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AJvYcCVSPJGVCHB6lGVWs2hGkIKAKb/mmluq9oUka52d8VL1kggccxlcSFQG2H4etMaScuot7I+Y8UOqIISf17c=@vger.kernel.org X-Gm-Message-State: AOJu0YzA/aXAEq2hqxX0aCmAHW7nTYc46Zf+X9Jp5MNJ/SLA1KoAOdUR zQVY9KQ7v4XpxYBXaqc13Mqs/F+zmRW8rcf6QXTXatHYH67JYaVT5NyL+TIwxcaEjpKfEwf57Hb UnvWgqA== X-Google-Smtp-Source: AGHT+IHhbLvCYGsBh6ODhMnEDvAuta6cPkH1KNgVvHSQ9KHYqVszyeRaOArV3kO5lGiA3vXVq/dSXjWdUKY= X-Received: from pjbga18.prod.google.com ([2002:a17:90b:392:b0:32e:c813:df48]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:4b0d:b0:32d:d5f1:fe7f with SMTP id 98e67ed59e1d1-33b51118e6amr20842431a91.15.1760131849296; Fri, 10 Oct 2025 14:30:49 -0700 (PDT) Date: Fri, 10 Oct 2025 14:30:36 -0700 In-Reply-To: <20250924174255.2141847-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250924174255.2141847-1-seanjc@google.com> X-Mailer: git-send-email 2.51.0.740.g6adb054d12-goog Message-ID: <176013138845.972857.17974431872471984207.b4-ty@google.com> Subject: Re: [PATCH v3] KVM: selftests: Test prefault memory during concurrent memslot removal From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yan Zhao Content-Type: text/plain; charset="utf-8" On Wed, 24 Sep 2025 10:42:55 -0700, Sean Christopherson wrote: > Expand the prefault memory selftest to add a regression test for a KVM bug > where TDX's retry logic (to avoid tripping the zero-step mitigation) would > result in deadlock due to the memslot deletion waiting on prefaulting to > release SRCU, and prefaulting waiting on the memslot to fully disappear > (KVM uses a two-step process to delete memslots, and KVM x86 retries page > faults if a to-be-deleted, a.k.a. INVALID, memslot is encountered). > > [...] Applied to kvm-x86 fixes, with a massaged changelog to call out that it's KVM's retry logic, not the TDX-specific zero-step logic that is being tested. [1/1] KVM: selftests: Test prefault memory during concurrent memslot removal https://github.com/kvm-x86/linux/commit/1bcc3f879127 -- https://github.com/kvm-x86/linux/tree/next