[RFC PATCH v5 071/104] KVM: TDX: restore debug store when TD exit

isaku.yamahata@intel.com posted 104 patches 3 years, 9 months ago
There is a newer version of this series
[RFC PATCH v5 071/104] KVM: TDX: restore debug store when TD exit
Posted by isaku.yamahata@intel.com 3 years, 9 months ago
From: Isaku Yamahata <isaku.yamahata@intel.com>

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

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 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 3cb2fbd1c12c..37cf7d43435d 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -620,6 +620,7 @@ 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
Re: [RFC PATCH v5 071/104] KVM: TDX: restore debug store when TD exit
Posted by Paolo Bonzini 3 years, 8 months ago
On 3/4/22 20:49, isaku.yamahata@intel.com wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> Because debug store is clobbered, restore it on TD exit.
> 
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> ---
>   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 3cb2fbd1c12c..37cf7d43435d 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -620,6 +620,7 @@ 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;
>   

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>