diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2024-03-09 11:48:35 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-03-09 11:48:35 -0500 |
| commit | 7d8942d8e73843de35b3737b8be50f8fef6796bb (patch) | |
| tree | 593e26864092f6829b25a1847cb5e2172ae7de53 /virt | |
| parent | 0cbca1bf44a0b8666c91ce3438f235c6fe70fbf1 (diff) | |
| parent | 2dfd2383034421101300a3b7325cf339a182d218 (diff) | |
Merge tag 'kvm-x86-guest_memfd_fixes-6.8' of https://github.com/kvm-x86/linux into HEAD
KVM GUEST_MEMFD fixes for 6.8:
- Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to
avoid creating ABI that KVM can't sanely support.
- Update documentation for KVM_SW_PROTECTED_VM to make it abundantly
clear that such VMs are purely a development and testing vehicle, and
come with zero guarantees.
- 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 negative test that resulted in false passes
when verifying that KVM_MEM_GUEST_MEMFD memslots can't be dirty logged.
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ff588677beb7..054d20ec61b9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1615,7 +1615,13 @@ static int check_memory_region_flags(struct kvm *kvm, valid_flags &= ~KVM_MEM_LOG_DIRTY_PAGES; #ifdef CONFIG_HAVE_KVM_READONLY_MEM - valid_flags |= KVM_MEM_READONLY; + /* + * GUEST_MEMFD is incompatible with read-only memslots, as writes to + * read-only memslots have emulated MMIO, not page fault, semantics, + * and KVM doesn't allow emulated MMIO for private memory. + */ + if (!(mem->flags & KVM_MEM_GUEST_MEMFD)) + valid_flags |= KVM_MEM_READONLY; #endif if (mem->flags & ~valid_flags) |