|
From: | Richard Henderson |
Subject: | Re: [PATCH v4 1/3] target-arm: Add support for Fujitsu A64FX |
Date: | Tue, 17 Aug 2021 05:53:34 -1000 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 |
On 8/17/21 5:36 AM, Andrew Jones wrote:
On Tue, Aug 17, 2021 at 05:23:17AM -1000, Richard Henderson wrote:On 8/17/21 1:56 AM, Andrew Jones wrote:I guess it's fine. You could easily create a new cpu_arm_set_sve_vq() which would forbid changing the properties if you wanted to, but then we need to answer Peter's question in order to see if there's a precedent for that type of property.I don't see the point in read-only properties. If the user wants to set non-standard values on the command-line, let them. What is most important is getting the correct default from '-cpu a64fx'.So maybe we should just go ahead and add all sve* properties, but then make sure the default vq map is correct.
I think that's the right answer.Presently we have a kvm_supported variable that's initialized by kvm_arm_sve_get_vls(). I think we want to rename that variable and provide a version of that function for tcg. Probably we should have done that before, with a trivial function for -cpu max to set all bits.
Then eliminate most of the other kvm_enabled() checks in arm_cpu_sve_finalize. I think the only one we keep is the last, where we verify that the final sve_vq_map matches kvm_enabled exactly, modulo max_vq.
This should minimize the differences in behaviour between tcg and kvm. r~
[Prev in Thread] | Current Thread | [Next in Thread] |