diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 16 |
4 files changed, 27 insertions, 2 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 5a1faf3f043e..f4a555beef19 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -401,6 +401,7 @@ struct kvm_vcpu_arch { struct kvm_mmu_memory_cache mmu_page_header_cache; struct fpu guest_fpu; + bool eager_fpu; u64 xcr0; u64 guest_supported_xcr0; u32 guest_xstate_size; diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 59b69f6a2844..1d08ad3582d0 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -16,6 +16,8 @@ #include <linux/module.h> #include <linux/vmalloc.h> #include <linux/uaccess.h> +#include <asm/i387.h> /* For use_eager_fpu. Ugh! */ +#include <asm/fpu-internal.h> /* For use_eager_fpu. Ugh! */ #include <asm/user.h> #include <asm/xsave.h> #include "cpuid.h" @@ -95,6 +97,8 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) best->ebx = xstate_required_size(vcpu->arch.xcr0, true); + vcpu->arch.eager_fpu = guest_cpuid_has_mpx(vcpu); + /* * The existing code assumes virtual address is 48-bit in the canonical * address checks; exit if it is ever changed. diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index c3b1ad9fca81..496b3695d3d3 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -117,4 +117,12 @@ static inline bool guest_cpuid_has_rtm(struct kvm_vcpu *vcpu) best = kvm_find_cpuid_entry(vcpu, 7, 0); return best && (best->ebx & bit(X86_FEATURE_RTM)); } + +static inline bool guest_cpuid_has_mpx(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry(vcpu, 7, 0); + return best && (best->ebx & bit(X86_FEATURE_MPX)); +} #endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5f3818846465..ea306adbbc13 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7060,7 +7060,9 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) fpu_save_init(&vcpu->arch.guest_fpu); __kernel_fpu_end(); ++vcpu->stat.fpu_reload; - kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); + if (!vcpu->arch.eager_fpu) + kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); + trace_kvm_fpu(0); } @@ -7076,11 +7078,21 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu) struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id) { + struct kvm_vcpu *vcpu; + if (check_tsc_unstable() && atomic_read(&kvm->online_vcpus) != 0) printk_once(KERN_WARNING "kvm: SMP vm created on host with unstable TSC; " "guest TSC will not be reliable\n"); - return kvm_x86_ops->vcpu_create(kvm, id); + + vcpu = kvm_x86_ops->vcpu_create(kvm, id); + + /* + * Activate fpu unconditionally in case the guest needs eager FPU. It will be + * deactivated soon if it doesn't. + */ + kvm_x86_ops->fpu_activate(vcpu); + return vcpu; } int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) |