I tested this patch with the bug's reproducer, the problem has gone. Tested-by: Lei Yang <leiyang@xxxxxxxxxx> On Thu, Dec 19, 2024 at 10:41 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > On Wed, 18 Dec 2024 13:36:11 -0800, Sean Christopherson wrote: > > Treat slow-path TDP MMU faults as spurious if the access is allowed given > > the existing SPTE to fix a benign warning (other than the WARN itself) > > due to replacing a writable SPTE with a read-only SPTE, and to avoid the > > unnecessary LOCK CMPXCHG and subsequent TLB flush. > > > > If a read fault races with a write fault, fast GUP fails for any reason > > when trying to "promote" the read fault to a writable mapping, and KVM > > resolves the write fault first, then KVM will end up trying to install a > > read-only SPTE (for a !map_writable fault) overtop a writable SPTE. > > > > [...] > > Applied very quickly to kvm-x86 fixes, so that it can get at least one day in > -next before I send it to Paolo. > > [1/1] KVM: x86/mmu: Treat TDP MMU faults as spurious if access is already allowed > https://github.com/kvm-x86/linux/commit/55f60a6498e7 > > -- > https://github.com/kvm-x86/linux/tree/next >
