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[PATCH 1/2] KVM: x86: simplify handling of PKRU

Started byPaolo Bonzini <pbonzini@redhat.com>
First post2017-08-23 23:30 +0200
Last post2017-08-24 12:20 +0200
Articles 5 — 2 participants

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  [PATCH 1/2] KVM: x86: simplify handling of PKRU Paolo Bonzini <pbonzini@redhat.com> - 2017-08-23 23:30 +0200
    Re: [PATCH 1/2] KVM: x86: simplify handling of PKRU Yang Zhang <yang.zhang.wz@gmail.com> - 2017-08-24 11:10 +0200
      Re: [PATCH 1/2] KVM: x86: simplify handling of PKRU Paolo Bonzini <pbonzini@redhat.com> - 2017-08-24 11:20 +0200
        Re: [PATCH 1/2] KVM: x86: simplify handling of PKRU Yang Zhang <yang.zhang.wz@gmail.com> - 2017-08-24 12:10 +0200
          Re: [PATCH 1/2] KVM: x86: simplify handling of PKRU Paolo Bonzini <pbonzini@redhat.com> - 2017-08-24 12:20 +0200

#1718655 — [PATCH 1/2] KVM: x86: simplify handling of PKRU

FromPaolo Bonzini <pbonzini@redhat.com>
Date2017-08-23 23:30 +0200
Subject[PATCH 1/2] KVM: x86: simplify handling of PKRU
Message-ID<uhLnP-5N6-3@gated-at.bofh.it>
Move it to struct kvm_arch_vcpu, replacing guest_pkru_valid with a
simple comparison against the host value of the register.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/kvm_cache_regs.h   |  5 -----
 arch/x86/kvm/mmu.h              |  2 +-
 arch/x86/kvm/svm.c              |  7 -------
 arch/x86/kvm/vmx.c              | 23 ++++++-----------------
 5 files changed, 8 insertions(+), 30 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 643308143bea..beb185361045 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -491,6 +491,7 @@ struct kvm_vcpu_arch {
 	unsigned long cr4;
 	unsigned long cr4_guest_owned_bits;
 	unsigned long cr8;
+	u32 pkru;
 	u32 hflags;
 	u64 efer;
 	u64 apic_base;
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 762cdf2595f9..e1e89ee4af75 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -84,11 +84,6 @@ static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu)
 		| ((u64)(kvm_register_read(vcpu, VCPU_REGS_RDX) & -1u) << 32);
 }
 
-static inline u32 kvm_read_pkru(struct kvm_vcpu *vcpu)
-{
-	return kvm_x86_ops->get_pkru(vcpu);
-}
-
 static inline void enter_guest_mode(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.hflags |= HF_GUEST_MASK;
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 3ed6192d93b1..1b3095264fcf 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -168,7 +168,7 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 		* index of the protection domain, so pte_pkey * 2 is
 		* is the index of the first bit for the domain.
 		*/
-		pkru_bits = (kvm_read_pkru(vcpu) >> (pte_pkey * 2)) & 3;
+		pkru_bits = (vcpu->arch.pkru >> (pte_pkey * 2)) & 3;
 
 		/* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */
 		offset = (pfec & ~1) +
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 32c8d8f62985..f2355135164c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1826,11 +1826,6 @@ static void svm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 	to_svm(vcpu)->vmcb->save.rflags = rflags;
 }
 
-static u32 svm_get_pkru(struct kvm_vcpu *vcpu)
-{
-	return 0;
-}
-
 static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
 {
 	switch (reg) {
@@ -5438,8 +5433,6 @@ static void svm_setup_mce(struct kvm_vcpu *vcpu)
 	.get_rflags = svm_get_rflags,
 	.set_rflags = svm_set_rflags,
 
-	.get_pkru = svm_get_pkru,
-
 	.tlb_flush = svm_flush_tlb,
 
 	.run = svm_vcpu_run,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ddabed8425b3..c603f658c42a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -639,8 +639,6 @@ struct vcpu_vmx {
 
 	u64 current_tsc_ratio;
 
-	bool guest_pkru_valid;
-	u32 guest_pkru;
 	u32 host_pkru;
 
 	/*
@@ -2392,11 +2390,6 @@ static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 		to_vmx(vcpu)->emulation_required = emulation_required(vcpu);
 }
 
-static u32 vmx_get_pkru(struct kvm_vcpu *vcpu)
-{
-	return to_vmx(vcpu)->guest_pkru;
-}
-
 static u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu)
 {
 	u32 interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
@@ -9239,8 +9232,9 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
 		vmx_set_interrupt_shadow(vcpu, 0);
 
-	if (vmx->guest_pkru_valid)
-		__write_pkru(vmx->guest_pkru);
+	if (static_cpu_has(X86_FEATURE_OSPKE) &&
+	    vcpu->arch.pkru != vmx->host_pkru)
+		__write_pkru(vcpu->arch.pkru);
 
 	atomic_switch_perf_msrs(vmx);
 	debugctlmsr = get_debugctlmsr();
@@ -9388,13 +9382,10 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	 * back on host, so it is safe to read guest PKRU from current
 	 * XSAVE.
 	 */
-	if (boot_cpu_has(X86_FEATURE_OSPKE)) {
-		vmx->guest_pkru = __read_pkru();
-		if (vmx->guest_pkru != vmx->host_pkru) {
-			vmx->guest_pkru_valid = true;
+	if (static_cpu_has(X86_FEATURE_OSPKE)) {
+		vcpu->arch.pkru = __read_pkru();
+		if (vcpu->arch.pkru != vmx->host_pkru)
 			__write_pkru(vmx->host_pkru);
-		} else
-			vmx->guest_pkru_valid = false;
 	}
 
 	/*
@@ -11875,8 +11866,6 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu)
 	.get_rflags = vmx_get_rflags,
 	.set_rflags = vmx_set_rflags,
 
-	.get_pkru = vmx_get_pkru,
-
 	.tlb_flush = vmx_flush_tlb,
 
 	.run = vmx_vcpu_run,
-- 
1.8.3.1

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#1719037

FromYang Zhang <yang.zhang.wz@gmail.com>
Date2017-08-24 11:10 +0200
Message-ID<uhWjg-4uA-5@gated-at.bofh.it>
In reply to#1718655
On 2017/8/24 5:26, Paolo Bonzini wrote:
> Move it to struct kvm_arch_vcpu, replacing guest_pkru_valid with a
> simple comparison against the host value of the register.

Thanks for refine the patches.:)

> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   arch/x86/include/asm/kvm_host.h |  1 +
>   arch/x86/kvm/kvm_cache_regs.h   |  5 -----
>   arch/x86/kvm/mmu.h              |  2 +-
>   arch/x86/kvm/svm.c              |  7 -------
>   arch/x86/kvm/vmx.c              | 23 ++++++-----------------
>   5 files changed, 8 insertions(+), 30 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 643308143bea..beb185361045 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -491,6 +491,7 @@ struct kvm_vcpu_arch {
>   	unsigned long cr4;
>   	unsigned long cr4_guest_owned_bits;
>   	unsigned long cr8;
> +	u32 pkru;
>   	u32 hflags;
>   	u64 efer;
>   	u64 apic_base;
> diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
> index 762cdf2595f9..e1e89ee4af75 100644
> --- a/arch/x86/kvm/kvm_cache_regs.h
> +++ b/arch/x86/kvm/kvm_cache_regs.h
> @@ -84,11 +84,6 @@ static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu)
>   		| ((u64)(kvm_register_read(vcpu, VCPU_REGS_RDX) & -1u) << 32);
>   }
>   
> -static inline u32 kvm_read_pkru(struct kvm_vcpu *vcpu)
> -{
> -	return kvm_x86_ops->get_pkru(vcpu);
> -}
> -
>   static inline void enter_guest_mode(struct kvm_vcpu *vcpu)
>   {
>   	vcpu->arch.hflags |= HF_GUEST_MASK;
> diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
> index 3ed6192d93b1..1b3095264fcf 100644
> --- a/arch/x86/kvm/mmu.h
> +++ b/arch/x86/kvm/mmu.h
> @@ -168,7 +168,7 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
>   		* index of the protection domain, so pte_pkey * 2 is
>   		* is the index of the first bit for the domain.
>   		*/
> -		pkru_bits = (kvm_read_pkru(vcpu) >> (pte_pkey * 2)) & 3;
> +		pkru_bits = (vcpu->arch.pkru >> (pte_pkey * 2)) & 3;
>   
>   		/* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */
>   		offset = (pfec & ~1) +
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 32c8d8f62985..f2355135164c 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1826,11 +1826,6 @@ static void svm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
>   	to_svm(vcpu)->vmcb->save.rflags = rflags;
>   }
>   
> -static u32 svm_get_pkru(struct kvm_vcpu *vcpu)
> -{
> -	return 0;
> -}
> -
>   static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
>   {
>   	switch (reg) {
> @@ -5438,8 +5433,6 @@ static void svm_setup_mce(struct kvm_vcpu *vcpu)
>   	.get_rflags = svm_get_rflags,
>   	.set_rflags = svm_set_rflags,
>   
> -	.get_pkru = svm_get_pkru,
> -
>   	.tlb_flush = svm_flush_tlb,
>   
>   	.run = svm_vcpu_run,
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index ddabed8425b3..c603f658c42a 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -639,8 +639,6 @@ struct vcpu_vmx {
>   
>   	u64 current_tsc_ratio;
>   
> -	bool guest_pkru_valid;
> -	u32 guest_pkru;
>   	u32 host_pkru;
>   
>   	/*
> @@ -2392,11 +2390,6 @@ static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
>   		to_vmx(vcpu)->emulation_required = emulation_required(vcpu);
>   }
>   
> -static u32 vmx_get_pkru(struct kvm_vcpu *vcpu)
> -{
> -	return to_vmx(vcpu)->guest_pkru;
> -}
> -
>   static u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu)
>   {
>   	u32 interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
> @@ -9239,8 +9232,9 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
>   	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
>   		vmx_set_interrupt_shadow(vcpu, 0);
>   
> -	if (vmx->guest_pkru_valid)
> -		__write_pkru(vmx->guest_pkru);
> +	if (static_cpu_has(X86_FEATURE_OSPKE) &&

We expose protection key to VM without check whether OSPKE is enabled or 
not. Why not check guest's cpuid here which also can avoid unnecessary 
access to pkru?

> +	    vcpu->arch.pkru != vmx->host_pkru)
> +		__write_pkru(vcpu->arch.pkru);
>   
>   	atomic_switch_perf_msrs(vmx);
>   	debugctlmsr = get_debugctlmsr();
> @@ -9388,13 +9382,10 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
>   	 * back on host, so it is safe to read guest PKRU from current
>   	 * XSAVE.
>   	 */
> -	if (boot_cpu_has(X86_FEATURE_OSPKE)) {
> -		vmx->guest_pkru = __read_pkru();
> -		if (vmx->guest_pkru != vmx->host_pkru) {
> -			vmx->guest_pkru_valid = true;
> +	if (static_cpu_has(X86_FEATURE_OSPKE)) {
> +		vcpu->arch.pkru = __read_pkru();
> +		if (vcpu->arch.pkru != vmx->host_pkru)
>   			__write_pkru(vmx->host_pkru);
> -		} else
> -			vmx->guest_pkru_valid = false;
>   	}
>   
>   	/*
> @@ -11875,8 +11866,6 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu)
>   	.get_rflags = vmx_get_rflags,
>   	.set_rflags = vmx_set_rflags,
>   
> -	.get_pkru = vmx_get_pkru,
> -
>   	.tlb_flush = vmx_flush_tlb,
>   
>   	.run = vmx_vcpu_run,
> 


-- 
Yang
Alibaba Cloud Computing

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#1719050

FromPaolo Bonzini <pbonzini@redhat.com>
Date2017-08-24 11:20 +0200
Message-ID<uhWsW-4xQ-23@gated-at.bofh.it>
In reply to#1719037
On 24/08/2017 11:09, Yang Zhang wrote:
>> +    if (static_cpu_has(X86_FEATURE_OSPKE) &&
> 
> We expose protection key to VM without check whether OSPKE is enabled or
> not. Why not check guest's cpuid here which also can avoid unnecessary
> access to pkru?

Checking guest CPUID is pretty slow.  We could check CR4.PKE though.

Also, using static_cpu_has with OSPKE is probably wrong.  But if we do
check CR4.PKE, we can check X86_FEATURE_PKU instead, so something like

	if (static_cpu_has(X86_FEATURE_PKU) &&
	    kvm_read_cr4_bits(vcpu, X86_CR4_PKE) &&
	    vcpu->arch.pkru != vmx->host_pkru)

... but then, kvm_read_cr4_bits is also pretty slow---and we don't
really need it, since all CR4 writes cause a vmexit.  So for now I'd
stay with this patch, only s/static_cpu_has/boot_cpu_has/g.

Of course you can send improvements on top!

Paolo

>> +        vcpu->arch.pkru != vmx->host_pkru)
>> +        __write_pkru(vcpu->arch.pkru);

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#1719103

FromYang Zhang <yang.zhang.wz@gmail.com>
Date2017-08-24 12:10 +0200
Message-ID<uhXfj-52T-1@gated-at.bofh.it>
In reply to#1719050
On 2017/8/24 17:19, Paolo Bonzini wrote:
> On 24/08/2017 11:09, Yang Zhang wrote:
>>> +    if (static_cpu_has(X86_FEATURE_OSPKE) &&
>>
>> We expose protection key to VM without check whether OSPKE is enabled or
>> not. Why not check guest's cpuid here which also can avoid unnecessary
>> access to pkru?
> 
> Checking guest CPUID is pretty slow.  We could check CR4.PKE though.
> 
> Also, using static_cpu_has with OSPKE is probably wrong.  But if we do
> check CR4.PKE, we can check X86_FEATURE_PKU instead, so something like
> 
> 	if (static_cpu_has(X86_FEATURE_PKU) &&
> 	    kvm_read_cr4_bits(vcpu, X86_CR4_PKE) &&
> 	    vcpu->arch.pkru != vmx->host_pkru)
> 
> ... but then, kvm_read_cr4_bits is also pretty slow---and we don't
> really need it, since all CR4 writes cause a vmexit.  So for now I'd
> stay with this patch, only s/static_cpu_has/boot_cpu_has/g.
> 
> Of course you can send improvements on top!

ok, since most OS distributions don't support protection key so far 
which means vcpu->arch.pkru always 0 in it and i remember host_pkru will 
be set to 55555554 be default. To avoid the unnecessary access to pkru, 
how about the following change:

@@ -4338,6 +4331,9 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, 
unsigned long cr4)
                         return 1;
         }

+       if (cr4 & X86_CR4_PKE)
+               to_vmx(vcpu)->guest_pkru_valid = true;
+
         if (to_vmx(vcpu)->nested.vmxon && !nested_cr4_valid(vcpu, cr4))
                 return 1;

@@ -9020,8 +9016,10 @@ static void __noclone vmx_vcpu_run(struct 
kvm_vcpu *vcpu)
         if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                 vmx_set_interrupt_shadow(vcpu, 0);

-       if (vmx->guest_pkru_valid)
-               __write_pkru(vmx->guest_pkru);
+       if (static_cpu_has(X86_FEATURE_OSPKE) &&
+           vmx->guest_pkru_valid &&
+           vcpu->arch.pkru != vmx->host_pkru)
+               __write_pkru(vcpu->arch.pkru);

         atomic_switch_perf_msrs(vmx);
         debugctlmsr = get_debugctlmsr();
@@ -9169,13 +9167,11 @@ static void __noclone vmx_vcpu_run(struct 
kvm_vcpu *vcpu)
          * back on host, so it is safe to read guest PKRU from current
          * XSAVE.
          */
-       if (boot_cpu_has(X86_FEATURE_OSPKE)) {
-               vmx->guest_pkru = __read_pkru();
-               if (vmx->guest_pkru != vmx->host_pkru) {
-                       vmx->guest_pkru_valid = true;
+       if (static_cpu_has(X86_FEATURE_OSPKE) &&
+           vmx->guest_pkru_valid) {
+               vcpu->arch.pkru = __read_pkru();
+               if (vcpu->arch.pkru != vmx->host_pkru)
                         __write_pkru(vmx->host_pkru);
-               } else
-                       vmx->guest_pkru_valid = false;
         }

         /*

-- 
Yang
Alibaba Cloud Computing

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#1719116

FromPaolo Bonzini <pbonzini@redhat.com>
Date2017-08-24 12:20 +0200
Message-ID<uhXp0-563-31@gated-at.bofh.it>
In reply to#1719103
On 24/08/2017 12:05, Yang Zhang wrote:
> On 2017/8/24 17:19, Paolo Bonzini wrote:
>> On 24/08/2017 11:09, Yang Zhang wrote:
>>>> +    if (static_cpu_has(X86_FEATURE_OSPKE) &&
>>>
>>> We expose protection key to VM without check whether OSPKE is enabled or
>>> not. Why not check guest's cpuid here which also can avoid unnecessary
>>> access to pkru?
>>
>> Checking guest CPUID is pretty slow.  We could check CR4.PKE though.
>>
>> Also, using static_cpu_has with OSPKE is probably wrong.  But if we do
>> check CR4.PKE, we can check X86_FEATURE_PKU instead, so something like
>>
>>     if (static_cpu_has(X86_FEATURE_PKU) &&
>>         kvm_read_cr4_bits(vcpu, X86_CR4_PKE) &&
>>         vcpu->arch.pkru != vmx->host_pkru)
>>
>> ... but then, kvm_read_cr4_bits is also pretty slow---and we don't
>> really need it, since all CR4 writes cause a vmexit.  So for now I'd
>> stay with this patch, only s/static_cpu_has/boot_cpu_has/g.
>>
>> Of course you can send improvements on top!
> 
> ok, since most OS distributions don't support protection key so far
> which means vcpu->arch.pkru always 0 in it and i remember host_pkru will
> be set to 55555554 be default. To avoid the unnecessary access to pkru,
> how about the following change:

Even better: reading guest's CR4.PKE is actually _not_ slow because
X86_CR4_PKE is not part of KVM_POSSIBLE_CR4_GUEST_BITS.  So
kvm_read_cr4_bits(vcpu, X86_CR4_PKE) is compiled to just "vcpu->arch.cr4
& X86_CR4_PKE".

We need to be careful though to disable guest PKU if host OSPKE is off,
because otherwise __read_pkru and __write_pkru cause a #GP.

I've sent v2 of the series now, incorporating your suggestion.  Thanks!

Paolo

> @@ -4338,6 +4331,9 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu,
> unsigned long cr4)
>                         return 1;
>         }
> 
> +       if (cr4 & X86_CR4_PKE)
> +               to_vmx(vcpu)->guest_pkru_valid = true;
> +
>         if (to_vmx(vcpu)->nested.vmxon && !nested_cr4_valid(vcpu, cr4))
>                 return 1;
> 
> @@ -9020,8 +9016,10 @@ static void __noclone vmx_vcpu_run(struct
> kvm_vcpu *vcpu)
>         if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
>                 vmx_set_interrupt_shadow(vcpu, 0);
> 
> -       if (vmx->guest_pkru_valid)
> -               __write_pkru(vmx->guest_pkru);
> +       if (static_cpu_has(X86_FEATURE_OSPKE) &&
> +           vmx->guest_pkru_valid &&
> +           vcpu->arch.pkru != vmx->host_pkru)
> +               __write_pkru(vcpu->arch.pkru);
> 
>         atomic_switch_perf_msrs(vmx);
>         debugctlmsr = get_debugctlmsr();
> @@ -9169,13 +9167,11 @@ static void __noclone vmx_vcpu_run(struct
> kvm_vcpu *vcpu)
>          * back on host, so it is safe to read guest PKRU from current
>          * XSAVE.
>          */
> -       if (boot_cpu_has(X86_FEATURE_OSPKE)) {
> -               vmx->guest_pkru = __read_pkru();
> -               if (vmx->guest_pkru != vmx->host_pkru) {
> -                       vmx->guest_pkru_valid = true;
> +       if (static_cpu_has(X86_FEATURE_OSPKE) &&
> +           vmx->guest_pkru_valid) {
> +               vcpu->arch.pkru = __read_pkru();
> +               if (vcpu->arch.pkru != vmx->host_pkru)
>                         __write_pkru(vmx->host_pkru);
> -               } else
> -                       vmx->guest_pkru_valid = false;
>         }
> 
>         /*
>

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