From patchwork Wed Dec 4 00:24:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Mattson X-Patchwork-Id: 11271987 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8118A138D for ; Wed, 4 Dec 2019 00:25:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 59993206E4 for ; Wed, 4 Dec 2019 00:25:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tT/Rr/kx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726060AbfLDAYx (ORCPT ); Tue, 3 Dec 2019 19:24:53 -0500 Received: from mail-pl1-f201.google.com ([209.85.214.201]:50795 "EHLO mail-pl1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726008AbfLDAYx (ORCPT ); Tue, 3 Dec 2019 19:24:53 -0500 Received: by mail-pl1-f201.google.com with SMTP id c18so2592105plo.17 for ; Tue, 03 Dec 2019 16:24:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=XK0YqNOqBf++GW8F+qSvBh8TlM8iwDKRqB87FNLDCgc=; b=tT/Rr/kx2NL+uP/dyMOEO4OkQHXc9vjgXyZcicRSdOUtcdV/73ldlf8aY6lte6i/bb KRf3u2MinFH+v3H+jGztK51Od+CxT0PfLNUZnRRFDKv/Qs3unSs19EAohp0f/KCAKE74 EfBPj/WmQ4/o0gSDUtKUiQHMhI/TN992+Z1vDxmNJRLGBd6kiGWXCoWpQhPGoBWpbzaq 1EZHAQJEXueQy7kOJKdGAYOjv9oE626KyTkeG6fVSpSo5hSUiG0JcXK4fji+RPFl7NIT g2L2Edet2dSmOzSAJ/JIsx2/1BiJXJg4d8yNusg93GzY7rzXb7yOt5yclP8B4kHqDSp0 BlGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=XK0YqNOqBf++GW8F+qSvBh8TlM8iwDKRqB87FNLDCgc=; b=FBJnWjYRVY8vAj3Mh2c6nfpkT3PQCGPm5IWmcTjb3GZQ/PTuSHCrSDYU+6muovsEwE PMA0XnNqFHHyIP4fImu2CM2QC2CuyMUPG6wLmWNf8w9gwryGYKqnB2RLfXzikfreDbjk IrP2bchuvGUAQz//9ZpfyVnX0LsybW9sddFXUS2pD4orYNre+904KtbZpKsYeAMza767 Eu9FiCm6x0BwEb2//CwyAQyZ71zmYV1XYeg9Patz/f8sldezBq9UiknG4FDcm1PiPyMz 4PECsAFRZycu/t3WnNeYDDNE7kzCoZEp7W+p8/mWB/9s1o7lJgoPQUznkmTjfY0SjM4x Uyng== X-Gm-Message-State: APjAAAW2lwBXyzncmSh4UTsE8UHXKdmTobZZFlGly04zXp2Jkqril2Jp /t6wYuTHWOppvphW1cofLKraNrpAmTJHAVGa6ClqNO1iZQqy+aC8pE2O5uQ7Wbl64Pn8UVvVyNc bxq1bDIGobvFd1PsYg7mNc4FqZ+KqxXDqYz77w8216ahTyTZ3/K0V/+2mgN/h48k= X-Google-Smtp-Source: APXvYqymFATEUdEorat4ogLD0EWFv2FYNhX+bHfY/3gn+xxCEeG91yQNlwKI8Z83Vg6OslGl7MfjCBeg3fMKMw== X-Received: by 2002:a63:de08:: with SMTP id f8mr466986pgg.107.1575419092432; Tue, 03 Dec 2019 16:24:52 -0800 (PST) Date: Tue, 3 Dec 2019 16:24:42 -0800 Message-Id: <20191204002442.186018-1-jmattson@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.24.0.393.g34dc348eaf-goog Subject: [PATCH v2] kvm: vmx: Stop wasting a page for guest_msrs From: Jim Mattson To: kvm@vger.kernel.org, Sean Christopherson , Paolo Bonzini Cc: Jim Mattson , Liran Alon Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org We will never need more guest_msrs than there are indices in vmx_msr_index. Thus, at present, the guest_msrs array will not exceed 168 bytes. Signed-off-by: Jim Mattson Reviewed-by: Liran Alon --- v1 -> v2: Changed NR_GUEST_MSRS to NR_SHARED_MSRS. Added BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != NR_SHARED_MSRS). arch/x86/kvm/vmx/vmx.c | 12 ++---------- arch/x86/kvm/vmx/vmx.h | 8 +++++++- 2 files changed, 9 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 1b9ab4166397d..e3394c839dea6 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6666,7 +6666,6 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu) free_vpid(vmx->vpid); nested_vmx_free_vcpu(vcpu); free_loaded_vmcs(vmx->loaded_vmcs); - kfree(vmx->guest_msrs); kvm_vcpu_uninit(vcpu); kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.user_fpu); kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu); @@ -6723,12 +6722,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) goto uninit_vcpu; } - vmx->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); - BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) * sizeof(vmx->guest_msrs[0]) - > PAGE_SIZE); - - if (!vmx->guest_msrs) - goto free_pml; + BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != NR_SHARED_MSRS); for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) { u32 index = vmx_msr_index[i]; @@ -6760,7 +6754,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) err = alloc_loaded_vmcs(&vmx->vmcs01); if (err < 0) - goto free_msrs; + goto free_pml; msr_bitmap = vmx->vmcs01.msr_bitmap; vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_TSC, MSR_TYPE_R); @@ -6822,8 +6816,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) free_vmcs: free_loaded_vmcs(vmx->loaded_vmcs); -free_msrs: - kfree(vmx->guest_msrs); free_pml: vmx_destroy_pml_buffer(vmx); uninit_vcpu: diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 7c1b978b2df44..a4f7f737c5d44 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -22,6 +22,12 @@ extern u32 get_umwait_control_msr(void); #define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4)) +#ifdef CONFIG_X86_64 +#define NR_SHARED_MSRS 7 +#else +#define NR_SHARED_MSRS 4 +#endif + #define NR_LOADSTORE_MSRS 8 struct vmx_msrs { @@ -206,7 +212,7 @@ struct vcpu_vmx { u32 idt_vectoring_info; ulong rflags; - struct shared_msr_entry *guest_msrs; + struct shared_msr_entry guest_msrs[NR_SHARED_MSRS]; int nmsrs; int save_nmsrs; bool guest_msrs_ready;