On 09/09/2015 08:05, Xiao Guangrong wrote:
> Unify the update in vmx_cpuid_update()
> 
> Signed-off-by: Xiao Guangrong <[email protected]>

What if we instead start fresh from vmx_secondary_exec_control, like this:

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4504cbc1b287..98c4d3f1653a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8660,11 +8660,26 @@ static int vmx_get_lpage_level(void)
                return PT_PDPE_LEVEL;
 }
 
+static void vmcs_set_secondary_exec_control(u32 new_ctl)
+{
+       /*
+        * These bits in the secondary execution controls field
+        * are dynamic, the others are mostly based on the hypervisor
+        * architecture and the guest's CPUID.  Do not touch the
+        * dynamic bits.
+        */
+       u32 mask = SECONDARY_EXEC_ENABLE_PML | SECONDARY_EXEC_SHADOW_VMCS;
+       u32 cur_ctl = vmcs_read32(SECONDARY_EXEC_CONTROL);
+
+       vmcs_write32(SECONDARY_EXEC_CONTROL,
+                    (new_ctl & ~mask) | (cur_ctl & mask));
+}
+
 static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 {
        struct kvm_cpuid_entry2 *best;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
-       u32 clear_exe_ctrl = 0;
+       u32 secondary_exec_ctl = vmx_secondary_exec_control(vmx);
 
        vmx->rdtscp_enabled = false;
        if (vmx_rdtscp_supported()) {
@@ -8672,7 +8681,7 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
                if (best && (best->edx & bit(X86_FEATURE_RDTSCP)))
                        vmx->rdtscp_enabled = true;
                else
-                       clear_exe_ctrl |= SECONDARY_EXEC_RDTSCP;
+                       secondary_exec_ctl &= ~SECONDARY_EXEC_RDTSCP;
 
                if (nested) {
                        if (vmx->rdtscp_enabled)
@@ -8689,18 +8698,13 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
        if (vmx_invpcid_supported() &&
            (!best || !(best->ebx & bit(X86_FEATURE_INVPCID)) ||
            !guest_cpuid_has_pcid(vcpu))) {
-               clear_exe_ctrl |= SECONDARY_EXEC_ENABLE_INVPCID;
+               secondary_exec_ctl &= ~SECONDARY_EXEC_ENABLE_INVPCID;
 
                if (best)
                        best->ebx &= ~bit(X86_FEATURE_INVPCID);
        }
 
-       if (clear_exe_ctrl) {
-               u32 exec_ctl = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
-
-               exec_ctl &= ~clear_exe_ctrl;
-               vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_ctl);
-       }
+       vmcs_set_secondary_exec_control(secondary_exec_ctl);
 
        if (static_cpu_has(X86_FEATURE_PCOMMIT) && nested) {
                if (guest_cpuid_has_pcommit(vcpu))

> ---
>  arch/x86/kvm/vmx.c | 21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 97e3340..5a074d0 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -8673,19 +8673,15 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
>  {
>       struct kvm_cpuid_entry2 *best;
>       struct vcpu_vmx *vmx = to_vmx(vcpu);
> -     u32 exec_control;
> +     u32 clear_exe_ctrl = 0;
>  
>       vmx->rdtscp_enabled = false;
>       if (vmx_rdtscp_supported()) {
> -             exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
>               best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
>               if (best && (best->edx & bit(X86_FEATURE_RDTSCP)))
>                       vmx->rdtscp_enabled = true;
> -             else {
> -                     exec_control &= ~SECONDARY_EXEC_RDTSCP;
> -                     vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
> -                                     exec_control);
> -             }
> +             else
> +                     clear_exe_ctrl |= SECONDARY_EXEC_RDTSCP;
>  
>               if (nested && !vmx->rdtscp_enabled)
>                       vmx->nested.nested_vmx_secondary_ctls_high &=
> @@ -8697,14 +8693,19 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
>       if (vmx_invpcid_supported() &&
>           (!best || !(best->ebx & bit(X86_FEATURE_INVPCID)) ||
>           !guest_cpuid_has_pcid(vcpu))) {
> -             exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
> -             exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;
> -             vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
> +             clear_exe_ctrl |= SECONDARY_EXEC_ENABLE_INVPCID;
>  
>               if (best)
>                       best->ebx &= ~bit(X86_FEATURE_INVPCID);
>       }
>  
> +     if (clear_exe_ctrl) {
> +             u32 exec_ctl = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
> +
> +             exec_ctl &= ~clear_exe_ctrl;
> +             vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_ctl);
> +     }
> +
>       if (!guest_cpuid_has_pcommit(vcpu) && nested)
>               vmx->nested.nested_vmx_secondary_ctls_high &=
>                       ~SECONDARY_EXEC_PCOMMIT;
> 
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