From mboxrd@z Thu Jan 1 00:00:00 1970 From: alex.bennee@linaro.org (Alex =?utf-8?Q?Benn=C3=A9e?=) Date: Fri, 06 Jul 2018 11:11:39 +0100 Subject: [RFC PATCH 00/16] KVM: arm64: Initial support for SVE guests In-Reply-To: References: <1529593060-542-1-git-send-email-Dave.Martin@arm.com> <87h8lc93jc.fsf@linaro.org> <20180706090534.GD26019@e103592.cambridge.arm.com> <87d0w090vv.fsf@linaro.org> Message-ID: <87601s8yhw.fsf@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Peter Maydell writes: > On 6 July 2018 at 10:20, Alex Benn?e wrote: >> For the most part in QEMU with KVM we just treat the list of registers >> we get from the OS as an opaque blob of things we save to memory and >> pass back. > > This is specifically not the case for the SVE registers -- we > will need extra code to handle them. (The current code only > allows for the possibility of 64-bit registers, so if we'd > allowed the kernel to hand it the larger SVE registers it would > just have fallen over. This is why QEMU needs to specifically > enable SVE via the VCPU_INIT call.) Ahh right. So currently both the KVM_GET_REG_LIST and the core registers use KVM_GET/SET_ONE_REG which certainly won't do the trick. So I guess we need another IOCTL (or to enhance the current one) and a KVM capability bit as well? > > thanks > -- PMM -- Alex Benn?e