Anirudh Rayabharam writes: > On Wed, Jun 22, 2022 at 06:48:50PM +0200, Vitaly Kuznetsov wrote: >> Anirudh Rayabharam writes: >> >> > On Wed, Jun 22, 2022 at 04:35:27PM +0200, Vitaly Kuznetsov wrote: >> >> ... >> >> >> >> >> I've tried to pick it up but it's actually much harder than I think. The >> >> patch has some minor issues ('&vmcs_config.nested' needs to be switched >> >> to '&vmcs_conf->nested' in nested_vmx_setup_ctls_msrs()), but the main >> >> problem is that the set of controls nested_vmx_setup_ctls_msrs() needs >> >> is NOT a subset of vmcs_config (setup_vmcs_config()). I was able to >> >> identify at least: >> >> ... >> >> I've jsut sent "[PATCH RFC v1 00/10] KVM: nVMX: Use vmcs_config for >> setting up nested VMX MSRs" which implements Sean's suggestion. Hope >> this is the way to go for mainline. >> >> > >> > How about we do something simple like the patch below to start with? >> > This will easily apply to stable and we can continue improving upon >> > it with follow up patches on mainline. >> > >> >> Personally, I'm not against this for @stable. Alternatively, in case the > > I think it's a good intermediate fix for mainline too. It is easier to land > it in stable if it already exists in mainline. It can stay in mainline > until your series lands and replaces it with the vmcs_config approach. > > What do you think? > Paolo's call but personally I think both series can make 5.20 so there's no need for an intermediate solution. >> only observed issue is with TSC scaling, we can add support for it for >> KVM-on-Hyper-V but not for Hyper-V-on-KVM (a small subset of "[PATCH >> 00/11] KVM: VMX: Support TscScaling and EnclsExitingBitmap whith >> eVMCS"). I can prepare patches if needed. > > Will it fit in stable's 100 line rule? > Yes, please take a look at the attached patches (5.18.y based). First 3 are identical to what I've sent for mainline, the last one is reduced to only support TSC scaling for KVM on Hyper-V (but not Hyper-V on KVM). Compile tested only, proceed with caution) -- Vitaly