From: Sean Christopherson <seanjc@google.com>
To: Michael Roth <michael.roth@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PULL 13/19] KVM: SEV: Implement gmem hook for invalidating private pages
Date: Wed, 15 May 2024 15:32:31 -0700 [thread overview]
Message-ID: <ZkU3_y0UoPk5yAeK@google.com> (raw)
In-Reply-To: <20240510211024.556136-14-michael.roth@amd.com>
On Fri, May 10, 2024, Michael Roth wrote:
> Implement a platform hook to do the work of restoring the direct map
> entries of gmem-managed pages and transitioning the corresponding RMP
> table entries back to the default shared/hypervisor-owned state.
...
> +void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end)
> +{
> + kvm_pfn_t pfn;
> +
> + pr_debug("%s: PFN start 0x%llx PFN end 0x%llx\n", __func__, start, end);
> +
> + for (pfn = start; pfn < end;) {
> + bool use_2m_update = false;
> + int rc, rmp_level;
> + bool assigned;
> +
> + rc = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
> + if (WARN_ONCE(rc, "SEV: Failed to retrieve RMP entry for PFN 0x%llx error %d\n",
> + pfn, rc))
> + goto next_pfn;
This is comically trivial to hit, as it fires when running guest_memfd_test on a
!SNP host. Presumably the correct fix is to simply do nothing for !sev_snp_guest(),
but that's easier said than done due to the lack of a @kvm in .gmem_invalidate().
That too is not a big fix, but that's beside the point. IMO, the fact that I'm
the first person to (completely inadvertantly) hit this rather basic bug is a
good hint that we should wait until 6.11 to merge SNP support.
next prev parent reply other threads:[~2024-05-15 22:32 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-10 21:10 [PULL 00/19] KVM: Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Michael Roth
2024-05-10 21:10 ` [PULL 01/19] KVM: MMU: Disable fast path if KVM_EXIT_MEMORY_FAULT is needed Michael Roth
2024-05-10 21:10 ` [PULL 02/19] KVM: SEV: Select KVM_GENERIC_PRIVATE_MEM when CONFIG_KVM_AMD_SEV=y Michael Roth
2024-05-10 21:10 ` [PULL 03/19] KVM: SEV: Add initial SEV-SNP support Michael Roth
2024-05-10 21:10 ` [PULL 04/19] KVM: SEV: Add KVM_SEV_SNP_LAUNCH_START command Michael Roth
2024-05-10 21:10 ` [PULL 05/19] KVM: SEV: Add KVM_SEV_SNP_LAUNCH_UPDATE command Michael Roth
2024-05-10 21:10 ` [PULL 06/19] KVM: SEV: Add KVM_SEV_SNP_LAUNCH_FINISH command Michael Roth
2024-05-10 21:10 ` [PULL 07/19] KVM: SEV: Add support to handle GHCB GPA register VMGEXIT Michael Roth
2024-05-10 21:10 ` [PULL 08/19] KVM: SEV: Add support to handle MSR based Page State Change VMGEXIT Michael Roth
2024-05-10 21:10 ` [PULL 09/19] KVM: SEV: Add support to handle " Michael Roth
2024-05-12 2:06 ` Michael Roth
2024-05-10 21:10 ` [PULL 10/19] KVM: SEV: Add support to handle RMP nested page faults Michael Roth
2024-05-10 21:10 ` [PULL 11/19] KVM: SEV: Support SEV-SNP AP Creation NAE event Michael Roth
2024-05-10 21:10 ` [PULL 12/19] KVM: SEV: Implement gmem hook for initializing private pages Michael Roth
2024-05-10 21:10 ` [PULL 13/19] KVM: SEV: Implement gmem hook for invalidating " Michael Roth
2024-05-15 22:32 ` Sean Christopherson [this message]
2024-05-16 3:11 ` Michael Roth
2024-05-21 16:55 ` Paolo Bonzini
2024-05-16 12:45 ` Paolo Bonzini
2024-05-10 21:10 ` [PULL 14/19] KVM: x86: Implement hook for determining max NPT mapping level Michael Roth
2024-05-10 21:10 ` [PULL 15/19] KVM: SEV: Avoid WBINVD for HVA-based MMU notifications for SNP Michael Roth
2024-05-10 21:10 ` [PULL 16/19] KVM: SVM: Add module parameter to enable SEV-SNP Michael Roth
2024-05-10 21:10 ` [PULL 17/19] KVM: SEV: Provide support for SNP_GUEST_REQUEST NAE event Michael Roth
2024-05-17 20:41 ` Edgecombe, Rick P
2024-05-17 22:01 ` Paolo Bonzini
2024-05-18 15:04 ` [PATCH] KVM: SEV: Fix guest memory leak when handling guest requests Michael Roth
2024-05-20 14:17 ` Sean Christopherson
2024-05-20 22:50 ` Michael Roth
2024-05-20 23:32 ` Sean Christopherson
2024-05-21 2:00 ` Michael Roth
2024-05-21 14:09 ` Sean Christopherson
2024-05-21 15:34 ` Michael Roth
2024-05-21 16:58 ` Sean Christopherson
2024-05-21 21:00 ` Michael Roth
2024-05-20 23:02 ` [PATCH v2] " Michael Roth
2024-05-10 21:10 ` [PULL 18/19] KVM: SEV: Provide support for SNP_EXTENDED_GUEST_REQUEST NAE event Michael Roth
2024-05-13 15:19 ` Nathan Chancellor
2024-05-13 16:53 ` Paolo Bonzini
2024-05-13 17:05 ` Michael Roth
2024-05-13 17:20 ` Paolo Bonzini
2024-05-13 21:18 ` Michael Roth
2024-05-10 21:10 ` [PULL 19/19] crypto: ccp: Add the SNP_VLEK_LOAD command Michael Roth
2024-05-12 7:14 ` [PULL 00/19] KVM: Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Paolo Bonzini
2024-05-12 8:17 ` Paolo Bonzini
2024-05-13 1:06 ` Michael Roth
2024-05-13 22:08 ` Sean Christopherson
2024-05-31 3:22 ` Michael Roth
2024-06-03 16:44 ` Paolo Bonzini
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