On 27/08/2024 10:04 pm, Kirill A. Shutemov wrote:
On Wed, Aug 21, 2024 at 01:52:49PM +1200, Huang, Kai wrote:
+ * attribute is no longer reliable. It reflects the initial state of the
+ * control for the TD, but it will not be updated if someone (e.g. bootloader)
+ * changes it before the kernel starts. Kernel must check TDCS_TD_CTLS bit to
+ * determine if SEPT #VEs are enabled or disabled.
+ */
+static void disable_sept_ve(u64 td_attr)
+{
+ const char *msg = "TD misconfiguration: SEPT #VE has to be disabled";
The original msg was:
"TD misconfiguration: SEPT_VE_DISABLE attribute must be set."
Any reason to change?
Because the attribute is not the only way to control if #VE is going to be
injected.
+ bool debug = td_attr & ATTR_DEBUG;
+ u64 config, controls;
+
+ /* Is this TD allowed to disable SEPT #VE */
+ tdg_vm_rd(TDCS_CONFIG_FLAGS, &config);
+ if (!(config & TDCS_CONFIG_FLEXIBLE_PENDING_VE)) {
Does this field ID exist in TDX1.0? I.e., whether it can fail here and
should we check the return value first?
See TDG.VM.RD definition:
R8 Contents of the field
In case of no success, as indicated by RAX, R8 returns 0.
No need in error checking here.
OK. Thanks.
diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h
index 7e12cfa28bec..fecb2a6e864b 100644
--- a/arch/x86/include/asm/shared/tdx.h
+++ b/arch/x86/include/asm/shared/tdx.h
@@ -19,9 +19,17 @@
#define TDG_VM_RD 7
#define TDG_VM_WR 8
-/* TDCS fields. To be used by TDG.VM.WR and TDG.VM.RD module calls */
+/* TDX TD-Scope Metadata. To be used by TDG.VM.WR and TDG.VM.RD */
I am not sure whether this change is necessary.
It is more in-line with spec json dump.
+#define TDCS_CONFIG_FLAGS 0x1110000300000016
+#define TDCS_TD_CTLS 0x1110000300000017
The TDX 1.5 spec 'td_scope_metadata.json' says they are 0x9110000300000016
and 0x9110000300000017.
The spec is broken. It is going to be fixed. I use correct values.
OK. I didn't know they are going to change the value in the JSON file.
I know the bit 63 is ignored by the TDX module, but since (IIUC) those two
fields are introduced in TDX1.5, it's just better to follow what TDX1.5 spec
says.
Newer modules will ignore this bit and both values are going to
acceptable.
Yeah.
Acked-by: Kai Huang <kai.huang@xxxxxxxxx>
