On 8/22/2023 10:42 PM, Daniel P. Berrangé wrote:
On Tue, Aug 22, 2023 at 10:30:47PM +0800, Xiaoyao Li wrote:
On 8/21/2023 5:16 PM, Daniel P. Berrangé wrote:
On Fri, Aug 18, 2023 at 05:50:01AM -0400, Xiaoyao Li wrote:
Validate TD attributes with tdx_caps that fixed-0 bits must be zero and
fixed-1 bits must be set.
Besides, sanity check the attribute bits that have not been supported by
QEMU yet. e.g., debug bit, it will be allowed in the future when debug
TD support lands in QEMU.
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Acked-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
---
target/i386/kvm/tdx.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 629abd267da8..73da15377ec3 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -32,6 +32,7 @@
(1U << KVM_FEATURE_PV_SCHED_YIELD) | \
(1U << KVM_FEATURE_MSI_EXT_DEST_ID))
+#define TDX_TD_ATTRIBUTES_DEBUG BIT_ULL(0)
#define TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE BIT_ULL(28)
#define TDX_TD_ATTRIBUTES_PKS BIT_ULL(30)
#define TDX_TD_ATTRIBUTES_PERFMON BIT_ULL(63)
@@ -462,13 +463,32 @@ int tdx_kvm_init(MachineState *ms, Error **errp)
return 0;
}
-static void setup_td_guest_attributes(X86CPU *x86cpu)
+static int tdx_validate_attributes(TdxGuest *tdx)
+{
+ if (((tdx->attributes & tdx_caps->attrs_fixed0) | tdx_caps->attrs_fixed1) !=
+ tdx->attributes) {
+ error_report("Invalid attributes 0x%lx for TDX VM (fixed0 0x%llx, fixed1 0x%llx)",
+ tdx->attributes, tdx_caps->attrs_fixed0, tdx_caps->attrs_fixed1);
+ return -EINVAL;
+ }
+
+ if (tdx->attributes & TDX_TD_ATTRIBUTES_DEBUG) {
+ error_report("Current QEMU doesn't support attributes.debug[bit 0] for TDX VM");
+ return -EINVAL;
+ }
Use error_setg() in both cases, passing in a 'Error **errp' object,
and 'return -1' instead of returning an errno value.
why return -1 instead of -EINVAL?
Returning errno values is useful if the method isn't providing an
"Error **errp" parameter, because it lets the caller report a
more detailed error message via strerror(). Once you add a Error **
parameter though, there is almost never any reason for the caller
to care about the original errno value, and so we use 0 / -1 as
success/fail indicators.
I see.
Thanks,
-Xiaoyao
With regards,
Daniel
