Messages in this thread | | | Date | Sat, 25 Nov 2017 17:50:10 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 20/43] x86/entry: Clean up SYSENTER_stack code |
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On Sat, 25 Nov 2017, Borislav Petkov wrote: > > - > > + wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1), 0); > > wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0); > > Right, so we have now two TSS thingies, AFAICT: > > tss = &per_cpu(cpu_tss, cpu); > > which is cpu_tss and then indirectly, we have also: > > &get_cpu_entry_area((cpu))->tss > > And those are two different things in my guest here: > > [ 0.044002] tss: 0xf5747000 > [ 0.044706] entry area tss: 0xffef1000 > > What is the logic here? We carry two TSSs per CPU - one which is RO > for the entry area and the other is the actual cpu_tss thing? Or am I > misreading it?
entry area tss is a alias mapping of cpu_tss
+ set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, tss), + &per_cpu(cpu_tss, cpu), + sizeof(struct tss_struct) / PAGE_SIZE, + PAGE_KERNEL);
Thanks,
tglx
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