Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "KVM GUEST_MEMFD fixes for 6.8:

   - Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY
     to avoid creating an inconsistent ABI (KVM_MEM_GUEST_MEMFD is not
     writable from userspace, so there would be no way to write to a
     read-only guest_memfd).

   - Update documentation for KVM_SW_PROTECTED_VM to make it abundantly
     clear that such VMs are purely for development and testing.

   - Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term
     plan is to support confidential VMs with deterministic private
     memory (SNP and TDX) only in the TDP MMU.

   - Fix a bug in a GUEST_MEMFD dirty logging test that caused false
     passes.

  x86 fixes:

   - Fix missing marking of a guest page as dirty when emulating an
     atomic access.

   - Check for mmu_notifier invalidation events before faulting in the
     pfn, and before acquiring mmu_lock, to avoid unnecessary work and
     lock contention with preemptible kernels (including
     CONFIG_PREEMPT_DYNAMIC in non-preemptible mode).

   - Disable AMD DebugSwap by default, it breaks VMSA signing and will
     be re-enabled with a better VM creation API in 6.10.

   - Do the cache flush of converted pages in svm_register_enc_region()
     before dropping kvm->lock, to avoid a race with unregistering of
     the same region and the consequent use-after-free issue"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  SEV: disable SEV-ES DebugSwap by default
  KVM: x86/mmu: Retry fault before acquiring mmu_lock if mapping is changing
  KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region()
  KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive
  KVM: selftests: Create GUEST_MEMFD for relevant invalid flags testcases
  KVM: x86/mmu: Restrict KVM_SW_PROTECTED_VM to the TDP MMU
  KVM: x86: Update KVM_SW_PROTECTED_VM docs to make it clear they're a WIP
  KVM: Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY
  KVM: x86: Mark target gfn of emulated atomic instruction as dirty

1 files changed, 11 insertions, 1 deletions

diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c
index 40337f566eeb..06b43ed23580 100644
--- a/tools/testing/selftests/kvm/set_memory_region_test.c
+++ b/tools/testing/selftests/kvm/set_memory_region_test.c
@@ -367,11 +367,21 @@ static void test_invalid_memory_region_flags(void)
 	}
 
 	if (supported_flags & KVM_MEM_GUEST_MEMFD) {
+		int guest_memfd = vm_create_guest_memfd(vm, MEM_REGION_SIZE, 0);
+
 		r = __vm_set_user_memory_region2(vm, 0,
 						 KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_GUEST_MEMFD,
-						 0, MEM_REGION_SIZE, NULL, 0, 0);
+						 0, MEM_REGION_SIZE, NULL, guest_memfd, 0);
 		TEST_ASSERT(r && errno == EINVAL,
 			    "KVM_SET_USER_MEMORY_REGION2 should have failed, dirty logging private memory is unsupported");
+
+		r = __vm_set_user_memory_region2(vm, 0,
+						 KVM_MEM_READONLY | KVM_MEM_GUEST_MEMFD,
+						 0, MEM_REGION_SIZE, NULL, guest_memfd, 0);
+		TEST_ASSERT(r && errno == EINVAL,
+			    "KVM_SET_USER_MEMORY_REGION2 should have failed, read-only GUEST_MEMFD memslots are unsupported");
+
+		close(guest_memfd);
 	}
 }