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KVM: extend kvm_range_has_memory_attributes() to check subset of attributes

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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>
This commit is contained in:
Paolo Bonzini 2024-07-11 18:27:54 -04:00
parent e300614f10
commit 4b5f67120a
3 changed files with 9 additions and 8 deletions
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2
arch/x86/kvm/mmu/mmu.c
View File

@ -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); const unsigned long end = start + KVM_PAGES_PER_HPAGE(level);
if (level == PG_LEVEL_2M) 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)) { for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) {
if (hugepage_test_mixed(slot, gfn, level - 1) || if (hugepage_test_mixed(slot, gfn, level - 1) ||

2
include/linux/kvm_host.h
View File

@ -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, 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, bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
struct kvm_gfn_range *range); struct kvm_gfn_range *range);
bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, bool kvm_arch_post_set_memory_attributes(struct kvm *kvm,

13
virt/kvm/kvm_main.c
View File

@ -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 * 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, 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); XA_STATE(xas, &kvm->mem_attr_array, start);
unsigned long mask = kvm_supported_mem_attributes(kvm);
unsigned long index; unsigned long index;
void *entry; void *entry;
mask &= kvm_supported_mem_attributes(kvm);
if (attrs & ~mask) if (attrs & ~mask)
return false; return false;
if (end == start + 1) if (end == start + 1)
return kvm_get_memory_attributes(kvm, start) == attrs; return (kvm_get_memory_attributes(kvm, start) & mask) == attrs;
guard(rcu)(); guard(rcu)();
if (!attrs) 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); entry = xas_next(&xas);
} while (xas_retry(&xas, entry)); } 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; 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); mutex_lock(&kvm->slots_lock);
/* Nothing to do if the entire range as the desired attributes. */ /* 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; goto out_unlock;
/* /*