[PATCH v3 33/70] i386/tdx: Set kvm_readonly_mem_enabled to false for TDX VM

Xiaoyao Li
2023-11-15T07:19:33Z

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 <xiaoyao.li@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
---
target/i386/kvm/tdx.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 05ca841d0b66..50e68f9c1a41 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -472,6 +472,15 @@ 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;
}
--
2.34.1