[PATCH stable-5.7.y backport 1/2] KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()

From: Will Deacon
Date: Mon Aug 24 2020 - 07:35:27 EST


commit fdfe7cbd58806522e799e2a50a15aee7f2cbb7b6 upstream.

The 'flags' field of 'struct mmu_notifier_range' is used to indicate
whether invalidate_range_{start,end}() are 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 'flags' parameter to kvm_unmap_hva_range() so that
architectures are aware as to whether or not they are permitted to block.

Cc: <stable@xxxxxxxxxxxxxxx> # v5.7 only
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Message-Id: <20200811102725.7121-2-will@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
---
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/mmu.c | 3 ++-
virt/kvm/arm/mmu.c | 2 +-
virt/kvm/kvm_main.c | 3 ++-
10 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 26fca93cd697..397e20a35975 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -440,7 +440,7 @@ 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, unsigned flags);
int 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 caa2b936125c..8861e9d4eb1f 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -939,7 +939,7 @@ 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, unsigned flags);
int 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 7dad7a293eae..2514e51d908b 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -518,7 +518,8 @@ 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,
+ unsigned flags)
{
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 1dc63101ffe1..b82e46ecd7fb 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -58,7 +58,8 @@
#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,
+ unsigned flags);
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 int 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 5690a1f9b976..13f107dff880 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -837,7 +837,8 @@ void kvmppc_core_commit_memory_region(struct kvm *kvm,
kvm->arch.kvm_ops->commit_memory_region(kvm, mem, old, new, change);
}

-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,
+ unsigned flags)
{
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 df9989cf7ba3..9b402c345154 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -734,7 +734,8 @@ 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,
+ unsigned flags)
{
/* 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 86e2e0272c57..d4c5d1d6c6f5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1606,7 +1606,8 @@ asmlinkage void kvm_spurious_fault(void);
_ASM_EXTABLE(666b, 667b)

#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,
+ unsigned flags);
int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 70cf2c1a1423..59d096cacb26 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1972,7 +1972,8 @@ 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,
+ unsigned flags)
{
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 8a9d13e8e904..9510965789e3 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -2046,7 +2046,7 @@ 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, unsigned flags)
{
if (!kvm->arch.pgd)
return 0;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 77aa91fb08d2..66b7a9dbb77d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -428,7 +428,8 @@ 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, range->start, range->end);
+ need_tlb_flush = kvm_unmap_hva_range(kvm, range->start, range->end,
+ range->flags);
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