From a3833b81b05d0ae92ae085959dd8da136ec91868 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Thu, 3 Dec 2020 16:20:32 +0000 Subject: [PATCH] KVM: x86/xen: latch long_mode when hypercall page is set up Signed-off-by: David Woodhouse --- arch/x86/include/asm/kvm_host.h | 6 ++++++ arch/x86/kvm/xen.c | 16 +++++++++++++++- include/uapi/linux/kvm.h | 3 +++ 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b4bcdebd6e4c..016a005cc2ad 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -905,6 +905,11 @@ struct msr_bitmap_range { unsigned long *bitmap; }; +/* Xen emulation context */ +struct kvm_xen { + bool long_mode; +}; + enum kvm_irqchip_mode { KVM_IRQCHIP_NONE, KVM_IRQCHIP_KERNEL, /* created with KVM_CREATE_IRQCHIP */ @@ -984,6 +989,7 @@ struct kvm_arch { struct hlist_head mask_notifier_list; struct kvm_hv hyperv; + struct kvm_xen xen; #ifdef CONFIG_KVM_MMU_AUDIT int audit_point; diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index a3fd791b0354..55da739267b1 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -25,6 +25,13 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) mutex_unlock(&kvm->lock); switch (data->type) { + case KVM_XEN_ATTR_TYPE_LONG_MODE: + if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) + return -EINVAL; + + kvm->arch.xen.long_mode = !!data->u.long_mode; + r = 0; + break; default: break; } @@ -40,6 +47,10 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) mutex_lock(&kvm->lock); switch (data->type) { + case KVM_XEN_ATTR_TYPE_LONG_MODE: + data->u.long_mode = kvm->arch.xen.long_mode; + r = 0; + break; default: break; } @@ -53,6 +64,10 @@ int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data) struct kvm *kvm = vcpu->kvm; u32 page_num = data & ~PAGE_MASK; u64 page_addr = data & PAGE_MASK; + bool lm = is_long_mode(vcpu); + + /* Latch long_mode for shared_info pages etc. */ + vcpu->kvm->arch.xen.long_mode = lm; /* * If Xen hypercall intercept is enabled, fill the hypercall @@ -87,7 +102,6 @@ int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data) return 1; } } else { - int lm = is_long_mode(vcpu); u64 blob_addr = lm ? kvm->arch.xen_hvm_config.blob_addr_64 : kvm->arch.xen_hvm_config.blob_addr_32; u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64 diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 334796799dbc..11644954a2e2 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1594,10 +1594,13 @@ struct kvm_xen_hvm_attr { __u16 type; __u16 pad[3]; union { + __u8 long_mode; __u64 pad[8]; } u; }; +#define KVM_XEN_ATTR_TYPE_LONG_MODE 0x0 + /* Secure Encrypted Virtualization command */ enum sev_cmd_id { /* Guest initialization commands */ -- 2.11.0