From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D204C4332F for ; Fri, 11 Mar 2022 08:48:45 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 883AD4B093; Fri, 11 Mar 2022 03:48:45 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@google.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eODzegoq+5mu; Fri, 11 Mar 2022 03:48:44 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AD9B849EC1; Fri, 11 Mar 2022 03:48:42 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 3D54A40C58 for ; Thu, 10 Mar 2022 19:25:35 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hP2vcxwaYnk9 for ; Thu, 10 Mar 2022 19:25:34 -0500 (EST) Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id E1E6C40C2B for ; Thu, 10 Mar 2022 19:25:33 -0500 (EST) Received: by mail-pj1-f73.google.com with SMTP id 41-20020a17090a0fac00b001bfcd158e65so2244637pjz.6 for ; Thu, 10 Mar 2022 16:25:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=j95pgE4Sx8peHA829tzkUc37bNityDTC3xUJdMO2UzA=; b=eY6emTpNoacvuiaoysnSFSYEGI+0B+krHa4P/Kh4D2MAjDRyvsIDsQzdiBWa0mReKe wLLIOmJC46PoM8Ve2y9iabrtTA3QVfRHxFm60wkR7QuQ3z3KjIr+FBV3ypD6+hqr/YlG oW2es0oK5N9Ctdp+T7UEZqjXrpgspiy/S7kJWnoT89pQXVGng1c0NPgbAZi4G2rX77Df GywIyvqUz+kS6x19Cro3q/w81nweCY468m7CiSYcFHlOvSXrGNZgMoAREj7DhcA1MQv+ Usb8QAEJ//5umwpZGGeozCTn8uddNLyxyhaHsmzSCQQKz02S7oHN67gRirf+EMGfG7em pUfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=j95pgE4Sx8peHA829tzkUc37bNityDTC3xUJdMO2UzA=; b=sqvDdT6vS2i7/gLJGivShTYZT8d8wkLtazMYIpeJyPGIDOz9PY8XfTfHoUD6asAxV8 aW7Mw6z6SZj2/LaFq4dWMPCmA1UfCRNIp3Xr5njD9/3zSd0dEux6KaEQogRinRoTE0Ce /GuwDkQhx3iz11OoRG8lgEmNV59WheZlzHI0mJut7IeFcVObd2Bs4dHAigj6K0Y8H1sF l/kSKjCZ0QyOIrruRLDHW9mxchYVT1BFRjCF3yjRkBgHq+VnjxD+V0Qe/idBx6cjbmdk juA1ZXAfYvFG3vsLSgW6ZHGUsgB3+MY/p39OPURGWbSa8f1tEpykJuTp7lfQwEN4y8PI hGAQ== X-Gm-Message-State: AOAM531J32QVFQI6t0exDjD905af1aW2XR7pivev9FyM6ZFEb3sHH3MC Rnlju45oExI9Uji86DMvSWhvMPHxqdll4A== X-Google-Smtp-Source: ABdhPJyr0Yxi/VkLVPG0JOeVLGZN1qgnMSwCFGFVa2lsMkBsD9BSYG73ywf0RhTzqzlrQfQDXUPJWYoLTcZWYQ== X-Received: from dmatlack-heavy.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:19cd]) (user=dmatlack job=sendgmr) by 2002:a05:6a00:1a0b:b0:4cf:9a9:5c5f with SMTP id g11-20020a056a001a0b00b004cf09a95c5fmr7693681pfv.45.1646958332777; Thu, 10 Mar 2022 16:25:32 -0800 (PST) Date: Fri, 11 Mar 2022 00:25:03 +0000 In-Reply-To: <20220311002528.2230172-1-dmatlack@google.com> Message-Id: <20220311002528.2230172-2-dmatlack@google.com> Mime-Version: 1.0 References: <20220311002528.2230172-1-dmatlack@google.com> X-Mailer: git-send-email 2.35.1.723.g4982287a31-goog Subject: [PATCH v2 01/26] KVM: x86/mmu: Optimize MMU page cache lookup for all direct SPs From: David Matlack To: Paolo Bonzini X-Mailman-Approved-At: Fri, 11 Mar 2022 03:48:41 -0500 Cc: Albert Ou , "open list:KERNEL VIRTUAL MACHINE FOR MIPS \(KVM/mips\)" , Marc Zyngier , Huacai Chen , "open list:KERNEL VIRTUAL MACHINE FOR MIPS \(KVM/mips\)" , David Matlack , Aleksandar Markovic , Palmer Dabbelt , "open list:KERNEL VIRTUAL MACHINE FOR RISC-V \(KVM/riscv\)" , Paul Walmsley , Ben Gardon , maciej.szmigiero@oracle.com, "moderated list:KERNEL VIRTUAL MACHINE FOR ARM64 \(KVM/arm64\)" , Peter Feiner X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Commit fb58a9c345f6 ("KVM: x86/mmu: Optimize MMU page cache lookup for fully direct MMUs") skipped the unsync checks and write flood clearing for full direct MMUs. We can extend this further and skip the checks for all direct shadow pages. Direct shadow pages are never marked unsynced or have a non-zero write-flooding count. Checking sp->role.direct alos generates better code than checking direct_map because, due to register pressure, direct_map has to get shoved onto the stack and then pulled back off. No functional change intended. Reviewed-by: Sean Christopherson Signed-off-by: David Matlack --- arch/x86/kvm/mmu/mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 3b8da8b0745e..3ad67f70e51c 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2034,7 +2034,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, int direct, unsigned int access) { - bool direct_mmu = vcpu->arch.mmu->direct_map; union kvm_mmu_page_role role; struct hlist_head *sp_list; unsigned quadrant; @@ -2075,7 +2074,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, continue; } - if (direct_mmu) + /* unsync and write-flooding only apply to indirect SPs. */ + if (sp->role.direct) goto trace_get_page; if (sp->unsync) { base-commit: ce41d078aaa9cf15cbbb4a42878cc6160d76525e -- 2.35.1.723.g4982287a31-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm