[v1,19/40] i386/tdx: Set kvm_readonly_mem_enabled to false for TDX VM

Commit Message

Xiaoyao Li Aug. 2, 2022, 7:47 a.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 0162d7cc9df4..3aa0e374a514 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -461,6 +461,15 @@  int tdx_kvm_init(MachineState *ms, Error **errp)
 
     update_tdx_cpuid_lookup_by_tdx_caps();
 
+    /*
+     * 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;
+
     tdx_guest = tdx;
 
     return 0;