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From: Paolo Bonzini <pbonzini@redhat.com>
To: Huaitong Han <huaitong.han@intel.com>, gleb@kernel.org
Cc: kvm@vger.kernel.org, guangrong.xiao@linux.intel.com
Subject: Re: [PATCH V5 7/9] KVM, pkeys: expose CPUID/CR4 to guest
Date: Mon, 21 Mar 2016 12:36:32 +0100	[thread overview]
Message-ID: <56EFDCC0.1080307@redhat.com> (raw)
In-Reply-To: <1458554760-4374-8-git-send-email-huaitong.han@intel.com>



On 21/03/2016 11:05, Huaitong Han wrote:
> X86_FEATURE_PKU is referred to as "PKU" in the hardware documentation:
> CPUID.7.0.ECX[3]:PKU. X86_FEATURE_OSPKE is software support for pkeys,
> enumerated with CPUID.7.0.ECX[4]:OSPKE, and it reflects the setting of
> CR4.PKE(bit 22).
> 
> Signed-off-by: Huaitong Han <huaitong.han@intel.com>
> Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> ---
>  arch/x86/include/asm/kvm_host.h |  3 ++-
>  arch/x86/kvm/cpuid.c            | 33 +++++++++++++++++++++++++--------
>  arch/x86/kvm/cpuid.h            |  8 ++++++++
>  arch/x86/kvm/x86.c              |  9 ++++++---
>  4 files changed, 41 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 0acd135..f3cfbea 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -83,7 +83,8 @@
>  			  | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_MCE     \
>  			  | X86_CR4_PGE | X86_CR4_PCE | X86_CR4_OSFXSR | X86_CR4_PCIDE \
>  			  | X86_CR4_OSXSAVE | X86_CR4_SMEP | X86_CR4_FSGSBASE \
> -			  | X86_CR4_OSXMMEXCPT | X86_CR4_VMXE | X86_CR4_SMAP))
> +			  | X86_CR4_OSXMMEXCPT | X86_CR4_VMXE | X86_CR4_SMAP \
> +			  | X86_CR4_PKE))
>  
>  #define CR8_RESERVED_BITS (~(unsigned long)X86_CR8_TPR)
>  
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 6525e92..7dc7a5a 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -81,6 +81,17 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
>  			apic->lapic_timer.timer_mode_mask = 1 << 17;
>  	}
>  
> +	best = kvm_find_cpuid_entry(vcpu, 7, 0);
> +	if (!best)
> +		return 0;
> +
> +	/* Update OSPKE bit */
> +	if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
> +		best->ecx &= ~F(OSPKE);
> +		if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
> +			best->ecx |= F(OSPKE);
> +	}
> +
>  	best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
>  	if (!best) {
>  		vcpu->arch.guest_supported_xcr0 = 0;
> @@ -354,6 +365,9 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
>  	const u32 kvm_supported_word10_x86_features =
>  		F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
>  
> +	/* cpuid 7.0.ecx*/
> +	const u32 kvm_supported_word11_x86_features = F(PKU) | 0 /*OSPKE*/;
> +
>  	/* all calls to cpuid_count() should be made on the same cpu */
>  	get_cpu();
>  
> @@ -371,9 +385,9 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
>  		break;
>  	case 1:
>  		entry->edx &= kvm_supported_word0_x86_features;
> -		cpuid_mask(&entry->edx, 0);
> +		cpuid_mask(&entry->edx, CPUID_1_EDX);

Unrelated to this patch, I'll look at these changes for 4.7.

>  		entry->ecx &= kvm_supported_word4_x86_features;
> -		cpuid_mask(&entry->ecx, 4);
> +		cpuid_mask(&entry->ecx, CPUID_1_ECX);
>  		/* we support x2apic emulation even if host does not support
>  		 * it since we emulate x2apic in software */
>  		entry->ecx |= F(X2APIC);
> @@ -428,13 +442,16 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
>  		/* Mask ebx against host capability word 9 */
>  		if (index == 0) {
>  			entry->ebx &= kvm_supported_word9_x86_features;
> -			cpuid_mask(&entry->ebx, 9);
> +			cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
>  			// TSC_ADJUST is emulated
>  			entry->ebx |= F(TSC_ADJUST);
> -		} else
> +			entry->ecx &= kvm_supported_word11_x86_features;
> +			cpuid_mask(&entry->ecx, CPUID_7_ECX);

This is now word 16, so:

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b40445612135..1ecaed58b8c0 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -372,7 +372,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 		F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
 
 	/* cpuid 7.0.ecx*/
-	const u32 kvm_supported_word11_x86_features = F(PKU) | 0 /*OSPKE*/;
+	const u32 kvm_supported_word16_x86_features = F(PKU) | 0 /*OSPKE*/;
 
 	/* all calls to cpuid_count() should be made on the same cpu */
 	get_cpu();
@@ -451,8 +451,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 			cpuid_mask(&entry->ebx, 9);
 			// TSC_ADJUST is emulated
 			entry->ebx |= F(TSC_ADJUST);
-			entry->ecx &= kvm_supported_word11_x86_features;
-			cpuid_mask(&entry->ecx, CPUID_7_ECX);
+			entry->ecx &= kvm_supported_word16_x86_features;
+			cpuid_mask(&entry->ecx, 16);
 			if (!tdp_enabled)
 				/*
 				 * PKU is not yet implemented for shadow

Paolo

> +		} else {
>  			entry->ebx = 0;
> +			entry->ecx = 0;
> +		}
>  		entry->eax = 0;
> -		entry->ecx = 0;
>  		entry->edx = 0;
>  		break;
>  	}
> @@ -559,9 +576,9 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
>  		break;
>  	case 0x80000001:
>  		entry->edx &= kvm_supported_word1_x86_features;
> -		cpuid_mask(&entry->edx, 1);
> +		cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
>  		entry->ecx &= kvm_supported_word6_x86_features;
> -		cpuid_mask(&entry->ecx, 6);
> +		cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
>  		break;
>  	case 0x80000007: /* Advanced power management */
>  		/* invariant TSC is CPUID.80000007H:EDX[8] */
> @@ -595,7 +612,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
>  		break;
>  	case 0xC0000001:
>  		entry->edx &= kvm_supported_word5_x86_features;
> -		cpuid_mask(&entry->edx, 5);
> +		cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
>  		break;
>  	case 3: /* Processor serial number */
>  	case 5: /* MONITOR/MWAIT */
> diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
> index c8eda14..3bacab1 100644
> --- a/arch/x86/kvm/cpuid.h
> +++ b/arch/x86/kvm/cpuid.h
> @@ -79,6 +79,14 @@ static inline bool guest_cpuid_has_fsgsbase(struct kvm_vcpu *vcpu)
>  	return best && (best->ebx & bit(X86_FEATURE_FSGSBASE));
>  }
>  
> +static inline bool guest_cpuid_has_pku(struct kvm_vcpu *vcpu)
> +{
> +	struct kvm_cpuid_entry2 *best;
> +
> +	best = kvm_find_cpuid_entry(vcpu, 7, 0);
> +	return best && (best->ecx & bit(X86_FEATURE_PKU));
> +}
> +
>  static inline bool guest_cpuid_has_longmode(struct kvm_vcpu *vcpu)
>  {
>  	struct kvm_cpuid_entry2 *best;
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 9a3c226..2ee48c5 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -720,7 +720,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
>  {
>  	unsigned long old_cr4 = kvm_read_cr4(vcpu);
>  	unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE |
> -				   X86_CR4_SMEP | X86_CR4_SMAP;
> +				   X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE;
>  
>  	if (cr4 & CR4_RESERVED_BITS)
>  		return 1;
> @@ -737,6 +737,9 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
>  	if (!guest_cpuid_has_fsgsbase(vcpu) && (cr4 & X86_CR4_FSGSBASE))
>  		return 1;
>  
> +	if (!guest_cpuid_has_pku(vcpu) && (cr4 & X86_CR4_PKE))
> +		return 1;
> +
>  	if (is_long_mode(vcpu)) {
>  		if (!(cr4 & X86_CR4_PAE))
>  			return 1;
> @@ -762,7 +765,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
>  	    (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
>  		kvm_mmu_reset_context(vcpu);
>  
> -	if ((cr4 ^ old_cr4) & X86_CR4_OSXSAVE)
> +	if ((cr4 ^ old_cr4) & (X86_CR4_OSXSAVE | X86_CR4_PKE))
>  		kvm_update_cpuid(vcpu);
>  
>  	return 0;
> @@ -7114,7 +7117,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
>  
>  	mmu_reset_needed |= kvm_read_cr4(vcpu) != sregs->cr4;
>  	kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
> -	if (sregs->cr4 & X86_CR4_OSXSAVE)
> +	if (sregs->cr4 & (X86_CR4_OSXSAVE | X86_CR4_PKE))
>  		kvm_update_cpuid(vcpu);
>  
>  	idx = srcu_read_lock(&vcpu->kvm->srcu);
> 

  reply	other threads:[~2016-03-21 11:36 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-21 10:05 [PATCH V5 0/9] KVM, pkeys: add memory protection-key support Huaitong Han
2016-03-21 10:05 ` [PATCH V5 1/9] KVM, pkeys: disable pkeys for guests in non-paging mode Huaitong Han
2016-03-21 10:05 ` [PATCH V5 2/9] KVM, pkeys: add pkeys support for xsave state Huaitong Han
2016-03-21 10:05 ` [PATCH V5 3/9] x86: pkey: introduce write_pkru() for KVM Huaitong Han
2016-03-21 10:05 ` [PATCH V5 4/9] KVM, pkeys: save/restore PKRU when guest/host switches Huaitong Han
2016-03-21 10:28   ` Paolo Bonzini
2016-03-21 10:37     ` Han, Huaitong
2016-03-21 10:05 ` [PATCH V5 5/9] KVM, pkeys: introduce pkru_mask to cache conditions Huaitong Han
2016-03-21 17:43   ` Paolo Bonzini
2016-03-21 10:05 ` [PATCH V5 6/9] KVM, pkeys: add pkeys support for permission_fault logic Huaitong Han
2016-03-21 10:55   ` Paolo Bonzini
2016-03-21 12:41     ` Han, Huaitong
2016-03-21 10:05 ` [PATCH V5 7/9] KVM, pkeys: expose CPUID/CR4 to guest Huaitong Han
2016-03-21 11:36   ` Paolo Bonzini [this message]
2016-03-21 11:56     ` Han, Huaitong
2016-03-21 12:08       ` Paolo Bonzini
2016-03-21 10:05 ` [PATCH V5 8/9] KVM, pkeys: disable PKU feature without ept Huaitong Han
2016-03-21 11:01   ` Paolo Bonzini
2016-03-21 10:06 ` [PATCH V5 9/9] Revert "KVM: MMU: precompute page fault error code" Huaitong Han

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