Re: [PATCH] KVM/X86: Check input sreg values before loading vcpu

[rkrcmar@xxxxxxxxxx]

2018-02-27 06:57+0000, Tianyu Lan:
> From: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx>
> 
> This patch is to check sreg value first and then load vcpu in order
> to avoid redundant loading/putting vcpu.
> 
> Signed-off-by: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx>
> ---

Patch "KVM: x86: KVM_CAP_SYNC_REGS" made significant changes to the
sregs setter, so the patch cannot be applied in current form.

I think that moving the X86_CR4_OSXSAVE check to guest_cpuid_has still
makes sense, but avoiding the vcpu_load/put would produce worse code
elsewhere and avoiding the load/put is not critical as any error is
probably going to be the end for this VM.

Thanks.