From 0b020f5af0922d288e92845d622eca41d76786fb Mon Sep 17 00:00:00 2001
From: Peter Gonda <pgonda@google.com>
Date: Thu, 21 Oct 2021 10:43:01 -0700
Subject: [PATCH] KVM: SEV: Add support for SEV-ES intra host migration
For SEV-ES to work with intra host migration the VMSAs, GHCB metadata,
and other SEV-ES info needs to be preserved along with the guest's
memory.
Signed-off-by: Peter Gonda <pgonda@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-4-pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/svm/sev.c | 48 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 47 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 8b529022f0cf0..f63f9156964f6 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1612,6 +1612,46 @@ static void sev_migrate_from(struct kvm_sev_info *dst,
list_replace_init(&src->regions_list, &dst->regions_list);
}
+static int sev_es_migrate_from(struct kvm *dst, struct kvm *src)
+{
+ int i;
+ struct kvm_vcpu *dst_vcpu, *src_vcpu;
+ struct vcpu_svm *dst_svm, *src_svm;
+
+ if (atomic_read(&src->online_vcpus) != atomic_read(&dst->online_vcpus))
+ return -EINVAL;
+
+ kvm_for_each_vcpu(i, src_vcpu, src) {
+ if (!src_vcpu->arch.guest_state_protected)
+ return -EINVAL;
+ }
+
+ kvm_for_each_vcpu(i, src_vcpu, src) {
+ src_svm = to_svm(src_vcpu);
+ dst_vcpu = kvm_get_vcpu(dst, i);
+ dst_svm = to_svm(dst_vcpu);
+
+ /*
+ * Transfer VMSA and GHCB state to the destination. Nullify and
+ * clear source fields as appropriate, the state now belongs to
+ * the destination.
+ */
+ memcpy(&dst_svm->sev_es, &src_svm->sev_es, sizeof(src_svm->sev_es));
+ dst_svm->vmcb->control.ghcb_gpa = src_svm->vmcb->control.ghcb_gpa;
+ dst_svm->vmcb->control.vmsa_pa = src_svm->vmcb->control.vmsa_pa;
+ dst_vcpu->arch.guest_state_protected = true;
+
+ memset(&src_svm->sev_es, 0, sizeof(src_svm->sev_es));
+ src_svm->vmcb->control.ghcb_gpa = INVALID_PAGE;
+ src_svm->vmcb->control.vmsa_pa = INVALID_PAGE;
+ src_vcpu->arch.guest_state_protected = false;
+ }
+ to_kvm_svm(src)->sev_info.es_active = false;
+ to_kvm_svm(dst)->sev_info.es_active = true;
+
+ return 0;
+}
+
int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd)
{
struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info;
@@ -1640,7 +1680,7 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd)
if (ret)
goto out_fput;
- if (!sev_guest(source_kvm) || sev_es_guest(source_kvm)) {
+ if (!sev_guest(source_kvm)) {
ret = -EINVAL;
goto out_source;
}
@@ -1660,10 +1700,16 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd)
if (ret)
goto out_dst_vcpu;
+ if (sev_es_guest(source_kvm)) {
+ ret = sev_es_migrate_from(kvm, source_kvm);
+ if (ret)
+ goto out_source_vcpu;
+ }
sev_migrate_from(dst_sev, src_sev);
kvm_vm_dead(source_kvm);
ret = 0;
+out_source_vcpu:
sev_unlock_vcpus_for_migration(source_kvm);
out_dst_vcpu:
sev_unlock_vcpus_for_migration(kvm);
--
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