From 73137f59246da530c29674a506f83a18fe327946 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 3 Jun 2024 12:37:26 -0400 Subject: [PATCH] KVM: SEV: Don't WARN() if RMP lookup fails when invalidating gmem pages The hook only handles cleanup work specific to SNP, e.g. RMP table entries and flushing caches for encrypted guest memory. When run on a non-SNP-enabled host (currently only possible using KVM_X86_SW_PROTECTED_VM, e.g. via KVM selftests), the callback is a noop and will WARN due to the RMP table not being present. It's actually expected in this case that the RMP table wouldn't be present and that the hook should be a noop, so drop the WARN_ONCE(). Reported-by: Sean Christopherson Closes: https://lore.kernel.org/kvm/ZkU3_y0UoPk5yAeK@google.com/ Fixes: 8eb01900b018 ("KVM: SEV: Implement gmem hook for invalidating private pages") Suggested-by: Paolo Bonzini Signed-off-by: Michael Roth Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/sev.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 39f8eeea5659..526b9bfb7234 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -4682,6 +4682,9 @@ void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end) { kvm_pfn_t pfn; + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) + return; + pr_debug("%s: PFN start 0x%llx PFN end 0x%llx\n", __func__, start, end); for (pfn = start; pfn < end;) { @@ -4690,11 +4693,7 @@ void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end) 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; - - if (!assigned) + if (rc || !assigned) goto next_pfn; use_2m_update = IS_ALIGNED(pfn, PTRS_PER_PMD) &&