在 2018年09月27日 10:06, Baoquan He 写道: > Hi Lianbo, > > On 09/26/18 at 05:34pm, lijiang wrote: >> When SME is enabled on AMD machine, the memory is encrypted in the first >> kernel. In this case, SME also needs to be enabled in kdump kernel, and >> we have to remap the old memory with the memory encryption mask. >> >> Here we only talk about the case that SME is active in the first kernel, >> and only care it's active too in kdump kernel. there are four cases we >> need considered. >> >> a. dump vmcore >> It is encrypted in the first kernel, and needs be read out in kdump >> kernel. >> >> b. crash notes >> When dumping vmcore, the people usually need to read the useful >> information from notes, and the notes is also encrypted. >> >> c. iommu device table >> It is allocated by kernel, need fill its pointer into mmio of amd iommu. >> It's encrypted in the first kernel, need read the old content to analyze >> and get useful information. >> >> d. mmio of amd iommu >> Register reported by amd firmware, it's not RAM, we don't encrypt in >> both the first kernel and kdump kernel. >> >> To achieve the goal, the solution is: >> 1. add a new bool parameter "encrypted" to __ioremap_caller() >> It is a low level function, and check the newly added parameter, if it's >> true and in kdump kernel, will remap the memory with sme mask. >> >> 2. add a new function ioremap_encrypted() to explicitly passed in a "true" >> value for "encrypted". >> For above a, b, c, we will call ioremap_encrypted(); >> >> 3. adjust all existed ioremap wrapper functions, passed in "false" for >> encrypted to make them an before. >> >> ioremap_encrypted()\ >> ioremap_cache() | >> ioremap_prot() | >> ioremap_wt() |->__ioremap_caller() >> ioremap_wc() | >> ioremap_uc() | >> ioremap_nocache() / > > Thanks, I think it's better. Since no code change, just patch log > improvement, maybe you can repost a series and carry both Tom and > Joerg's ACK. > Thank you, Baoquan. I will resend a series, and add Tom's Reviewed-by for all patches, also add Joerg's Acked-by for patch 3/4. Thanks. Lianbo _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
