From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="V3PTo1N2" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2AEE38E for ; Mon, 27 Nov 2023 23:28:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701156523; 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=Y5BdmHDgt38rlTrgeOjpNrZmrPx70EBF4G1nvkRBLTc=; b=V3PTo1N2BoCkYCW9YBPspEbQS7VEAm6gC3uJqzyt1WNkFreYuh4yJPBQ9qTqYWWuJUbGj2 GtdHAf9rPdPTUkKoa/dxxNEw+ZDeE8D4i4DAdFwJxkuCBhaGf2K20o/OnNOpTSIvi3gbtb 9TZOiSA5gVVhv/xqrS7Eciz+bP2Q+nw= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-186-CL5-PQrNOJS2w4pIEQWbAg-1; Tue, 28 Nov 2023 02:28:41 -0500 X-MC-Unique: CL5-PQrNOJS2w4pIEQWbAg-1 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-332f5ac9f49so2075742f8f.2 for ; Mon, 27 Nov 2023 23:28:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701156520; x=1701761320; h=content-transfer-encoding:mime-version:user-agent:references :in-reply-to:date:cc:to:from:subject:message-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Y5BdmHDgt38rlTrgeOjpNrZmrPx70EBF4G1nvkRBLTc=; b=FO/PoX2tj/fFy+zwodwKm/6fz99kuACIWwE2gtJZZkmzWFm0b2pPhC0CJaiDCGluSO UVLecFcUvsZ5kZeJmALZIIh/Z6xrNv6nTd360YpyaL5K0JwaApWDM9VI0bZDG9oZ2VGE EhEo6OLhqAwEbwvsp7piJZKiymkJbwkJ+7sc1ldCDcAsMKeqcSkmkTVBYlw8mD8TCJoE WAlVROgzqWaRf+HlexnHkenJCc9i8JzIzHvBj/XsgJgmannILhOxG9sYGxNiYQLMBtNe I/113Kx/LVP14YJQOYyN/JuwDTkFBYQxnWUn1gOvQ5jqe89a3aH9FRCT5mG7LmrRJRn8 3ZbQ== X-Gm-Message-State: AOJu0YzcqS96Q3JCHxGr/PaFK0HiCWY2iemAxLRs244DHJ0xRIoTigs0 wZog9fxTpIZe7leBMIFm+GllS+ghGL2n9lSxnLei6RQ9M2Re+sNwY8k7bBjhDEFCZTJqfLnNku3 ItM4vjvgbSviGocYuCbPyGVOD X-Received: by 2002:a5d:424a:0:b0:332:c5f8:a082 with SMTP id s10-20020a5d424a000000b00332c5f8a082mr10166406wrr.13.1701156520347; Mon, 27 Nov 2023 23:28:40 -0800 (PST) X-Google-Smtp-Source: AGHT+IFZq3ysto0FjKshj9voU9tQJ6efJmJfszdfClmLvNLefhFl6RycgLDTK4Zz2uTRdBk65VFnUg== X-Received: by 2002:a5d:424a:0:b0:332:c5f8:a082 with SMTP id s10-20020a5d424a000000b00332c5f8a082mr10166397wrr.13.1701156520034; Mon, 27 Nov 2023 23:28:40 -0800 (PST) Received: from starship ([77.137.131.4]) by smtp.gmail.com with ESMTPSA id w21-20020a05600c475500b0040b2976eb02sm16296878wmo.10.2023.11.27.23.28.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Nov 2023 23:28:39 -0800 (PST) Message-ID: <70d51e5f3b202a059009913f165b133265ea4cc2.camel@redhat.com> Subject: Re: [RFC 12/33] KVM: x86: hyper-v: Handle VSM hcalls in user-space From: Maxim Levitsky To: Nicolas Saenz Julienne , kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com, anelkz@amazon.com, graf@amazon.com, dwmw@amazon.co.uk, jgowans@amazon.com, corbert@lwn.net, kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, x86@kernel.org, linux-doc@vger.kernel.org Date: Tue, 28 Nov 2023 09:28:37 +0200 In-Reply-To: <20231108111806.92604-13-nsaenz@amazon.com> References: <20231108111806.92604-1-nsaenz@amazon.com> <20231108111806.92604-13-nsaenz@amazon.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit On Wed, 2023-11-08 at 11:17 +0000, Nicolas Saenz Julienne wrote: > Let user-space handle all hypercalls that fall under the AccessVsm > partition privilege flag. That is: > - HVCALL_MODIFY_VTL_PROTECTION_MASK: > - HVCALL_ENABLE_PARTITION_VTL: > - HVCALL_ENABLE_VP_VTL: > - HVCALL_VTL_CALL: > - HVCALL_VTL_RETURN: > The hypercalls are processed through the KVM_EXIT_HYPERV_HVCALL exit. > Additionally, expose the cpuid bit. > > Signed-off-by: Nicolas Saenz Julienne > --- > arch/x86/kvm/hyperv.c | 15 +++++++++++++++ > include/asm-generic/hyperv-tlfs.h | 7 ++++++- > 2 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index a3970d52eef1..a266c5d393f5 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -2462,6 +2462,11 @@ static bool kvm_hv_is_xmm_output_hcall(u16 code) > return false; > } > > +static inline bool kvm_hv_is_vtl_call_return(u16 code) > +{ > + return code == HVCALL_VTL_CALL || code == HVCALL_VTL_RETURN; > +} > + > static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu) > { > bool fast = !!(vcpu->run->hyperv.u.hcall.input & HV_HYPERCALL_FAST_BIT); > @@ -2471,6 +2476,9 @@ static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu) > if (kvm_hv_is_xmm_output_hcall(code) && hv_result_success(result) && fast) > kvm_hv_write_xmm(vcpu->run->hyperv.u.hcall.xmm); > > + if (kvm_hv_is_vtl_call_return(code)) > + return kvm_skip_emulated_instruction(vcpu); Can you add justification for this? If this is justified, does it make sense to move this code to kvm_hv_hypercall_complete (which also calls kvm_skip_emulated_instruction()) > + > return kvm_hv_hypercall_complete(vcpu, result); > } > > @@ -2525,6 +2533,7 @@ static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc) > case HVCALL_SEND_IPI_EX: > case HVCALL_GET_VP_REGISTERS: > case HVCALL_SET_VP_REGISTERS: > + case HVCALL_MODIFY_VTL_PROTECTION_MASK: > return true; > } > > @@ -2745,6 +2754,11 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) > goto hypercall_userspace_exit; > case HVCALL_GET_VP_REGISTERS: > case HVCALL_SET_VP_REGISTERS: > + case HVCALL_MODIFY_VTL_PROTECTION_MASK: > + case HVCALL_ENABLE_PARTITION_VTL: > + case HVCALL_ENABLE_VP_VTL: > + case HVCALL_VTL_CALL: > + case HVCALL_VTL_RETURN: > goto hypercall_userspace_exit; > default: Also those new hypercalls also should be added to hv_check_hypercall_access. > ret = HV_STATUS_INVALID_HYPERCALL_CODE; > @@ -2912,6 +2926,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, > ent->ebx |= HV_SIGNAL_EVENTS; > ent->ebx |= HV_ENABLE_EXTENDED_HYPERCALLS; > ent->ebx |= HV_ACCESS_VP_REGISTERS; > + ent->ebx |= HV_ACCESS_VSM; > > ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE; > ent->edx |= HV_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE; Best regards, Maxim Levitsky > diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h > index 24ea699a3d8e..a8b5c8a84bbc 100644 > --- a/include/asm-generic/hyperv-tlfs.h > +++ b/include/asm-generic/hyperv-tlfs.h > @@ -89,6 +89,7 @@ > #define HV_ACCESS_STATS BIT(8) > #define HV_DEBUGGING BIT(11) > #define HV_CPU_MANAGEMENT BIT(12) > +#define HV_ACCESS_VSM BIT(16) > #define HV_ACCESS_VP_REGISTERS BIT(17) > #define HV_ENABLE_EXTENDED_HYPERCALLS BIT(20) > #define HV_ISOLATION BIT(22) > @@ -147,9 +148,13 @@ union hv_reference_tsc_msr { > /* Declare the various hypercall operations. */ > #define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE 0x0002 > #define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST 0x0003 > -#define HVCALL_ENABLE_VP_VTL 0x000f > #define HVCALL_NOTIFY_LONG_SPIN_WAIT 0x0008 > #define HVCALL_SEND_IPI 0x000b > +#define HVCALL_MODIFY_VTL_PROTECTION_MASK 0x000c > +#define HVCALL_ENABLE_PARTITION_VTL 0x000d > +#define HVCALL_ENABLE_VP_VTL 0x000f > +#define HVCALL_VTL_CALL 0x0011 > +#define HVCALL_VTL_RETURN 0x0012 > #define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX 0x0013 > #define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX 0x0014 > #define HVCALL_SEND_IPI_EX 0x0015