_gfn << PAGE_SHIFT;
spin_lock(&kvm->mmu_lock);
for (n = memslot->npages; n; --n) {
- ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+ ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
if (ptep && pte_present(*ptep))
kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
kvm->arch.lpid);
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index dc97e5be76f61..7f1fc5db13eab 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -1362,7 +1362,7 @@ static long int __kvmhv_nested_page_fault(struct kvm_run *run,
/* See if can find translation in our partition scoped tables for L1 */
pte = __pte(0);
spin_lock(&kvm->mmu_lock);
- pte_p = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+ pte_p = find_kvm_secondary_pte(kvm, gpa, &shift);
if (!shift)
shift = PAGE_SHIFT;
if (pte_p)
--
2.25.1