KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/arch/mips/kvm/interrupt.h b/arch/mips/kvm/interrupt.h
new file mode 100644
index 000000000..07bc0160b
--- /dev/null
+++ b/arch/mips/kvm/interrupt.h
@@ -0,0 +1,43 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * KVM/MIPS: Interrupts
+ * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+ */
+
+/*
+ * MIPS Exception Priorities, exceptions (including interrupts) are queued up
+ * for the guest in the order specified by their priorities
+ */
+
+#define MIPS_EXC_RESET              0
+#define MIPS_EXC_SRESET             1
+#define MIPS_EXC_DEBUG_ST           2
+#define MIPS_EXC_DEBUG              3
+#define MIPS_EXC_DDB                4
+#define MIPS_EXC_NMI                5
+#define MIPS_EXC_MCHK               6
+#define MIPS_EXC_INT_TIMER          7
+#define MIPS_EXC_INT_IO_1           8
+#define MIPS_EXC_INT_IO_2           9
+#define MIPS_EXC_EXECUTE            10
+#define MIPS_EXC_INT_IPI_1          11
+#define MIPS_EXC_INT_IPI_2          12
+#define MIPS_EXC_MAX                13
+/* XXXSL More to follow */
+
+#define C_TI        (_ULCAST_(1) << 30)
+
+extern u32 *kvm_priority_to_irq;
+u32 kvm_irq_to_priority(u32 irq);
+
+int kvm_mips_pending_timer(struct kvm_vcpu *vcpu);
+
+void kvm_mips_deliver_interrupts(struct kvm_vcpu *vcpu, u32 cause);
+
+#ifdef CONFIG_CPU_LOONGSON64
+extern void kvm_init_loongson_ipi(struct kvm *kvm);
+#endif