[v7,33/52] i386/tdx: Set kvm_readonly_mem_enabled to false for TDX VM

Commit Message

Xiaoyao Li Jan. 24, 2025, 1:20 p.m. UTC

TDX only supports readonly for shared memory but not for private memory.

In the view of QEMU, it has no idea whether a memslot is used as shared
memory of private. Thus just mark kvm_readonly_mem_enabled to false to
TDX VM for simplicity.

Signed-off-by: Xiaoyao Li <[e-mail]>
Acked-by: Gerd Hoffmann <[e-mail]>
---
 target/i386/kvm/tdx.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 982ed779df4a..f4d95b0a4029 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -382,6 +382,15 @@  static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
         return -EOPNOTSUPP;
     }
 
+    /*
+     * Set kvm_readonly_mem_allowed to false, because TDX only supports readonly
+     * memory for shared memory but not for private memory. Besides, whether a
+     * memslot is private or shared is not determined by QEMU.
+     *
+     * Thus, just mark readonly memory not supported for simplicity.
+     */
+    kvm_readonly_mem_allowed = false;
+
     qemu_add_machine_init_done_notifier(&tdx_machine_done_notify);
 
     tdx_guest = tdx;