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| author | Paolo Bonzini <pbonzini@redhat.com> | 2024-07-11 18:27:54 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-07-26 14:46:15 -0400 |
| commit | 4b5f67120a88c713b82907d55a767693382e9e9d (patch) | |
| tree | 66ccc638b7d2b86d86580eb501769beaa65ea984 /virt | |
| parent | e300614f10bd2f33252c8ba40b34d6c3fbf95d72 (diff) | |
| download | lwn-4b5f67120a88c713b82907d55a767693382e9e9d.tar.gz lwn-4b5f67120a88c713b82907d55a767693382e9e9d.zip | |
KVM: extend kvm_range_has_memory_attributes() to check subset of attributes
While currently there is no other attribute than KVM_MEMORY_ATTRIBUTE_PRIVATE,
KVM code such as kvm_mem_is_private() is written to expect their existence.
Allow using kvm_range_has_memory_attributes() as a multi-page version of
kvm_mem_is_private(), without it breaking later when more attributes are
introduced.
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 30328ff2d840..92901656a0d4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2408,21 +2408,21 @@ static u64 kvm_supported_mem_attributes(struct kvm *kvm) /* * Returns true if _all_ gfns in the range [@start, @end) have attributes - * matching @attrs. + * such that the bits in @mask match @attrs. */ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, - unsigned long attrs) + unsigned long mask, unsigned long attrs) { XA_STATE(xas, &kvm->mem_attr_array, start); - unsigned long mask = kvm_supported_mem_attributes(kvm); unsigned long index; void *entry; + mask &= kvm_supported_mem_attributes(kvm); if (attrs & ~mask) return false; if (end == start + 1) - return kvm_get_memory_attributes(kvm, start) == attrs; + return (kvm_get_memory_attributes(kvm, start) & mask) == attrs; guard(rcu)(); if (!attrs) @@ -2433,7 +2433,8 @@ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, entry = xas_next(&xas); } while (xas_retry(&xas, entry)); - if (xas.xa_index != index || xa_to_value(entry) != attrs) + if (xas.xa_index != index || + (xa_to_value(entry) & mask) != attrs) return false; } @@ -2532,7 +2533,7 @@ static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, mutex_lock(&kvm->slots_lock); /* Nothing to do if the entire range as the desired attributes. */ - if (kvm_range_has_memory_attributes(kvm, start, end, attributes)) + if (kvm_range_has_memory_attributes(kvm, start, end, ~0, attributes)) goto out_unlock; /* |