Belatedly, same complaints as the LAM series[*], this patch doesn't actually virtual LASS. Just squash this with the previous patch, "KVM: VMX: Implement and apply vmx_is_lass_violation() for LASS protection", though I would keep the shortlog from this patch. [*] https://lore.kernel.org/all/ZN1CjTQ0zWiOxk6j@xxxxxxxxxx On Thu, Jun 01, 2023, Zeng Guang wrote: > Virtualize CR4.LASS[bit 27] under KVM control instead of being guest-owned > as CR4.LASS generally set once for each vCPU at boot time and won't be > toggled at runtime. Besides, only if VM has LASS capability enumerated with > CPUID.(EAX=07H.ECX=1):EAX.LASS[bit 6], KVM allows guest software to be able > to set CR4.LASS. > > Updating cr4_fixed1 to set CR4.LASS bit in the emulated IA32_VMX_CR4_FIXED1 > MSR for guests and allow guests to enable LASS in nested VMX operaion as well. > > Notes: Setting CR4.LASS to 1 enable LASS in IA-32e mode. It doesn't take > effect in legacy mode even if CR4.LASS is set. > > Signed-off-by: Zeng Guang <guang.zeng@xxxxxxxxx> > Tested-by: Xuelian Guo <xuelian.guo@xxxxxxxxx>
