From: Tom Lendacky <thomas.lendacky@amd.com>
To: Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@intel.com>
Cc: Michael Roth <michael.roth@amd.com>,
x86@kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev,
linux-mm@kvack.org, linux-crypto@vger.kernel.org,
linux-kernel@vger.kernel.org, tglx@linutronix.de,
mingo@redhat.com, jroedel@suse.de, hpa@zytor.com,
ardb@kernel.org, pbonzini@redhat.com, seanjc@google.com,
vkuznets@redhat.com, jmattson@google.com, luto@kernel.org,
dave.hansen@linux.intel.com, slp@redhat.com, pgonda@google.com,
peterz@infradead.org, srinivas.pandruvada@linux.intel.com,
rientjes@google.com, tobin@ibm.com, vbabka@suse.cz,
kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com,
sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com,
jarkko@kernel.org, ashish.kalra@amd.com, nikunj.dadhania@amd.com,
pankaj.gupta@amd.com, liam.merwick@oracle.com,
zhi.a.wang@intel.com, Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [PATCH v1 11/26] x86/sev: Invalidate pages from the direct map when adding them to the RMP table
Date: Fri, 12 Jan 2024 14:28:13 -0600 [thread overview]
Message-ID: <63297d29-bb24-ac5e-0b47-35e22bb1a2f8@amd.com> (raw)
In-Reply-To: <20240112200751.GHZaGcF0-OZVJiIB7y@fat_crate.local>
On 1/12/24 14:07, Borislav Petkov wrote:
> On Fri, Jan 12, 2024 at 12:00:01PM -0800, Dave Hansen wrote:
>> On 12/30/23 08:19, Michael Roth wrote:
>>> If the kernel uses a 2MB directmap mapping to write to an address, and
>>> that 2MB range happens to contain a 4KB page that set to private in the
>>> RMP table, that will also lead to a page-fault exception.
I thought there was also a desire to remove the direct map for any pages
assigned to a guest as private, not just the case that the comment says.
So updating the comment would probably the best action.
>>
>> I thought we agreed long ago to just demote the whole direct map to 4k
>> on kernels that might need to act as SEV-SNP hosts. That should be step
>> one and this can be discussed as an optimization later.
Won't this accomplish that without actually demoting a lot of long-live
kernel related mappings that would never be demoted? I don't think we need
to demote the whole mapping to 4K.
Thanks,
Tom
>
> What would be the disadvantage here? Higher TLB pressure when running
> kernel code I guess...
>
next prev parent reply other threads:[~2024-01-12 20:28 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-30 16:19 [PATCH v1 00/26] Add AMD Secure Nested Paging (SEV-SNP) Initialization Support Michael Roth
2023-12-30 16:19 ` [PATCH v1 01/26] x86/cpufeatures: Add SEV-SNP CPU feature Michael Roth
2023-12-31 11:50 ` Borislav Petkov
2023-12-31 16:44 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 02/26] x86/speculation: Do not enable Automatic IBRS if SEV SNP is enabled Michael Roth
2023-12-30 16:19 ` [PATCH v1 03/26] iommu/amd: Don't rely on external callers to enable IOMMU SNP support Michael Roth
2024-01-04 10:30 ` Borislav Petkov
2024-01-04 10:58 ` Joerg Roedel
2023-12-30 16:19 ` [PATCH v1 04/26] x86/sev: Add the host SEV-SNP initialization support Michael Roth
2024-01-04 11:05 ` Jeremi Piotrowski
2024-01-05 16:09 ` Borislav Petkov
2024-01-05 16:21 ` Borislav Petkov
2024-01-08 16:49 ` Jeremi Piotrowski
2024-01-08 17:04 ` Borislav Petkov
2024-01-09 11:56 ` Jeremi Piotrowski
2024-01-09 12:29 ` Borislav Petkov
2024-01-09 12:44 ` Borislav Petkov
2024-02-14 16:56 ` Jeremi Piotrowski
2024-01-04 11:16 ` Borislav Petkov
2024-01-04 14:42 ` Borislav Petkov
2024-01-05 19:19 ` Borislav Petkov
2024-01-05 21:27 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 05/26] x86/mtrr: Don't print errors if MtrrFixDramModEn is set when SNP enabled Michael Roth
2023-12-30 16:19 ` [PATCH v1 06/26] x86/sev: Add RMP entry lookup helpers Michael Roth
2023-12-30 16:19 ` [PATCH v1 07/26] x86/fault: Add helper for dumping RMP entries Michael Roth
2024-01-10 9:59 ` Borislav Petkov
2024-01-10 20:18 ` Jarkko Sakkinen
2024-01-10 22:14 ` Borislav Petkov
2024-01-10 11:13 ` Borislav Petkov
2024-01-10 15:20 ` Tom Lendacky
2024-01-10 15:27 ` Borislav Petkov
2024-01-10 15:51 ` Tom Lendacky
2024-01-10 15:55 ` Borislav Petkov
2024-01-10 15:10 ` Tom Lendacky
2023-12-30 16:19 ` [PATCH v1 08/26] x86/traps: Define RMP violation #PF error code Michael Roth
2023-12-30 16:19 ` [PATCH v1 09/26] x86/fault: Dump RMP table information when RMP page faults occur Michael Roth
2023-12-30 16:19 ` [PATCH v1 10/26] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction Michael Roth
2024-01-12 14:49 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 11/26] x86/sev: Invalidate pages from the direct map when adding them to the RMP table Michael Roth
2024-01-12 19:48 ` Borislav Petkov
2024-01-12 20:00 ` Dave Hansen
2024-01-12 20:07 ` Borislav Petkov
2024-01-12 20:27 ` Vlastimil Babka
2024-01-15 9:06 ` Borislav Petkov
2024-01-15 9:14 ` Vlastimil Babka
2024-01-15 9:16 ` Mike Rapoport
2024-01-15 9:20 ` Borislav Petkov
2024-01-12 20:28 ` Tom Lendacky [this message]
2024-01-12 20:37 ` Dave Hansen
2024-01-15 9:23 ` Vlastimil Babka
2024-01-16 16:19 ` Michael Roth
2024-01-16 16:50 ` Michael Roth
2024-01-16 20:12 ` Mike Rapoport
2024-01-26 1:49 ` Michael Roth
2024-01-16 18:22 ` Borislav Petkov
2024-01-16 20:22 ` Dave Hansen
2024-01-26 1:35 ` Michael Roth
2024-01-15 9:09 ` Borislav Petkov
2024-01-16 16:21 ` Dave Hansen
2024-01-17 9:34 ` Borislav Petkov
2024-01-15 9:01 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 12/26] crypto: ccp: Define the SEV-SNP commands Michael Roth
2024-01-15 9:41 ` Borislav Petkov
2024-01-26 1:56 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 13/26] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP Michael Roth
2024-01-15 11:19 ` Borislav Petkov
2024-01-15 19:53 ` Borislav Petkov
2024-01-26 2:48 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 14/26] crypto: ccp: Provide API to issue SEV and SNP commands Michael Roth
2024-01-17 9:48 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 15/26] x86/sev: Introduce snp leaked pages list Michael Roth
2024-01-08 10:45 ` Vlastimil Babka
2024-01-09 22:19 ` Kalra, Ashish
2024-01-10 8:59 ` Vlastimil Babka
2023-12-30 16:19 ` [PATCH v1 16/26] crypto: ccp: Handle the legacy TMR allocation when SNP is enabled Michael Roth
2023-12-30 16:19 ` [PATCH v1 17/26] crypto: ccp: Handle non-volatile INIT_EX data " Michael Roth
2024-01-18 14:03 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 18/26] crypto: ccp: Handle legacy SEV commands " Michael Roth
2024-01-19 17:18 ` Borislav Petkov
2024-01-19 17:36 ` Tom Lendacky
2024-01-19 17:48 ` Borislav Petkov
2024-01-26 13:29 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 19/26] iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown Michael Roth
2023-12-30 16:19 ` [PATCH v1 20/26] crypto: ccp: Add debug support for decrypting pages Michael Roth
2024-01-10 14:59 ` Sean Christopherson
2024-01-11 0:50 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 21/26] crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump Michael Roth
2024-01-21 11:49 ` Borislav Petkov
2024-01-26 3:03 ` Kalra, Ashish
2024-01-26 13:38 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 22/26] KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe Michael Roth
2024-01-21 11:51 ` Borislav Petkov
2024-01-26 3:44 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 23/26] x86/cpufeatures: Enable/unmask SEV-SNP CPU feature Michael Roth
2023-12-30 16:19 ` [PATCH v1 24/26] crypto: ccp: Add the SNP_PLATFORM_STATUS command Michael Roth
2024-01-21 12:29 ` Borislav Petkov
2024-01-26 3:32 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 25/26] crypto: ccp: Add the SNP_COMMIT command Michael Roth
2024-01-21 12:35 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 26/26] crypto: ccp: Add the SNP_SET_CONFIG command Michael Roth
2024-01-21 12:41 ` Borislav Petkov
2024-01-26 13:30 ` Michael Roth
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