Re: [PATCH] intel-iommu: Set status bit after operation completed

[Peter Xu]

Hi, Zhenzhong,

On Thu, Mar 09, 2023 at 05:23:19PM +0800, Zhenzhong Duan wrote:
> According to SDM 11.4.4.2 Global Status Register:
> "This field is cleared by hardware when software sets the SRTP field in the
> Global Command register. This field is set by hardware when hardware
> completes the ‘Set Root Table Pointer’ operation using the value provided
> in the Root Table Address register"
> 
> Follow above spec to clear then set RTPS after finish all works, this way
> helps avoiding potential race with guest kernel. Though linux kernel is
> single threaded in writing GCMD_REG and checking GSTS_REG.
> 
> Same reasion for GSTS_REG.TES

Is this a real bug?  Or, when it'll make a difference to the guest?

Thanks,

-- 
Peter Xu