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[213.175.37.12]) by smtp.gmail.com with ESMTPSA id v191sm7860699wme.36.2021.10.11.05.45.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Oct 2021 05:45:35 -0700 (PDT) Date: Mon, 11 Oct 2021 14:45:34 +0200 From: Andrew Jones To: Alexandru Elisei Cc: maz@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, james.morse@arm.com, suzuki.poulose@arm.com Subject: Re: [PATCH v2 2/3] KVM: arm64: Use get_raz_reg() for userspace reads of PMSWINC_EL0 Message-ID: <20211011124534.m7zzpsv3ymp5xxzo@gator> References: <20211011105840.155815-1-alexandru.elisei@arm.com> <20211011105840.155815-3-alexandru.elisei@arm.com> MIME-Version: 1.0 In-Reply-To: <20211011105840.155815-3-alexandru.elisei@arm.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=drjones@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211011_054542_262103_6ED8D911 X-CRM114-Status: GOOD ( 16.74 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Oct 11, 2021 at 11:58:39AM +0100, Alexandru Elisei wrote: > PMSWINC_EL0 is a write-only register and was initially part of the VCPU > register state, but was later removed in commit 7a3ba3095a32 ("KVM: > arm64: Remove PMSWINC_EL0 shadow register"). To prevent regressions, the > register was kept accessible from userspace as Read-As-Zero (RAZ). > > The read function that is used to handle userspace reads of this > register is get_raz_id_reg(), which, while technically correct, as it > returns 0, it is not semantically correct, as PMSWINC_EL0 is not an ID > register as the function name suggests. > > Add a new function, get_raz_reg(), to use it as the accessor for > PMSWINC_EL0, as to not conflate get_raz_id_reg() to handle other types > of registers. > > No functional change intended. > > Signed-off-by: Alexandru Elisei > --- > arch/arm64/kvm/sys_regs.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > Reviewed-by: Andrew Jones _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel