From b9baba861489041b37b54fc7ee0b0006b5327151 Mon Sep 17 00:00:00 2001 From: Huaitong Han Date: Tue, 22 Mar 2016 16:51:21 +0800 Subject: [PATCH] KVM, pkeys: expose CPUID/CR4 to guest 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). This patch disables CPUID:PKU without ept, because pkeys is not yet implemented for shadow paging. Signed-off-by: Huaitong Han Reviewed-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 3 ++- arch/x86/kvm/cpuid.c | 23 +++++++++++++++++++++-- arch/x86/kvm/cpuid.h | 8 ++++++++ arch/x86/kvm/x86.c | 9 ++++++--- 4 files changed, 37 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 0d75ecdfa077..f62a9f37f79f 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -84,7 +84,8 @@ | 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 00a69ecdd401..8efb839948e5 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -88,6 +88,16 @@ 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) { + /* 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; @@ -360,6 +370,9 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, const u32 kvm_cpuid_D_1_eax_x86_features = F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; + /* cpuid 7.0.ecx*/ + const u32 kvm_cpuid_7_0_ecx_x86_features = F(PKU) | 0 /*OSPKE*/; + /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); @@ -437,10 +450,16 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, cpuid_mask(&entry->ebx, CPUID_7_0_EBX); // TSC_ADJUST is emulated entry->ebx |= F(TSC_ADJUST); - } else + entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; + cpuid_mask(&entry->ecx, CPUID_7_ECX); + /* PKU is not yet implemented for shadow paging. */ + if (!tdp_enabled) + entry->ecx &= ~F(PKU); + } else { entry->ebx = 0; + entry->ecx = 0; + } entry->eax = 0; - entry->ecx = 0; entry->edx = 0; break; } diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 66a6581724ad..e17a74b1d852 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -80,6 +80,14 @@ 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 d0a5918da654..98ae1fb9fd66 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -723,7 +723,7 @@ 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; @@ -740,6 +740,9 @@ 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; @@ -765,7 +768,7 @@ 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; @@ -7128,7 +7131,7 @@ 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); -- 2.11.0