Commit 4b5f6712 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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: default avatarMichael Roth <michael.roth@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e300614f

arch/x86/kvm/mmu/mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -7513,7 +7513,7 @@ static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot, 
	const unsigned long end = start + KVM_PAGES_PER_HPAGE(level);



	if (level == PG_LEVEL_2M)

		return kvm_range_has_memory_attributes(kvm, start, end, attrs);

		return kvm_range_has_memory_attributes(kvm, start, end, ~0, attrs);



	for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) {

		if (hugepage_test_mixed(slot, gfn, level - 1) ||

include/linux/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -2414,7 +2414,7 @@ static inline unsigned long kvm_get_memory_attributes(struct kvm *kvm, gfn_t gfn 
}



bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end,

				     unsigned long attrs);

				     unsigned long mask, unsigned long attrs);

bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,

					struct kvm_gfn_range *range);

bool kvm_arch_post_set_memory_attributes(struct kvm *kvm,

virt/kvm/kvm_main.c

+7 −6
Original line number Diff line number Diff line
@@ -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;



	/*