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[71.212.47.143]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-22ac7cbdfe7sm69599435ad.207.2025.04.12.09.43.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Apr 2025 09:43:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1744476197; x=1745080997; darn=nongnu.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=IM3ruFcSn/3xOMWTqbq6MJahwA1zxl/1qzgndn9+Nfs=; b=kFLEJBSZkk6KtOva2jPg69+aKz5pwO7YcNv3eqBOQMHTS9m4bQv+SPizZGRIgihwLY AC0P/Q6vooXrmglw4K8E9lfRTH1MKR6v3Te9Jbb/rqLAp2RAQuluj5nNgm/2KrnWuJk3 4v5DA3FqhJ0CX0sfr/Z9F7/NJyOPDyA3gMXBBwTRVuHejLZLbDLS+TlfxrUSpaciGcrF mQoc7+Z2ii3+DXAB/O+QrsSqVCiVlqQ6ZhEvez8hsaJOkv8huGldi7zdO4eYOUJ5tlqR 8Bg/NgaE51E+W2yPZvqhN395p8uMb8UhVQYLkqkSR9pN5EB6/t31tQtxj5/VXNnzjgV+ wcvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744476197; x=1745080997; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=IM3ruFcSn/3xOMWTqbq6MJahwA1zxl/1qzgndn9+Nfs=; b=it1PSNc825otxRI8NyufyAHyeHdXJkbbqkUBNQmzrfyOIjW7eFhEiSqvdvzG1erq4d EUDuBOTiHiobRJfeNVxqZ+40+PyBYvYner4NYd77EXh2Z+B6e6e0xpoAMnOTVkjhVUMO KAf0/9a/RZQuttoQGhsMro9FCqiVqC9hbf0ixaw6zhHf8lTUdq0nQE4p+O2nFgnr9q7k d/iBGRnkNYjlYe+/ipgnv8D2BdHfdfPSz40JdiEXtjWJHTh9e+za46AuRnHGc1NNxw9Y NbkoCCBd4lIbjdL2UO+bLUPxUJMaYNbabswha6kBVUoug1WMyAvYDsfaJelz9veTfyhp Rf7A== X-Gm-Message-State: AOJu0YwRK38Jk79Pmm5y9DlL8f9qqXLUpuBqvCKFq1avvqbSsCK+kRvw bcIlg3Jeiz3fDtVnOhy3EBydIZyGzjUbmrbxpSgRaQ6tb5iEYPsIndIQSjwgwExuV12i2zJLmLD b X-Gm-Gg: ASbGncsfzUD0aV42XJVZbfZIqBZ7qTwHtJPLRnZCRE5fSaExTrhvmlGolI3TQ3bRkb/ kypyHYrMko15K0bOIEfrwU8//mXaVanZ67lrXQsq7uoNcQfZWJRBGFmsJ1LxQqYD08X2/mt20ur 6yXMKPtg2B049AYS0evp096ncqasl1Uki0h3nn5qtjeshNsOrK+QWy/8n8uimVydeMywXsKvDYY KwIjQpGOsgFlJhixpdIAZPchxebxWkyk52HGVTz5d37bI6wvdtw4iIdzw0YlyQvFxqxTPu2bF+m YOrsXY1rL/DwlnU3FqqlUdKZnN/LWggyoAI1PlqPsdqbVrArqCmKCMPqUS1U+tVt20zTNymvU/8 = X-Google-Smtp-Source: AGHT+IGvp3g9SuDJXf+bjgO+CRhpBREkZbCVJXFDwapP6nUmAfKm5bBNCQbJNcHrrixfTr44BV3u3Q== X-Received: by 2002:a17:903:144e:b0:21f:4c8b:c4de with SMTP id d9443c01a7336-22bea4f26dcmr79945445ad.42.1744476196981; Sat, 12 Apr 2025 09:43:16 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Cc: berrange@redhat.com, stefanha@gmail.com, philmd@linaro.org Subject: [PATCH for-10.0] docs: Document removal of 64-bit on 32-bit emulation Date: Sat, 12 Apr 2025 09:43:15 -0700 Message-ID: <20250412164315.36161-1-richard.henderson@linaro.org> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::633; envelope-from=richard.henderson@linaro.org; helo=mail-pl1-x633.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1744476259525019000 Content-Type: text/plain; charset="utf-8" With acce728cbc6c we disallowed configuring 64-bit guests on 32-bit hosts, but forgot to document that in removed-features. Signed-off-by: Richard Henderson Reviewed-by: Alex Benn=C3=A9e Reviewed-by: Daniel P. Berrang=C3=A9 Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- docs/about/removed-features.rst | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.= rst index 2527a91795..790a5e481c 100644 --- a/docs/about/removed-features.rst +++ b/docs/about/removed-features.rst @@ -858,6 +858,15 @@ QEMU. Since all recent x86 hardware from the past >10= years is capable of the 64-bit x86 extensions, a corresponding 64-bit OS should be used instead. =20 +32-bit hosts for 64-bit guests (removed in 10.0) +'''''''''''''''''''''''''''''''''''''''''''''''' + +In general, 32-bit hosts cannot support the memory space or atomicity +requirements of 64-bit guests. Prior to 10.0, QEMU attempted to +work around the atomicity issues in system mode by running all vCPUs +in a single thread context; in user mode atomicity was simply broken. +From 10.0, QEMU has disabled configuration of 64-bit guests on 32-bit host= s. + Guest Emulator ISAs ------------------- =20 --=20 2.43.0