[PATCH v5 42/69] KVM: arm64: nv: Unmap/flush shadow stage 2 page tables
Marc Zyngier
maz at kernel.org
Mon Nov 29 12:01:23 PST 2021
From: Christoffer Dall <christoffer.dall at linaro.org>
Unmap/flush shadow stage 2 page tables for the nested VMs as well as the
stage 2 page table for the guest hypervisor.
Note: A bunch of the code in mmu.c relating to MMU notifiers is
currently dealt with in an extremely abrupt way, for example by clearing
out an entire shadow stage-2 table. This will be handled in a more
efficient way using the reverse mapping feature in a later version of
the patch series.
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
Signed-off-by: Jintack Lim <jintack.lim at linaro.org>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
arch/arm64/include/asm/kvm_mmu.h | 3 +++
arch/arm64/include/asm/kvm_nested.h | 3 +++
arch/arm64/kvm/mmu.c | 31 +++++++++++++++++++----
arch/arm64/kvm/nested.c | 39 +++++++++++++++++++++++++++++
4 files changed, 71 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 7250594e3d68..63b2eb5f4bcb 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -158,6 +158,8 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
void __iomem **haddr);
int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
void **haddr);
+void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu,
+ phys_addr_t addr, phys_addr_t end);
void free_hyp_pgds(void);
void kvm_unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size);
@@ -166,6 +168,7 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu);
void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu);
int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
phys_addr_t pa, unsigned long size, bool writable);
+void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end);
int kvm_handle_guest_abort(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 3f3d8e10bd99..2987806850f0 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -114,6 +114,9 @@ extern int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa,
extern int kvm_s2_handle_perm_fault(struct kvm_vcpu *vcpu,
struct kvm_s2_trans *trans);
extern int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2);
+extern void kvm_nested_s2_wp(struct kvm *kvm);
+extern void kvm_nested_s2_clear(struct kvm *kvm);
+extern void kvm_nested_s2_flush(struct kvm *kvm);
int handle_wfx_nested(struct kvm_vcpu *vcpu, bool is_wfe);
extern bool __forward_traps(struct kvm_vcpu *vcpu, unsigned int reg,
u64 control_bit);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d63f60f95abc..a9e743f39bfd 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -190,13 +190,20 @@ void kvm_unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size)
__unmap_stage2_range(mmu, start, size, true);
}
+void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu,
+ phys_addr_t addr, phys_addr_t end)
+{
+ stage2_apply_range_resched(kvm_s2_mmu_to_kvm(mmu), addr, end, kvm_pgtable_stage2_flush);
+}
+
static void stage2_flush_memslot(struct kvm *kvm,
struct kvm_memory_slot *memslot)
{
phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
+ struct kvm_s2_mmu *mmu = &kvm->arch.mmu;
- stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_flush);
+ kvm_stage2_flush_range(mmu, addr, end);
}
/**
@@ -219,6 +226,8 @@ static void stage2_flush_vm(struct kvm *kvm)
kvm_for_each_memslot(memslot, slots)
stage2_flush_memslot(kvm, memslot);
+ kvm_nested_s2_flush(kvm);
+
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
}
@@ -621,6 +630,8 @@ void stage2_unmap_vm(struct kvm *kvm)
kvm_for_each_memslot(memslot, slots)
stage2_unmap_memslot(kvm, memslot);
+ kvm_nested_s2_clear(kvm);
+
spin_unlock(&kvm->mmu_lock);
mmap_read_unlock(current->mm);
srcu_read_unlock(&kvm->srcu, idx);
@@ -690,12 +701,12 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
}
/**
- * stage2_wp_range() - write protect stage2 memory region range
+ * kvm_stage2_wp_range() - write protect stage2 memory region range
* @mmu: The KVM stage-2 MMU pointer
* @addr: Start address of range
* @end: End address of range
*/
-static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
+void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
{
struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_wrprotect);
@@ -727,7 +738,8 @@ static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
spin_lock(&kvm->mmu_lock);
- stage2_wp_range(&kvm->arch.mmu, start, end);
+ kvm_stage2_wp_range(&kvm->arch.mmu, start, end);
+ kvm_nested_s2_wp(kvm);
spin_unlock(&kvm->mmu_lock);
kvm_flush_remote_tlbs(kvm);
}
@@ -751,7 +763,7 @@ static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT;
phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
- stage2_wp_range(&kvm->arch.mmu, start, end);
+ kvm_stage2_wp_range(&kvm->arch.mmu, start, end);
}
/*
@@ -766,6 +778,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
gfn_t gfn_offset, unsigned long mask)
{
kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
+ kvm_nested_s2_wp(kvm);
}
static void kvm_send_hwpoison_signal(unsigned long address, short lsb)
@@ -1405,6 +1418,7 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
(range->end - range->start) << PAGE_SHIFT,
range->may_block);
+ kvm_nested_s2_clear(kvm);
return false;
}
@@ -1436,6 +1450,7 @@ bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
PAGE_SIZE, __pfn_to_phys(pfn),
KVM_PGTABLE_PROT_R, NULL);
+ kvm_nested_s2_clear(kvm);
return false;
}
@@ -1454,6 +1469,11 @@ bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
range->start << PAGE_SHIFT);
pte = __pte(kpte);
return pte_valid(pte) && pte_young(pte);
+
+ /*
+ * TODO: Handle nested_mmu structures here using the reverse mapping in
+ * a later version of patch series.
+ */
}
bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
@@ -1664,6 +1684,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
spin_lock(&kvm->mmu_lock);
kvm_unmap_stage2_range(&kvm->arch.mmu, gpa, size);
+ kvm_nested_s2_clear(kvm);
spin_unlock(&kvm->mmu_lock);
}
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index fb748f2b9e87..b7e10f6178b9 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -517,6 +517,45 @@ int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2)
return kvm_inject_nested_sync(vcpu, esr_el2);
}
+/* expects kvm->mmu_lock to be held */
+void kvm_nested_s2_wp(struct kvm *kvm)
+{
+ int i;
+
+ for (i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (kvm_s2_mmu_valid(mmu))
+ kvm_stage2_wp_range(mmu, 0, kvm_phys_size(kvm));
+ }
+}
+
+/* expects kvm->mmu_lock to be held */
+void kvm_nested_s2_clear(struct kvm *kvm)
+{
+ int i;
+
+ for (i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (kvm_s2_mmu_valid(mmu))
+ kvm_unmap_stage2_range(mmu, 0, kvm_phys_size(kvm));
+ }
+}
+
+/* expects kvm->mmu_lock to be held */
+void kvm_nested_s2_flush(struct kvm *kvm)
+{
+ int i;
+
+ for (i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (kvm_s2_mmu_valid(mmu))
+ kvm_stage2_flush_range(mmu, 0, kvm_phys_size(kvm));
+ }
+}
+
/*
* Inject wfx to the virtual EL2 if this is not from the virtual EL2 and
* the virtual HCR_EL2.TWX is set. Otherwise, let the host hypervisor
--
2.30.2
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