[PATCH stable-4.19.y backport 1/2] KVM: Pass MMU notifier 'blockable' flag to kvm_unmap_hva_range()

Will Deacon
2020-08-24T11:31:42Z

commit fdfe7cbd58806522e799e2a50a15aee7f2cbb7b6 upstream.

The 'blockable' flag passed to the 'invalidate_range_start()' call back
of 'struct mmu_notifier' is used to indicate whether the function is
permitted to block. In the case of
kvm_mmu_notifier_invalidate_range_start(), this field is not forwarded
on to the architecture-specific implementation of kvm_unmap_hva_range()
and therefore the backend cannot sensibly decide whether or not to
block.

Add an extra 'blockable' parameter to kvm_unmap_hva_range() so that
architectures are aware as to whether or not they are permitted to block.

Cc: <stable@vger.kernel.org> # v4.19 only
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20200811102725.7121-2-will@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[will: Backport to 4.19; use 'blockable' instead of non-existent range flags]
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm/include/asm/kvm_host.h | 2 +-
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/mips/include/asm/kvm_host.h | 2 +-
arch/mips/kvm/mmu.c | 3 ++-
arch/powerpc/include/asm/kvm_host.h | 3 ++-
arch/powerpc/kvm/book3s.c | 3 ++-
arch/powerpc/kvm/e500_mmu_host.c | 3 ++-
arch/x86/include/asm/kvm_host.h | 3 ++-
arch/x86/kvm/mmu.c | 3 ++-
virt/kvm/arm/mmu.c | 2 +-
virt/kvm/kvm_main.c | 2 +-
11 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index c9128bb187f9..471859cbfe0b 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -234,7 +234,7 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,

#define KVM_ARCH_WANT_MMU_NOTIFIER
int kvm_unmap_hva_range(struct kvm *kvm,
- unsigned long start, unsigned long end);
+ unsigned long start, unsigned long end, bool blockable);
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);

unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index e9afdfcb8403..5e720742d647 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -370,7 +370,7 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,

#define KVM_ARCH_WANT_MMU_NOTIFIER
int kvm_unmap_hva_range(struct kvm *kvm,
- unsigned long start, unsigned long end);
+ unsigned long start, unsigned long end, bool blockable);
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 2b3fdfc9e0e7..c254761cb8ad 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -936,7 +936,7 @@ enum kvm_mips_fault_result kvm_trap_emul_gva_fault(struct kvm_vcpu *vcpu,

#define KVM_ARCH_WANT_MMU_NOTIFIER
int kvm_unmap_hva_range(struct kvm *kvm,
- unsigned long start, unsigned long end);
+ unsigned long start, unsigned long end, bool blockable);
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index d8dcdb350405..098a7afd4d38 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -512,7 +512,8 @@ static int kvm_unmap_hva_handler(struct kvm *kvm, gfn_t gfn, gfn_t gfn_end,
return 1;
}

-int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)
+int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
+ bool blockable)
{
handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 2f95e38f0549..7b54d8412367 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -68,7 +68,8 @@
#define KVM_ARCH_WANT_MMU_NOTIFIER

extern int kvm_unmap_hva_range(struct kvm *kvm,
- unsigned long start, unsigned long end);
+ unsigned long start, unsigned long end,
+ bool blockable);
extern int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
extern int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
extern void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index cc05f346e042..bc9d1321dc73 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -812,7 +812,8 @@ void kvmppc_core_commit_memory_region(struct kvm *kvm,
kvm->arch.kvm_ops->commit_memory_region(kvm, mem, old, new);
}

-int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)
+int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
+ bool blockable)
{
return kvm->arch.kvm_ops->unmap_hva_range(kvm, start, end);
}
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 8f2985e46f6f..bbb02195dc53 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -737,7 +737,8 @@ static int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
return 0;
}

-int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)
+int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
+ bool blockable)
{
/* kvm_unmap_hva flushes everything anyways */
kvm_unmap_hva(kvm, start);
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ce7b3b22ae86..4876411a072a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1465,7 +1465,8 @@ asmlinkage void __noreturn kvm_spurious_fault(void);
____kvm_handle_fault_on_reboot(insn, "")

#define KVM_ARCH_WANT_MMU_NOTIFIER
-int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end);
+int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
+ bool blockable);
int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 92ff656e1810..a2ff5c214738 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1956,7 +1956,8 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
return kvm_handle_hva_range(kvm, hva, hva + 1, data, handler);
}

-int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)
+int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
+ bool blockable)
{
return kvm_handle_hva_range(kvm, start, end, 0, kvm_unmap_rmapp);
}
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index a5bc10d30618..3957ff0ecda5 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1825,7 +1825,7 @@ static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *dat
}

int kvm_unmap_hva_range(struct kvm *kvm,
- unsigned long start, unsigned long end)
+ unsigned long start, unsigned long end, bool blockable)
{
if (!kvm->arch.pgd)
return 0;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 1218ea663c6d..2155b52b17ec 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -410,7 +410,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
* count is also read inside the mmu_lock critical section.
*/
kvm->mmu_notifier_count++;
- need_tlb_flush = kvm_unmap_hva_range(kvm, start, end);
+ need_tlb_flush = kvm_unmap_hva_range(kvm, start, end, blockable);
need_tlb_flush |= kvm->tlbs_dirty;
/* we've to flush the tlb before the pages can be freed */
if (need_tlb_flush)
--
2.28.0.297.g1956fa8f8d-goog