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[2a02:3100:a1e8:7401:78b1:a175:5d13:e92e]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4995420c68fsm358800705e9.1.2026.08.09.23.52.21 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Sun, 09 Aug 2026 23:52:22 -0700 (PDT) From: Karl Mehltretter To: Marc Zyngier , Oliver Upton , kvmarm@lists.linux.dev Cc: Karl Mehltretter , Fuad Tabba , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Paolo Bonzini , Shuah Khan , Eric Auger , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [RFC PATCH 0/2] KVM: arm64: fix VGICv3 redistributor rollback Date: Mon, 10 Aug 2026 08:52:15 +0200 Message-Id: X-Mailer: git-send-email 2.39.5 (Apple Git-154) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260809_235225_568933_E5D3CCF6 X-CRM114-Status: UNSURE ( 7.83 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org A failed REDIST_REGION update can unregister redistributor iodevs belonging to earlier regions without clearing their cached base addresses. A corrected retry then succeeds without restoring the missing iodevs. Limit rollback to vCPUs assigned to the newly added region. Extend vgic_init to access an earlier redistributor after a failed update and retry. Commits 8542a8f95a67, 59112e9c390b, and 0d92e4a7ffd5 progressively fixed cleanup after a failed region update. Preserving earlier regions follows that model. Built with GCC 15.2.0 and tested under QEMU 10.2.1 TCG with -machine virt,virtualization=on,gic-version=3 and -cpu max. Both runs reached the VGICv3 tests. The patched kernel passed; the same selftest against the unpatched base failed with: Unexpected MMIO exit at 0x8050008 Karl Mehltretter (2): KVM: arm64: vgic-v3: Roll back failed redistributor region setup KVM: arm64: selftests: Test VGICv3 redistributor region retry arch/arm64/kvm/vgic/vgic-mmio-v3.c | 42 ++++--- tools/testing/selftests/kvm/arm64/vgic_init.c | 115 +++++++++++++----- 2 files changed, 112 insertions(+), 45 deletions(-) base-commit: b9b3e33b70b71e516930117e21de3ad2a7723747 -- 2.53.0