diff options
| author | Mingwei Zhang <mizhang@google.com> | 2022-04-21 03:14:06 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-04-21 13:16:59 -0400 |
| commit | d45829b351ee6ec5f54dd55e6aca1f44fe239fe6 (patch) | |
| tree | 45ec8b9159c81c734d5263ffbdeac9acd7f4ba8d | |
| parent | 4bbef7e8eb8c2c7dabf57d97decfd2b4f48aaf02 (diff) | |
| download | linux-d45829b351ee6ec5f54dd55e6aca1f44fe239fe6.tar.bz2 | |
KVM: SVM: Flush when freeing encrypted pages even on SME_COHERENT CPUs
Use clflush_cache_range() to flush the confidential memory when
SME_COHERENT is supported in AMD CPU. Cache flush is still needed since
SME_COHERENT only support cache invalidation at CPU side. All confidential
cache lines are still incoherent with DMA devices.
Cc: stable@vger.kerel.org
Fixes: add5e2f04541 ("KVM: SVM: Add support for the SEV-ES VMSA")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Message-Id: <20220421031407.2516575-3-mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index b77b3913e2d9..9a0375987029 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2239,11 +2239,14 @@ static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va) unsigned long addr = (unsigned long)va; /* - * If hardware enforced cache coherency for encrypted mappings of the - * same physical page is supported, nothing to do. + * If CPU enforced cache coherency for encrypted mappings of the + * same physical page is supported, use CLFLUSHOPT instead. NOTE: cache + * flush is still needed in order to work properly with DMA devices. */ - if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) + if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) { + clflush_cache_range(va, PAGE_SIZE); return; + } /* * VM Page Flush takes a host virtual address and a guest ASID. Fall |