From patchwork Tue Feb 27 23:20:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13574561 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BAF825646F for ; Tue, 27 Feb 2024 23:21:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709076069; cv=none; b=hF0a3IzfuQyQcu+wGbOHcNGDQZOyEI1e2YUL3dSGQVwRGXNv949wLvlIoX83fCesJWjh+xb/6BwgFRuCgO929rL7i1mZWSRkqsVz92vqcX+OCRaIDPidUMUYmbkaaV+iURXZA7vJ0kyAXBn1/PNZ+roeNgve2R67RbIN85A4DJA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709076069; c=relaxed/simple; bh=xUVw7fXoacY4/pc5sQTyG/1nRlL3cCuIM3lhyJEyoIY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=CqjhMsF/cOQyTfUhzWRXtaY06HjIv9wS+RsLBssHYsaM6ZdC9xwQdBrF32qvvpfVqf5vEO7DYfghgCkZDlo47E9mVzit45CAMEZL4vt2x0oxRbd7oUn/cQwGUANXIEXi0ctl3XZXuf9/U3kX9UKveDML7oxa7F0Lsc0fivEzmSc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=aa6PCdu7; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aa6PCdu7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709076065; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+O4rcOhZjnZIOKFP4bygzCU7WBo22CUzCZVS+rsRY3w=; b=aa6PCdu7UyxGq37//sT2smrgxoeyPC0jPZ4GEKr5xm1OiPgW5JPtGD7Zi3Mty6k73XQ7M+ 6bufhcQYvn0rDeDTIyEXvM1+2QR6NmO96r4hu0oRfTPWi/aLvBNRsjpDzYfJ0Z1X0jI8oW Wxk1gWccqeh13ePoPn4IFh9DpmQtQ3I= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-421-c7YNxph7OouOQRwOHxqPbA-1; Tue, 27 Feb 2024 18:21:02 -0500 X-MC-Unique: c7YNxph7OouOQRwOHxqPbA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 77E17108BCA4; Tue, 27 Feb 2024 23:21:02 +0000 (UTC) Received: from virtlab511.virt.lab.eng.bos.redhat.com (virtlab511.virt.lab.eng.bos.redhat.com [10.19.152.198]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4A7E042283; Tue, 27 Feb 2024 23:21:02 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: seanjc@google.com, michael.roth@amd.com, isaku.yamahata@intel.com, thomas.lendacky@amd.com Subject: [PATCH 07/21] KVM: VMX: Introduce test mode related to EPT violation VE Date: Tue, 27 Feb 2024 18:20:46 -0500 Message-Id: <20240227232100.478238-8-pbonzini@redhat.com> In-Reply-To: <20240227232100.478238-1-pbonzini@redhat.com> References: <20240227232100.478238-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 From: Isaku Yamahata To support TDX, KVM is enhanced to operate with #VE. For TDX, KVM uses the suppress #VE bit in EPT entries selectively, in order to be able to trap non-present conditions. However, #VE isn't used for VMX and it's a bug if it happens. To be defensive and test that VMX case isn't broken introduce an option ept_violation_ve_test and when it's set, BUG the vm. Suggested-by: Paolo Bonzini Signed-off-by: Isaku Yamahata Message-Id: Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/vmx.h | 12 +++++++ arch/x86/kvm/vmx/vmcs.h | 5 +++ arch/x86/kvm/vmx/vmx.c | 69 +++++++++++++++++++++++++++++++++++++- arch/x86/kvm/vmx/vmx.h | 6 +++- 4 files changed, 90 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index 76ed39541a52..f703bae0c4ac 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -70,6 +70,7 @@ #define SECONDARY_EXEC_ENCLS_EXITING VMCS_CONTROL_BIT(ENCLS_EXITING) #define SECONDARY_EXEC_RDSEED_EXITING VMCS_CONTROL_BIT(RDSEED_EXITING) #define SECONDARY_EXEC_ENABLE_PML VMCS_CONTROL_BIT(PAGE_MOD_LOGGING) +#define SECONDARY_EXEC_EPT_VIOLATION_VE VMCS_CONTROL_BIT(EPT_VIOLATION_VE) #define SECONDARY_EXEC_PT_CONCEAL_VMX VMCS_CONTROL_BIT(PT_CONCEAL_VMX) #define SECONDARY_EXEC_ENABLE_XSAVES VMCS_CONTROL_BIT(XSAVES) #define SECONDARY_EXEC_MODE_BASED_EPT_EXEC VMCS_CONTROL_BIT(MODE_BASED_EPT_EXEC) @@ -225,6 +226,8 @@ enum vmcs_field { VMREAD_BITMAP_HIGH = 0x00002027, VMWRITE_BITMAP = 0x00002028, VMWRITE_BITMAP_HIGH = 0x00002029, + VE_INFORMATION_ADDRESS = 0x0000202A, + VE_INFORMATION_ADDRESS_HIGH = 0x0000202B, XSS_EXIT_BITMAP = 0x0000202C, XSS_EXIT_BITMAP_HIGH = 0x0000202D, ENCLS_EXITING_BITMAP = 0x0000202E, @@ -630,4 +633,13 @@ enum vmx_l1d_flush_state { extern enum vmx_l1d_flush_state l1tf_vmx_mitigation; +struct vmx_ve_information { + u32 exit_reason; + u32 delivery; + u64 exit_qualification; + u64 guest_linear_address; + u64 guest_physical_address; + u16 eptp_index; +}; + #endif diff --git a/arch/x86/kvm/vmx/vmcs.h b/arch/x86/kvm/vmx/vmcs.h index 7c1996b433e2..b25625314658 100644 --- a/arch/x86/kvm/vmx/vmcs.h +++ b/arch/x86/kvm/vmx/vmcs.h @@ -140,6 +140,11 @@ static inline bool is_nm_fault(u32 intr_info) return is_exception_n(intr_info, NM_VECTOR); } +static inline bool is_ve_fault(u32 intr_info) +{ + return is_exception_n(intr_info, VE_VECTOR); +} + /* Undocumented: icebp/int1 */ static inline bool is_icebp(u32 intr_info) { diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 9239a89dea22..6468f421ba9e 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -126,6 +126,9 @@ module_param(error_on_inconsistent_vmcs_config, bool, 0444); static bool __read_mostly dump_invalid_vmcs = 0; module_param(dump_invalid_vmcs, bool, 0644); +static bool __read_mostly ept_violation_ve_test; +module_param(ept_violation_ve_test, bool, 0444); + #define MSR_BITMAP_MODE_X2APIC 1 #define MSR_BITMAP_MODE_X2APIC_APICV 2 @@ -868,6 +871,12 @@ void vmx_update_exception_bitmap(struct kvm_vcpu *vcpu) eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) | (1u << DB_VECTOR) | (1u << AC_VECTOR); + /* + * #VE isn't used for VMX. To test against unexpected changes + * related to #VE for VMX, intercept unexpected #VE and warn on it. + */ + if (ept_violation_ve_test) + eb |= 1u << VE_VECTOR; /* * Guest access to VMware backdoor ports could legitimately * trigger #GP because of TSS I/O permission bitmap. @@ -2603,6 +2613,9 @@ static int setup_vmcs_config(struct vmcs_config *vmcs_conf, &_cpu_based_2nd_exec_control)) return -EIO; } + if (!ept_violation_ve_test) + _cpu_based_2nd_exec_control &= ~SECONDARY_EXEC_EPT_VIOLATION_VE; + #ifndef CONFIG_X86_64 if (!(_cpu_based_2nd_exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) @@ -2627,6 +2640,7 @@ static int setup_vmcs_config(struct vmcs_config *vmcs_conf, return -EIO; vmx_cap->ept = 0; + _cpu_based_2nd_exec_control &= ~SECONDARY_EXEC_EPT_VIOLATION_VE; } if (!(_cpu_based_2nd_exec_control & SECONDARY_EXEC_ENABLE_VPID) && vmx_cap->vpid) { @@ -4592,6 +4606,7 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) exec_control &= ~SECONDARY_EXEC_ENABLE_VPID; if (!enable_ept) { exec_control &= ~SECONDARY_EXEC_ENABLE_EPT; + exec_control &= ~SECONDARY_EXEC_EPT_VIOLATION_VE; enable_unrestricted_guest = 0; } if (!enable_unrestricted_guest) @@ -4715,8 +4730,40 @@ static void init_vmcs(struct vcpu_vmx *vmx) exec_controls_set(vmx, vmx_exec_control(vmx)); - if (cpu_has_secondary_exec_ctrls()) + if (cpu_has_secondary_exec_ctrls()) { secondary_exec_controls_set(vmx, vmx_secondary_exec_control(vmx)); + if (secondary_exec_controls_get(vmx) & + SECONDARY_EXEC_EPT_VIOLATION_VE) { + if (!vmx->ve_info) { + /* ve_info must be page aligned. */ + struct page *page; + + BUILD_BUG_ON(sizeof(*vmx->ve_info) > PAGE_SIZE); + page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (page) + vmx->ve_info = page_to_virt(page); + } + if (vmx->ve_info) { + /* + * Allow #VE delivery. CPU sets this field to + * 0xFFFFFFFF on #VE delivery. Another #VE can + * occur only if software clears the field. + */ + vmx->ve_info->delivery = 0; + vmcs_write64(VE_INFORMATION_ADDRESS, + __pa(vmx->ve_info)); + } else { + /* + * Because SECONDARY_EXEC_EPT_VIOLATION_VE is + * used only when ept_violation_ve_test is true, + * it's okay to go with the bit disabled. + */ + pr_err("Failed to allocate ve_info. disabling EPT_VIOLATION_VE.\n"); + secondary_exec_controls_clearbit(vmx, + SECONDARY_EXEC_EPT_VIOLATION_VE); + } + } + } if (cpu_has_tertiary_exec_ctrls()) tertiary_exec_controls_set(vmx, vmx_tertiary_exec_control(vmx)); @@ -5204,6 +5251,12 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) if (is_invalid_opcode(intr_info)) return handle_ud(vcpu); + /* + * #VE isn't supposed to happen. Block the VM if it does. + */ + if (KVM_BUG_ON(is_ve_fault(intr_info), vcpu->kvm)) + return -EIO; + error_code = 0; if (intr_info & INTR_INFO_DELIVER_CODE_MASK) error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE); @@ -6393,6 +6446,18 @@ void dump_vmcs(struct kvm_vcpu *vcpu) if (secondary_exec_control & SECONDARY_EXEC_ENABLE_VPID) pr_err("Virtual processor ID = 0x%04x\n", vmcs_read16(VIRTUAL_PROCESSOR_ID)); + if (secondary_exec_control & SECONDARY_EXEC_EPT_VIOLATION_VE) { + struct vmx_ve_information *ve_info; + + pr_err("VE info address = 0x%016llx\n", + vmcs_read64(VE_INFORMATION_ADDRESS)); + ve_info = __va(vmcs_read64(VE_INFORMATION_ADDRESS)); + pr_err("ve_info: 0x%08x 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%04x\n", + ve_info->exit_reason, ve_info->delivery, + ve_info->exit_qualification, + ve_info->guest_linear_address, + ve_info->guest_physical_address, ve_info->eptp_index); + } } /* @@ -7433,6 +7498,8 @@ static void vmx_vcpu_free(struct kvm_vcpu *vcpu) free_vpid(vmx->vpid); nested_vmx_free_vcpu(vcpu); free_loaded_vmcs(vmx->loaded_vmcs); + if (vmx->ve_info) + free_page((unsigned long)vmx->ve_info); } static int vmx_vcpu_create(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index e3b0985bb74a..1ea1e5c8930d 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -364,6 +364,9 @@ struct vcpu_vmx { DECLARE_BITMAP(read, MAX_POSSIBLE_PASSTHROUGH_MSRS); DECLARE_BITMAP(write, MAX_POSSIBLE_PASSTHROUGH_MSRS); } shadow_msr_intercept; + + /* ve_info must be page aligned. */ + struct vmx_ve_information *ve_info; }; struct kvm_vmx { @@ -576,7 +579,8 @@ static inline u8 vmx_get_rvi(void) SECONDARY_EXEC_ENABLE_VMFUNC | \ SECONDARY_EXEC_BUS_LOCK_DETECTION | \ SECONDARY_EXEC_NOTIFY_VM_EXITING | \ - SECONDARY_EXEC_ENCLS_EXITING) + SECONDARY_EXEC_ENCLS_EXITING | \ + SECONDARY_EXEC_EPT_VIOLATION_VE) #define KVM_REQUIRED_VMX_TERTIARY_VM_EXEC_CONTROL 0 #define KVM_OPTIONAL_VMX_TERTIARY_VM_EXEC_CONTROL \