Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-09 Thread Boris Ostrovsky
>> >> PV guests don't go through Linux x86 early boot code. They start at >> xen_start_kernel() (well, xen-head.S:startup_xen(), really) and merge >> with baremetal path at x86_64_start_reservations() (for 64-bit). >> > > Ok, I don't think anything needs to be done then. The sme_me_mask is set >

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-09 Thread Tom Lendacky
On 6/9/2017 1:43 PM, Boris Ostrovsky wrote: On 06/09/2017 02:36 PM, Tom Lendacky wrote: On 6/8/2017 5:01 PM, Andrew Cooper wrote: On 08/06/2017 22:17, Boris Ostrovsky wrote: On 06/08/2017 05:02 PM, Tom Lendacky wrote: On 6/8/2017 3:51 PM, Boris Ostrovsky wrote: What may be needed is making s

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-09 Thread Andrew Cooper
On 09/06/17 19:43, Boris Ostrovsky wrote: > On 06/09/2017 02:36 PM, Tom Lendacky wrote: >>> basis, although (as far as I am aware) Xen as a whole would be able to >>> encompass itself and all of its PV guests inside one single SME >>> instance. >> Yes, that is correct. Thinking more about this, it

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-09 Thread Boris Ostrovsky
On 06/09/2017 02:36 PM, Tom Lendacky wrote: > On 6/8/2017 5:01 PM, Andrew Cooper wrote: >> On 08/06/2017 22:17, Boris Ostrovsky wrote: >>> On 06/08/2017 05:02 PM, Tom Lendacky wrote: On 6/8/2017 3:51 PM, Boris Ostrovsky wrote: >>> What may be needed is making sure X86_FEATURE_SME is not se

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-09 Thread Tom Lendacky
On 6/8/2017 5:01 PM, Andrew Cooper wrote: On 08/06/2017 22:17, Boris Ostrovsky wrote: On 06/08/2017 05:02 PM, Tom Lendacky wrote: On 6/8/2017 3:51 PM, Boris Ostrovsky wrote: What may be needed is making sure X86_FEATURE_SME is not set for PV guests. And that may be something that Xen will nee

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-08 Thread Andrew Cooper
On 08/06/2017 22:17, Boris Ostrovsky wrote: > On 06/08/2017 05:02 PM, Tom Lendacky wrote: >> On 6/8/2017 3:51 PM, Boris Ostrovsky wrote: > What may be needed is making sure X86_FEATURE_SME is not set for PV > guests. And that may be something that Xen will need to control through eithe

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-08 Thread Boris Ostrovsky
On 06/08/2017 05:02 PM, Tom Lendacky wrote: > On 6/8/2017 3:51 PM, Boris Ostrovsky wrote: >> >>> What may be needed is making sure X86_FEATURE_SME is not set for PV guests. >>> >>> And that may be something that Xen will need to control through either >>> CPUID or MSR support for the PV g

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-08 Thread Tom Lendacky
On 6/8/2017 3:51 PM, Boris Ostrovsky wrote: What may be needed is making sure X86_FEATURE_SME is not set for PV guests. And that may be something that Xen will need to control through either CPUID or MSR support for the PV guests. Only on newer versions of Xen. On earlier versions (2-3 y

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-08 Thread Boris Ostrovsky
> >> What may be needed is making sure X86_FEATURE_SME is not set for PV >> guests. > > And that may be something that Xen will need to control through either > CPUID or MSR support for the PV guests. Only on newer versions of Xen. On earlier versions (2-3 years old) leaf 0x8007 is passed to

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-08 Thread Tom Lendacky
On 6/7/2017 5:06 PM, Boris Ostrovsky wrote: On 06/07/2017 03:14 PM, Tom Lendacky wrote: The cr3 register entry can contain the SME encryption bit that indicates the PGD is encrypted. The encryption bit should not be used when creating a virtual address for the PGD table. Create a new function,

Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

2017-06-07 Thread Boris Ostrovsky
On 06/07/2017 03:14 PM, Tom Lendacky wrote: > The cr3 register entry can contain the SME encryption bit that indicates > the PGD is encrypted. The encryption bit should not be used when creating > a virtual address for the PGD table. > > Create a new function, read_cr3_pa(), that will extract the