[PATCH 1/2] KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()

From: Will Deacon
Date: Tue Aug 11 2020 - 06:27:38 EST


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>
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>
---
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/kvm/mmu.c | 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/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 e21d4a01372f..759d62343e1d 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -443,7 +443,7 @@ 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/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 31058e6e7c2a..5f6b35c33618 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -2203,7 +2203,7 @@ 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/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 363e7a89d173..ef1d25d49ec8 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -981,7 +981,7 @@ 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 49bd160f4d85..0783ac9b3240 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 7e2d061d0445..bccf0ba2da2e 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 41fedec69ac3..49db50d1db04 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -834,7 +834,8 @@ 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 d6c1069e9954..ed0c9c43d0cf 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 be5363b21540..c6908a3d551e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1641,7 +1641,8 @@ 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 6d6a0ae7800c..9516a958e780 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1971,7 +1971,8 @@ 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/kvm_main.c b/virt/kvm/kvm_main.c
index 0a68c9d3d3ab..9e925675a886 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -427,7 +427,8 @@ 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)
--
2.28.0.236.gb10cc79966-goog