Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 23/09/16 06:37, Borislav Petkov wrote: On Thu, Sep 22, 2016 at 08:23:36PM +0200, Paolo Bonzini wrote: Unless this is part of some spec, it's easier if things are the same in SME and SEV. Yeah, I was pondering over how sprinkling sev_active checks might not be so clean. I'm wondering if

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 09/22/2016 12:07 PM, Borislav Petkov wrote: > On Thu, Sep 22, 2016 at 05:05:54PM +0200, Paolo Bonzini wrote: >> Which paragraph? > > "Linux relies on BIOS to set this bit if BIOS has determined that the > reduction in the physical address space as a result of enabling memory > encryption..." >

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On Thu, Sep 22, 2016 at 02:49:22PM -0500, Tom Lendacky wrote: > > I thought that reduction is the reservation of bits for the SME mask. > > > > What other reduction is there? > > There is a reduction in physical address space for the SME mask and the > bits used to aid in identifying the ASID

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 09/22/2016 02:11 PM, Borislav Petkov wrote: > On Thu, Sep 22, 2016 at 02:04:27PM -0500, Tom Lendacky wrote: >> That's not what I mean here. If the BIOS sets the SMEE bit in the >> SYS_CFG msr then, even if the encryption bit is never used, there is >> still a reduction in physical address

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 22/09/2016 20:47, Tom Lendacky wrote: > > Because the firmware volume is written to high memory in encrypted form, > > and because the PEI phase runs in 32-bit mode, the firmware code will be > > encrypted; on the other hand, data that is placed in low memory for the > > kernel can be

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 09/22/2016 09:45 AM, Paolo Bonzini wrote: > > > On 22/09/2016 16:35, Borislav Petkov wrote: @@ -230,6 +230,10 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd); pgd = efi_pgd;

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On Thu, Sep 22, 2016 at 08:23:36PM +0200, Paolo Bonzini wrote: > Unless this is part of some spec, it's easier if things are the same in > SME and SEV. Yeah, I was pondering over how sprinkling sev_active checks might not be so clean. I'm wondering if we could make the EFI regions presented to

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 22/09/2016 19:46, Tom Lendacky wrote: >> > Do you mean, it is encrypted here because we're in the guest kernel? > Yes, the idea is that the SEV guest will be running encrypted from the > start, including the BIOS/UEFI, and so all of the EFI related data will > be encrypted. Unless this is

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On Thu, Sep 22, 2016 at 07:08:50PM +0200, Paolo Bonzini wrote: > That's not how I read it. I just figured that the BIOS has some magic > things high in the physical address space and if you reduce the physical > address space the BIOS (which is called from e.g. EFI runtime services) > would have

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 22/09/2016 19:07, Borislav Petkov wrote: >> Which paragraph? > "Linux relies on BIOS to set this bit if BIOS has determined that the > reduction in the physical address space as a result of enabling memory > encryption..." > > Basically, you can enable SME in the BIOS and you're all set.

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On Thu, Sep 22, 2016 at 05:05:54PM +0200, Paolo Bonzini wrote: > Which paragraph? "Linux relies on BIOS to set this bit if BIOS has determined that the reduction in the physical address space as a result of enabling memory encryption..." Basically, you can enable SME in the BIOS and you're all

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 22/09/2016 16:59, Borislav Petkov wrote: > On Thu, Sep 22, 2016 at 04:45:51PM +0200, Paolo Bonzini wrote: >> The main difference between the SME and SEV encryption, from the point >> of view of the kernel, is that real-mode always writes unencrypted in >> SME and always writes encrypted in

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On Thu, Sep 22, 2016 at 04:45:51PM +0200, Paolo Bonzini wrote: > The main difference between the SME and SEV encryption, from the point > of view of the kernel, is that real-mode always writes unencrypted in > SME and always writes encrypted in SEV. But UEFI can run in 64-bit mode > and learn

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On 22/09/2016 16:35, Borislav Petkov wrote: >> > @@ -230,6 +230,10 @@ int __init efi_setup_page_tables(unsigned long >> > pa_memmap, unsigned num_pages) >> >efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd); >> >pgd = efi_pgd; >> > >> > + flags = _PAGE_NX | _PAGE_RW; >> > + if

Re: [RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

On Mon, Aug 22, 2016 at 07:25:25PM -0400, Brijesh Singh wrote: > From: Tom Lendacky > > EFI data is encrypted when the kernel is run under SEV. Update the > page table references to be sure the EFI memory areas are accessed > encrypted. > > Signed-off-by: Tom Lendacky

[RFC PATCH v1 09/28] x86/efi: Access EFI data as encrypted when SEV is active

From: Tom Lendacky EFI data is encrypted when the kernel is run under SEV. Update the page table references to be sure the EFI memory areas are accessed encrypted. Signed-off-by: Tom Lendacky --- arch/x86/platform/efi/efi_64.c | 14