[RFC PATCH v6 072/104] KVM: TDX: restore debug store when TD exit

From: isaku . yamahata
Date: Thu May 05 2022 - 14:24:12 EST


From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Because debug store is clobbered, restore it on TD exit.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/events/intel/ds.c | 1 +
arch/x86/kvm/vmx/tdx.c | 1 +
2 files changed, 2 insertions(+)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 376cc3d66094..cdba4227ad3b 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2256,3 +2256,4 @@ void perf_restore_debug_store(void)

wrmsrl(MSR_IA32_DS_AREA, (unsigned long)ds);
}
+EXPORT_SYMBOL_GPL(perf_restore_debug_store);
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 7af7c84f8891..f92941586b42 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -661,6 +661,7 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu)
tdx_vcpu_enter_exit(vcpu, tdx);

tdx_user_return_update_cache();
+ perf_restore_debug_store();
tdx_restore_host_xsave_state(vcpu);
tdx->host_state_need_restore = true;

--
2.25.1