From: Vlastimil Babka <vbabka@suse.cz>
To: Joerg Roedel <jroedel@suse.de>, Dave Hansen <dave.hansen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, linux-coco@lists.linux.dev,
linux-mm@kvack.org, linux-crypto@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Ard Biesheuvel <ardb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Dov Murik <dovmurik@linux.ibm.com>,
Tobin Feldman-Fitzthum <tobin@ibm.com>,
Borislav Petkov <bp@alien8.de>,
Michael Roth <michael.roth@amd.com>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Andi Kleen <ak@linux.intel.com>,
tony.luck@intel.com, marcorr@google.com,
sathyanarayanan.kuppuswamy@linux.intel.com,
Mike Kravetz <mike.kravetz@oracle.com>
Subject: Re: [PATCH Part2 v5 08/45] x86/fault: Add support to handle the RMP fault for user address
Date: Wed, 25 Aug 2021 11:16:56 +0200 [thread overview]
Message-ID: <c5a8f7e8-7146-0737-81a1-1faceb6992ab@suse.cz> (raw)
In-Reply-To: <YSUhg/87jZPocLDP@suse.de>
On 8/24/21 18:42, Joerg Roedel wrote:
> On Mon, Aug 23, 2021 at 07:50:22AM -0700, Dave Hansen wrote:
>> It *has* to be done in KVM, IMNHO.
>>
>> The core kernel really doesn't know much about SEV. It *really* doesn't
>> know when its memory is being exposed to a virtualization architecture
>> that doesn't know how to split TLBs like every single one before it.
>>
>> This essentially *must* be done at the time that the KVM code realizes
>> that it's being asked to shove a non-splittable page mapping into the
>> SEV hardware structures.
>>
>> The only other alternative is raising a signal from the fault handler
>> when the page can't be split. That's a *LOT* nastier because it's so
>> much later in the process.
>>
>> It's either that, or figure out a way to split hugetlbfs (and DAX)
>> mappings in a failsafe way.
>
> Yes, I agree with that. KVM needs a check to disallow HugeTLB pages in
> SEV-SNP guests, at least as a temporary workaround. When HugeTLBfs
> mappings can be split into smaller pages the check can be removed.
FTR, this is Sean's reply with concerns in v4:
https://lore.kernel.org/linux-coco/YPCuTiNET%2FhJHqOY@google.com/
I think there are two main arguments there:
- it's not KVM business to decide
- guest may do all page state changes with 2mb granularity so it might be fine
with hugetlb
The latter might become true, but I think it's more probable that sooner
hugetlbfs will learn to split the mappings to base pages - I know people plan to
work on that. At that point qemu will have to recognize if the host kernel is
the new one that can do this splitting vs older one that can't. Preferably
without relying on kernel version number, as backports exist. Thus, trying to
register a hugetlbfs range that either is rejected (kernel can't split) or
passes (kernel can split) seems like a straightforward way. So I'm also in favor
of adding that, hopefuly temporary, check.
Vlastimil
> Regards,
>
> Joerg
>
next prev parent reply other threads:[~2021-08-25 9:17 UTC|newest]
Thread overview: 239+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 15:58 [PATCH Part2 v5 00/45] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 01/45] x86/cpufeatures: Add SEV-SNP CPU feature Brijesh Singh
2021-09-16 16:56 ` Borislav Petkov
2021-09-16 17:35 ` Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 02/45] iommu/amd: Introduce function to check SEV-SNP support Brijesh Singh
2021-09-16 17:26 ` Borislav Petkov
2021-08-20 15:58 ` [PATCH Part2 v5 03/45] x86/sev: Add the host SEV-SNP initialization support Brijesh Singh
2021-09-24 8:58 ` Borislav Petkov
2021-08-20 15:58 ` [PATCH Part2 v5 04/45] x86/sev: Add RMP entry lookup helpers Brijesh Singh
2021-09-24 9:49 ` Borislav Petkov
2021-09-27 16:01 ` Brijesh Singh
2021-09-27 16:04 ` Brijesh Singh
2021-09-29 12:56 ` Borislav Petkov
2022-06-02 11:57 ` Jarkko Sakkinen
2021-08-20 15:58 ` [PATCH Part2 v5 05/45] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction Brijesh Singh
2021-09-24 14:04 ` Borislav Petkov
2021-09-27 16:06 ` Brijesh Singh
2021-10-15 18:05 ` Sean Christopherson
2021-10-15 20:18 ` Brijesh Singh
2021-10-15 20:27 ` Sean Christopherson
2021-10-15 20:36 ` Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 06/45] x86/sev: Invalid pages from direct map when adding it to RMP table Brijesh Singh
2021-09-29 14:34 ` Borislav Petkov
2021-09-30 16:19 ` Brijesh Singh
2021-10-01 11:06 ` Borislav Petkov
2021-08-20 15:58 ` [PATCH Part2 v5 07/45] x86/traps: Define RMP violation #PF error code Brijesh Singh
2021-09-29 17:25 ` Borislav Petkov
2021-08-20 15:58 ` [PATCH Part2 v5 08/45] x86/fault: Add support to handle the RMP fault for user address Brijesh Singh
2021-08-23 14:20 ` Dave Hansen
2021-08-23 14:36 ` Brijesh Singh
2021-08-23 14:50 ` Dave Hansen
2021-08-24 16:42 ` Joerg Roedel
2021-08-25 9:16 ` Vlastimil Babka [this message]
2021-08-25 13:50 ` Tom Lendacky
2021-09-29 18:19 ` Borislav Petkov
2021-08-20 15:58 ` [PATCH Part2 v5 09/45] x86/fault: Add support to dump RMP entry on fault Brijesh Singh
2021-09-29 18:38 ` Borislav Petkov
2021-08-20 15:58 ` [PATCH Part2 v5 10/45] crypto: ccp: shutdown SEV firmware on kexec Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 11/45] crypto:ccp: Define the SEV-SNP commands Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 12/45] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 13/45] crypto:ccp: Provide APIs to issue SEV-SNP commands Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 14/45] crypto: ccp: Handle the legacy TMR allocation when SNP is enabled Brijesh Singh
2022-02-25 18:03 ` Alper Gun
2022-03-01 14:12 ` Brijesh Singh
2022-06-14 0:10 ` Alper Gun
2021-08-20 15:58 ` [PATCH Part2 v5 15/45] crypto: ccp: Handle the legacy SEV command " Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 16/45] crypto: ccp: Add the SNP_PLATFORM_STATUS command Brijesh Singh
2021-09-10 3:18 ` Marc Orr
2021-09-13 11:17 ` Brijesh Singh
2021-09-22 17:35 ` Dr. David Alan Gilbert
2021-09-23 18:01 ` Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 17/45] crypto: ccp: Add the SNP_{SET,GET}_EXT_CONFIG command Brijesh Singh
2021-09-01 21:02 ` Connor Kuehl
2021-09-01 23:06 ` Brijesh Singh
2021-09-10 3:27 ` Marc Orr
2021-09-13 11:29 ` Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 18/45] crypto: ccp: Provide APIs to query extended attestation report Brijesh Singh
2021-09-10 3:30 ` Marc Orr
2021-09-12 7:46 ` Dov Murik
2021-08-20 15:58 ` [PATCH Part2 v5 19/45] KVM: SVM: Add support to handle AP reset MSR protocol Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 20/45] KVM: SVM: Provide the Hypervisor Feature support VMGEXIT Brijesh Singh
2021-10-12 20:38 ` Sean Christopherson
2021-08-20 15:58 ` [PATCH Part2 v5 21/45] KVM: SVM: Make AVIC backing, VMSA and VMCB memory allocation SNP safe Brijesh Singh
2021-09-22 18:55 ` Dr. David Alan Gilbert
2021-09-23 18:09 ` Brijesh Singh
2021-09-23 18:39 ` Dr. David Alan Gilbert
2021-09-23 22:23 ` Brijesh Singh
2021-09-23 19:17 ` Marc Orr
2021-09-23 20:44 ` Brijesh Singh
2021-09-23 20:55 ` Marc Orr
2021-10-12 20:44 ` Sean Christopherson
2021-08-20 15:58 ` [PATCH Part2 v5 22/45] KVM: SVM: Add initial SEV-SNP support Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 23/45] KVM: SVM: Add KVM_SNP_INIT command Brijesh Singh
2021-09-05 6:56 ` Dov Murik
2021-09-05 13:59 ` Brijesh Singh
2021-09-10 3:32 ` Marc Orr
2021-09-13 11:32 ` Brijesh Singh
2021-09-16 15:50 ` Peter Gonda
2022-06-13 20:58 ` Alper Gun
2022-06-13 23:15 ` Ashish Kalra
2022-06-13 23:33 ` Alper Gun
2022-06-14 0:21 ` Ashish Kalra
2022-06-14 15:37 ` Peter Gonda
2022-06-14 16:11 ` Kalra, Ashish
2022-06-14 16:30 ` Peter Gonda
2022-06-14 17:16 ` Kalra, Ashish
2022-06-14 18:58 ` Alper Gun
2022-06-14 20:23 ` Kalra, Ashish
2022-06-14 20:29 ` Peter Gonda
2022-06-14 20:39 ` Kalra, Ashish
2021-08-20 15:58 ` [PATCH Part2 v5 24/45] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_START command Brijesh Singh
2021-08-20 15:58 ` [PATCH Part2 v5 25/45] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_UPDATE command Brijesh Singh
2021-09-27 16:43 ` Peter Gonda
2021-09-27 19:33 ` Brijesh Singh
2021-10-05 15:01 ` Peter Gonda
2021-08-20 15:58 ` [PATCH Part2 v5 26/45] KVM: SVM: Mark the private vma unmerable for SEV-SNP guests Brijesh Singh
2021-09-23 17:18 ` Dr. David Alan Gilbert
2021-10-12 18:46 ` Sean Christopherson
2021-10-13 12:39 ` Brijesh Singh
2021-10-13 14:34 ` Sean Christopherson
2021-10-13 14:51 ` Brijesh Singh
2021-10-13 15:33 ` Sean Christopherson
2021-08-20 15:59 ` [PATCH Part2 v5 27/45] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_FINISH command Brijesh Singh
2022-05-18 20:21 ` Marc Orr
2022-05-18 20:35 ` Kalra, Ashish
2021-08-20 15:59 ` [PATCH Part2 v5 28/45] KVM: X86: Keep the NPT and RMP page level in sync Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 29/45] KVM: x86/mmu: Move 'pfn' variable to caller of direct_page_fault() Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 30/45] KVM: x86/mmu: Introduce kvm_mmu_map_tdp_page() for use by TDX and SNP Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 31/45] KVM: x86: Introduce kvm_mmu_get_tdp_walk() for SEV-SNP use Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 32/45] KVM: x86: Define RMP page fault error bits for #NPF Brijesh Singh
2021-09-30 23:41 ` Marc Orr
2021-10-01 13:03 ` Borislav Petkov
2021-08-20 15:59 ` [PATCH Part2 v5 33/45] KVM: x86: Update page-fault trace to log full 64-bit error code Brijesh Singh
2021-10-13 21:23 ` Sean Christopherson
2021-08-20 15:59 ` [PATCH Part2 v5 34/45] KVM: SVM: Do not use long-lived GHCB map while setting scratch area Brijesh Singh
2021-10-13 21:20 ` Sean Christopherson
2021-10-15 16:11 ` Brijesh Singh
2021-10-15 16:44 ` Sean Christopherson
2021-08-20 15:59 ` [PATCH Part2 v5 35/45] KVM: SVM: Remove the long-lived GHCB host map Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 36/45] KVM: SVM: Add support to handle GHCB GPA register VMGEXIT Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 37/45] KVM: SVM: Add support to handle MSR based Page State Change VMGEXIT Brijesh Singh
2021-09-28 9:56 ` Dr. David Alan Gilbert
2021-10-12 21:48 ` Sean Christopherson
2021-10-13 17:04 ` Sean Christopherson
2021-10-13 17:05 ` Brijesh Singh
2021-10-13 17:24 ` Sean Christopherson
2021-10-13 17:49 ` Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 38/45] KVM: SVM: Add support to handle " Brijesh Singh
2021-09-28 10:17 ` Dr. David Alan Gilbert
2021-09-28 23:20 ` Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 39/45] KVM: SVM: Introduce ops for the post gfn map and unmap Brijesh Singh
2021-10-13 0:23 ` Sean Christopherson
2021-10-13 18:10 ` Brijesh Singh
2021-10-13 20:10 ` Sean Christopherson
2021-10-13 21:49 ` Brijesh Singh
2021-10-13 22:10 ` Sean Christopherson
2021-10-13 22:31 ` Brijesh Singh
2021-10-13 20:16 ` Sean Christopherson
2021-10-15 16:31 ` Brijesh Singh
2021-10-15 17:16 ` Sean Christopherson
2022-09-08 21:21 ` Michael Roth
2022-09-08 22:28 ` Michael Roth
2022-09-14 8:05 ` Sean Christopherson
2022-09-14 11:02 ` Marc Orr
2022-09-14 16:15 ` Sean Christopherson
2022-09-14 16:32 ` Marc Orr
2022-09-14 16:39 ` Marc Orr
2022-09-19 17:56 ` Michael Roth
2021-08-20 15:59 ` [PATCH Part2 v5 40/45] KVM: x86: Export the kvm_zap_gfn_range() for the SNP use Brijesh Singh
2021-08-20 15:59 ` [PATCH Part2 v5 41/45] KVM: SVM: Add support to handle the RMP nested page fault Brijesh Singh
2021-09-29 12:24 ` Dr. David Alan Gilbert
2021-10-13 17:57 ` Sean Christopherson
2021-08-20 15:59 ` [PATCH Part2 v5 42/45] KVM: SVM: Provide support for SNP_GUEST_REQUEST NAE event Brijesh Singh
2021-09-29 21:33 ` Peter Gonda
2021-09-29 22:00 ` Peter Gonda
2021-08-20 15:59 ` [PATCH Part2 v5 43/45] KVM: SVM: Use a VMSA physical address variable for populating VMCB Brijesh Singh
2021-10-15 18:58 ` Sean Christopherson
2021-08-20 15:59 ` [PATCH Part2 v5 44/45] KVM: SVM: Support SEV-SNP AP Creation NAE event Brijesh Singh
2021-10-15 19:50 ` Sean Christopherson
2021-10-20 21:48 ` Brijesh Singh
2021-10-20 23:01 ` Sean Christopherson
2021-08-20 15:59 ` [PATCH Part2 v5 45/45] KVM: SVM: Add module parameter to enable the SEV-SNP Brijesh Singh
2021-11-12 15:43 ` [PATCH Part2 v5 00/45] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Peter Gonda
2021-11-12 17:59 ` Dave Hansen
2021-11-12 18:35 ` Borislav Petkov
2021-11-12 19:48 ` Sean Christopherson
2021-11-12 20:04 ` Borislav Petkov
2021-11-12 20:37 ` Sean Christopherson
2021-11-12 20:53 ` Borislav Petkov
2021-11-12 21:12 ` Peter Gonda
2021-11-12 21:20 ` Andy Lutomirski
2021-11-12 22:04 ` Borislav Petkov
2021-11-12 22:52 ` Peter Gonda
2021-11-13 0:00 ` Sean Christopherson
2021-11-13 0:10 ` Marc Orr
2021-11-13 18:34 ` Sean Christopherson
2021-11-14 7:54 ` Marc Orr
2021-11-15 17:16 ` Sean Christopherson
2021-11-15 16:36 ` Joerg Roedel
2021-11-15 17:25 ` Sean Christopherson
2021-11-12 21:30 ` Marc Orr
2021-11-12 21:37 ` Dave Hansen
2021-11-12 21:40 ` Marc Orr
2021-11-12 21:39 ` Andy Lutomirski
2021-11-12 21:43 ` Marc Orr
2021-11-12 22:54 ` Peter Gonda
2021-11-13 0:53 ` Sean Christopherson
2021-11-13 1:04 ` Marc Orr
2021-11-13 18:28 ` Sean Christopherson
2021-11-14 7:41 ` Marc Orr
2021-11-15 18:17 ` Sean Christopherson
2021-11-15 16:52 ` Joerg Roedel
2021-11-15 16:18 ` Brijesh Singh
2021-11-15 18:44 ` Sean Christopherson
2021-11-15 18:58 ` Brijesh Singh
2021-11-12 21:16 ` Marc Orr
2021-11-12 21:23 ` Andy Lutomirski
2021-11-12 21:35 ` Borislav Petkov
2021-11-15 12:30 ` Dr. David Alan Gilbert
2021-11-15 14:42 ` Joerg Roedel
2021-11-15 15:33 ` Dr. David Alan Gilbert
2021-11-15 16:20 ` Joerg Roedel
2021-11-15 16:32 ` Dr. David Alan Gilbert
2021-11-15 18:26 ` Sean Christopherson
2021-11-15 18:41 ` Marc Orr
2021-11-15 19:15 ` Sean Christopherson
2021-11-16 3:07 ` Marc Orr
2021-11-16 5:14 ` Andy Lutomirski
2021-11-16 13:21 ` Joerg Roedel
2021-11-16 18:26 ` Sean Christopherson
2021-11-16 18:39 ` Peter Gonda
2021-11-16 13:30 ` Joerg Roedel
2021-11-16 5:00 ` Andy Lutomirski
2021-11-16 13:02 ` Joerg Roedel
2021-11-16 20:08 ` Sean Christopherson
2021-11-15 16:16 ` Joerg Roedel
2021-11-22 15:23 ` Brijesh Singh
2021-11-22 17:03 ` Vlastimil Babka
2021-11-22 18:01 ` Brijesh Singh
2021-11-22 18:30 ` Dave Hansen
2021-11-22 19:06 ` Brijesh Singh
2021-11-22 19:14 ` Dave Hansen
2021-11-22 20:33 ` Brijesh Singh
2021-11-22 21:34 ` Sean Christopherson
2021-11-22 22:51 ` Dave Hansen
2021-11-23 5:15 ` Luck, Tony
2021-11-23 7:18 ` Borislav Petkov
2021-11-23 15:36 ` Sean Christopherson
2021-11-23 16:26 ` Borislav Petkov
2021-11-23 8:55 ` Vlastimil Babka
2021-11-24 16:03 ` Joerg Roedel
2021-11-24 17:48 ` Dave Hansen
2021-11-24 19:34 ` Vlastimil Babka
2021-11-25 10:05 ` Joerg Roedel
2021-11-29 14:44 ` Brijesh Singh
2021-11-29 14:58 ` Vlastimil Babka
2021-11-29 16:13 ` Brijesh Singh
2021-11-30 19:40 ` Vlastimil Babka
2021-11-29 16:41 ` Dave Hansen
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