target/i386: sev: Do not pin the ram device memory region

The RAM device presents a memory region that should be handled
as an IO region and should not be pinned.

In the case of the vfio-pci, RAM device represents a MMIO BAR
and the memory region is not backed by pages hence
KVM_MEMORY_ENCRYPT_REG_REGION fails to lock the memory range.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1667249
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Message-Id: <20190204222322.26766-3-brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/sev.c b/target/i386/sev.c
index 20b2d325d81bdf6d4f280272157b521c3ab66217..cd77f6b5d477d42e1ae7ffe36b527c8766c132ec 100644 (file)
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -131,6 +131,17 @@ sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size)
 {
     int r;
     struct kvm_enc_region range;
+    ram_addr_t offset;
+    MemoryRegion *mr;
+
+    /*
+     * The RAM device presents a memory region that should be treated
+     * as IO region and should not be pinned.
+     */
+    mr = memory_region_from_host(host, &offset);
+    if (mr && memory_region_is_ram_device(mr)) {
+        return;
+    }
 
     range.addr = (__u64)(unsigned long)host;
     range.size = size;