diff mbox series

[v2,5/5] KVM: Disallow all flags for KVM-internal memslots

Message ID 20250111002022.1230573-6-seanjc@google.com (mailing list archive)
State New
Headers show
Series KVM: kvm_set_memory_region() cleanups | expand

Commit Message

Sean Christopherson Jan. 11, 2025, 12:20 a.m. UTC 
Disallow all flags for KVM-internal memslots as all existing flags require
some amount of userspace interaction to have any meaning.  In addition to
guarding against KVM goofs, explicitly disallowing dirty logging of KVM-
internal memslots will (hopefully) allow exempting KVM-internal memslots
from the KVM_MEM_MAX_NR_PAGES limit, which appears to exist purely because
the dirty bitmap operations use a 32-bit index.

Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 virt/kvm/kvm_main.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ecd4a66b22f3..a8a84bf450f9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2057,6 +2057,9 @@  int kvm_set_internal_memslot(struct kvm *kvm,
 	if (WARN_ON_ONCE(mem->slot < KVM_USER_MEM_SLOTS))
 		return -EINVAL;
 
+	if (WARN_ON_ONCE(mem->flags))
+		return -EINVAL;
+
 	return kvm_set_memory_region(kvm, mem);
 }
 EXPORT_SYMBOL_GPL(kvm_set_internal_memslot);