[PATCH v6 54/60] i386/cgs: Introduce x86_confidential_guest_check_features()

Xiaoyao Li
2024-11-05T06:40:13Z

To do cgs specific feature checking. Note the feature checking in
x86_cpu_filter_features() is valid for non-cgs VMs. For cgs VMs like
TDX, what features can be supported has more restrictions.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
target/i386/confidential-guest.h | 13 +++++++++++++
target/i386/kvm/kvm.c | 8 ++++++++
2 files changed, 21 insertions(+)

diff --git a/target/i386/confidential-guest.h b/target/i386/confidential-guest.h
index 2dde29889c23..3018f38e18bf 100644
--- a/target/i386/confidential-guest.h
+++ b/target/i386/confidential-guest.h
@@ -43,6 +43,7 @@ struct X86ConfidentialGuestClass {
void (*cpu_realizefn)(X86ConfidentialGuest *cg, CPUState *cpu, Error **errp);
uint32_t (*adjust_cpuid_features)(X86ConfidentialGuest *cg, uint32_t feature,
uint32_t index, int reg, uint32_t value);
+ int (*check_features)(X86ConfidentialGuest *cg, CPUState *cs);
};

/**
@@ -103,4 +104,16 @@ static inline int x86_confidential_guest_adjust_cpuid_features(X86ConfidentialGu
}
}

+static inline int x86_confidential_guest_check_features(X86ConfidentialGuest *cg,
+ CPUState *cs)
+{
+ X86ConfidentialGuestClass *klass = X86_CONFIDENTIAL_GUEST_GET_CLASS(cg);
+
+ if (klass->check_features) {
+ return klass->check_features(cg, cs);
+ }
+
+ return 0;
+}
+
#endif
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f067961fba43..42dc5b78faf0 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -2086,6 +2086,14 @@ int kvm_arch_init_vcpu(CPUState *cs)
int r;
Error *local_err = NULL;

+ if (current_machine->cgs) {
+ r = x86_confidential_guest_check_features(
+ X86_CONFIDENTIAL_GUEST(current_machine->cgs), cs);
+ if (r < 0) {
+ return r;
+ }
+ }
+
memset(&cpuid_data, 0, sizeof(cpuid_data));

cpuid_i = 0;
--
2.34.1