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[97.113.7.119]) by smtp.gmail.com with ESMTPSA id b3sm4883437pfp.65.2019.08.23.15.27.02 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Aug 2019 15:27:03 -0700 (PDT) To: Tony Nguyen , qemu-devel@nongnu.org References: <4b71fd52ebd39e3122f8b702b53ecb04f6af4c26.1566466906.git.tony.nguyen@bt.com> From: Richard Henderson Openpgp: preference=signencrypt Message-ID: <5690df72-4140-5c3e-3a6c-0606b1d37083@linaro.org> Date: Fri, 23 Aug 2019 15:27:01 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <4b71fd52ebd39e3122f8b702b53ecb04f6af4c26.1566466906.git.tony.nguyen@bt.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::443 Subject: Re: [Qemu-devel] [PATCH v9 17/20] cpu: TLB_FLAGS_MASK bit to force memory slow path X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/23/19 11:36 AM, Tony Nguyen wrote: > The fast path is taken when TLB_FLAGS_MASK is all zero. > > TLB_FORCE_SLOW is simply a TLB_FLAGS_MASK bit to force the slow path, > there are no other side effects. > > Signed-off-by: Tony Nguyen > Reviewed-by: Richard Henderson > --- > include/exec/cpu-all.h | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) FYI, while looking at this again, we do not need a new bit. You can simply set TLB_MMIO for this use case, like we do for ROM. This seems to be the only change to be made for this patch set; I can fix this up myself while queuing. r~